June/July 2015 - New York State Dental Association

Transcription

the new york state dental journal
Volume81 Number 4
June/July 2015
14A Life of Service to Community and Profession
A conversation with NYSDA President David J. Miller, D.D.S.
18Preparing and Restoring Composite Resin Restorations
The Advantage of High Magnification Loupes or the Dental Surgical Operating Microscope
John Mamoun, D.M.D.
Use of magnification, combined with co-axial illumination, may facilitate the creation of
stable composite resin restorations that are less likely to develop caries, cracks or margin
stains over years of service.
24Necrotizing Fasciitis
Cover: NYSDA 2015-2016 President David
J. Miller, D.D.S., with wife, Patrice, at home
in East Meadow on Long Island.
(Kristin L. Gray Photography)
2Editorial
End the fluoride madness
4 Attorney on Law
Supreme mistake
8 Letters
9 Association Activities
50 Component News
59 Read, Learn, Earn
61 Classifieds
64 Index to Advertisers
68 Addendum
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Louis Christensen, D.D.S.; Heath Evans, D.D.S.; David Cundick, D.D.S.; Matt McShane,
D.D.S.; Kevin Penna, D.D.S.; Rory Sadoff, D.D.S.
A rare, rapidly progressing infection with significant morbidity and high mortality rates,
necrotizing fasciitis rarely appears in the head and neck region. Authors describe their experience
with the disease and discuss proposed treatment options. Case presentation and literature review.
29Adhesive Approach Using Internal Coping for Vertical Root Fractured Teeth with
Flared Root Canals
Shuhei Takeuchi, D.D.S., Ph.D.; Toshiaki Sekita, D.D.S., Ph.D.; Ken`ichi Kobayashi, D.D.S., Ph.D.
Intentional replantation method that uses internal resin coping, with a reinforcing effect on
thin root canal dentin, may be useful therapy for fractured teeth with flared root canals.
34Inflammatory Myofibroblastic Tumor of the Oral Cavity
A Great Mimicker
Nitesh Naresh, M.D.S; Ajay Malik, M.D.; Priya Jeyraj, M.D.S.; Shashidevi Haranal, M.D.S.
Inflammatory myofibroblastic tumor is a seldom-described tumor of indefinite etiology and
pathogenesis that occurs primarily in the lungs. Authors describe the clinical, histological
and operative features of a case of IMT of the oral cavity.
37Segmental Dento-alveolar Intrusive Osteotomy in Posterior Maxilla with
Lack of Inter-arch Distance for Prosthetic Rehabilitation
A Technique Combined with Sinus Floor Elevation
Adi Lorean, D.M.D.; Ziv Mazor, D.M.D.; Eitan Mijiritsky, D.M.D.; Horia Barbu, D.M.D.;
Liran Levin, D.M.D.
Authors present technique for segmental dento-alveolar intrusive osteotomy combined with
sinus floor elevation that can serve as a viable treatment option in the posterior maxilla
with lack of inter-arch distance due to severe overeruption.
42Comparison of Cone-beam Computed Tomography and Multi-slice Spiral Computed
Tomography Bone Density Measurements in the Maxilla and Mandible
Steven Doyle, D.M.D.; Mauricio J. Wiltz, D.D.S.; Richard A. Kraut, D.D.S.
Comparison study of cone-beam computer tomography and multi-slice spiral computed
tomography bone density measurements in the maxilla and mandible undertaken to
determine if discrepancies between imaging modalities exist concluded that care should be
taken when relying upon CBCT to determine bone density, especially in low-density regions.
46Standards, Regulation and Registration of Dental Laboratories
An Industry Update
Paul Giovannone, C.D.T.
The domestic dental laboratory industry is being significantly stressed by many factors,
among them, foreign competition, that are changing the way prosthetic devices and
restorations are manufactured and delivered to dentists.
editorial
We Must Not Waiver
Dentistry faces a formidable foe in those who would ban fluoride from our drinking water.
For the health of the children, we must continue our public education efforts.
O
n May 5, the Oneida City Common
Council voted 5 to 1 to keep fluoride out of the city
water supply. This was a victory for anti-fluoridationists, who campaigned vigorously to keep the
water fluoride-free. Looking at the vote, I think it
was a financial decision on the part of the Common
Council rather than a vote against fluoride. To institute a fluoridation project, Oneida would have had
to spend $40,000 for the necessary equipment and
an additional $30,000 for the fluoride itself. At a
time when municipal budgets are tight, it makes
sense that the Oneida Common Council would not
want to spend money on a controversial project
when more favorable projects are in need of funding.
I say this because on that same day, in Rockport,
MA, citizens voted 1,186 to 800 in favor of continuing fluoridation of that community’s water supply. I
assume the same pro- and anti-fluoridation arguments were made in the days leading up to the vote.
However, one difference in the two processes was
only six people voted in Oneida and over 1,900 voted
in Rockport. It’s possible that the six people voting in
Oneida were more influenced by fiscal concerns
than were the voters in Massachusetts, because that
was their job. It’s also possible that the nearly 2,000
people who voted in Rockport were more concerned
about their health and what could be done to help
2
JUNE/JULY 2015 • The New York State Dental Journal
make it as optimal as possible. Additionally, Rockport
has a history of fluoridation and experience with its
possible side effects. And the residents there have
first-hand knowledge of the arguments made against
adding fluoride to the water supply and have concluded it’s so much bluster.
Anti-fluoridationists will use any tactic to keep
fluoride from being added to community water supplies. A study out of Harvard in 2012 entitled
“Developmental Fluoride Neurotoxicity: A Systematic
Review and Meta-analysis” by Choi et al., published in
Environmental Health Perspectives, questioned whether fluoride affected neurological development. The
researchers concluded that there was a significant difference in the IQ’s of children exposed to high levels of
fluoride in drinking water. Anti-fluoridationists have
seized on this study to support their contention that
fluoride causes adverse effects in developing children.
What they fail to mention, but what is included in the
Harvard study, is that the levels of fluoride these children were exposed to were much greater than what is
recommended when fluoride is added to community
water supplies. Also, the children cited in the study
were exposed to environmental fluoride from coal
burning, adding to their overall intake.
There’s one other thing about the studies cited
in the Environmental Health Perspectives article.
THE NEW YORK STATE DENTAL JOURNAL
They were all from China, with the exception of one from Iran. China does not
fluoridate its community water supplies, and hasn’t since 2002. And, in areas
where water contains naturally occurring fluoride, the concentrations are close to
what is recommended in the United States. In these areas, there was no difference
in the IQ of children exposed to fluoride and those who were not exposed.
Finally, the China studies had no controls. They were simply epidemiological studies of populations exposed environmentally to fluoride with no control over the concentration of that exposure. By contrast, all studies done with strictly controlled populations have shown a significant decrease in the caries rates among children exposed to
the optimal concentration of fluoride with no adverse health effects. Of course, antifluoridationists never cite these studies, and they have a habit of misrepresenting studies that purport to support their position, but with careful reading actually don’t.
Anti-fluoridationists also point to Europe, where water supplies are fluoride-free with
no adverse effect on caries rates. However, there is one big difference between Europe and
the United States. In Europe, unlike in this country, school-based dental care is made available to children. In fact, a great many children in this country do not see a dentist regularly, which contributes to the high pediatric caries rate seen here. In many cases, a fluoridated water supply is the only defense these children have against tooth decay.
We all know, or should know, that fluoridated water significantly reduces the
incidence of caries in children and in adults. Studies have shown that reduction to
be as high as 60% in children and around 30% in adults. The Centers for Disease
Control has cited community water fluoridation as one of the top medical achievements of the 20th century and has ranked it higher than the health effects of smoking. The ADA has made fluoridation a key component of its Action for Dental
Health, a nationwide effort to improve access to care for people suffering from
untreated dental disease, to strengthen public and private safety nets, and to educate and prevent oral health disease in communities across the country.
Recently, the Department of Health and Human Services lowered the recommended
ratio of fluoride to water to 0.7 parts per million. This recommendation is based on
sound scientific research. Unfortunately, for the anti-fluoridationists, no amount of
fluoride in the water supply will ever be acceptable. They are a strong, vocal minority in
this debate. They often rely upon junk science, and they misinterpret sound research.
They will leave no stone unturned in their fight against this proven health initiative. It is
our responsibility to educate the public on the safety and efficacy of water fluoridation. We
must never waiver in our support of this important tool for eradicating childhood caries.
About that Cover
On another note, the cover for the March issue of The NYSDJ garnered a great deal
of comment, much of it negative. If you remember, this cover shows a clinician
working on a patient wearing a facemask with his nose exposed. Please know we
are all cognizant of the proper infection control protocols we must follow in the
practice of dentistry. Unfortunately, we did not take this picture. Most of our covers
are stock photos taken from online photo sources. We have no control over their
content other than accepting or rejecting a photo as appropriate. In this case, we
failed to notice that the dentist was not wearing his facemask properly. For this, we
apologize. It was an inadvertent oversight on our part. Please know we will work
more diligently in the future so that such an error does not occur again.
EDITOR
Kevin J. Hanley, D.D.S.
MANAGING EDITOR
Mary Grates Stoll
ADVERTISING MANAGER
Jeanne DeGuire
ART DIRECTORS
Kathryn Sikule / Ed Stevens
EDITORIAL REVIEW BOARD
Frank C. Barnashuk, D.D.S.
David A. Behrman, D.M.D.
Michael R. Breault, D.D.S.
Ralph H. Epstein, D.D.S.
Daniel H. Flanders, D.D.S.
Joel M. Friedman, D.D.S.
Chester J. Gary, D.D.S., J.D.
G. Kirk Gleason, D.D.S.
John T. Grbic, D.M.D., M.S., MMSc.
Brian T. Kennedy, D.D.S.
Stanley M. Kerpel, D.D.S.
Elliott M. Moskowitz, D.D.S., M.Sd
Francis J. Murphy, D.D.S.
Eugene A. Pantera Jr., D.D.S.
Robert M. Peskin, D.D.S.
Georgios Romanos, D.D.S.,
D.M.D., Ph.D., Prof.Dr.med.dent
Robert E. Schifferle, D.D.S., MMSc., Ph.D.
PRINTER
Fort Orange Press, Albany
NYSDJ (ISSN 0028-7571) is published six times a year,
in January, March, April, June/July, August/ September and November, by the New York State Dental Association, 20 Corporate Woods Boulevard, Suite 602,
Albany, NY 12211. In February, May, October and December, subscribers receive the NYSDA News. Periodicals postage paid at Albany, NY. Subscription rates $25
per year to the members of the New York State Dental
Association; rates for nonmembers: $75 per year or $12
per issue, U.S. and Canada; $135 per year foreign or $22
per issue. Postmaster: Please send change of address to
the New York State Dental Association, Suite 602, 20
Corporate Woods Boulevard, Albany, NY 12211. Editorial and advertising offices are at Suite 602, 20 Corporate Woods Boulevard, Albany, NY 12211. Telephone
(518) 465-0044. Fax (518) 465-3219. E-mail info@
nysdental.org. Website www.nysdental.org. Microform
and article copies are available through National Archive Publishing Co., 300 N. Zeebe Rd., Ann Arbor, MI
48106-1346.
D.D.S.
The New York State Dental Journal • JUNE/JULY 2015
3
A Life of Service to
Community and
Profession
David Miller shares special moment with Murray, a brown Rhodesian hound mix, which like
his canine household companion, Magic, is a rescue dog, retrieved from town public shelter
11 years ago. The Millers view each day with their dogs as a gift.
A Conversation with
NYSDA President
David J. Miller, D.D.S.
David Miller, NYSDA President for 2015-2016, didn’t have a privileged upbringing, and his achievements in organized and hospital dentistry have not been without challenges. But determination
and encouragement from others who foresaw his capabilities and
talents got him to where he is today: the top elected official of the
second largest dental constituency in the country and department
chairman at a downstate medical center.
Perhaps it’s because he has had to work hard to get ahead
that he has chosen to devote his professional life to helping the
disadvantaged, the disabled, special needs patients and the countless others who society often forgets or overlooks. This includes
rescuing abused and abandoned animals, a passion he shares with
his wife, Patrice.
The first in his family to attend college, Dr. Miller said he
reasoned that because he was paying for his education, he needed
to work harder to succeed. Following his graduation from Georgetown University School of Dentistry, he entered the general practice residency program at Woodhull Hospital in Brooklyn. “During my residency, I realized there was so much more to learn, and
it would be the first and last time I was paid to learn. This would
set the stage for my advocacy for PGY-1 in New York State.”
Dr. Miller was named chairman of the Department of Dental Medicine at Interfaith Medical
Center in 2014. Interfaith is a 287-bed hospital in Brooklyn, dedicated to improving
community access to care on site and at numerous off-campus facilities.
14
What follows is more information about David Miller,
gleaned from a recent conversation.
Kristin L. Gray Photography
David and Patrice Miller, at home with their children. From left, David Jr., Patrice, Elizabeth, Victoria.
Can you tell us about yourself?
Where did you grow up?
Valley Stream, Nassau County, Long Island. My father, Robert,
was a steamfitter, a union man. My mother, Loretta, was a dental
assistant. I am the oldest of three children. I have a brother, Robert, and sister, Irene.
Where did you meet your wife?
Patrice and I attended the same high school, Valley Stream
North. We were married during my second year at Georgetown.
Patrice is an artist. She volunteers at Horse Ability, an equine
assisted therapy center, and at the Town of Hempstead animal
shelter. She is my office manager.
Children?
Patrice and I have four children. Patrice, 29, is a producer, choreographer and writer. Victoria, 27, is an actor, holistic health
coach and teacher. Our son, David, 26, works with me at Interfaith Medical Center, where he’s director of emergency management. He has a master’s degree in public health and is an EMS
Lieutenant in the fire department. Our daughter Elizabeth is 24,
has a master’s degree in sociology and works for the Multiple
Sclerosis Society.
Who was most influential in your becoming a dentist?
At first, it was Patrice’s father and mother, Dr. Patrick O’Malley, a
podiatrist, and Genevieve, a teacher, who encouraged me to go to
college. As for choosing dentistry to be my profession, that would
be Vito Cardo, an oral and maxillofacial surgeon who lived next
door to Patrice and her family and was my mentor. Dr. Cardo directed the oral surgery residency program at St. Mary’s Hospital in
Brooklyn. He brought me there and allowed me to shadow him.
The experience opened my eyes to dentistry, especially treating atrisk populations. Another thing that happened as a result of the
time I spent at St. Mary’s, I got to witness the comfort and compassion delivered by the nuns and priests there. It’s something
that stayed with me years later when I was attending Georgetown
School of Dentistry and opted to do my rotation at D.C. General Hospital. It brought me into contact with the indigent, and I
found I felt very comfortable treating these patients.
What do you do to relax/unwind?
Work out in the gym. Ride my bike. I like to garden, especially
working with flowers. And spending time with my family exploring New York City and the natural beauty of Long Island.
What is your idea of a perfect day?
Time at the gym. A bike ride to the beach—I’ve always had an
The New York State Dental Journal • JUNE/JULY 2015 15
Joining up with general practice and pediatric residents and staff at Interfaith Medical Center in Brooklyn, where Dr. Miller chairs Department of Dental Medicine. From left: Julianna Bair, resident;
Gretchen Henson, program director, advanced education in pediatric dentistry; Esther Yun, resident; Victor Cheung, resident; Yusif Umar, resident; behind, Barbara Graham, resident; in front, Tanya
Modica, resident; Alexandre Lee, resident; Krystle Dean-Duru, resident; James Fitzgerald, assistant director, general practice residency program; Shuang Liu, resident.
affinity to the ocean; no matter the season or the weather, I feel
most comfortable when I’m near the water. Then home for a
swim in our pool, some wine and fish on the grill with my family and our dogs.
Did you ever imagine you would be president of NYSDA?
Certainly not when I first became involved with organized dentistry. And I became involved to find solutions to issues I encountered in my practice and in the hospital. I learned early on the
importance of being at “the table,” where my voice was heard and
I learned from leaders and mentors in our profession.
What are your goals for the coming year?
Growing membership is important. But I realize I have a short
window of time to make a difference. I will focus attention on
our special needs patients. This is why my President-elect’s conference, the “Oral Health Stakeholders Summit on the Future of
Special Needs Dentistry” that took place in May in the Legislative Office Building in Albany was so important. We may not be
able to affect the economics of care for this population, but we
can fight to ensure quality dental care and access for New York’s
most vulnerable patients. We can establish centers for medical
and dental excellence, and CODA special needs residencies.
An avid cyclist, Dr. Miller frequently travels to the shore to take in the ocean,
regardless of the weather.
16
THE PARTICULARS
Employment
Chairman, Department of Dental Medicine, Interfaith Medical
Center, Brooklyn.
General Dentist, East Meadow, Nassau County, Long Island.
Dr. Miller is assisted in his East Meadow dental office by, from left: wife, Patrice,
office manager; Eleanor Villar, dental assistant; Brittany Dracker, hygienist;
Monique Midy, hygienist.
Education
General Practice Residency, Woodhull Hospital, Brooklyn.
D.D.S., Georgetown University School of Dentistry, Washington, DC.
B.S., St. John’s University, Queens.
Professional Offices/Titles
Board of Directors, the Special Care Dentistry Association; Assistant Professor
of Clinical Dentistry, New York Medical College, Valhalla; Assistant Clinical Professor of Dentistry, Columbia University School of Dental Medicine, New York.
Honors/Awards
St. Luke Medal for Distinguished Physician of Year, from St. Vincent Catholic
Medical Centers of Brooklyn/Queens; recognized by City of New York Office
of the Chief Medical Examiner for service as member of Dental Identification
Team for the Sept. 11, 2001, World Trade Center and American Airlines Flight
587 disaster, Nov. 12, 2001; The NYSDA Bernard P. Tillis Award for editorial
excellence; Fellow, American College of Dentists; Fellow, International College
of Dentists; Fellow, Pierre Fauchard Academy.
Dr. Miller with Bishop Joseph Sullivan, who was chairman of the Board of Catholic
Medical Center of Brooklyn and Queens, and former New York City Mayor
Edward Koch.
Dr. Miller and Gov. Andrew Cuomo.
Award presented to Dr. Miller
on being named distinguished
physician of the year by St.
Vincent Catholic Medical Centers
of Brooklyn/Queens.
Service to Community
Medical/dental mission to Columbia, South America; over a decade serving
on the Board of Trustees of St. Francis Hospital, Mercy Medical Center and
Catholic Charities Health System; Medical Reserve Corps; over a decade of
volunteering for Give Kids A Smile; Mission of Mercy; Donated Dental Services; 30 years of treating special needs patients.
Addendum
l Dr. Miller’s first dental office was in a garage attached to the family home in
East Meadow. He, his family and friends spent nights and weekends for a year to
build it. His wife, Patrice, was the decorator. Dr. Miller currently occupies a more
conventional office, also in East Meadow, that includes an apartment for his
mother-in-law, Genevieve.
l Early on in his career, Dr. Miller proved he can succeed. Right out of his residency, he applied for the position of director of general practice residency program at Catholic Medical Centers of Brooklyn and Queens. The department
chairman, Raymond Zambito, gave him the opportunity—and just one year to
get the program accredited. He did. And he stayed there for 24 years, until the
hospital system closed.
l David and Patrice share a commitment to rescuing and caring for abandoned and/or mistreated animals. Dr. Miller shares a vivid memory of the
Christmas Eve he and his wife suspended plans for a family observance of the
holiday to care for 20 therapy horses.
l Reflecting on the success he has achieved in his career, Dr. Miller acknowledges three people for making it possible. They are Vito Cardo, Raymond
Zambito and Burt Wasserman. “I thank them for believing in me and giving
me the opportunity,” he said.
l If he had to choose a life philosophy, Dr. Miller said it would be encompassed in the famous quote by Mahatma Gandhi: “The best way to find yourself is to lose yourself in service to others.”
The New York State Dental Journal • JUNE/JULY 2015 17
restorative dentistry
Preparing and Restoring Composite
Resin Restorations
The Advantage of High Magnification Loupes or the
Dental Surgical Operating Microscope
John Mamoun, D.M.D.
ABSTRACT
Use of magnification, such as 6x to 8x binocular surgical loupes or the surgical operating microscope,
combined with co-axial illumination, may facilitate
the creation of stable composite resin restorations
that are less likely to develop caries, cracks or margin stains over years of service. Microscopes facilitate
observation of clinically relevant microscopic visual
details, such as microscopic amounts of demineralization or caries at preparation margins; microscopic
areas of soft, decayed tooth structure; microscopic
amounts of moisture contamination of the preparation during bonding; or microscopic marginal gaps in
the composite. Preventing microscope-level errors in
composite fabrication can result in a composite restoration that, at initial placement, appears perfect
when viewed under 6x to 8x magnification and which
also is free of secondary caries, marginal staining or
cracks at multi-year follow-up visits.
18
Use of microscope-level magnification, combined with co-axial
illumination (MLMCI), may improve a dentist’s ability to prepare, bond, restore and adjust composite restorations,1-3 compared to the use of unaided vision and non-co-axial, shadowforming overhead lighting. A co-axial light axis is coincident
with the visual axis of the dentist’s eyes, resulting in shadowfree illumination.4-6
Diagnosis and Removal of Dental Caries
MLMCI facilitates observation of the colors and textures of carious
material and verification that a slow-speed round bur has removed
all soft, carious tooth material from the margins and base of the
preparation.7-14 Microscopically precise tactile sensitivity enables
associating the feel of an explorer probing a soft carious point
with the point on the preparation surface where the caries exists.
MLMCI also makes possible detection of sub-gingival plaque, food
particles or calculus that is contiguous with a preparation margin.
And it aids in distinguishing this material from caries, stained but
non-carious tooth structure or healthy marginal tooth structure.
MLMCI facilitates detection of microscopic caries at the
contact points of inter-proximal surfaces and caries at the superior aspect of Class III preparations, as well as caries hidden
underneath cusp tips or undercut areas of a posterior prepara-
Figure 1. Initial opening into grooves shows brown carious spots and thin carious veins
embedded in chalky white halos of de-mineralization.
Figure 2. At initial stage of preparation of mid-buccal groove, vein of carious material,
contiguous with a V-shaped notch at margin, exists on inner surface of preparation wall.
tion. It assists in verifying removal of all sub-gingival decay from
the apical aspect of the Class V preparation and in verifying that
proximal box walls, margins and point angles of Class II preparations are free of carious material and chalky white demineralization. Co-axial lighting illuminates the apical aspect of the
proximal box, which is boxed into a crevice formed by the sides
of the proximal box, which hinders the shadow-free penetration
of overhead lighting.
In cross-section, the grooves of posterior teeth have a V-shaped
notch shape. If a preparation extends into a groove, and there
is a V-shaped notch at the terminus of this groove aspect of the
preparation, such as at the buccal extreme of a mid-buccal groove
preparation aspect, then composite that is placed at this aspect may
not flow intimately into the sharply angled notch (Figures 1, 2).
This can result in a microscopic gap or a food or debris trap at the
aspect of the restoration margin that is located at that preparation
extremity, which may eventually result in a non-carious marginal
stain. Also, caries, visible as a microscopic brown line embedded
in a halo of chalky white demineralization, may exist on the inner
surface of the preparation wall at the notch area and be contiguous
with the apex of the V-shaped notch (Figure 2). Composite placed
up against this notch may not only form a food trap, but this food
trapping might also nurture the carious lesion, eventually resulting
in a carious stain in this area.
MLMCI facilitates observation and rounding off of microscopic
V-shaped notches at preparation extremities and removal of associated caries, including any microscopic vein of decay at the preparation base that also extends contiguously to the preparation margin
(Figure 2). On maxillary anterior teeth, it enables detection of Vshaped notches and groove boundaries in cingulum grooves.
Creating Mechanical Retention in Preparation
Mechanical retention helps to reinforce a composite bond.15-18
MLMCI facilitates precise angling of a 330 bur or a 33 ½ bur to
create mechanically retentive loci in a preparation. It helps verify
that undercuts are distributed homogeneously throughout the
preparation, and that for any particular direction of force that
will be placed on the future restoration, there will be a locus of
mechanical retention that will be able to resist that force. And
it helps verify that an abfraction lesion preparation has a welldefined apical margin, and that the mesial and distal aspects of
the preparation have well-defined, boxy edges.
Optimizing Bio-mechanical Stability of Composite Restoration
If a tooth presents with a carious hole on the occlusal surface or
a marginal ridge, the dentist observes with MLMCI if an opposing
pointy plunger cusp occludes directly into that hole. One example
is a lingual cusp on a maxillary molar that protrudes more occlusally than the average level of the maxillary occlusal plane and that
occludes into an opposing tooth such that the cusp tip is apical to
the average mandibular occlusal plane. The dentist can use an aluminum oxide composite polishing bur to round off approximately
1 mm to 1.5 mm of the opposing protrusive cusp, ideally without
exposing dentin. MLMCI facilitates verifying if all aspects of a
preparation are deep enough to ensure that the resulting composite placed in the preparation will have adequate thickness to resist
occlusal forces.
Matrix and Wedge
MLMCI facilitates the observation of microscopic gaps in the matrix band seal of a Class III preparation and helps in determining
19
Figure 3. Magnification shows no microscopic amount of moisture contamination around
preparation margin. (Photo courtesy of Dr. Donato Napoletano)
Figure 4. Magnification shows flowable composite flows without air bubbles into all microscopic aspects of pulp chamber and around post of endodontically treated tooth. (Photo courtesy
whether a wedge of a different thickness, base width or position
improves the seal. It helps in distinguishing between the interfaces of the wedge, the clear matrix band and the preparation
margin, and aids in observing if the apical aspect of the clear
matrix band wraps around the palatal-inter-proximal line angle
of the tooth being restored and is between the gingiva and the
tooth surface instead of on top of the gingiva or wrapping around
the neighboring tooth.
While pulling on a Class III matrix band to push the composite into the preparation, the dentist uses MLMCI to determine if
composite is flowing into all microscopic aspects of the preparation and margin and if microscopic adjustments to the direction
of pull on the clear matrix band improves the direction of composite flow. Such microscope-level visual observation is useful if
malposition of the anterior teeth hinders the ability to firmly grip
the matrix band.
Moreover, MLMCI aids in verifying that there is no moisture
seepage at the matrix band around Class II or Class III preparations after isolating with cotton rolls or placing thinner dry
angles19 if the cotton rolls do not fit in the vestibules around the
matrix band. And it facilitates observing that no plaque, food particles, calculus or gingival material has been trapped between the
matrix band and the preparation margin. Matrix band gaps can
be sealed with a flowable composite, which can be placed without
using an apically directed force that would otherwise expand the
gap. Using MLMCI, the dentist observes when the composite has
flowed enough to seal the proximal box margin but has not yet
flowed apically past the margin.
Isolating the Preparation
MLMCI helps clinicians detect microscopic amounts of moisture
contamination in the preparation and verify moisture removal
through air drying (Figure 3). A magnified view of the vestibules
allows a dentist to observe the rate of saturation of cotton rolls
and dry angles, which indicates at what rate these should be replaced. MLMCI also enables distinguishing the upward movement
of spatter into a maxillary second molar preparation from saliva
pooling in the mandibular retromolar pad area. And it helps the
dentist see the interface between tooth structure and the gingiva,
which prevents laceration of the gingiva during preparation of
marginal areas or when wedging matrix bands, thereby preventing blood contamination of the preparation.
20
of Dr. Donato Napoletano)
Total Etching of the Preparation
Some dentists promote,20-23 while others discourage,24 total etching of composite preparations with 37% phosphoric acid. One advantage of etching is that, when an etched and dried frosty white
preparation is viewed with MLMCI, V-shaped notches at groove extremes, carious pinpoints and veins, and even frank decay that the
dentist may have unintentionally left in the preparation stand out
more obviously from healthy dentin and enamel than if viewing a
dried but not etched preparation. MLMCI allows a dentist to verify
that all aspects of the preparation are etched and frosty white.
Bonding the Preparation
MLMCI facilitates verifying that the tip of a bonding brush or micro-applicator is thin enough in diameter to penetrate all aspects
of the preparation and observing if microscopic differences in the
angle of the bonding brush improves its contact with the preparation surface. It enables observation of air bubbles that prevent
the bonding agent from wetting parts of the preparation. Some
bonding experts suggest that a preparation surface has an optimal
degree of wetness to effect bonding when the surface is slightly
moist instead of being completely desiccated.25-27 And it aids in
differentiating between degrees of preparation wetness, such as a
desiccated surface, a slightly moist matte surface or a surface wet
with pools of moisture.
Using Hand Instruments to Condense Composites
MLMCI allows a dentist to visually detect microscopic amounts
of up-pull of a sticky composite increment by hand instruments
when incrementally filling composite. Microscopically precise
tactile sensation enables association of a feeling of up-pull with
the angle of instrument placement and the depth of instrument
tip penetration into the composite. MLMCI aids a dentist in detecting if such up-pull is due to microscopic amounts of composite flowing over undercut aspects of ball condensers or inverted
cone condensers when the instrument tip is embedded in the
composite material. A magnified view of the composite shows if
it is flowing into all aspects of the preparation and if microscopic
adjustments to the angle and direction of the hand instrument
working tip directs composite flow into a required direction.
Bulk Filling Preparation with Composite
A basic technique of bulk filling is to use a composite applicator
gun to slightly overfill the preparation with composite, then use a
gloved finger, moistened with acid-free bonding agent or flowable
composite (to prevent the gloved finger from sticking to the composite), to push the composite into the preparation. The dentist
then releases the gloved finger from the composite and verifies,
using MLMCI, that the finger did not up-pull any composite from
the preparation and that the entire preparation perimeter is in
contact with composite material. The dentist removes composite
excess that has flowed past the sides or into the inter-proximal
spaces of the tooth and then light-polymerizes the composite.
When bulk filling posterior occlusal-buccal preparations,
where the occlusal and buccal surfaces are contiguous, MLMCI
facilitates verification that the finger forces did not cause the
composite at the occlusal-buccal line angle to lift up slightly,
thereby creating a void under the composite at this line angle.
Handling Flowable Composite
MLMCI makes it possible to detect microscopic air bubbles in
flowable composite, located either inside or on the external surface or margin of the flowable composite bolus. The dentist breaks
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21
up air bubbles with an explorer tip and observes, using MLMCI,
that the flowable composite has settled into the space once occupied by the air bubbles. It allows a dentist to detect when an
increment of flowable composite has flowed into complete contact with the surface of the preparation, or with the surface of
composite over which the increment was placed (Figure 4).
Light Polymerization of Composite
MLMCI enables a dentist to differentiate between microscopic changes in the angle and direction of the polymerization light and in the
distance from the restorative material to the light. The dentist can
observe how microscopic changes to the light angle result in some
microscopic aspects of the restoration that were not illuminated with
previously utilized light angles to now become illuminated with other,
different light angles. A dentist can visually estimate the location of
each microscopic volume of the composite restoration, to ensure that
each microscopic volume element of composite has been exposed to
enough illumination to effect polymerization. In areas of minimal
clearance, like the second molar areas, MLMCI allows a dentist to
detect if microscopic aspects of a restoration are inaccessible to the
polymerization light due to a non-ergonomic shape of the light tip.
Trimming and Polishing of Composite Restorations
MLMCI makes it possible to distinguish between the color of
composite and the color of tooth structure. It allows a dentist
to better estimate where the margin of the preparation is buried under an excess of composite material, by visually relating
the location of various microscopic points along the preparation perimeter to microscopic morphological landmarks on the
tooth surface. This facilitates trimming composite restorations to
the preparation margins. Excess composite that extends beyond
the preparation margin is essentially a thin flap that overlies the
tooth surface. Food and debris may collect underneath the flap,
eventually causing a carious or non-carious stain under the flap.
At a postoperative visit, if the stain is non-carious, the dentist
may be able to use MLMCI to detect and polish away the flap.
When polishing the facial surfaces of anterior teeth, magnification facilitates angling a triangle-shaped polishing bur so that
multiple points on the bur contact the composite surface simultaneously, preventing divot formation on the composite surface.
MLMCI enables a dentist to identify and remove microscopic pits
in the margin of the finished composite or microscopically shallow concavities on an anterior facial composite that cause esthetically displeasing shadows to form on the surface.
MLMCI aids a dentist in detecting the inter-proximal margin
of Class III composite and in distinguishing this margin visually
from inter-proximal overhangs of composite material. It also facilitates detection of bonding agent that flowed into the gingival sulcus
around an anterior tooth and hardened after light polymerization.
22
Microscopically precise tactile sensation enables a dentist to detect
microscopic composite ledges or reliefs at the margin of Class V
preparations and to precisely angle a triangle-shaped polishing bur
in order to trim overhangs without ditching the composite margin.
The dentist can directly observe if an explorer tip is closely hugging
margin surfaces when detecting Class V overhangs. If polishing a
Class V overhang abrades the gingiva, causing gingival bleeding, the
dentist can smear the blood into the composite using an explorer tip
and then observe, with MLMCI, if microscopic amounts of blood
pool at overhang areas along the composite margin. This pooled
blood is visible as a red line segment at margin overhangs.
3. Adjusting Occlusion
MLMCI facilitates identifying which opposing wear facets, cusp
tips and fossa should mesh with one another with microscopic
intimacy in maximum intercuspation by observing to microscopic precision the perimeters of opposing wear facets and the microscopic topographical features of opposing tooth surfaces. The
dentist then observes if grinding away articulating paper marks on
the composite restoration results in an incremental microscopic
decrease in the separation between opposing tooth surfaces.
MLMCI also aids in observing if the use of different brands or
thicknesses of articulating paper, or the use of articulating paper on
moist, versus dry surfaces, results in microscopic differences in the
locations and sizes of articulating paper marks.28,29 The dentist can
then determine which marks, produced under which circumstances,
result in improvements in the articulation when the marks are reduced. If reducing articulating paper marks does not result in microscopic improvements of the occlusion, then the restoration may
be optimally adjusted; however, if the occlusion is still off, the marks
may be inaccurate. Here, the dentist can attempt to use MLMCI to
directly observe pre-maturities that require reduction.
10. 11. 4. 5. 6. 7. 8. 9. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. Conclusion
MLMCI may improve a dentist’s ability to detect and remove microscopic caries, microscopic amounts of moisture contamination or microscopic bio-mechanical compromising factors when
preparing and restoring direct composite restorations. This may
allow a dentist to produce composite restorations that, even after years of service, appear free of caries, stains or cracks30 when
viewed under microscope-level magnification. p
24. 25. 26. 27. 28. 29. The author thanks Donato Napoletano, D.M.D., for providing some of the
surgical operating microscope photographs used in this article. Queries about
this article can be sent to Dr. Mamoun at [email protected].
30. Makhija SK, Gordan VV, Gilbert GH, Litaker MS, Rindal DB, Pihlstrom DJ, Qvist V; Dental
Practice-Based Research Network Collaborative Group. Practitioner, patient and carious
lesion characteristics associated with type of restorative material: findings from The Dental
Practice-Based Research Network. J Am Dent Assoc 2011 Jun;142(6):622-32.
Mamoun JS. A rationale for the use of high-powered magnification or microscopes in general dentistry. Gen Dent 2009 Jan-Feb;57(1):18-26;quiz 27-8, 95-6.
van As G. Magnification and the alternatives for microdentistry. Compend Contin Educ
Dent 2001 Nov;22(11A):1008-12,1014-6.
Napoletano D. Dental Operating Microscopes: Don’t Equip an Operatory Without One!
Inside Dentistry. 2007 May(3)5.
Strassler HE, Porter J, Serio CL. Contemporary treatment of incipient caries and the rationale for conservative operative techniques. Dent Clin North Am 2005 Oct;49(4):867-87.
Maltz M, Jardim JJ, Mestrinho HD, Yamaguti PM, Podestá K, Moura MS, de Paula LM. Partial Removal of carious dentine: a multicenter randomized controlled trial and 18-month
follow-up results. Caries Res 2012 Nov 28;47(2):103-109.
Mertz-Fairhurst EJ, Schuster GS, Fairhurst CW. Arresting caries by sealants: results of a
clinical study. J Am Dent Assoc 1986 Feb;112(2):194-7.
Kidd EA. How ‘clean’ must a cavity be before restoration? Caries Res 2004 May Jun;38(3):305-13.
Thompson V, Craig RG, Curro FA, Green WS, Ship JA. Treatment of deep carious lesions by complete excavation or partial removal: a critical review. J Am Dent Assoc 2008
Jun;139(6):705-12.
Foley J, Evans D, Blackwell A. Partial caries removal and cariostatic materials in carious primary
molar teeth: a randomised controlled clinical trial. Br Dent J 2004;197(11):697-701;discussion 689.
Ricketts DN, Kidd EA, Innes N, Clarkson J. Complete or ultraconservative removal of decayed tissue in unfilled teeth. Cochrane Database Syst Rev 2006; issue 3.
Maltz M, de Oliveira EF, Fontanella V, Bianchi R. A clinical, microbiologic, and radiographic study
of deep caries lesions after incomplete caries removal. Quintessence Int 2002; 33:151–159.
McCoy RB, Anderson MH, Lepe X, Johnson GH. Clinical success of class V composite resin
restorations without mechanical retention. J Am Dent Assoc 1998 May;129(5):593-9.
Brännström M, Mattsson B, Torstenson B. Materials techniques for lining composite resin
restorations: a critical approach. J Dent 1991 Apr;19(2):71-9.
Belli R, Sartori N, Peruchi LD, Guimarães JC, Araújo E, Monteiro S Jr, Baratieri LN, Lohbauer U. Slow progression of dentin bond degradation during one-year water storage under
simulated pulpal pressure. J Dent 2010 Oct;38(10):802-10.
Abdalla AI, El Eraki M, Feilzer AJ. The effect of direct and indirect water storage on the
microtensile dentin bond strength of a total-etch and two self-etching adhesives. Am J Dent
2007 Dec;20(6):370-4.
Mamoun J, Salamah M. Use of the dry angle isolation adjunct in general dentistry: a clinical
approach. Dent Assist 2010 Jan-Feb;79(1):13-4, 36-7.
Poitevin A, De Munck J, Van Ende A, Suyama Y, Mine A, Peumans M, Van Meerbeek B. Bonding effectiveness of self-adhesive composites to dentin and enamel. Dent Mater 2012 Oct 26.
Manuja N, Nagpal R, Pandit IK. Dental adhesion: mechanism, techniques and durability. J
Clin Pediatr Dent 2012 Spring;36(3):223-34.
Van Landuyt KL, Peumans M, De Munck J, Cardoso MV, Ermis B, Van Meerbeek B. Threeyear clinical performance of a HEMA-free one-step self-etch adhesive in non-carious cervical lesions. Eur J Oral Sci 2011 Dec;119(6):511-6.
Mine A, De Munck J, Cardoso MV, Van Landuyt KL, Poitevin A, Kuboki T, Yoshida Y, Suzuki
K, Lambrechts P, Van Meerbeek B. Bonding effectiveness of two contemporary self-etch
adhesives to enamel and dentin. J Dent 2009 Nov;37(11):872-83.
Christensen GJ. Has the ‘total-etch’ concept disappeared? J Am Dent Assoc 2006
Jun;137(6):817-20.
Kanca J 3rd. Effect of resin primer solvents and surface wetness on resin composite bond
strength to dentin. Am J Dent 1992 Aug;5(4):213-5.
Kanca J 3rd. Effect of primer dwell time on dentin bond strength. Gen Dent 1998 NovDec;46(6):608-12.
Perdigão J, Frankenberger R. Effect of solvent and rewetting time on dentin adhesion. Quintessence Int 2001;32:385–390.
Wassell RW, Barker D, Steele JG. Crowns and other extra-coronal restorations: try-in and
cementation of crowns. Br Dent J 2002 Jul 13;193(1):17-20, 23-8.
Kelleher M G D, Setchell D J. An investigation of marking materials used in occlusal adjustment. Br Dent J 1984;156:96-102.
Clark DJ. Reclaiming endodontics and reinventing restorative, part 2. Dent Today 2010
Nov;29(11):156, 158-61.
John S. Mamoun, D.M.D., is in private practice in Manalapan, NJ.
REFERENCES
1. 2. Demarco FF, Corrêa MB, Cenci MS, Moraes RR, Opdam NJ. Longevity of posterior composite restorations: not only a matter of materials. Dent Mater 2012 Jan;28(1):87-101.
Brunthaler A, König F, Lucas T, Sperr W, Schedle A. Longevity of direct resin composite
restorations in posterior teeth. Clin Oral Investig 2003 Jun;7(2):63-70.
Dr. Mamoun
23
oral surgery
Necrotizing Fasciitis Case Presentation and
Literature Review
Louis Christensen, D.D.S.; Heath Evans, D.D.S.; David Cundick, D.D.S.; Matt McShane, D.D.S.;
Kevin Penna, D.D.S.; Rory Sadoff, D.D.S.
ABSTRACT
Necrotizing fasciitis is a rare, rapidly progressing infection with significant morbidity and high mortality
rates. Rarely does necrotizing fasciitis appear in the
head and neck region; rather, it usually affects the
limbs and abdomen of patients. This article presents
our institution’s experience with the disease and provides a discussion of proposed treatment options.
Necrotizing fasciitis is a rapidly progressing infection characterized by significant morbidity and high mortality rates. The description of necrotizing fasciitis dates back to the times of Hippocrates; it has been known by a variety of names: malignant
ulcer, gangrenous ulcer, putrid ulcer, phagedenis ulcer, hospital
gangrene and necrotizing cellulitis. In 1952, the disease was given
its current name: “necrotizing fasciitis.”1
Necrotizing fasciitis in the head and neck region is rare and
represents a disease process clinicians may not have in-depth experience with. This article presents our institution’s experience
with the disease and provides an additional case for the literature.
Case Report
A 48-year-old Hispanic male presented to our institution’s
emergency room with a one-day history of right facial edema
24
and pain, for which the oral and maxillofacial surgery service
(OMS) was consulted. The patient denied history of trauma to
the area. He reported a past medical history significant for hypertension and end-stage renal disease, for which he received
dialysis three times a week. He also reported an unknown reaction to penicillin.
On physical exam, the patient was sitting upright in bed.
There was significant right temporal, periorbital, canine, buccal,
submental and bilateral submandibular edema, which was erythematous and extremely painful to palpation (Figure 1). The patient presented with a maximal incisal opening of 10 mm, which
limited our ability to assess the floor of the mouth and posterior
oropharynx. The patient’s dentition had multiple grossly carious,
non-restorable teeth. A maxillofacial computer tomography with
contrast was obtained. It demonstrated cellulitis of the right preseptal facial region and submandibular regions. No focal fluid
collection was noted (Figure 2). The patient demonstrated a white
blood cell count (WBC) of 6.51 with 33% banding, platelets of
46,000, temperature of 102.8 and acceptable oxygen saturation.
Despite his compromised medical condition, his electrolytes were
acceptable for a patient with end-stage renal disease.
The patient was admitted to the medical intensive care unit
(MICU) for facial cellulitis and airway observation until operating room time became available. Of paramount concern for this
patient was securing his airway for surgery. Due to the loss of
anatomic landmarks and deviation of the airway, a nasal fiber optic intubation was recommended and was successfully performed.
Surgical incision and drainage of right canine, temporal, submental and bilateral submandibular spaces, along with extraction
of all non-restorable teeth were performed by the OMS service.
The OMS service placed six Jackson-Pratt (JP) and one Penrose
drain exposing the affected fascial spaces. Upon exploration of
affected spaces, a dishwater-like discharge was noted from the
affected spaces.
The patient remained nasally intubated in the MICU for the
next several days (Figure 3). He received daily bedside wound care
by the OMS service. This included evaluation of drain sites and
irrigation of JP drains with normal saline. Based on clinical appearance, radiographic and laboratory findings, it was determined
the patient was improving, and the drains were removed as they
were no longer productive. The last of the drains was removed on
the sixth postoperative day.
On the seventh day, the patient unexpectedly began to deteriorate into septic shock requiring vasopressor support. Because
of his deteriorating condition, the patient was taken back to the
operating room for further exploration and additional incision
and drainage of wounds. Drains were placed in subcutaneous layers, where minimal resistance was felt with finger dissection, and
areas of necrosis were debrided. The patient eventually required
tracheotomy on hospital day 15 for treatment of acute respiratory
distress syndrome and anticipated continued mechanical ventilation. The OMS service continued to perform daily wound care
each day at bedside, consisting of irrigation and debridement of
tissue as needed. On hospital day 33, the patient was taken to the
OR for placement of a permacath to replace his clotted arteriovenous fistula by the general surgery service. The OMS team performed exploration of the wounds and further debridement of
the area at this time.
The patient remained in the MICU for 37 days prior to being
transferred to the pulmonary care unit, where he continued to
receive daily bedside wound care by OMS (Figure 4). On hospital
day 47, he was discharged to a sub-acute rehab facility. Upon his
discharge, an area of tissue directly lateral to the right commissure was open, for which the OMS team had planned reconstruction of the affected area. Numerous attempts were made to have
the patient follow up. Approximately six months after discharge,
the patient returned to the OMS clinic. Upon examination, the
area lateral to the right commissure had healed with an acceptable esthetic result to the patient; therefore, plans for the soft
tissue reconstruction were abandoned (Figure 5).
In summary, the patient underwent three surgeries in the
operating room, with culture swabs and tissue biopsies submitted. The cultures demonstrated beta hemolytic streptococcus
group A (Streptococcus pyogenos). The infectious disease service
Figure 1. Initial
presentation.
Figure 2. Initial computer
tomography.
Figure 3. Postop initial
surgery.
Figure 4. Preop photo before third
surgery hospital day 26.
Figure 5. Patient at six-month follow-up.
25
was consulted and directed antibiotic therapy. After evaluation
of cultures, the infectious disease service tailored the patient’s
antibiotic regime with amikacin (aminogylcoside), aztrenam
(monobactam), clindamycin (lincosamide) and tigecyline (glycylcycline). Hyperbaric oxygen therapy was recommended, but
because of the patient’s unstable nature, he never received it.
The patient presented with a WBC upon admission of 6.51.
He displayed minimal changes in his WBC following surgical intervention and during his stay in MICU. The lack of immune response contributed to the patient’s development of septic shock.
As a result of the patient’s leukocytosis, infectious disease recommended Neupogen (filgrastim). Neupogen is a granulocyte
colony-stimulating factor (GCSF) used for the treatment of neutropenia in patients undergoing chemotherapy.
Discussion
Necrotizing fasciitis is a disease process that results in liquefaction of the subcutaneous layer while sparing the overlying skin. If
not treated early and aggressively, significant morbidity and mortality can occur.
A limited number of necrotizing fasciitis cases are reported
yearly. Approximately 10% of reported cases occur in the head
and neck region, with around 30% of patients being diagnosed
correctly at the time of admission.2 Overall, mortality rates associated with all cases of necrotizing fasciitis are 46%; when of
odontogenic origin, the mortality rate is 20%.3,4
Necrotizing fasciitis is generally considered a mixed aerobic/
anaerobic polymicrobial infection; however, there are reported
cases of monomicrobial infection.5 Several different bacteria are
commonly isolated on microbiologic examination, including
Group A b hemolytic streptococcus (streptococcus pyogenes), Clostridium perfringens, staphylococcus aureus and enterobacteriaceae.6
The disease usually affects someone with immune dysfunction,
such as diabetes, chronic malnutrition, or others with end-stage
organ disease, trauma, burns and childbirth.7
Necrotizing fasciitis is characterized by rapid progression of
subcutaneous necrosis affecting underlying fascia. It results in
large amounts of edema along fascial planes. The disease typically
starts two to four days following the initial injury. The injury may
result from trauma, surgery, injections, contusions, abrasions,
lacerations, peritonsillar abscesses, odontogenic infections and/
or minor or forgotten injuries.8-12 The disease process can progress rapidly, initially appearing as an area of erythematous, edematous, hot, painful wound. The infected area can subsequently
become numb due to compression and/or destruction of cutaneous nerves.13
The infection spreads rapidly via the subcutaneous fat and
connective tissue layer, causing liquefaction of this layer. The
liquefaction that occurs during necrotizing fasciitis is due to
26
the breakdown of collagen by collagenase and hyaluronidase
produced by beta hemolytic streptococcus,13 although multiple
other organisms have been documented in wounds.6 The resulting necrosis of the overlying skin gives way to the characteristic
offensive odor and dishwater-like pus.2 Venous return from the
affected site decreases due to thrombosis of vessels, causing a pale
color of the skin initially, followed by a purplish color then a
black color, indicating ischemic necrosis.2 An intense inflammatory reaction occurs with a significant amount of polymorphonuclear infiltrates, focal necrosis and microabscess formation by
the offending bacteria. The intense inflammatory response results
in tachycardia, fever and, potentially, septic shock.2 Typically, the
disease progresses along fascial planes and does not affect muscle.
However, myositis (affected muscle) can be present and can cause
devastating loss of tissue, resulting in exposure of bone.
If left untreated, this area of necrosis can rapidly progress
along the fascial planes and descend into the neck and mediastinum.14,15 This greatly increases the risk of mortality.15 Evidence
of descending necrotizing mediastinitis include: A. severe oropharyngeal infection; B. characteristic radiographic features of mediastinitis; C. documentation of necrotizing mediastinal infection;
and D. establishment of relationship between oropharyngeal infection and descending necrotizing mediastinitis.14
Diagnosis of necrotizing fasciitis in the head and neck region at the time of presentation can be difficult. Clinical examination typically reveals minimal resistance to exploration of the
subcutaneous tissues with a finger. Biopsy of affected tissue is
of limited value due to necrosis; consequently, adjacent healthy
looking tissue should be biopsied. According to Stamenkovic, use
of frozen sections and the histologic appearance of dense polymorphonuclear infiltrates within the dermal layers confirm the
diagnosis of necrotizing fasciitis.17 Computer tomography is the
most commonly used radiographic method to evaluate the disease. Necrotizing fasciitis may demonstrate thickening and infiltrates of the cutis and subcutis, thickening of superficial and
deep fascial planes, fluid collections, gas collections, mediastinitis
and/or pleural/pericardial effusions upon radiographic examination.17
Balcerak has proposed staging of the necrotizing fasciitis
based on cutaneous findings.19 Stage I, or early stages, consist of
tenderness, erythema and swelling.18 The formation of blisters
and bullae is characteristic of Stage II, or the intermediate stage.18
Stage III is the most devastating, and includes crepitus, skin anesthesia and necrosis.18
Suspicion of necrotizing fasciitis should warrant admission
to the hospital for further work and initial antibiotic therapy. Of
critical importance in patients with necrotizing fasciitis of the
head and neck region is airway management due to the significant edema.19 Because of the potential difficulties that can be
encountered during intubation of a patient with necrotizing fasciitis, consideration should be given to a surgical airway. Should a
surgical airway be required, care should be taken to avoid spread
of the infection into the tracheotomy site.12 As our case demonstrated, edema can be quite extensive, causing obliteration of anatomic landmarks, which can make a tracheostomy very difficult.
Early tracheostomy has been shown to shorten the length of mechanical ventilation, intensive care unit (ICU) stay and reduced
complication rate.20,21
Invasive hemodynamic monitoring, fluid resuscitation and
vasopressor therapy may be required in the management of these
patients due to sepsis and septic shock. Intravenous antibiotics
will be required in the treatment of necrotizing fasciitis. Antibiotic therapy is guided by cultures; however, a triple antibiotic regime
of penicillinase-/methicillinase-resistant penicillin, an aminoglycoside, and clindamycin or metronidazole is required.12,22
The mainstay of treatment for necrotizing fasciitis remains
aggressive surgical therapy. Wide surgical debridement should occur; tissue should be removed until areas of normal bleeding tissue are encountered without regard to reconstruction. Attempts
at preservation of the facial nerve need to be made, if possible.23
Wound cultures and biopsies should be collected and sent for appropriate pathologic examination and used to direct antibiotic
therapy. A variety of solutions have been proposed as wound irrigates, including 1% hydrogen peroxide and normal saline, eusol
and Betadine.24,25,26 Wounds are irrigated daily and frequent wetto-dry dressings applied to affected areas. The surgical wounds are
left open or packed with gauze impregnated with antibiotics. The
patient is consistently re-evaluated for development of areas of
necrosis. According to Weiss et al., a patient will typically require
three operating room visits for irrigation, debridement and packing of wound.14
While surgical debridement and antibiotics are the mainstays
of treatment, other adjunctive therapies have been suggested, including hyperbaric oxygen and vacuum-assisted closure devices.
The use of HBO has been studied by multiple authors in conjunction with surgical therapy and has achieved good outcomes.27-29
The use of vacuum-assisted devices has been used for a variety
of different wounds throughout the body. In recent years, use of
vacuum-assisted devices as an adjunct for craniofacial injuries,
including necrotizing fasciitis, has been described with good results.30 Our case presents a unique esthetic result not typically
seen with secondary granulation of the affected area.
Conclusion
Initial management of patients with necrotizing fasciitis centers on
airway management, with strong consideration given to a surgical
airway if difficult airway is anticipated and/or prolonged mechanical ventilation is anticipated. After securing the airway, aggressive
27
surgical management should be performed, along with culture-directed antibiotic therapy. Admission to an ICU setting for continuous monitoring and intensive medical therapy should be considered. Daily evaluation of surgical site and wound care should be
performed. Adjunctive therapies, such as hyperbaric oxygen and/or
vacuum-assisted closure devices, can be considered. p
11.
Queries about this article can be sent to Dr. Christensen at [email protected].
16.
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literature and case report. J Oral Surg 2011;69:2786.
Sander A, Borgermann J, Kosling S, Silber RF, Bloching MB. Descending necrotizing mediastinitis: early detection and radical surgery are crucial. J Oral Maxillofac Surg 2007;65:794-800.
Estrera AS, Landay MJ, Grisham JM, Sinn DP, Platt MR. Descending necrotizing mediastinitis. Surg Gynecol Obstet 1983;157:545.
Stamenkovic I, Lew PD. Early recognition of potentially fatal necrotizing fasciitis: the use of
frozen section biopsy. N Engl J Med 1984;310:1689.
Becker M, Zbaren P, Hermans R, Becker CD, Marchal F, Kurt AM, Marre S, et al. Necrotizing
fasciitis of the head and neck: role of CT in diagnosis and management. Radiology 1997;
202(2):471–6.
Balcerak R, Sisto J, Bosack R. Cervicofacial necrotizing fasciitis: report of three cases and
literature review. J Oral Maxillofac Surg 1988;46:450.
Martin DR. Molecular epidemiology of group A streptococcus M type 1 infection. J Infect
Dis 1993;167:112.
Griffiths J, Barber VS, Morgan L, Young JD. Systematic review and meta-analysis of studies of the timing of tracheostomy in adult patients undergoing artificial ventilation. BMJ
2005;330:1243–7.
Bickenbach J, Fries M, Offermanns V, Von Stillfried R, Rossaint R, Marx G, et al. Impact
of early vs late tracheostomy on weaning: a retrospective analysis. Minerva Anestesiol
2011;77:1176–83.
Huang WS, Hsieh SC, Hsieh CS, et al. Use of vacuum assisted wound closure to manage limb
wounds in patients suffering from acute necrotizing fasciitis. Asian J Surg 2006;29:135.
Brook I, Frazier EH. Clinical and microbiological features of necrotizing fasciitis. J Clin
Microbiol 1995;33:2382.
Mruthyunjaya B. Necrotizing fasciitis: report of case. J Oral Surg 1981;39:60.
Drake-Lee AB, Broughton SJ, Rampling A, et al. Necrotizing fasciitis. J Laryngol Otol
1983;197:193.
Drespi YP, Lawson WT, Blaugrund SM, et al. Massive necrotizing infections of the neck.
Head Neck Surg 1981;3:475.
Mohammedi I, Ceruse P, Duperret S, et al. Cervical necrotizing fasciitis: 10 years experience
at a single institution. Intensive Care Med 1999;25:829, Neck Surg 1995;112:274.
Krespi YP, Lawson W, Blaugrund SM, et al. Massive necrotizing infections of the neck. Head
Neck Surg 1981;3:475.
Korhonen K, Kuttila K, Niinikoski J. Tissue gas tensions in patients with necrotizing fasciitis
and healthy controls during treatment with hyperbaric oxygen: a clinical study. Eur J Surg
2000;166:530.
Shupak A, Shoshani O, Goldenberg I, et al. necrotizing fasciitis: an indication for hyperbaric
oxygen therapy? Surgery 1995;118:873.
Byrnside V, Glasgow M, Gurnuluoglu R. The vacuum-assisted closure in treating craniofacial wounds. J Oral Maxillofac Surg 2010;68: 935-942.
Dr. Christensen
Dr. Evans
Dr. Cundick
Dr. McShane
Dr. Penna
Louis Christensen, D.D.S., is a resident at Nassau University Medical Center, East Meadow, NY.
Heath Evans, D.D.S., is in private practice in Tulsa, OK.
David Cundick, D.D.S., is in private practice in Farmington, NM.
Matt McShane, D.D.S., is a resident at Nassau University Medical Center, East Meadow, NY.
Kevin Penna, D.D.S., is attending at Nassau University Medical Center, East Meadow, NY.
Rory Sadoff, D.D.S., is chairman, Oral and Maxillofacial Surgery, Nassau University Medical
Center, East Meadow, NY.
28
root fractures
Adhesive Approach Using Internal
Coping for Vertical Root Fractured
Teeth with Flared Root Canals
Shuhei Takeuchi, D.D.S., Ph.D.; Toshiaki Sekita, D.D.S., Ph.D.; Ken`ichi Kobayashi, D.D.S., Ph.D.
ABSTRACT
Vertical root fractures are often observed in teeth with
endodontic treatment and post space preparation.
Frequently, because such teeth have flared root canals
with thin dentin walls, conventional treatments are
disadvantageous in terms of adhesiveness, sealability
and risk of refracture. Here we devised an intentional
replantation method that uses internal resin coping,
with a reinforcing effect on thin root canal dentin.
In two patients treated with this method, satisfactory
conditions have been maintained. This report suggests
that an intentional replantation method in which an
internal resin coping is employed may be a useful therapy for fractured teeth with flared root canals.
A vertical root fracture (VRF) is defined as a longitudinal fracture
confined to the root that usually initiates on the internal canal
wall and extends outward onto the root surface.1 VRFs are associated with pain, swelling, fistulas, tooth mobility, deep localized
periodontal pockets and vertical bone defects; they cause progres-
sive destruction of periodontal tissue. The prognosis for teeth
with VRFs is extremely poor, and tooth extraction is recognized
as the appropriate treatment in most cases. When a VRF occurs
in an abutment tooth of a fixed or removable partial denture,
large-scale prosthetic retreatment is often unavoidable. Therefore,
establishing a way to prevent VRFs and thereby preserve root-fractured teeth would be of great clinical significance.
Among conventional therapies for VRF teeth reported thus
far, adhesion methods that use adhesive resin cement, in particular 4-META/MMA-TBB dentin-bonded resin (SB: Super-Bond C&B;
Sun Medical Co, Kyoto, Japan), have produced successful outcomes.2
Furthermore, the utility of adhesion methods using SB, which include bonding through the root canal, as well as extraoral bonding and replantation as conservative therapies for VRF teeth has
become quite clear from histopathological3-5 and clinical investigations6-8 of these techniques.
VRFs due to trauma or excessive occlusal force are often observed in teeth with endodontic treatment and post space preparation. Frequently, such teeth have flared root canals with thin dentin walls. Thus far, however, there are no reports that focus on VRF
teeth with flared root canals, which have poor long-term prognoses
because their low fracture strength complicates adhesive processes
and surgical maneuvers. Therefore, by applying Lui’s method,9 a
29
technique that produces beneficial outcomes by reinforcing thin
dentin walls, we devised an intra- extraoral bonding and replantation method in which external bonding during intentional replantation is performed upon carrying out internal bonding by a resin
coping procedure to reinforce thin root canal dentin (Figure 1).
Here we report two cases in which successful outcomes were
obtained after performing this new adhesive replantation method
on VRF teeth with flared root canals.
Figure 1. Schematic diagram of adhesive replantation method that uses internal coping.
Figure 2. Intraoral view at time of vertical root fracture for Case One. Mesiodistal fracture
line and buccal fistula are confirmed. Deep periodontal pockets are present along fracture line.
a)
b)
Figure 3. Model a) and internal resin coping b) for Case One.
30
Case One
A 72-year-old man visited the Tokyo Medical and Dental University
Hospital, Faculty of Dentistry, seeking full-mouth treatment. His primary complaint was occlusal discomfort. The patient presented with
posterior bite collapse and loss of anterior guidance due to severe tooth
decay and loss of tooth. His dental state was classified as Eichner Class
B2 (two supporting zones). The treatment plan involved a full-mouth
prosthesis with increased occlusal vertical dimension.
In the course of treatment, the post crown that had been fitted
onto the maxillary right central incisor separated and a mesiodistal
fracture line was confirmed. Periodontal pocket depth (PD) of 7
mm, bleeding on probing (BoP) and mesiodistal tooth movement
were observed; a fistula had formed in the area corresponding to
the buccal root apex (Figure 2). As loss of this tooth could potentially cause occlusal force imbalance following prosthesis, we decided to attempt a conservative treatment. Moreover, because this
tooth had a flared root canal with a thin residual tooth structure,
we applied an adhesive replantation method using internal coping.
After endodontic treatment and post space preparation, we
took impressions with hydrophilic silicon and fabricated a model.
After the cavity on the produced model was filled with dual-cure
core resin (Estelite Core Quick; Tokuyama Dental Co., Tokyo, Japan), a fiber post (GC Fiber Post; GC Co., Tokyo, Japan), coated with a separating medium, was inserted to photo-cure the resin. Subsequently,
the fiber post was removed, the internal coping was removed from
the model, and light irradiation was performed (Figure 3).
After sandblasting and silane coupling treatments, the internal coupling was bonded to the tooth of concern with SB. Tooth
extraction at the time of intentional replantation was performed
carefully for periodontal tissue by using only diamond forceps
(Figure 4). Bone loss and granulation tissue perpendicular to the
mesiodistal direction were confirmed in the alveolar socket. The
sulcus preparation on the fracture line to remove infection was
carried out while injecting physiological saline and then sealed
with SB. At the same time, an apicoectomy was performed and
the root-end cavity was filled with mineral trioxide aggregate cement (ProRoot; Dentsply-Sankin K.K., Tokyo, Japan). The tooth was replanted into the alveolar socket after rotating it 90°.
After three months, core buildup was performed directly with
the dual-cure core resin using a fiber post, and treatment transitioned to the final prosthesis. Currently, 2.5 years have elapsed
and the patient has not complained of any symptoms. The periodontal pocket depth is 2 mm to 3 mm throughout the entire
circumference and there is no BoP. X-ray photographs show a
certain amount of mesiodistal bone resorption when compared
with photographs taken after replantation. However, as there is
no inflammation and the condition has not progressed, we are
satisfied with the outcome thus far (Figure 5).
Case Two
A 72-year-old woman visited the hospital with ill-fitting dentures
as her primary complaint. During the fabrication of treatment dentures, the crown separated along with the post. A fracture line was
confirmed on the buccal side of the flared root canal (Figure 6). A
PD of 7 mm and BoP were observed along the fracture line; moderate buccolingual tooth movement was noted. The residual dentin
wall was remarkably thin throughout the entire circumference, so
while tooth extraction was appropriate, we decided to attempt preserving the tooth because of the patient’s concern for aesthetics.
We planned to perform the adhesive replantation method using
internal coping, followed by a prosthetic procedure with an attachment for dentures. The post space was formed by inserting a 0.02-tapered gutta-percha point (#130). The fabrication process is shown
in Figure 7. Replantation was performed on a different day from the
bonding of the internal coping (Figure 8). The tooth was placed in its
original position without rotation when returned to the alveolar socket following apicoectomy due to root curvature. After three months, a
magnetic denture attachment was fabricated and fitted with SB.
Currently, six months have elapsed. There have been no Xray findings suggestive of an infection. And the patient shows no
clinical symptoms, such as discomfort. Prognosis is satisfactory
given that the PD in the fractured area is 2 mm and neither BoP
nor tooth movement has been observed (Figure 9).
Figure 4. Photograph of tooth extraction for Case One. Fracture line observed at arrow.
a)
b)
Discussion
Conventional treatments for VRF reported to date include a
wire-binding splint technique,10 a screw fixation technique11 and
bonding techniques that employ adhesive cements. Among these,
an adhesion method using SB was first tested in 1982 by Masaka,
who has obtained successful outcomes for over 10 years.2
The biocompatibility and sealability of four types of adhesive
resin cement used in bonding treatments, including SB, were evaluated by culturing human periodontal ligament cells on each type
of cement and measuring the number of cells that adhered and
proliferated. SB showed the greatest amount of cellular attachment
and growth.3 In addition, the same four cements were tested in an
experiment in which the cat tooth roots were extracted and fractured vertically, then bonded and replanted. Histopathological investigations four weeks later showed that inflammatory resorption
and substitutive resorption were significantly lower for SB than for
the other resin cements due to its high polymerization rate and the
Figure 5. a) X-ray photographs for Case One at initial examination, 2 months after replantation and 2.5 years after replantation (from left to right). b) Intraoral view at 2.5 years after
replantation. With periodontal pocket of 2-3 mm and no BoP, condition is favorable.
Figure 6. Intraoral view at time of vertical root fracture for Case Two.
31
a)b)
c)d)
Figure 7. a) Impression for fabricating internal resin coping. Markedly flared root canal is
evident. b) Model for Case Two. c) Insertion of 0.02-tapered gutta-percha point (#130) to
form post space. d) Internal resin coping with gripper.
Figure 8. Photograph of tooth extraction for Case Two. Fracture line at arrow and cyst at root
apex are observed.
a)
b)
Figure 9. Intraoral view a) and X-ray photograph b) at 6 months after replantation for
Case Two. Periodontal pocket is 2 mm with neither BoP nor tooth movement, demonstrating
satisfactory progress.
32
low toxicity and residual percentage of its monomers. These results
suggest the utility of SB for adhesive treatment of VRF.4
The success of adhesive treatment of VRF teeth is determined
by the degree to which the healthy periodontal ligaments are preserved and postsurgical refracture is prevented. Here, when performing conventional treatment of a VRF tooth with a flared root
canal, we considered the following problems: 1. The uncertainty
of removing infection in the fractured area; 2. The uncertainty
regarding sealability of the fractured area; 3. The risk of new fractures during replantation; 4. The influence of resin polymerization shrinkage on the thinned tooth structure; and 5. The risk of
refracture after surgery. Given that these problems originate in
thin root canal dentin with low fracture strength, we focused on
Lui’s method,9 which reinforces the remaining tooth structure.
Lui’s method increases fracture strength by reinforcing the
thinned wall of the root canal with a composite resin and further
forming a small, tapered post space. The procedure involves inserting
a fiber post coated in separating medium into the root canal filled
with a composite resin, photo-curing the resin, removing the post and
then directly/indirectly building up the core and post. This reinforcing
technique has been verified by a number of studies. Yoldas12 evaluated
stress transfer of different post and core systems to the cervical part
of the artificially created flared root canals by using strain gauges. As
a result, the resin reinforced specimens either with a cast post-core or
pre-fabricated post, and the resin core transferred stress to the cervical
part of the artificial roots at a rate lower than that of the conventional
cast post-core system. Goncalves13 studied the fracture resistance of
human maxillary incisors experimentally weakened roots reinforced
with composite resins, compared with conventional systems that use
cast and prefabricated posts. The fracture resistance reinforced by
composite resins was greater than that reinforced by the cast posts,
and comparable to the level of the control specimens.
The adhesive therapy we devised here yielded a tooth structure
reinforcing effect and enabled the fracture line to be bonded and
sealed with certainty. In addition, simplification of the surgical
maneuvers required for intentional replantation in addition to reducing the extraoral treatment time, should also contribute to the
preservation of the healthiest possible periodontal ligaments and,
thereby, lead to successful outcomes. This therapy is likely to be
appropriate for cases of VRF with partial separation, but not for
cases of complete separation in which taking impressions for the
production of internal coping is difficult. In the future, we plan to
conduct follow-up studies of long-term prognoses and investigate
whether a wider range of cases might benefit from therapy.
Conclusion
The adhesive replantation method devised here, which employs internal coping, can simplify surgical treatment and shorten extraoral
treatment time, allowing for preservation of the healthiest possible
periodontal ligaments. Moreover, the method reduces the risk of re-
fracture after surgery. These factors suggest that this method may
be useful as a therapy for fractured teeth with flared root canals. p
11. Queries about this article can be sent to Dr. Takeuchi at [email protected]
13. 12. Rajan RM, Kandasamy D, Kumar PS. Vertical tooth fracture: reunion with a miniature lag
screw. NYSDJ 2009;75(4):44-46.
Yoldas O, Akova T, Uysal H. An experimental analysis of stress in simulated flare root canals
subjected to various post-core applications. J Oral Rehabil 2005;32(6):427-432.
Goncalves LA, Vasan LP, Paulino SM, Sousa Neto MD. Fracture resistance of weakened roots restored
with a transilluminating post and adhesive restorative materials. J Prosthet Dent 2006;96(5):339-344.
REFERENCES
1. 2. Walton RE. Principles and Practice of Endodontics. 2nd ed. Philadelphia: WB Saunders; 1995. pp487.
Masaka N. Long-term observation of fractured tooth roots preserved by adhesion. J Adhes
Dent 1995;13(3):156-170.
3. Sugaya T, Kato H. Fundamental studies of periodontal destruction after vertical root fracture and treatment. Clin Res Dent 2004;1(1):8-17.
4. Noguchi H, Sugaya T, Kato H. Treatment of vertically fractured root by cohesion Part 1:
Evaluations of cytotoxicity of adhesive resin cement with cultured periodontal ligament
cells. Jpn J Conserv Dent 1997;40:1445-1452.
5. Noguchi H, Sugaya T, Kato H. Treatment of vertically fractured root by cohesion Part 2:
Histological evaluation on cohesion with adhesive resin cement and replantation. Jpn J
Conserv Dent 1997;40:1453-1460.
6. Sugaya T, Kawanami M, Noguchi H, Kato H, Masaka N. Periodontal healing after bonding
treatment of vertical root fracture. Dent Traumatol 2001;17:174-179.
7. Hayashi M, Kinomoto Y, Miura M, Sato I, Takeshige F, Ebisu S. Short-term evaluation of intentional replantation of vertically fractured roots reconstructed with dentin-bonded resin.
J Endod 2002;28:120-124.
8. Hayashi M, Kinomoto Y, Takeshige F, Ebisu S. Prognosis of intentional replantation of vertically fractured roots reconstructed with dentin-bonded resin. J Endod 2004;30(3):145-148.
9. Lui JL. Enhanced post crown retention in resin composite-reinforced, compromised, rootfilled teeth: A case report. Quint Int 1999;30:601-606.
10. Takatsu T, Matsushita T, Hide A, Gotanda M, Choltacha H, Hosoda H. A wire splint technique for saving the fractured tooth-outline of the technique and its clinical application to
the crown-root fracture cases. J Adhes Dent 1989;7:45-56.
Dr. Takeuchi
Dr. Sekita
Dr. Kobayashi
Shuhei Takeuchi, D.D.S., Ph.D., is assistant professor, gerodontology and oral rehabilitation,
Department of Gerodontology, Division of Gerontology and Gerodontology, Graduate School, Tokyo
Medical and Dental University.
Toshiaki Sekita, D.D.S., Ph.D., is junior associate professor, gerodontology and oral rehabilitation, Department of Gerodontology, Division of Gerontology and Gerodontology, Graduate School,
Tokyo Medical and Dental University.
Ken ichi Kobayashi, D.D.S., Ph.D., is junior associate professor, gerodontology and oral rehabilitation, Department of Gerodontology, Division of Gerontology and Gerodontology, Graduate School,
Tokyo Medical and Dental University.
33
oral pathology
Inflammatory Myofibroblastic
Tumor of the Oral Cavity
A Great Mimicker
Nitesh Naresh, M.D.S; Ajay Malik, M.D.; Priya Jeyaraj, M.D.S.; Shashidevi Haranal, M.D.S.
ABSTRACT
Inflammatory myofibroblastic tumor (IMT) is a
seldom-described tumor of indefinite etiology and
pathogenesis. It occurs primarily in the lungs, but
has occurred in other extra-pulmonary sites. Histologically, these lesions appear as an inflammatory
infiltrate within a variably myofibrotic background.
Current evidence shows that inflammatory myofibroblastic tumors are neoplastic processes resulting from
chromosomal translocations that frequently cause an
overexpression of ALK kinase, often assessed using
immunohistochemical studies. Currently, the biological behavior of oral IMT is still uncertain. This article illustrates the clinical, histological and operative
features of a case of IMT of the oral cavity.
Inflammatory myofibroblastic tumor (IMT) is a rare fibro-inflammatory entity of unknown origin consisting of variable numbers
of inflammatory cells, both acute and chronic, and spindle cells. It
was originally seen in the lung and illustrated by Brunn in 1939. It
received its name from Umiker et al. in 1954 because of its clinical
and radiological behavior that mimics a malignant process.1
34
IMT has many synonyms: plasma cell granuloma (PCG), inflammatory pseudo tumor (IPT), xanthogranuloma, histiocytoma and
myofibrohistiocytic proliferation.2 The lung, gastrointestinal tract
and orbit are the most common sites for IMT.3 It is an unusual
lesion in the maxillofacial region and can easily be mistaken for a
malignancy. The final outcome is based upon the histopathological diagnosis; and it has been reported in different sites of the oral
cavity, i.e., gingival, tongue, buccal mucosa, palate, mandible and
the salivary gland.4
Case Report
A 70-year-old woman presented with a chief complaint of a gradually increasing, painless swelling in the left gingival-retromolar
region for six months. Intraoral examination revealed a sessile,
lobulated, round to oval, pinkish mass, firm in consistency, measuring 3 cm x 4 cm in the right gingivo-buccal area that was
engulfing the lower left second molar tooth on the buccal aspect.
The tooth was mobile (Figure 1A). The patient’s oral hygiene was
poor, with multiple root stumps and mobile teeth. Her family
history was noncontributory. No abnormalities were present in
her general physical and systemic examinations. The panoramic
radiograph showed no significant findings.
The patient gave a history of tobacco use in the form of
mishri, a roasted tobacco powder, that she had been using since
childhood to brush her teeth. She had changed back to toothpaste
only a few months previously on the advice of the local dentist
who had referred her to us, suspecting a malignant lesion. A differential diagnosis of fibroma, pyogenic granuloma, oral squamous carcinoma and verrucous carcinoma was made.
Owing to the size of the tumor and the anxiety of the patient,
we decided to perform an excisional biopsy. The lesion was removed completely under local anesthesia, along with the associated tooth. A palliative periodontal Coe-pack dressing was placed
over the surgical area to facilitate healing. The patient reported
for regular follow-up for one month. Healing was uneventful,
with no signs of recurrence. The entire excised lesion was sent for
histopathological examination.
The H-E stained section showed parakeratinized surface epithelium, distinct fasciculated arrangement of collagen fibers interspersed with spindle to oblong cells. The background stroma
showed focal myxoid and sclerotic areas. The inflammatory cells
were an admixture of plasma cells, histiocytes and lymphocytes.
No nuclear atypia or fungal organisms were detected (Figure 1B).
Spindle cells were positive for vimentin and showed focal positivity for ALK-1 (Figure 1C, 1D); they were negative for CD-68,
confirming that the spindle cells were myofibroblastic in origin.
Discussion
IMT manifests as an aggressive, recurrent lesion composed of a
benign lympho-plasmacytic and myofibroblastic infiltrate. Clinically, it presents as a painless indurated mass or swelling of relatively short duration. It tends to occur more often in children and
young adults.3,4
Although its histopathologic nature is benign, it may be difficult to differentiate this lesion from a malignant tumor because
of its local invasiveness and its tendency to recur. The etiology and
pathogenesis of IMT still remain a mystery. Some investigators
consider it an immunologic host response to many different stimuli, including infectious agents, microorganisms, adjacent necrotic
tissue, neoplasms, foreign bodies and some kinds of tissue injury.5
According to the World Health Organization, IMTs are classified
as tumors of intermediate biological potential due to a tendency of
local recurrence and a small risk of distance metastasis.6
Histologically, IMT is composed of interwoven fascicles of
myofibroblastic spindle cells admixed with prominent infiltrate
of lymphocytes and plasma cells. Three histological patterns that
are described have no discernible association with the clinical behavior, namely:
l Myxoid/vascular pattern resembling inflammatory granulation tissue.
l Compact spindle cell pattern with fascicular and/or storiform areas with variation in cellular density.
l Hypocellular, densely collagenized and reminiscent of fibrous
scar.
Figure 1A. Lobulated, pink mass in gingivo-buccal area.
Figure 1B. High-power views of lesion showing proliferation of spindle cells
admixed with numerous chronic inflammatory cells in fibrous background.
Figure 1C. Spindle cells showing positivity to vimentin.
Figure 1D. Focal ALK-1 positivity seen in spindle cells.
35
The three patterns may well be equally represented within the
tumor often blending into one another with one or two patterns
predominating.7 In all forms, the inflammatory background is a
typical microscopic feature.8
The differential diagnoses that can be considered when evaluating such a case are low-grade spindle cell lesions, like leiomyoma, solitary fibrous tumor, nodular fasciitis and peripheral
nerve sheath tumor. Immunohistochemistry is important for the
final diagnosis. And the spindle cells are usually positive for vimentin, desmin, muscle-specific actin and smooth-muscle-actin
(SMA).4,6 The presence of an oral tumor with rapid growth and
spontaneous regression after biopsy, associated with the morphology and arrangement of the myofibroblastic cells and the
dense inflammatory component, is the principal feature that led
us to a final diagnosis of IMT.
IMT of the oral cavity has been treated as a benign lesion with
satisfactory results. Simple excision of the tumor has proved to
be effective in controlling these, without recurrences when complete. Other treatment modalities described in the literature are
steroid therapy, curettage, radiotherapy and chemotherapy. Longterm follow-up is mandatory in IMT, because some cases have
behaved as true malignant tumors. Yet rare cases may undergo
spontaneous regression, as seen in the report presented here.1,7,8
Conclusion
We have described a case of a circumscribed tumor of the gingivobuccal complex showing a proliferation of fibro-inflammatory
nature, diagnosed as IMT, in a 70-year-old female that resolved
after excision and has not recurred. However, IMTs are tumors
with unpredictable clinical behavior, requiring complete surgical
excision and continuous monitoring of clinical consequences.
Therefore, it is important to recognize the distinction among
similar appearing tumors in order to provide better guidelines for
treatment and outcome. p
Queries about this article can be sent to Maj. Naresh at [email protected].
REFERENCES
1.
2.
3.
4.
5.
6.
7.
8.
Narla LD, Newman B, Spottswood SS, Narla, S, Koll, IR. Inflammatory pseudotumor. Radiographics 2003;23:719-29.
Shek AW, Wu PC, Samman N. Inflammatory pseudotumour of the mouth and maxilla. J
Clin Pathol 1996;49:164-67.
Ide F, Shimoyama T, Horie N. Intravenous myofibroblastic pseudotumour of the buccal
mucosa. Oral Oncol 1998;34:232-35.
Oh JH, Yim JH, Yoon BW, Choi BJ, Lee DW, Kwon YD. Inflammatory pseudotumor in the
mandible. J Craniofac Surg 2008;19:1552-523.
Nakayama K, Inoue Y, Aiba T, Kono K, Wakasa K, Yamada R. Unusual CT and MR findings
of inflammatory pseudotumor in the parapharyngeal space: case report. AJNR Am J Neuroradiol 2001;22:1394–1397.
Gleason BC, Hornick JL. Inflammatory myofibroblastic tumours: where are we now? J Clin
Pathol 2008; 61: 428-37.
Gale N, Zidar N , Podbhoj J, Volavsek M, Luzar B. Inflammatory myofibroblastic tumor of paranasal sinuses with fatal outcome. Reactive lesion or tumor? J Clin Pathol 2003;56:715-17.
Watanabe K, Tajino T, Sekiguchi M, Suzuki T. Inflammatory myofibroblastic tumor of the
bone. Arch Pathol Lab Med 2000;124:1514-17.
Dr. Naresh
Dr. Malik
Dr. Jeyaraj
Dr. Haranal
Maj. Nitesh Naresh, M.D.S., is reader, oral pathology and microbiology, Department of Dental
Surgery, Armed Forces Medical College, Pune, India.
Col. Ajay Malik, M.D., is professor, Department of Pathology, Armed Forces Medical College,
Pune, India.
Col. Priya Jeyaraj, M.D.S., is classified specialist, oral and maxillofacial surgery, Command
Military Dental Centre.
Shashidevi Haranal, M.D.S., is consultant, oral and maxillofacial surgery, Pune, India.
36
oral surgery
Segmental Dento-alveolar Intrusive Osteotomy
in Posterior Maxilla with Lack of Inter-arch
Distance for Prosthetic Rehabilitation
A Technique Combined with Sinus Floor Elevation
Adi Lorean, D.M.D.; Ziv Mazor, D.M.D.; Eitan Mijiritsky, D.M.D.; Horia Barbu, D.M.D.; Liran Levin, D.M.D.
ABSTRACT
The aim of this paper is to present a technique for seg-
operatively. The opposing dentition was later treated
mental dento-alveolar intrusive osteotomy in a posteri-
by implant placement. The average follow-up time for
or maxilla with lack of inter-arch distance for prosthet-
those cases was 5.4 months. Vitality test four months
ic rehabilitation combined with sinus floor elevation.
after surgery was positive.
Methods: A full thickness flap is elevated expos-
Conclusion: The presented technique for segmen-
ing the lateral wall of the maxillary sinus. A lateral
tal dento-alveolar intrusive osteotomy combined with
window is opened and the Schneiderian membrane
sinus floor elevation can serve as a viable treatment
elevated. Segmental dento-alveolar osteotomy is per-
option in the posterior maxilla with lack of inter-
formed. After complete detachment of the segment,
arch distance due to severe overeruption.
it is adapted and fixed to the new position using the
pre-prepared guide, making sure not to damage or
perforate the Schneiderian membrane.
Results: Four cases of segmental dento-alveolar
intrusive osteotomy in a posterior maxilla combined
with sinus floor elevation were performed utilizing
the above-mentioned technique. All surgeries went
according to plan, and healing was uneventful except
for swelling and pain that lasted for 10-14 days post-
Patterns of tooth loss are changing throughout the population, with
more patients remaining dentate until old age. During this time, a
number of posterior teeth may be lost, leaving antagonists unopposed. As a consequence, a dramatic loss of inter-occlusal space following an extraction of an opposing tooth might be observed.1
Kiliaridis et al. identified that overeruption greater than 2
mm occurs in 24% of unopposed teeth, with 18% having no
demonstrable overeruption at all. This leaves a total group with
some overeruption of 82%, which, in terms of restoration, could
have clinical significance.2
37
The unopposed upper first molar, in both healthy mouths and
those with some periodontal pathology present, was studied by
Compagnon and Woda. Their study showed that the majority of
overeruptions occurred in the early years following opposing tooth
loss. In later years, loss of periodontal support may be superimposed on the picture. In healthy individuals they noted that the
gingival margin remained at its original level on the tooth during
this occlusal tooth movement. The study found that after 10 years
of remaining unopposed, this periodontal migration reversed and
root exposure occurred. This was described by the authors as passive eruption.3 Craddock and Youngson reported that 83% of unopposed teeth are likely to overerupt, and that the extent of the
overeruption may be marked.2 They have stated that the incidence
and extent of overeruption is of clinical significance, not only
in terms of treatment planning to prevent undesirable vertical
movement, but also in restoration of the edentulous space.2
Overeruption of upper molars because of the loss of antagonists may cause problems, such as periodontal defects and occlusal interferences.4 Clinically, overeruption of posterior teeth may
complicate restoration of an edentulous space with either fixed
or removable prostheses. In severe cases, most or all of the inter-
38
occlusal space may be taken up by the vertical movement of the
unopposed tooth, prohibiting restoration of the space without extraction of the overerupted tooth. The extent of overeruption will
determine to what extent the overerupted tooth can be reduced or
the occlusal plane modified.2
To reconstruct the proper occlusion for the posterior dentition and to maintain periodontal health, an interdisciplinary and
comprehensive dental treatment is necessary.
Correction of the overerupted molar is a first and essential
step before other procedures can be started. Procedures such as
orthodontic intrusion, prosthodontic reduction and surgical impaction have been presented.5-7 However, prosthodontic reduction requires endodontic intervention and crown restoration
at the expense of tooth vitality, whereas orthodontic intrusion
might be a difficult and prolonged treatment modality.
At the maxillary posterior area, the maxillary sinus might
present a challenge when choosing the surgical impaction technique. Thus, the aim of this paper is to present a technique for
segmental dento-alveolar intrusive osteotomy in a posterior maxilla with lack of inter-arch distance for prosthetic rehabilitation
combined with sinus floor elevation.
1.
2.
Figures 1. & 2. Preoperative clinical and radiographic view. Note severe maxillary molar overeruption, making proper
occlusal rehabilitation unachievable.
Methods
In cases of severe maxillary molar overeruption, when proper occlusal rehabilitation is not achievable (Figure 1), the technique
presented here can be utilized. Prior to the surgery, study models
are prepared, and a mock-up surgery is performed on the model.
This model is also employed for preparation of the surgical guide to
be used for appropriate placement of the teeth during the surgery.
Under local anesthesia, a full thickness flap is elevated, exposing also the lateral wall of the maxillary sinus (Figure 2). A
lateral window is opened (Figure 3) and the Schneiderian membrane separated and elevated, as in lateral sinus augmentation
procedure. Segmental dento-alveolar osteotomy is performed using piezo-surgery (Figure 4). The line of the ostectomy is kept 4
mm to 5 mm above the teeth apices. Care is taken to preserve the
mucoperiosteal attachment on the palatal aspect, which might be
essential for the postoperative blood supply.
After complete detachment of the segment (Figure 5), it is
adapted to the new position using the pre-prepared guide (Figure 6), making sure not to damage or perforate the Schneiderian
Figure 4. Lateral window is opened and Schneiderian membrane
separated and elevated, as in lateral sinus augmentation procedure.
Figure 3. Under local anesthesia, full thickness flap is
elevated exposing lateral wall of maxillary sinus.
membrane. Pre-prepared fixation plates are used to fix the segment to the adjacent bone (Figure 7). Bone graft and covering
collagen membrane are placed on the operated site before primary
closure is achieved (Figure 8). The surgical guide is then used as
a splint, which is kept for 10 days. A postoperative panoramic
radiograph is taken to demonstrate the new segment in place
(Figure 9).
Results
Four cases of segmental dento-alveolar intrusive osteotomy in a
posterior maxilla with lack of inter-arch distance for prosthetic rehabilitation combined with sinus floor elevation were performed utilizing the technique described above. All surgeries went
according to plan, and healing was uneventful except for swelling
and pain that lasted between 10 and 14 days postoperatively. The
opposing dentition was later treated by implant placement and
the occlusion restored properly. The average follow-up time for
these cases was 5.4 months. Vitality test four months after surgery was positive for the non-root-canal-treated teeth.
Figure 5. Segmental dento-alveolar osteotomy is performed using piezosurgery and reciprocating saw. Line of ostectomy is kept 4 mm to 5 mm
above teeth apices. Care is taken to preserve mucoperiosteal attachment
on palatal aspect, which might be essential for postoperative blood supply.
Figure 6. Complete detachment of segment.
39
Figure 7. After complete detachment of segment,
it is adapted to new position using pre-prepared
guide making sure not to damage or perforate
Schneiderian membrane.
Figure 8. Pre-prepared fixation
plates are used to fix segment to
adjacent bone.
Discussion
There is a general belief that molars without antagonists overerupt,
leading to long-term dental problems, including occlusal interferes
and functional disturbances.4,8 Meanwhile, it is indicated that the
degree of overeruption differs for molars without antagonists.1
Possible explanations for this variation are the length of time
that these teeth were unopposed, the age of the subject when the
antagonist was lost9,10 and, possibly, the periodontal status of the
unopposed teeth.3
40
Figure 9. Bone graft and covering collagen membrane
are placed on operated area before primary closure is
achieved.
Figure 10. Postoperative
panoramic radiograph demonstrating new segment in place.
Correction of the overerupted maxillary molars can be achieved
by orthodontic intrusion, prosthodontic reduction or surgical
impaction. Each method has it pros and cons. Prosthodontic
reduction usually requires endodontic intervention and crown
restoration at the expense of tooth vitality; surgical impaction
involves a rather major segmental operation; and orthodontic
intrusion might be prolonged and demands calibrated anchorage support from intraoral multi-unit teeth and from extraoral
headgear wear.4 Quite often, patients with localized problems do
not perceive the extent of the treatment difficulty, which can require even a full arch strap-up to reinforce anchor units against
two overerupted upper molars. Thus, the question of how to
overcome localized problems with less cumbersome devices and
only a partial arch strap-up with fixed edgewise appliance (for
convenience, abbreviated as partial-fixed appliance) remains to
be answered.
Conventional orthodontic treatment adequately corrects
many overeruptions, but tends to be more acceptable for children
and adolescents than for adults, mainly due to peer pressure and
aesthetic considerations.11
Today, the incorporation of mini-implants, such as titanium
miniscrews and miniplates, for skeletal anchorage might ease
this treatment option,4 but a prolonged and rather complex orthodontic involvement is required.
This paper presents an optional technique for segmental
dento-alveolar intrusive osteotomy in a posterior maxilla with
lack of inter-arch distance for prosthetic rehabilitation combined
with sinus floor elevation. This technique could serve in appropriate cases to solve the issue of overeruption and provide space for
proper occlusal rehabilitation in a short time. However, it should
be remembered that this is a surgical invasive technique that
might lead to some postoperative complications and, as with any
surgical procedure, it is not risk-free.
Careful case selection, followed by meticulous planning and
appropriate surgical performance are very important in using the
proposed technique.
The short duration of treatment and the use of the patient’s own
teeth and tissues are two of the advantages of this option. Nevertheless, since these are only preliminary results of a limited
number of cases, further long-term and large cohort studies are
needed for additional assessment of this technique.
As with most conditions, however, prevention of the problem arising is often the best solution.11,12 Bearing in mind the
processes involved in eruption, dentists may well wish to use
some of the available techniques to predict, prevent, modify or
treat undesirable tooth movements and thereby create a mechanical and biological environment more conducive to successful restorative treatment. Awareness of the likelihood of
undesirable tooth movement following the loss of an antagonist
may encourage practitioners to plan for the sequelae of tooth
loss or, perhaps, to counsel their patients on the benefits of
avoiding extraction.11
Conclusions
The technique presented here for segmental dento-alveolar intrusive osteotomy combined with sinus floor elevation can serve as a
viable treatment option in the posterior maxilla with lack of inter-arch distance for prosthetic rehabilitation due to severe overeruption. Further long-term and large cohort studies are needed
for additional evaluation of this technique. p
Dr. Lorean
Dr. Mazor
Dr. Mijiritsky
Dr. Barbu
Dr. Levin
Adi Lorean, D.M.D., is lecturer in Department of Maxillo-Facial Surgery, Poriya Hospital, Tiberius,
Israel.
Ziv Mazor, D.M.D., is in private practice in Ra’anana, Israel.
Eitan Mijiritsky, D.M.D., is senior lecturer in Department of Oral Rehabilitation, The Maurice and
Gabriela Goldschleger School of Dental Medicine, Tel-Aviv University, Israel.
Horia Barbu, D.M.D., is senior lecturer in Department of Oral Implantology, Faculty of Dentistry,
Titu Maioresscu, Bucharest, Romania.
Liran Levin, D.M.D., is professor and head, Division of Periodontology, School of Dentistry, Faculty
of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.
No funding was received for this study, and the authors report no conflicts of interest. All authors contributed equally to this paper. Queries about this article can
be sent to Dr. Levin at [email protected].
REFERENCES
1.
2.
3.
4.
5.
6.
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Kiliaridis S, Lyka I, Friede H, Carlsson GE, Ahlqwist M. Vertical position, rotation and tipping of molars without antagonists. Int J Prosthodont 2000;13:480-486.
Craddock HL, Youngson CC. A study of the incidence of overeruption and occlusal interferences in unopposed posterior teeth. Br Dent J 2004 Mar 27;196(6):341-8.
Compagnon D, Woda A. Supraeruption of the unopposed maxillary first molar. J Prosthet
Dent 1991;66:29-34.
Yao CC, Wu CB, Wu HY, Kok SH, Chang HF, Chen YJ. Intrusion of the overerupted upper
left first and second molars by mini-implants with partial-fixed orthodontic appliances: a
case report. Angle Orthod 2004 Aug;74(4):550-7.
Daly P, Pitsillis A, Nicolopoulos C. Occlusal reconstruction of a collapsed bite by orthodontic treatment, pre-prosthetic surgery and implant supported prostheses. A case report. South
Afr Dent J 2001;56:278–282.
White R, Terry B. Segmental jaw surgery. In: Proffit W, White R, eds. Surgical-Orthodontic
Treatment. St Louis, Mo:Mosby;1991:283–319.
Melsen B. Management of severely compromised orthodontic patients. In: Nanda R, ed.
Biomechanics in Clinical Orthodontics. Philadelphia, Pa: WB Saunders. 1997:294–319.
Fujita T, Montet X, Tanne K, Kiliaridis S. Overeruption of periodontally affected unopposed
molars in adult rats. J Periodont Res 2010;45:271–276.
Christou P, Kiliaridis S. Three-dimensional changes in the position of unopposed molars in
adults. Eur J Orthod 2007;29:543-549.
Fujita T, Montet X, Tanne K, Kiliaridis S. Supraposition of unopposed molars in young and
adult rats. Arch Oral Biol 2009;54:40–44.
Craddock HL, Youngson CC. Eruptive tooth movement—the current state of knowledge. Br
Dent J 2004 Oct 9;197(7):385-91.
Levin L. Prevention—the (sometimes-forgotten) key to success. Quintessence Int. 2012
Oct;43(9):789.
41
medical imaging
Comparison of Cone-beam Computed
Tomography and Multi-slice Spiral Computed
Tomography Bone Density Measurements
in the Maxilla and Mandible
Steven Doyle, D.M.D.; Mauricio J. Wiltz, D.D.S.; Richard A. Kraut, D.D.S.
ABSTRACT
The purpose of this study was to compare cone-beam
computer tomography (CBCT) and multi-slice spiral
computed tomography (MSCT) bone density measurements in the maxilla and mandible to determine
whether any discrepancies between imaging modalities exist. Material & Methods: 33 sets of CBCT and
MSCT scans were evaluated using Simplant software.
Density measurements were made in eight regions
of interest on each scan and were compared and analyzed. Results: Correlation of density measurements at
specific regions of interest between CBCT and MSCT
was only fair and ranged from 0.61-0.86. High-density areas, such as the anterior mandible, showed a
higher correlation between imaging modalities than
low-density regions, such as the posterior maxilla.
Conclusion: Care should be taken when relying upon
CBCT to determine bone density, especially in lowdensity regions such as the posterior maxilla.
42
Accurate, three-dimensional diagnostic imaging is essential for
performing many oral and maxillofacial surgical procedures. The
most common three-dimensional imaging modalities employed by
oral surgeons today are multi-slice spiral computed tomography
(MSCT) and cone-beam computed tomography (CBCT).1,2 There
are clear benefits to CBCT over MSCT. These include diminished
radiation exposure, increased accessibility and reduced costs.1-5
However, MSCT is far superior in visualizing soft tissue, which is
why it remains the gold standard in maxillofacial imaging.6,7
The development of in-office CBCT devices over the last decade has caused many practitioners to rely primarily on CBCT
imaging for evaluating hard tissue, especially as it relates to
dental implant placement and related bone grafting. Of most
importance in dental implant surgery planning is determining the quantity and quality of bone, as well as the location of
certain anatomical structures. Bone quantity can be measured
linearly. Several studies have evaluated the accuracy of linear
measurements, as well as volumetric measurements in CBCT
and have found sub-millimeter accuracy and no significant differences when compared to MSCT.8-14 Multiple studies have also
evaluated the ability to identify and locate important anatomical structures, such as the inferior alveolar neurovascular canal and its associated foramina, and have found no significant
differences between CBCT and MSCT.1,9 However, controversy
remains regarding the accuracy of CBCT when evaluating bone
Figure 1. Example of region of interest, right canine mandible.
density, especially in low-density medullary bone, which is of
critical importance for predicting the stability and success rate
of dental implants.15,16
The aim of this study was to compare CBCT and MSCT bone
density measurements in the maxilla and mandible to determine
whether significant discrepancies between imaging modalities exist.
Materials and Methods
Since 2003, CBCT imaging has been performed in the Montefiore
Medical Center Oral and Maxillofacial Surgery Clinic. The Einstein Institution Review Board (IRB) approved this study. Many
of the patients who have undergone CBCT imaging in the clinic
have also undergone MSCT imaging by the Department of Radiology (GE Lightspeed VCT 64-Slices). A list of all maxillofacial
clinic patients that have had CBCT imaging was cross-referenced
with a list from a hospital database of all patients who have had
maxillofacial MSCT imaging to derive a list of patients that had
both MSCT and CBCT imaging of the maxillofacial region within
a one-month period of each.
Data from 33 patients with sets of acceptable CBCT and
MSCT scans were selected for analysis provided the following exclusion criterion was met: If a jaw fracture or pathologic lesion
(i.e., tumors, cysts, fractures) was present at any region of interest
(ROI), the ROI was not included in the data. The DICOM data of
the axial images from each of the scanner types was then loaded
into the three-dimensional visualization software (Simplant, Materialize Dental Inc., Glen Burnie, MD) and Hounsfield Unit (HU) measurements were taken at five ROI in the mandible and three ROI
in the maxilla using a 10 mm2 circular field in the cross-sectional
view. The measurements in the mandible were taken mid-alveolus
3 mm apically to teeth #22, #25 and #27, and bilaterally 2 mm
posterior to the most distal tooth at 8 mm inferior to the alveolar
crest. Measurements in the maxilla were taken mid-alveolus posterior to A point and bilaterally 2 mm posterior to the most distal
tooth at 2 mm superior to the alveolar crest (Figure 1). Each set of
DICOM data was measured twice to evaluate the amount of measuring error due to any potential difficulty finding and measuring
the same region of interest. A total of 701 density measurements
were recorded from 33 CBCT scans and 33 MSCT scans.
Figure 2. Example of region of interest, point A maxilla.
Statistical Analyses
Power analyses were performed based on published differences
(Dahmani-Causse, 2011) 6 for a=.05, two-tailed test with 80%
power. Means and standard deviations are presented for MSCT
and CBCT, as well as for the differences between MSCT and CBCT
and for the absolute difference. Means for the actual differences
were derived to detect any bias from zero, and means for the absolute differences were derived to determine the magnitude of
discrepancies between the MSCT and CBCT. Intraclass correlation coefficients (ICC) were computed between MSCT and CBCT
values to assess degree of agreement; Wilcoxon Signed Rank tests
43
TABLE 1
CBCT
ROI
N
Mean (HU)
Std Dev
Right Canine Mandible
29
456.8
202.2
Left Canine Mandible
28
445.9
237.6
Right Central Mandible
31
586.2
228.9
Right Distal Molar Mandible
25
317.5
198.7
Left Distal Molar Mandible
25
234.4
203.9
Point A Maxilla
25
415.0
225.1
Right Distal Molar Maxilla
20
7.31
195.9
Left Distal Molar Maxilla
22
-42.9
190.6
were conducted to determine whether raw
differences differed significantly from zero.
All tests of significance were two-tailed and
conducted at a=.05.
TABLE 2
MSCT
ROI
N
Mean (HU)
Std Dev
20
508.5
245.2
21
518.8
309.9
23
663.4
257.9
13
399.3
260.4
16
211.7
184.1
Point A Maxilla
20
605.4
213.4
13
104.8
156.9
15
125.3
227.4
TABLE 3
Intraclass Correlation Coefficients
ROI
CBCT1 vs CBCT2
MSCT1 vs MSCT2
CBCT vs MSCT
0.98136
0.97376
0.85541
0.99366
0.96107
0.88042
0.98877
0.97083
0.85517
0.9597
0.95719
0.81236
0.98133
0.9453
0.88603
Point A Maxilla
0.98245
0.92706
0.81819
0.98689
0.93684
0.69222
0.93112
0.98766
0.61644
TABLE 4
Absolute Differences Between MSCT and CBCT
ROI
N
Mean
Std Dev
Median
Min
Max
20
81.6
83.8
46.9
1.4
275.7
21
106.0
84.5
71.1
5.6
271.2
23
105.2
73.5
94.9
13.4
320.8
13
116.5
72.4
103.1
16.7
223.6
16
70.9
54.6
53.2
2.1
215.1
Point A Maxilla
17
110.0
64.2
123.5
11.5
223.4
13
128.9
79.1
147.1
17.5
246.2
15
185.2
85.6
180.6
22.6
374.7
44
Results
The means and standard deviations for
CBCT and MSCT are presented in Table 1
and Table 2, respectively, for each of the
eight regions. When the same eight regions
were measured twice on the same scan, by
the same individual, the agreement between
HU values ranged from .93 to .99 when
measuring CBCT scans, and between .92
to .99 when measuring MSCT scans (Table
3). This indicated a high degree of intraclass
agreement and minimal measurement error
associated with locating and measuring the
same regions of interest twice. Therefore,
any differences between CBCT and MSCT
values due to variability identifying the
same region of interest are expected to be
minimal.
However, correlation of density measurements between imaging modalities was
only fair. Intraclass correlation ranged from
.81 to .89 in the mandible and .61 to .81
in the maxilla (Table 3). It was noted that
the lower the mean HU value of a ROI, the
lower the correlation there was between imaging modalities. The mean HU of the left
distal molar maxilla was -42.9 on CBCT and
125.3 on MSCT, which resulted in a coefficient of correlation of .61. Similarly, the
right distal molar maxilla had mean values of 7.3 HU on CBCT and 104.7 HU on
MSCT, which calculated to a correlation of
.69. In contrast, in the denser regions, such
as the anterior mandible, where mean HU
values ranged from 508 to 660, the interclass correlations all exceeded 85.
Closer evaluation revealed that MSCT
HU values were consistently higher than
CBCT HU values for all but one of the regions of interest. When the two lowest density reference points in the posterior maxilla
were disregarded, mean HU values between
imaging modalities related to each other,
but MSCT values were 21.5% higher than
TABLE 5
MSCT Percentage Greater than CBCT
ROI
Mean absolute
difference
MSCT % greater
than CBCT
81.6
16%
106.0
20%
105.2
16%
116.5
29%
70.9
33%
Point A Maxilla
110.0
18%
128.9
120%
185.2
148%
the mean CBCT HU values with a range of 15% to 32% higher
(Table 5).
Discussion
Three-dimensional imaging is essential for performing many oral
and maxillofacial surgery procedures. Cone-beam computed tomography and multi-slice computed tomography are the imaging
modalities most commonly utilized by oral and maxillofacial surgeons. Many practitioners are relying increasingly on CBCT imaging
due to decreased costs, increased accessibility and decreased radiation exposure to patients when compared with MSCT. Other studies have compared the accuracy of linear distance measurement and
the ability to identify important anatomical structures, such as the
inferior alveolar neurovascular canal, and have found no significant
differences between MSCT and CBCT. However, MSCT is superior
for evaluating low-density tissues and controversy remains regarding the accuracy of CBCT when evaluating bone density, especially
in low-density medullary bone, which is of critical importance for
predicting the stability and success rate of dental implants.
In this study, bone density measurements were made at specific regions of interest in the maxilla and mandible in both CBCT and MSCT
scans of the same patient taken within 30 days of each other. When a
region of interest was measured twice on the same CBCT or MSCT scan,
there was a high degree of correlation between HU values obtained,
which indicated that the ability to relocate and measure the same anatomical region of interest was excellent. However, upon comparison of
CBCT and MSCT scans of the same patient, there was a marked discrepancy in Hounsfield values between the different imaging modalities.
Regions of interest that are typically denser bone, such as the
anterior mandible, showed much higher HU value correlations
between imaging modalities than regions of interest in the posterior maxilla and mandible, which are typically very low density
areas. Closer evaluation revealed a trend of MSCT measurements
being higher than CBCT measurements and, when analyzed as
a whole, MSCT measurements were approximately 20% greater
than their CBCT counterparts. However, definitive statistical relationship between the two was not found.
Based on this study, practitioners should use caution when relying on
CBCT imaging to evaluate areas of low-density bone in the maxilla
and mandible, especially as a predictive tool for successful osseointegration of dental implants, which is highly related to bone density. p
Queries about this article can be sent to Dr. Kraut at [email protected]
References
1.
Nahito M, Nakashara K, Yutaka S, et al. Comparison between cone-beam and multislice
computed tomography depicting mandibular neurovascular canal structures. Oral Surg
Oral Med Oral Pathol Oral Radiol Endo 2010;109:25-31.
2.
Loubele M, Bogaerts R, et al. Comparison between effective radiation dose of CBCT and
MSCT scanners for dentomaxillofacial applications. Eur J Radiol 2009;71:461-468.
3.
Tsiklakis K, Donta C, Gavala S, et al. Dose reduction in maxillofacial imaging using low
dose cone beam CT. Eur J Radiol 2005;56:413-417.
4.
Carrafiello G, Dizonno M, et al. Comparative study of jaws with multislice computed tomography and cone-bam computed tomography. Radiol Med 2010;115:600-611.
5.
Chau A, Fung K. Comparison of radiation dose for implant imaging using conventional spiral tomography, computed tomography, and cone-beam computed tomography. Oral Surg
Oral Med Oral Pathol Oral Radiol Endo 2009;107:559-565.
6.
Dahmani-Causse M, et al. Morphologic examination of the temporal bone by cone beam
computed tomography: comparison with multislice helical computed tomography. Eur Ann
Otorhinolaryngol Head Neck Dis 2011;128:230-235.
7.
Heiland M, Pohlenz P, et al. Cervical soft tissue imaging using a mobile CBCT scanner with
a flat panel detector in comparison with corresponding CT and MRI data. Oral Surg Oral
Med Oral Pathol Oral Radiol Endo 2007;104:814-820.
8.
Watanabe H, Honda E, et al. A comparative study for spatial resolution and subjective image characteristics of multi-slice CT and cone-beam CT for dental use. Eur J Radiology 2011;77:397-402.
9.
Maloney K, Bastidas J, et al. Cone beam computed tomography and simplant materializes
dental software versus direct measurement of the width and height of the posterior mandible: an anatomic study. J Oral Maxillofac Surg 2011;69:1923-1929.
10. Loubele M, Van Assche N, et al. Comparative localized linear accuracy of small-field conebeam CT and multislice CT for alveolar bone measurements. Oral Surg Oral Med Oral
Pathol Oral Radiol Endo 2008;105:512-518.
11. Suomalainen A, Vehmas T, et al. Accuracy of linear measurements using dental cone beam
and conventional multislice computed tomography. Dentomaxillofac Radiol 2008;37:10-7.
12. Ludlow JB, Laster WS, et al. Accuracy of measurements of mandibular anatomy in cone beam computed tomography images. Oral Surg Oral Med Oral Pathol Oral Radiol Endo 2997; 103:534-542.
13. Albuquerque M, Gaia B, Cavacanti M. Comparison between multislice and cone-beam
computerized tomography in volumetric assessment of cleft palate. Oral Surg Oral Med
Oral Pathol Oral Radiol Endo 2011;112:249-257.
14. Liang X, Lambrichts I, Sun Y. A comparison of cone beam computed tomography (CBCT)
and multisliceCY (MSCT). Part II: On 3D model accuracy. Eur J Radiol 2009;75:270-274.
15. Hohlweg-Marjert B, Metzger MC, Kummer T, Schulze D. Morphometric analysis-cone beam computed tomography to predict bone quality and quantity. J Cranio-maxillo-Facial Surgery 2011;39:330-334.
16. Hohlweg-Marjert B, Pautke C, Metzger M, Schulze D. Qualitative and quantitative evaluation
of boney structures based on DICOM dataset. J Oral Maxillofac Surg 2011; 69:2763-2770.
Dr. Doyle
Dr. Wiltz
Dr. Kraut
Steven Doyle, D.M.D., is chief resident, Department of Dentistry/Oral & Maxillofacial Surgery
Residency Program, Montefiore Medical Center, Bronx, NY.
Mauricio J. Wiltz, D.D.S., is attending, Department of Dentistry/Oral & Maxillofacial Surgery
Residency Program, Montefiore Medical Center, Bronx, NY.
Richard A. Kraut, D.D.S., is chairman/program director, Department of Dentistry/Oral & Maxillofacial Surgery Residency Program, Montefiore Medical Center, Bronx, NY.
45
risk management
Standards, Regulation and
Registration of Dental Laboratories
An Industry Update
Paul L. Giovannone, C.D.T.
ABSTRACT
State dental associations are showing increased interest in maintaining current standards and regulations affecting the dental laboratory industry as
mandated by the Food and Drug Administration.
The domestic dental laboratory industry is being
significantly stressed by foreign competition, rapid
technology development and unprecedented consolidation, which are changing the way that prosthetic
devices and restorations are manufactured and delivered to dentists. Of paramount importance to the
prescribing dentist is the accurate documentation of
the source and materials being used in prostheses
being delivered to patients.
During its 2014 Annual Session, the ADA House of Delegates
approved a resolution calling on individual states to encourage
their state boards to register dental labs within their jurisdictions.
Dental laboratory registration is currently required in nine states.
There are another seven states exploring legislation to require
dental laboratory registration. Material disclosure and identification of origin of manufacture are of paramount importance.1
Dental laboratory compliance with the Food and Drug Administration is not optional. All commercial dental appliance
manufacturers must comply with FDA Title 21 CFR Part 820
46
regulations, which specify that covered entities have good manufacturing practices (GMPs). These include an established, documented “Quality System for the design, manufacture, packaging,
labeling, storage, installation and servicing of finished medical devices intended for commercial distribution in the United
States.”2 While these regulations have been in effect since 1997,
in recent years, the FDA has begun inspecting U.S. dental laboratories to ensure compliance. While all dental laboratories must
comply with FDA regulations, domestic dental labs, for the most
part, do not have to be registered with the FDA.
Dental labs that must register with the FDA include:
1. All domestic and foreign labs that repackage or relabel materials.
2. All domestic and foreign labs that fabricate sleep apnea or
snoring devices.
3. All foreign dental laboratories shipping into the United States.
4. All domestic labs that ship directly to and from foreign dental labs.
Congress passed the Medical Device User Fee Stabilization
Act in August 2005, making it a requirement that labs identify
restorations and dental appliances that they distribute but do not
manufacture. If XYZ dental laboratory outsources to either a domestic or foreign lab that makes all or any part of the restoration
or dental appliance, it must clearly label that it is “Distributed by
XYZ” and disclose the point of manufacture origin.3 Title 21 CFR
Part 820 also requires that dental laboratories maintain identification/traceability of all patient contact materials. The dentist and laboratory must be able to identify and track all patient
contact materials back to the original material manufacturers.
Lot numbers should be included in material disclosures so that
a particular batch of materials may be identified and potentially
isolated in the event of adverse reactions.2 All forms should be in
duplicate (Figures 1, 2, 3).
The most recent data from the Department of Labor showed
there were 7,042 dental laboratories generating a payroll in 2011;
that data represents a 20% reduction of domestic dental laboratories in the two years from 2009 through 2011.4 A study conducted
by the National Association of Dental Laboratories (NADL) revealed a 39% decrease in domestic dental laboratories from 2006
projected through 2017. Foreign competition and rapid changes
in technology are big factors. For example, 25% of all domestic
dental laboratory sales and almost 40% of actual restorations are
currently manufactured overseas, according to NADL. There are 42
countries that currently have foreign dental laboratories registered
with the FDA.5
Mass digitization of the dental laboratory industry is in full
swing, and labs need to become digital to stay competitive. CAD/
CAM increases efficiency, accuracy, consistency and capacity. Production per technician increases exponentially; however, when
accounting for capital investment costs, raw materials, software
licensing fees, dongle fees, maintenance fees and equipment upgrades, there is decreased profitability at today’s competitive market
prices. Digitally capable labs are basically working with the same
possibilities in terms of materials, processing speed and quality.
Dental laboratories need to adapt with strong business
models to develop or maintain customer loyalty. According to
sales statistics provided by manufacturers of CAD/CAM ceramic blocks for “in office” milling, in 2014, there were over two
million ceramic crowns produced in dentists’ offices. While the
dental laboratory industry does not view this as a huge threat
to dental laboratory technicians, the reality is that volume alone
eliminates close to 1,000 ceramist jobs.
There are three phases in the industrialization of almost all
manufactured products: handmade, assembly line production
and automation. Large multinational dental laboratories and
corporations, whether privately held or publicly traded, are well
positioned not only to drive pricing down, but also to drive the
rapid digitization and automation of dental laboratory procedures. With the accuracy, consistency and efficiency that come
with CAD/CAM technology, well-capitalized companies have a
lot of capacity. And they are increasing market share by shifting
more and more financial resources toward branding and mass
marketing instead of toward mergers and acquisitions.
A big part of the pricing pressure problem facing domestic
and traditional dental laboratories is supply. Capacity has never
been higher and dental lab sales are stagnant. Even large manufacturers and suppliers of raw dental materials are now heavily
invested in automation. They process thousands of units a day
for outsourcing domestic dental laboratories. The high cost of “in
house” processing of raw materials like prosthodontic alloys and
Figure 1. Sample Tracking Form for Fixed Case.
Figure 2. Sample Tracking Form for Removable Case.
Figure 3. Sample Tracking Form for Implant Case.
47
ceramic material make partnering with large vendors very appealing. The long-term economic downturn has also played a role in
consolidation. Rolling back employee insurance benefits and intense competition for disposable income directly affects approval
rates for elective and cosmetic dentistry.
48
Summary
The domestic dental laboratory industry will continue to change
drastically. Foreign competition, rapid development of new technology and consolidation are the leading factors in this “adapt
or die” business environment. Even with thousands of dental
laboratory closings in the past few years, prostheses fabrication
capacity has skyrocketed. Pricing pressure will continue to drive
down profitability and cause traditional domestic dental laboratories that do not adapt quickly to fail. Material processing will
continue to shift from small local domestic dental labs to large
multinational dental laboratory operations and corporations that
are well capitalized and heavily invested in technology.
Does this state need dental laboratory registration? In a recent discussion between several New York State dental laboratory
owners and members of the NYSDA Council on Dental Education and Licensure (CDEL), it was generally agreed that increased
regulation of the dental laboratory industry in New York would
not necessarily result in further protection of the public. Education of NYSDA members and dental laboratories located in this
state regarding documentation of patient contact materials and
point of fabrication origin is needed and should be a priority.
The best advice for safeguarding patients and protecting a dental
practice from unforeseen liabilities due to poor or inferior dental
laboratory-produced products is to be well informed. There are
no FDA standard compliance forms. Dental laboratories are expected to develop their own product specific disclosure forms as
part of their GMPs and quality systems. Make sure you receive the
following paperwork from your dental lab with each and every
case: infection control documentation, identification of materials (IdentAlloy and IdentCeram stickers, 510K’s, FDA and ADA
material approvals) and disclosure of manufacturing origin. Dental laboratories must also disclose to a dentist if any portion of
the restorations and/or prosthetic devices is outsourced to other
manufacturers.
Dentists want to know, and providing the proper documentation
and traceability is a matter of FDA compliance and public safety. p
Queries about this article can be sent to Mr. Giovannone at [email protected].
2.
3.
4.
5.
6.
7.
8.
9.
Food and Drug Administration. Accessed 5/2/15. Available at: http://www.accessdata.fda.
gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm and SafeLink Consulting. Accessed 5/2/15.
Available at: http://www.safelinkconsulting.com/faqs.html
GovTrack US. Accessed 5/2/15. Available at: https://www.govtrack.us/congress/bills/109/
hr3423
United States Bureau of Labor Statistics. Accessed 5/2/15. Available at: http://www.bls.gov/
data/
National Association of Dental Laboratories (NADL). www.nadl.org
Thorn, Eric J. Dentistry Today, February 2012. Accessed 5/2/15. Available at: http://dentistrytoday.com/viewpoint/7720
Napier, Bennett. Dentaltown. Dentist and Laboratory Update. Accessed 5/2/15. Available at:
http://www.dentaltown.com/Dentaltown/Article.aspx?aid=3863&i=285&st=Dental%20
and%20Laboratory%20Update
NYS Dentistry: Laws, Rules, & Regulations. Accessed 5/2/15. Available at: http://www.
op.nysed.gov/prof/dent/article133.htm
License Statistics NYS Dentistry. Accessed 5/2/15. Available at: http://www.op.nysed.gov/
prof/dent/dentcounts.htm
Paul Giovannone, C.D.T., is chairman and CEO of Biogenic Dental Corp.,
Utica, NY, and its affiliates Biogenic Dental Laboratories, BTILaser, LLC, and
Dental Engineering Co. of America. He has been a certified dental technician
for over 25 years.
REFERENCES
1.
American Dental Association. Accessed 5/2/15. Available at: http://www.ada.org/en/publications/ada-news/2014-archive/march/dental-laboratory-summit-prompts-interactive-discu
49

June/July 2015 - New York State Dental Association

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