Treatment Planning for Orthodontic

©2014 JCO, Inc. May not be distributed without permission. www.jco-online.com
THE CUTTING EDGE
This column is compiled by JCO Technology Editor W. Ronald Redmond, DDS,
MS. To help keep our readers on The Cutting Edge, Dr. Redmond will spotlight a
particular area of orthodontic technology every few months. Your suggestions for
future subjects or authors are welcome.
In the past, treatment planning for orthodontic-restorative cases required the use of wax
setups, which were time consuming and frequently
inaccurate, depending on the skill of the lab technician. Collaborative dialogue with the interdisciplinary dental team was often “lost in translation”.
The advent of Invisalign* and Treat* software made it possible for planned treatment results
to be viewed not only by the patient, but by the
entire team. Still, because complex orthodonticrestorative cases are not generally treated with
Invisalign, the digital projections could not be
applied to these patients. For comprehensive treatment with fixed appliances, SureSmile provides a
computer-screen view of the end result that is far
more accurate than the old wax setup. Multiple
outcomes can be displayed to help reach a consensus among the patient and the treatment team. The
SureSmile software is extremely accurate, even
providing a Bolton analysis if needed.
This month’s Cutting Edge column shows
two cases treated with the SureSmile system. In
each case, after various treatment options were
presented, the patient, orthodontist, and restorative
dentist were all involved in the decision-making
process. The patient was able to evaluate the costbenefit ratio for each plan and thus make an
informed determination.
No longer does the final result exist only in
the mind of the orthodontist, or as a comparison
with samples of previously treated cases. Informed
consent has taken a tremendous leap forward!
WRR
Treatment Planning for
Orthodontic-Restorative Cases
with SureSmile Technology
RICHARD L. SCHECHTMAN, DDS
D
igital engineering has provided orthodontists
with such innovations as virtual impressions
and computer-designed in-office restorations. In
*Registered trademark of Align Technology, Inc., Santa Clara,
CA; www.aligntech.com.
Dr. Schechtman is in the private practice of orthodontics at 3630 Hill Blvd.,
Jefferson Valley, NY 10535; e-mail:
[email protected].
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Fig. 1 SureSmile’s OraScanner wand.
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Fig. 2 Case 1. 49-year-old male patient with upper and lower anterior spacing before treatment.
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recent years, my patients and I have benefited from
the use of SureSmile** technology, which allows
me to perform accurate, three-dimensional diagnostic simulations based on data supplied by the
handheld OraScanner** (Fig. 1), scanning either
the patient’s study casts or the dentition. SureSmile
also enables state-of-the-art finishing alignment
by delivering customized, robotically bent archwires. The system has been shown to reduce treatment times by an average 30%.1
Patients who present with spacing, crowding,
or missing teeth often require collaborative treatment plans involving both orthodontics and later
prosthodontic or periodontal procedures. The two
cases described in this article illustrate the power
of 3D virtual treatment simulations in planning
interdisciplinary care.
Case 1
A 49-year-old male presented with the chief
complaint of anterior spacing (Fig. 2). After standard records including study casts, photographs,
and cephalometric and panoramic records were
taken, the casts were scanned with an OraScanner.
Complete orthodontic space closure by
means of anterior retraction was ruled out due to
the potential instability of such movements. The
patient’s anterior teeth were well coordinated
cephalometrically relative to their lip support; any
significant retraction would have taken them out
of their “neutral zone” and encroached on the
tongue’s habitual position, potentially leading to a
“dished-in” profile. Posterior protraction was a
viable option, but would have required temporary
anchorage devices and significantly more treatment time.
The SureSmile software was used to simulate two other treatment options that would still
address the patient’s desire to eliminate his anterior spacing.
Option 1: SureSmile’s tooth-measurement function includes a calculation of the Bolton ratio. In
**Registered trademark of OraMetrix, Inc., Richardson, TX; www.
suresmile.com.
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Fig. 3 Case 1. Mesiodistal tooth measurements
automatically displayed by SureSmile** software.
this case, it indicated a relative maxillary toothsize deficiency, with the right and left maxillary
central incisors measuring 7.8mm and 8.6mm
wide, respectively (Fig. 3). A setup was created
with the 12 upper and lower anterior teeth repositioned for mesial and distal placement of veneers
to close the spaces (Fig. 4). The lower incisors
required much smaller build-ups, considering their
near-average pretreatment widths.
Option 2: The second option was to consolidate
the six anterior teeth in each arch, leaving residual spaces between the canines and first premolars for the addition of a third premolar in each
quadrant (Fig. 5A). The projected spaces measured between 4.4mm and 5.7mm mesiodistally
(Fig. 5B) —too small for implants, but wide
enough for bridges.
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Fig. 4 Case 1. Treatment option 1: Digital setups with upper and lower anterior teeth repositioned for placement of veneers. (Red arrow indicates calculation of mesial and distal build-ups required to close mandibular spaces.)
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A
B
Fig. 5 Case 1. A. Treatment option 2: Digital setups with spaces redistributed for placement of four additional premolars. B. Projected sizes of spaces available for third premolars.
The patient was not concerned about the size
of his teeth, and after evaluating the cost of each
treatment plan, he chose Option 2.
Full fixed appliances were used to realign the
dentition and maintain incisal and canine guidance. After 20 months of treatment, the appliances
were debonded and “flipper” retainers with premolar pontics were placed to maintain the spaces
cosmetically and functionally until the patient was
ready for fabrication of bridges (Fig. 6).
Case 2
A 16-year-old male was referred by his general dentist for evaluation of a congenitally missing
upper right lateral incisor (Fig. 7). Clinical examination showed Class I molar and mild Class II
canine relationships, a deep overbite, and normal
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overjet. The maxillary incisors were upright, but
the mandibular incisors appeared slightly retroclined. There was minor maxillary anterior spacing, with a midline deviation to the right; the right
lateral incisor was congenitally missing, and the
left lateral incisor was undersize. The patient’s
dental arches were symmetrical, with a slight lingual inclination of the buccal segments. He exhibited a straight profile and competent lips.
Considering the Class I occlusion and minimal overjet, the best option in this case was to open
space for prosthetic replacement of the missing
upper right lateral incisor. A simulation was performed to determine whether there would be
enough space for an implant after the buccal segments were uprighted and the maxillary midline
shifted to the left (Fig. 8). The resulting space
measured 5.4mm; compared with the 5.5mm
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Fig. 6 Case 1. Patient after 20 months of orthodontic treatment and placement of temporary pontics in
upper and lower first-premolar spaces.
mesiodistal width of the upper left lateral incisor,
this would allow the upper lateral incisors to be
symmetrical and approximately equal in size, but
was not enough space for a lateral-incisor implant.
Therefore, restoration with either a three-unit
Maryland bridge or a cantilever bridge (with
canine abutment) was planned.
Eleven months after placement of fixed
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appliances, the majority of planned movements
had been accomplished (Fig. 9A). Following the
SureSmile protocol, the patient’s teeth were then
digitized with the OraScanner to produce a 3D
“therapeutic” scan of the dentition and bracket
positions (Fig. 9B). The teeth were repositioned
using the SureSmile software (Fig. 10A), and the
information was transmitted to SureSmile for
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A
B
Fig. 7 Case 2. A. 16-year-old male patient with congenitally missing
upper right lateral incisor, undersize upper left lateral incisor, deep
overbite, and midline deviation before treatment. B. Pretreatment
SureSmile scans of study casts.
A
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A
B
C
Fig. 8 Case 2. A. Digital setups showing space opening for upper right lateral incisor and mesiodistal measurements of other maxillary teeth. B. Superimposition of simulated pretreatment (blue teeth) and posttreatment (white teeth) digital records. C. Space measurements (4.5mm + 0.9mm) indicate total of 5.4mm
available for maxillary right lateral incisor replacement.
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A
B
A
Fig. 9 Case 2. A. Patient after 11 months of fixed-appliance treatment. B. “Therapeutic” progress scan of
patient’s dentition.
A
B
Fig. 10 Case 2. A. SureSmile setup based on data from therapeutic scan. B. Eight months later, patient
shows significant improvement in posterior occlusion.
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A
A
B
Fig. 11 Case 2. A. Patient after 19 months of treatment (with and without “flipper” pontic in upper right
lateral incisor space), with lingual wires bonded between upper central incisors and between upper right
canine and first premolar to stabilize opened space until future restoration. B. Diagnostic simulation
closely matches actual treatment results.
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robotic fabrication of finishing archwires. Eight
months later, the posterior occlusion had improved
significantly (Fig. 10B).
Treatment was completed in 19 months (Fig.
11A). Final results closely matched the diagnostic
treatment simulation (Fig. 11B). Lingual wires
were bonded between the upper central incisors
and between the upper right canine and first premolar to retain the upper right lateral incisor space
until permanent restoration. A “flipper” retainer
provided a temporary cosmetic solution and helped
preserve the space as well. The patient’s gingival
display indicated that he could benefit from crown
lengthening of the upper canines and left lateral
incisor to harmonize their gingival heights with
those of the central incisors, which were ideal for
his smile line.
Discussion
When planning comprehensive orthodonticrestorative treatment, both orthodontists and prosthetic dentists have relied upon diagnostic wax
setups to simulate projected treatment outcomes.
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This method tends to be unreliable, since the thickness of the coping-saw blade will impede accurate
space measurements in situations with little tolerance for error—as when creating space for an
anterior implant.
Further frustrating our desire for precise
case results, we may accumulate errors during
treatment in terms of transverse coordination,
rotations, angulation, and vertical issues. Con­
ventional fixed-appliance therapy then requires a
series of archwire changes and complex, manual
wire bends over many visits to refine the alignment and occlusion.
As demonstrated in the two cases shown
here, SureSmile’s 3D digital diagnostic and finishing technologies can resolve both problems, making treatment more predictable and efficient for
clinician and patient alike.
REFERENCES
1. Sachdeva, R.C.; Aranha, S.L.; Egan, M.E.; Gross, H.T.;
Sachdeva, N.S.; Currier, G.F.; and Kadioglu, O.: Treatment
time: SureSmile vs conventional, Orthod. (Chic.) 13:72-85,
2012.
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