Complications of Maxillomandibular Advancement

Transcription

Complications of Maxillomandibular Advancement
Peter Waite, DDS, MD
Kenneth Guffey, DMD, MD
Introduction
Maxillomandibular advancement (MMA) usually involves a maxillary Le Fort I
osteotomy and bilateral sagittal split osteotomy of the mandible with advancement. It relieves
obstruction by expanding the skeletal framework and associated attached oropharyngeal and
hypopharyngeal soft tissues, thereby enlarging the pharyngeal space. By placing tension on the
soft tissue, it also reduces their collapsibility during negative pressure inspiration. MMA is
widely considered the most effective surgical method for treatment of sleep apnea, apart from
tracheostomy. Success rates have been generally high and dependent on the criteria of success
used, with values as high as 100% reported.1 A systematic review and meta-analysis by Holty
and Guilleminault2 demonstrated a success rate of 86%, defined as an apnea-hypopnea index
(AHI) of less than 20/h and 50% or greater reduction in the postsurgery AHI.2 In addition, a cure
rate of 43.2%, defined as an AHI of 5% or lower, was found.2,3
Although the procedure is highly effective, complications arise and must be appropriately
anticipated and managed to ensure successful outcomes. Fortunately, major complications are
rare. In the meta-analysis previously mentioned, major complications reported in 627 patients
with obstructive sleep apnea (OSA) consisted of 2 cardiac arrests, 1 dysrhythmia, and 1 mandible
fracture. Most complications were minor and included malocclusion, paresthesia, infection, and
minor hemorrhage. However, nonunion, velopharyngeal insufficiency (VPI), hardware failure,
unacceptable esthetic changes, significant relapse, and vascular compromise are all potential
untoward events that have been reported (Table 1). When excluding paresthesia and
malocclusion, minor complications occur at an incidence of approximately 3%.2
Table 1. Maxillomandibular Advancement Complication
Paresthesia
Infection
Malocclusion
PAGE 1 Complications of Maxillomandibular Advancement
Hardware failure
Bleeding
Vascular compromise
Relapse
Malunion/nonunion
Fracture
Velopharyngeal insufficiency Unacceptable
aesthetic changes
Respiratory compromise
The Role of Staging in Complications
The timing of MMA is controversial, and although many perform MMA as an initial
operation, one popular protocol is a staged approach to therapy. In this method, patients
diagnosed as having OSA undergo a phase 1 therapy consisting of uvulopalatopharyngoplasty
(UPPP) and possibly adjunctive procedures, such as genioglossus or hyoid advancement.
Maxillomandibular advancement is performed as a phase 2 surgery if phase 1 fails. Part of the
rationale behind the staging is the assumed morbidity and the view of MMA as an aggressive
procedure when compared with phase 1 operations. Another contributing factor is the initial
referral pattern of some institutions to surgeons who may be adept at phase 1 operations but not
trained to perform MMA. The dissatisfaction with poor success rates and associated morbidity
for UPPP and other procedures, coupled with the high success rates of MMA, has lead some
practitioners to offer MMA as the initial procedure of choice. Others advocate targeted therapy,
using clinical examination and radiographic findings to treat specific levels of obstruction with
“less invasive” procedures or MMA if obstruction at multiple levels is present. The staging of
these procedures is important to consider because the complication pattern differs between those
who underwent previous phase 1 surgery and those in whom MMA is the only surgical
procedure to address their sleep apnea.
Paresthesia
Paresthesia is common after MMA. The inferior alveolar nerve and maxillary branches of
the trigeminal nerve are most frequently involved, and transient neurosensory disturbance can be
found in up to 100% of patients, although approximately 86% resolve in 1 year.2,4 Riley and
colleagues5 reported a similar incidence of permanent nerve injury (12.5%)5. Because of the
temporary nature of these injuries, most do not consider nerve injury a complication unless
permanent or the result of major nerve branch transection. In the mandible it is important that a
slow, controlled split with adequate visualization of the inferior alveolar nerve be undertaken to
minimize trauma. The nerve should then be adequately freed from its bony canal with an elevator
or rotary instrument from the proximal segment as the mandible is split. The nerve should be free
of any bony impingement and distant from the area of screw placement during fixation of the
osteotomy.
Minimizing surgical trauma is especially important in this patient population because
most OSA patients are middle-aged or older, and their ability to recover from injury diminished
when compared with younger patients undergoing routine orthognathic surgery. Despite careful
dissection, manipulation and stretch on the nerve will often result in transient paresthesia in
almost all cases. It is therefore important to discuss this with patients before surgery because it is
not likely to be avoided. Given the high satisfaction rates with the surgery, this consequence is
acceptable to most patients. Despite adequate education, however, some patients will be
dissatisfied with this outcome.
Malocclusion
Minor occlusal discrepancies after MMA are likely very common and are potentially
more common in this population when compared with traditional patients undergoing
orthognathic surgery. These discrepancies are due to a variety of patient- and procedure-related
factors. Obesity, large advancements, and patient nonadherence to dietary restrictions, creating
excess strain on internal fixation, may all contribute to poor postoperative occlusion. Most
malocclusions are mild and usually managed conservatively. Waite and colleagues6 reported a
44% incidence of premature contacts that were all treated with equilibration and prosthetics. A
large series by Li and colleagues4 of 175 patients reported no major malocclusions, and all cases
were managed by dental adjustments. No incidence was reported in this study. In cases of major
discrepancy not amenable to occlusal adjustment, a surgical revision may be considered (Figure
1). Early recognition and correction are important in these cases to avoid the increased difficulty
associated with late revision after bony healing has occurred. Often, these patients are treated
without preoperative orthodontics, so it is prudent to establish ideal occlusion early because
small orthodontic movements will not be available to correct minor discrepancies
postoperatively. For some of these patients, initiation of postsurgical orthodontics should be
considered, particularly in those who are not candidates for a second surgery and who cannot be
corrected by equilibration or prosthetic rehabilitation.
A.
B.
C.
Figure 1. Malocclusion after maxillomandibular advancement. A, This patient sustained a left
posterior open bite after surgery. Dental restorations are present, making orthodontic bracketing
unfeasible, and the patient did not want replacement of her existing prosthesis. This patient was
treated with a surgical revision of the maxilla only. B, Postoperative radiograph after Le Fort I
osteotomy for correction of her malocclusion. C, Postoperative occlusion.
Fixation Failure
Addressing the additional strains placed on fixation is one area MMA differs the most
from standard orthognathic surgery. The correction of sleep apnea generally calls for a larger
advancement, with most advocating at least 10 mm of mandibular lengthening to maximize
airway expansion. As the mandible lengthens, the lever arm acting on the point of fixation
increases, increasing the chance of failure. Also, as the plate length increases, its ability to
withstand bite forces decreases. Another factor to consider is the demographics of this patient
population, with a higher number of male patients with their stronger bite forces and obese
individuals. All these factors can place considerable strain on internal fixation, particularly when
traditional methods are used, resulting in fixation failure and malocclusion, nonunion, or
malunion. Although traditional bilateral sagittal split osteotomy advancement may be
successfully managed in many cases with minimal fixation, such as a single superior border,
non–load-bearing plate along with a nonchew diet, often increased support is needed in these
patients. A variety of methods to address this issue have been described, including multiple
plates, larger load-bearing plates, bicortical screws, plate and bicortical screw combinations,
maxillomandibular fixation, and suspension wires (Figures 2-4). Each method has its own
advantages and drawbacks to consider and ultimately depends on the experience and preferences
of the practitioner. Bicortical screws, although frequently used in orthognathic surgery, may be
difficult to place or inadequate for fixation in MMA. A solid area of bony overlap with good
anterior-posterior spread and adequate adaptation is ideal for this method. As the amount of
advancement increases, the amount of bony overlap decreases. Also, because the mandible is
shaped like a “V,” with its widest portion posterior, as the distal segment is advanced the width
of the mandible between the 2 proximal segments increases. This may result in pushing of the
proximal segments laterally with decreased bony adaptation. (Figure 5). This pushing may be
overcome by recontouring of the segments with a rotary instrument, but in situations where this
is not successful, additional methods of fixation may have to be used.
A.
B.
Figure 2. Plating the mandible. A, A single mandibular plate spanning the large gap may be
adequate for traditional mandibular orthognathic movements. In this case it is augmented by the
use of a bicortical screw posteriorly. B, Panoramic image showing the fixation.
A.
B.
Figure 3. Fixation failure. A, Lateral cephalogram of a patient after maxillomandibular
advancement (MMA) with placement of a single plate at the mandibular osteotomy on each side.
Note the proximal segment rotation superiorly, resulting in early posterior contact and anterior
open bite. B, In another case, 2 strong monocortical plates are used per side to help maintain the
position of the segments.
A.
B.
Figure 4. Plate fracture. A, After maxillomandibular advancement, placement of a routine
monocortical plate resulted in fracture. B, After hardware removal, the left mandibular malunion
was corrected by realigning the proximal segment and placement of a larger plate.
A.
B.
C.
D.
Figure 5. Bicortical screw failure. Large advancement with failure of bicortical screws due to
poor bony overlap. A, Two weeks postoperatively, proximal segment rotation and poor bony
alignment are noted on a panoramic radiograph. B, Lateral cephalogram demonstrating anterior
open bite. C, Left side bicortical screws replaced with plate with realignment of the segments. D,
Lateral cephalogram demonstrating satisfactory occlusion.
In the maxilla, four 2.0-mm, L-shaped plates are commonly used.7 Although this is still
common in the author’s practice for orthognathic movements, for MMA we advocate the use of
2.0-mm prebent maxillary advancement plates (KLS-Martin, Umkirch, Germany). These plates
are available in different sizes, depending on the amount of advancement needed, and require
minimal manipulation for adaptation. The decrease in the amount of bending required reduces
weakening of the hardware and presumably helps maintain strength under cyclical loading. An
additional advantage is that these plates provide accurate advancement while eliminating the
need for measurements and thus reducing operative time (Figure 6). This method has shown
good initial results.8
Figure 6. Maxillary prebent plates. These plates are easily adapted. The number 8 marked on the
superior portion of the plate indicates the amount of advancement in millimeters.
Relapse
Despite technologic advancements in materials and techniques used for internal fixation,
relapse remains a concern in MMAs. The increased stress on fixation previously discussed,
technical errors, and soft tissue tension created as the maxilla and mandible advance all may
contribute to the potential for relapse. Relapse may adversely affect the postoperative occlusion
but in itself has not been reported to adversely affect treatment outcomes. A 10% to 20% surgical
relapse has been documented in up to 15% of patients after MMA; however, no apparent
increase in the AHI or subjective worsening of symptoms has occurred.4,9,10 In addition, surgical
relapse has not been shown to correlate with the amount of mandibular advancement.9 In a study
by Louis and colleagues, the amount of maxillary advancement also did not correlate with longterm skeletal relapse. Although a small increase in relapse was observed in the large
advancement group (1.9 ± 1.8 mm in those advanced 12.3 ± 2.8 mm), it did not achieve
statistical significance.11 No studies have compared fixation techniques for the maxilla and
mandible for MMA, so considerable variation is assumed among surgeons.
Modifications in surgical technique have been proposed to enhance stability of the
postoperative position. Although some advocate the use of step osteotomy in the maxilla to
enhance bony interface and long-term stability,7 good results can be produced with a standard Le
Fort I osteotomy design with 2.0-mm prebent plates for the maxilla previously discussed. In the
mandible, 2.0-mm, superior border plates with or without the use of additional bicortical screws
has produced good success. Regardless of technique, major skeletal relapse with recurrence of
symptomatic OSA, although rare, should be considered for a revision. In these patients,
alteration of the previous technique and addition of increased fixation or even a period of MMF
should be used. Relapse without recurrence of clinically significant OSA may be managed by
observation.
Nonunion and Malunion
Nonunion is a potential complication with any orthognathic surgical procedure and may
be the result of poor intrinsic healing capability or surgical technique. Even with adequate
fixation, large gaps in the maxilla and mandible may not demonstrate adequate osseus healing.
One option includes the use of bone grafts, although no consensus about their use or the
preferred technique exists. Maxillary advancement generally results in contact only in the
piriform aperture and zygomatic buttresses, producing a large gap in the lateral wall. Bone
harvested from the chin, ramus, iliac crest, or any autogenous site may be used, but
disadvantages, including increased operative time and donor site morbidity, must be considered.
For this reason, many advocate modified steps and strong fixation techniques to maximize bony
interface and maxillary stability, obviating the need for bone grafts. In a review of 131 patients
treated without bone grafting, only 4 (3%) developed nonunion, requiring iliac crest bone
grafting as a second procedure.3,7,12 Patients with large gaps are treated best by cadaveric tibial
bone graft shaped to mortise into the lateral wall defect. The “wedge” effect created by this
technique also presumably adds to maxillary stability and decreases relapse by resisting posterior
pull of the soft tissues. The graft is additionally secured by plate screws, which engage the graft,
and another single screw placed above the osteotomy can be used for additional security if
needed (Figures 7 and 8). There have been no known incidences of nonunion, although
comprehensive review has not been undertaken. Advantages of this technique include lack of
donor site morbidity and decreased operative time over autogenous bone grafting. The
disadvantage of this technique are increased cost and operative time when compared with no
bone grafting. Occasionally, infection of the bone graft may occur, or the bone graft may
become dislodged into the maxillary sinus. In patients with sinus symptoms who have
radiographs that show a radiopaque foreign body, removal of the graft should be considered. The
graft may then be refixated or consideration given to an alternative technique, such as
autogenous grafting.
A.
B.
Figure 7. Tibial bone graft. A, Tibial graft shaped and set into lateral wall defect. The wedge
effect provides stability and prevents dislodgement. Note the graft is placed before placement of
the screws adjacent to the recipient site. B, After placement of screws into the plate, engaging the
bone graft. In cases where adequate fixation with plate screws is not achieved, a single screw
can be placed into the graft superiorly as in this case.
Figure 8. Osseus union. Note the osseous union in the lateral maxillary wall on removal of
hardware. This patient was treated with cadaveric tibial bone shaped to fit the defect. It has been
completely replaced by the patient’s bone. The holes adjacent to the union represent the previous
location of the plate.
Infection
The rate of infection after orthognathic surgery has been reported to range from 1% to
33%.13 Orthognathic surgery is a clean contaminated procedure, and thus an inherent risk of
infection is acceptable. Fortunately, with current use of antibiotics, the rate of infection is low.
When compared with traditional orthognathic procedures, MMA is associated with several
factors that may increase the rate of infection, including increased patient age, length of surgery,
and comorbidities. Increased age and longer procedures have been associated with increased risk
of infection and plate removal in orthognathic surgery.14 The timing of antibiotic administration
may also influence these rates. Although the use of prophylactic antibiotics in the prevention of
surgical site infections is widely accepted, debate exists regarding the type and duration of
prophylaxis that should be used. Most consider a minimum of preoperative administration to be
standard of care, and studies have reported an increased incidence of infection in orthognathic
surgery patients when antibiotics are withheld.15 When discussing the duration of antibiotic
administration, however, conflicting reports have made a consensus difficult to establish.
Although many advocate short-term antibiotics involving single or multiple perioperative doses,
others support extending prophylaxis for 5 to 7 days postoperatively. Several reports have
indicated no difference in infection rates when short-term dosing schedules are compared with
extended protocols.16-20 Interestingly, several of these reports indicated increased infection rates
in the short-term group, although no statistical significance was reached.16,17,20 In contrast,
Baqain and colleagues demonstrated statistically significant higher morbidity scores and degree
of swelling with short-tem administration.16 In a randomized, double-blind clinical trial
comparing 1- and 5-day prophylaxis regimens, Bently and colleagues also demonstrated
significantly higher infection rates in the short-term group (6.7% vs 60%).21 A retrospective
review of 1294 orthognathic surgery patients by Chow and colleagues13 found similar results.
The authors recommend a conservative approach with preoperative antibiotics followed
by a 5- to 7-day postoperative course. Although the literature is insufficient to support a single
protocol, it is necessary to provide the best possible chance of avoiding this complication.
Postoperative infection can lead to considerable morbidity, including pain, swelling, nonunion,
and malocclusion, and may require removal of hardware. In addition, OSA patients have
multiple factors that may increase the risk of infection when compared with traditional
orthognathic patients, in whom most infection studies have been performed. They are older,
often require longer procedures, and may be immunocompromised secondary to their medical
condition or medications. When compared with orthognathic patients, OSA patients may have
less tolerance of a postoperative infection, and their medical comorbidities may make the clinical
sequelae of procedures required in the management of postoperative infections undesirable.
In the event that a postoperative infection presents, similar conservative management is
recommended. Simple infections may be managed by local measures, including opening the
wound and possible drain placement. Antibiotic dosages should be extended, and close
monitoring is warranted. Removal of hardware should be avoided until bony healing across the
osteotomy has occurred. Keep in mind that this may be delayed in the presence of infection. In
the incidence of chronic or recurrent infection requiring long-term antibiotic administration,
waiting 4 to 6 months before plate removal may allow for stability of the fragments to occur.
Cases of early infection poorly controlled with local measures and antibiotics, however, will
require hardware removal. If this is required before healing, stabilization can be achieved with
alternative methods. For the mandible, the patient should be placed in maxillomandibular
fixation if adequate dentition exists and reduction of the segments is achieved. This approach is
not advised for maxillary infections that require plate removal because the pull of the mandible
may increase the osteotomy gap, resulting in change in the maxillary position and nonunion. For
these cases, wiring to a stable buttress distant from the osteotomy, such as the zygoma or
piriform rim, can be performed, using the dentition or a maxillary splint as a second point of
fixation. External fixation is another option and is most often used in the mandible. It is hoped
that use of one of these methods will allow for proper union and circumvent the need for a
secondary revision procedure.
Ischemic Necrosis
Ischemic necrosis of the maxilla is a feared but fortunately rare complication of MMA. In
their review of 22 studies describing more than 600 patients undergoing MMA, Holty and
Guilleminault2 found no incidences of this potentially devastating complication. The occurrence
of necrosis is of particular concern in this patient population because of the amount of
advancement required. The advancement places excess stretch on the soft tissue envelope and
arterial blood supply, leading to decreased perfusion. Management involves careful monitoring
of maxillary perfusion intraoperatively and postoperatively and prompt action should it occur.
Perioperative techniques to preserve the maxillary blood supply that have been advocated
include alterations is incision design to maximize soft tissue envelope, preservation of the greater
palatine arteries, and close intraoperative monitoring of the gingival perfusion.
Poor perfusion noted during the procedure can be managed initially by decreasing the
amount of planned advancement and observing for a return of perfusion. Return would indicate
that the blood supply has not been interrupted but rather that the maxillary soft tissue envelope
has not been adequately relieved of tension. The soft tissues can then be stretched by strong pull
inferior and anterior with a large osteotome or other instrument, the maxilla replaced to the
planned position, and the perfusion reassessed. It is important that the maxilla sit in its final
position with minimal tension before fixation is applied. Some advocate replating the maxilla to
its preoperative position and discontinuation of the procedure completely. In more than 400 cases
performed at a single center, Li and colleagues22 reported only 2 cases requiring discontinuation
for this reason. They reported no incidences of necrosis using this protocol, which includes
routine preservation of the greater palatine arteries.
Because hypotensive anesthesia is routinely used during this portion of the procedure,
allowing return of normal blood pressure may alleviate signs of decreased perfusion and should
be considered early in the management algorithm. One preventive measure that can be taken is a
modification in the standard Le Fort incision to maximize the size of the vascular pedicle.
Shorter-length incisions may be used, but this will compromise visibility. A more effective
method is to use a standard-length incision with superior releases at the distal ends, which are
created at an approximately 45° angle superiorly along the body of the zygoma. Although the
horizontal portion is shortened, the total incision length does not change. This effectively
increases the pedicle width posteriorly while maintaining adequate visibility. It is prudent to
monitor these patients closely postoperatively as well, and any signs of hypoperfusion should be
dealt with immediately. A return to the operating room should not be delayed. Some have
advocated the use of nitroglycerin paste along the mucosa to increase perfusion, and although
this not done routinely, anecdotal reports have been favorable. A potential adverse outcome of
this method is a decrease in blood pressure, which will require close supervision.
Facial Aesthetics
Unlike traditional orthognathic surgery, aesthetic outcome is not a primary goal in MMA
for OSA. As a result, advancement of the maxilla and mandible could potentially result in
unaesthetic facial changes in the pursuit of expanding the parapharyngeal airway. Subjective
outcome studies have attempted to explore the magnitude of these facial changes based on
patient perception. In a study by Li and colleagues23 of 44 patients undergoing MMA, 96%
reported a change in facial appearance. Twenty-four patients (55%) found these changes
favorable, 14 were neutral, and only 3 found the changes to be unfavorable. Interestingly, 40 of
these patients were found to have maxillomandibular protrusion by cephalometric parameters
postoperatively. In another study of 70 MMA patients, 67% reported improved facial
appearance, 20% were indifferent, and only 3 patients (4%) were unsatisfied with their results. In
this study, 9% of patients did not even notice a change.12 Other smaller studies have
substantiated these results, some reporting no changes in facial appearance after MMA.24
Most subjective studies have reported overall low incidence of unacceptable aesthetics.
These findings are perhaps because most patients undergoing MMA are middle-aged and have
more facial aging and soft tissue laxity. Advancing the maxilla and mandible increases skeletal
support of these tissues and can result in facial rejuvenation. Because of the large amount of
advancement, most patients will demonstrate bimaxillary protrusion after surgery. It is hard to
predict which patients will find these changes unfavorable, which makes it difficult to avoid poor
aesthetic outcome. The main tenants of management in these patients are proper patient
education and expectant management. A report by Blumen and colleagues25 demonstrated much
higher poor outcomes in which 18% were either disappointed or unsatisfied with their
appearance. However, in this same study 94% stated they would recommend this operation to
friends and family. This finding is perhaps because of the high tolerance patients have of poor
facial aesthetic outcome in the setting of a highly successful treatment of their sleep apnea.
Regardless, patients must be made aware of these possible results. Some recommend caution in
younger patients, those with preexisting maxillomandibular protrusion, and nonobese patients
with thinner soft tissues.22 Computer-aided simulated surgery can be used for patient education
and may increase patient acceptance, but the accuracy of these methods has not been validated.
In patients with preexisting protrusion or proclined teeth, one may consider total or
segmental subapical osteotomy with dental setback simultaneously with advancement. Although
this will increase the amount of advancement that can be obtained while staying in an acceptable
aesthetic window, disadvantages include increased operative time, technical difficulty, the need
for preoperative extraction of teeth in some cases, and the potential for tooth damage.
Velopharyngeal Insufficiency
The advancement of the maxilla enlarges the oropharyngeal space and theoretically could
lead to incompetence of the soft palate and resultant VPI. This complication is fortunately rarely
reported after MMA26 but may be increased in patients undergoing staged therapy who had
undergone previous UPPP. Subjective changes in speech (24%) and swallowing (12%) were
noted in 42 patients who underwent sequential phase 1 and phase 2 surgery.23 All symptoms
resolved in 1 year. This same group in a larger series reported a much lower incidence
(approximately 10%) after MMA following UPPP.27 Although less frequency has been reported,
Bettega and colleagues28 reported that all patients who had undergone previous UPPP
experienced VPI after MMA. Patients should be informed of this complication, especially those
who have undergone previous pharyngeal procedures, but be reassured that it will most likely be
transient. Special consideration should be given to those with a history of cleft lip and palate or
other surgical procedures that result in velopharyngeal scarring because the likelihood is
presumably increased. In addition, careful history is warranted because some suggest those
experiencing significant VPI postoperatively likely exhibited this tendency preoperatively.29
Respiratory Complications and Postoperative Monitoring
One concern for patients undergoing MMA is the potential for respiratory complications
after MMA. Anesthetists at many surgical centers are particularly concerned about postoperative
obstruction after extubation in this patient population. In a study of 70 consecutive patients, Li
and colleagues performed nasopharyngolaryngoscopy before and 48 hours after surgery. They
noted lateral pharyngeal wall edema in all patients, 20% incidence of edema and ecchymosis of
the piriform sinus and aryepiglottic fold, and 6% incidence of hematoma of the hypopharyngeal
region, resulting in partial airway obstruction. None of their patients, however, developed
respiratory complications or required intervention. In addition, none of the patients treated at
their surgical center before this study experienced acute airway obstruction that required
tracheostomy or intubation. On the basis of these results, they advocated the use of postoperative
nasopharyngolaryngoscopy in all patients after MMA.30 In another study of 25 consecutive
MMA patients, cephalometric data immediately postoperatively during the period of maximum
edema demonstrated an increase in the posterior airway space from preoperative values.31
Another study demonstrated significant reduction in preoperative and postoperative desaturations
(15.2/h to 1.3/h) immediately after surgery.32 In light of these findings and clinical experience,
the airway is most likely significantly improved in the immediate postoperative period. Given the
nature of the disease, however, and the concern for potential complications, these patients are
usually best treated conservatively. As discussed previously, extubation in the operating room
with the surgeon and anesthesia team present is advised. In the rare event of respiratory distress,
it is best to be in a controlled setting with experienced personnel and proper equipment easily
accessible. Any airway distress should be addressed immediately with reintubation or an
emergency airway as needed.
Inpatient management with at least an overnight stay in an intensive care unit or other
closely monitored unit with one-on-one care is advised. Our protocol involves overnight
intensive care unit stay with transfer to a step-down unit on postoperative day 2 with close
nursing supervision. Narcotics should be used sparingly and when necessary can be combined
with nonnarcotic medications and proper patient education to avoid respiratory compromise in
this already high-risk population. Continuous pulse oximetry should be used, with supplemental
oxygen as needed to maintain adequate saturation, usually through an open face mask because
nasal breathing can be impaired. Postoperative continuous positive airway pressure can also be
considered in patients not responsive to oxygen administration, although this is rarely needed and
carries a potential risk of subcutaneous emphysema. Steroids and head of bed elevation are also
used by many to help control the amount of postoperative edema, which can contribute to
respiratory compromise.
Conclusion
MMA can be a highly effective and rewarding treatment for OSA. Serious complications,
although rare, can be potentially devastating to the patient and surgeon. The astute practitioner
can maximize the benefits and minimize complications of the procedure most effectively through
proper anticipation and prevention. Certain complications, however, are difficult to avoid, and
patient education is paramount. Once complications arise it is important to be familiar with
described management techniques to avoid potentially poor outcomes.
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Complications of Maxillomandibular Advancement

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