Maxillomandibular Advancement Surgery

Obstructive sleep apnea (OSA) is a common disorder, estimated to occur in 18 million Americans [1], but it’s estimated that 80% of people with this condition are not diagnosed. Untreated, OSA has been associated with significantly increased rates of hypertension, insulin resistance, depression, cardiovascular disease, motor vehicle accidents, and even dying from cancer.

Continuous positive airway pressure (CPAP) is considered the mainstay of treatment, but is not well-tolerated by a significant number of users. Long-term adherence rates for CPAP can be as low at 17% [2]. Dental appliances are also an acceptable option being recommended by the American Academy of Sleep Medicine as first line therapy alongside CPAP for those with mild to moderate OSA.

Results of surgical options are mixed, with success rates from about 10% for nasal surgery to well over 90% with maxillomandibular advancement (MMA). Multilevel procedures that include the soft palate and the tongue base report surgical success rates from 60% to 80%. In previous years, MMA used to be offered as second line therapy once the multilevel soft tissue procedures failed, but currently, it’s being offered as a first line treatment in carefully selected patients.

Surgical Considerations
Craniomaxillofacial abnormalities are a well-recognized predictor of OSA. MMA enlarges the skeletal framework, thus enlarging the narrowing at the levels of the retropalatal and retroglossal areas.

Although MMA surgery is similar to procedures performed for malocclusion, there are a few considerations when dealing with OSA patients. In general, occlusion is maintained since the maxilla and mandible are moved simultaneously anteriorly. Arch bars or orthodontic bands are usually placed before the procedure. A LeForte I maxillary osteotomy is performed, along with a sagittal split osteotomy for the mandible. Care must be taken to preserve the descending palatine artery and the inferior alveolar nerve. Screws, plates, or a combination of both maintain rigidity. After the procedure, proper occlusion is achieved using elastics, and intermaxillary fixation is rarely needed.


Peri-operative Considerations
Anesthesia considerations are important, especially in patients with severe OSA. Standard airway protocols should be followed for patients with any degree of obstructive sleep apnea. Fiberoptic intubation, or even a temporary tracheotomy are considerations in difficult to intubate patients. Blood transfusion is rarely needed, but two units can be made available.

Whether or not to place the patient in the ICU postoperatively is at the discretion of the surgeon. The patient is discharged home from the floor once tolerating fluids adequately, pain is controlled, and the airway is stable. Patients generally are discharged once able to tolerate a soft or liquid diet. Most people are able to gradually advance to a regular diet after 4-6 weeks. The elastics are gradually loosened and removed as well.


Surgical Results
Reported surgical success rates vary from 65% [3] to 100% [4]. However, different authors use different criteria for surgical success. One common definition is a postoperative RDI < 20 and an overall drop by 50%. Others use an RDI < 15 and an AI < 5, and some include oxygen desaturation criteria as well.

A meta-analysis by Holty and Guilleminault [5] pooled 53 reports describing 22 unique patient populations (627 patients), and found that the mean AHI decreased from 63.9/hr to 9.5/hr, with a pooled surgical success rate of 86%. Overall, 43.2% were cured (AHI < 5), with a 66.7% cure rate for those with a preoperative AHI < 30/hr. Long-term surgical success was maintained at 44 months. Predictors of surgical success included younger age, lower BMI, lower preoperative AHI, and greater degree of maxillary advancement.

Quality of life measures, excessive daytime sleepiness, and blood pressure were noted to be significantly improved as well.


Complications

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Moving the maxilla anteriorly can stretch or disrupt the blood supply, potentially leading to aseptic necrosis. This is a rare complication, which can be avoided by using meticulous technique. Sometimes the plates or screws can loosen. Better plating systems and attention to detail can minimize these complications. Occlusion can change postoperatively, requiring revision surgery or orthodontics. Velopharyngeal insufficiency (VPI) is a rare, but a reported event with MMA, with an increased risk if performed after a UPPP. In all cases, VPI resolved spontaneously within one year or resolved with speech therapy.

One study reported pain levels after sequential phase I (UPPP) and phase II surgery (MMA), with no significant differences between the two groups [6].

Holty’s meta-analysis also showed that MMA is safe with a major complication rate of 1% (mostly cardiac related). Facial numbness was present in 100% immediately postoperatively, and 14.2% at one year follow-up. Malocclusion was reported to be minimal in one study, and 44% in another. Excluding facial paresthesias and malocclusion, the minor complication rate was 3.1 %.


Improved Quality of Life
In skilled hands, MMA surgery is generally safe, and highly effective for treating obstructive sleep apnea. Younger age, lower BMI, and greater maxillary advancement are predictive of greater surgical success. Most patients report satisfaction with quality of life measures and daytime sleepiness.

As reported in this article and in various studies, surgical success rates and complication rates can vary widely from center to center. If the MMA is being considered, it’s important to seek out a surgeon that has specific experience in handling obstructive sleep apnea patients with documented good outcomes.


Dr. Park is an assistant professor of otorhinolaryngology at the Albert Einstein College of Medicine, a Fellow of the American Academy of Otolaryngology, board-certified in Otolaryngology and Sleep Medicine, and author of the book, “Sleep, Interrupted: A physician reveals the #1 reason why so many of us are sick and tired.”

References:

1. Young T, Evans L, Finn L, Palta M. Estimation of the clinically diag- nosed proportion of sleep apnea syndrome in middle aged men and women. Sleep 1997;9:705-6.

2. Weaver, T. E., & Grunstein, R. R. (2008). Adherence to Continuous Positive Airway Pressure Therapy The Challenge to Effective Treatment. Proceedings of the American Thoracic Society. 5(2);173-178.

3. Waite, P. D., Wooten, V., Lachner, J., & Guyette, R. F. (1989). Maxillomandibular advancement surgery in 23 patients with obstructive sleep apnea syndrome. Journal of oral and maxillofacial surgery 47(12);1256-61.

4. Prinsell, J. R. (1999). Maxillomandibular advancement surgery in a site-specific treatment approach for obstructive sleep apnea in 50 consecutive patients. CHEST Journal 116(6);1519-29.

5. Holty, J. E. C., & Guilleminault, C. (2010). Maxillomandibular advancement for the treatment of obstructive sleep apnea: a systematic review and meta-analysis. Sleep medicine reviews.

6. Li KK, Riley RW, Powell NB, Gervacio L, Troell RJ, Guilleminault C. Obstructive sleep apnea surgery: patient perspective and polysomnographic results. Oto- laryngol Head Neck Surg 2000;123:572-5.

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