Residency · Residency · Oral Maxillofacial Surgery

Maxillomandibular Advancement for OSA

Introduction

Maxillomandibular advancement (MMA) is the most effective surgical treatment for obstructive sleep apnea, achieving cure or significant improvement in 85 to 100% of patients. By simultaneously advancing the maxilla and mandible, MMA expands the retrolingual and retropalatal airway, increases pharyngeal muscle tension, and provides a durable skeletal solution for airway obstruction. The OMFS surgeon is uniquely trained to perform this procedure.

Mechanism of Action

MMA produces skeletal expansion of the pharyngeal airway at multiple levels simultaneously. Advancement of the maxilla pulls the soft palate and velopharyngeal musculature anteriorly, expanding the retropalatal space. Advancement of the mandible pulls the tongue base and suprahyoid musculature anteriorly, expanding the retrolingual space. Increased tension on the pharyngeal dilator muscles reduces collapsibility. Typical advancement of 10 to 12 mm increases the posterior airway space by 5 to 10 mm. Because MMA addresses the skeletal framework of the airway, it is effective regardless of the soft tissue pattern of obstruction.

Patient Selection

Indications

MMA is indicated for moderate to severe OSA (AHI greater than 15) with CPAP intolerance or failure, skeletal contribution to airway obstruction (retrognathia, midface deficiency, narrow PAS on cephalometric analysis), failure of prior soft tissue surgical procedures (UPPP, tongue base surgery), and patient preference for definitive surgical treatment over lifelong CPAP. Young, non-obese patients with skeletal deficiency are ideal candidates.

Contraindications

Contraindications include morbid obesity (BMI greater than 40) as the sole etiology, where outcomes are less predictable, severe uncontrolled cardiovascular or pulmonary disease, active psychiatric illness or unrealistic expectations, poor dental health or insufficient dentition for fixation (relative), and untreated temporomandibular joint disorders (relative).

Preoperative Workup

Polysomnography documents baseline AHI. Drug-induced sleep endoscopy (DISE) identifies obstruction levels and confirms multilevel collapse. A lateral cephalogram measures PAS, SNA, SNB, hyoid position, and occlusal plane angle. CBCT provides 3D airway volumetric analysis and enables virtual surgical planning. Dental models and orthodontic evaluation assess occlusion, and presurgical orthodontics are initiated if needed. Medical optimization includes cardiac risk assessment and sleep study-guided perioperative planning.

Surgical Technique

Planning

Virtual surgical planning (VSP) with 3D CT allows precise quantification of advancement. The target advancement is 10 to 12 mm at both the maxilla (Le Fort I) and mandible (BSSO). Counterclockwise rotation of the maxillomandibular complex is preferred, advancing the mandible more than the maxilla and maximizing retrolingual airway expansion. Occlusion is planned in the advanced position, with fabrication of intermediate and final surgical splints.

Le Fort I Osteotomy

The standard Le Fort I technique is used with complete down-fracture. The maxilla is advanced to the planned position and fixed with titanium plates and screws. An interpositional bone graft is placed for large advancements if necessary.

Bilateral Sagittal Split Osteotomy (BSSO)

The mandible is advanced and positioned into the final splint. Rigid fixation is achieved with bicortical screws or plates. The inferior alveolar nerve is identified and preserved. Advancement may be asymmetric to correct pre-existing asymmetry.

Adjunctive Procedures

Advancement genioplasty enhances chin projection and further tenses the suprahyoid muscles. Septoplasty and turbinate reduction address nasal obstruction that contributes to OSA. Uvulopalatopharyngoplasty may be combined in select cases for the retropalatal component. Hyoid suspension can be added for hypopharyngeal obstruction.

Counterclockwise Rotation

Rotation of the occlusal plane counterclockwise advances the mandible proportionally more than the maxilla, maximizing tongue base advancement and retrolingual airway expansion. It simultaneously normalizes facial aesthetics in retrognathic patients. Careful planning is required to maintain occlusal relationships.

Outcomes

Efficacy

The surgical success rate (AHI reduction greater than 50% and AHI less than 20) is 85 to 100%. The surgical cure rate (AHI less than 5) is 40 to 50%. Mean AHI reduction is from approximately 50-60 preoperatively to less than 10 postoperatively. Mean increase in posterior airway space is 5 to 10 mm. Improvements are seen in ESS, quality of life, blood pressure, and cardiovascular markers.

Stability

Skeletal relapse is minimal (1-2 mm) with rigid fixation. Long-term stability has been demonstrated at 5 to 10 year follow-up. Durability is superior to soft tissue procedures.

Facial Aesthetics

Most patients report improved facial appearance after MMA. Advancement of a retrognathic maxilla and mandible normalizes the profile. Increased lower face height may be perceived negatively in some patients, but counterclockwise rotation minimizes this effect. Nasal tip changes (upward rotation) may occur and should be discussed preoperatively.

Perioperative Management

Anesthesia Considerations

OSA patients have increased perioperative airway risk. Long-acting sedatives and opioids are avoided when possible. Nasal fiberoptic intubation may be required if a difficult airway is anticipated. Postoperative monitoring in the ICU or step-down unit for the first 24 hours is recommended.

Postoperative Care

Airway monitoring includes continuous pulse oximetry with head elevation at 30 to 45 degrees. Edema is managed with dexamethasone and cold compresses, with peak swelling at 48 to 72 hours. A liquid diet is maintained for 2 weeks followed by a soft diet for 4 to 6 weeks. Oral hygiene includes chlorhexidine rinses and gentle brushing. Elastics are applied at 1 to 2 weeks to guide occlusion during healing. CPAP is resumed postoperatively at reduced pressure if needed until the surgical effect is achieved. A follow-up PSG at 3 to 6 months postoperatively documents the AHI response.

Complications

Inferior alveolar nerve paresthesia is the most common complication, with temporary effects in 50 to 80% and permanent effects in 5 to 10% of patients. Unfavorable occlusion is managed with postoperative orthodontics and elastics. Relapse is minimal (1-2 mm) with rigid fixation. Hardware infection occurs in 2 to 5% and may require plate removal. Hemorrhage may arise from the descending palatine or internal maxillary artery. Velopharyngeal insufficiency is rare and more common with large maxillary advancements. TMJ dysfunction, including condylar resorption, may occur in susceptible patients (young females with preexisting condylar issues). Nonunion or malunion is rare with proper fixation technique.

Clinical Pearls

MMA is the most effective surgical treatment for OSA with success rates of 85 to 100%. Counterclockwise rotation maximizes retrolingual airway expansion while improving facial aesthetics. A target of 10 to 12 mm of advancement produces optimal airway results. OSA patients require heightened perioperative airway monitoring, and opioids should be minimized with close monitoring in the immediate postoperative period. Long-term outcomes are superior to soft tissue procedures, and most patients remain off CPAP at 5 to 10 year follow-up.

References

1. Holty JE, Guilleminault C. "Maxillomandibular Advancement for the Treatment of Obstructive Sleep Apnea: A Systematic Review and Meta-Analysis." Sleep Medicine Reviews. 2010;14(5):287-297.
2. Liu SY, et al. "Maxillomandibular Advancement for Obstructive Sleep Apnea." Oral and Maxillofacial Surgery Clinics of North America. 2019;31(4):433-446.
3. Zaghi S, et al. "Maxillomandibular Advancement for Treatment of Obstructive Sleep Apnea: A Meta-Analysis." JAMA Otolaryngology--Head and Neck Surgery. 2016;142(1):58-66.
4. Rojo-Sanchis C, et al. "Long-Term Effectiveness of Maxillomandibular Advancement Surgery." Journal of Oral and Maxillofacial Surgery. 2021;79(5):1084-1095.

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