Mandibular advancement for patients with obstructive sleep apnea syndrome : a comparison of bilateral mandibular distraction osteogenesis and bilateral sagittal split osteotomy

Abstract

Maxillomandibular advancement (MMA) is a well-established surgical treatment modality for patients with obstructive sleep apnea (OSA). The advancement of the mandible could be achieved by either bilateral sagittal split osteotomies (BSSO) or bilateral mandibular distraction osteogenesis (BMDO). It is very important to know the treatment outcomes, effectiveness, morbidities and potential complications of both treatments. This study aims (1) to evaluate the effectiveness and complications of MDO for treating OSA patients; (2)to compare the airway functions and skeletal stability of patients treated by BMDO and BSSO; (3) to assess the changes in airway dimensions brought about by BMDO and BSSO; (4) to evaluate the clinical morbidities, extent of neurosensory disturbance and temporomandibular joint functions associated with BMDO and BSSO; (5)to investigate the effects of BMDO and BSSO on patients’ facial aesthetics and quality of life(QoL). We hope to bridge the knowledge gap on mandibular advancement in MMA for OSA patientswith the new evidence generated in this study, and to provide surgeons and OSA patients a well-informed decision making on the choice of the preferred method in MMA. A systematic search on MDO as a treatment for OSA patients was performed. Mandibular distraction osteogenesis was shown to be highly effective in resolving OSA in both children and adults with retrognathic mandible. BMDO wasalso an invaluable means in alleviating airway obstructions in children in which traditional orthognathic surgery was deemed impossible Eighteen subjects with moderate to severe OSA were recruited in a randomized controlled trial, allocated in the BMDO and BSSO groupsfor a wide-range investigation on the 2 methodsfor mandibular advancement in MMA.

Airway functionswere significantly improved in terms of reduction in apnea/hyponea index and increase lowest oxygen saturation. The overall success and cure rates of MMA in this study were 88.9% and 61.1% respectively. Patients treated by BMDO showed significantly less skeletal relapse with a percentage of 6.7% comparing to 13.6% in patients treated by BSSO. However, there were minimal clinical significance brought about by this difference in large advancements of 10-15mm in this study. Patientsreceiving BMDO experienced more morbidities as there were frequent infectionsaround the distractor rods. There were also 3 cases of bony non-union in this group of patients, which was an uncommon complication in MMA.

Two groups of patients hadsimilar degrees of neurosensory disturbance and associated functional impairment, as well as temporomandibular joint functions, and all of these reduced to near-normal levels in long term. All patients reported improved subjective facial aesthetics to various extent after MMA. The general-health related and OSA-specific QoL of both groups of patients were significantly improved compared to baseline values.