A case of micrognathia with obstructive sleep apnea improved by mandibular distraction osteogenesis

Obstructive sleep apnea syndrome (OSAS) is a life-threatening breathing disorder. We describe a patient with micrognathia and OSAS who underwent mandibular advancement by bilateral mandibular distraction osteogenesis. A 36-year-old man had micrognathia due to neonatal bilateral temporomandibular joint ankylosis. He also had severe OSAS. Conservative treatment for OSAS, such as continuous positive airway pressure, had been attempted at another hospital, but was not successful. Before mandibular distraction, sleep apnea was severe; the apnea hyponea index (AHI) was 63, and the Epworth sleepiness scale (ESS) was 8. After distraction, AHI and ESS greatly improved to 8 and 1, respectively. Cephalometric analysis showed that the widths of the upper airways had increased. In conclusion, mandibular advancement by distraction osteogenesis was effecttive for correcting micrognathia associated with OSAS. There has been no relapse of malocclusion and no recurrence of OSAS for 2 years after the operation.