Maxillomandibular advancement surgery in patients with obstructive sleep apnea: mandibular morphology and stability.

Causal associations between various craniofacial morphologic variables and obstructive sleep apnea have been inferred and serve to justify many treatments. The purposes of this study were to examine the presurgical and postsurgical mandibular morphology of patients with obstructive sleep apnea who were undergoing maxillomandibular advancement and to assess the stability of the observed changes. Various mandibular morphologic variables of 32 male subjects were measured on presurgical, immediately postsurgical, and short-term and long-term postsurgical radiographs. The results demonstrated that presurgical mandibular morphology was not significantly different from that of control samples derived from the literature. The presurgical mandibular plane-hyoid measurement was an average of 11.4 mm greater than that in matched controls. On average, surgery resulted in a significantly longer mandible, a greater gonial angle, and a reduced mandibular plane-hyoid distance, although the response of the hyoid was quite variable. The surgical changes in mandibular length were relatively stable over the long-term. Obstructive sleep apnea did not appear to be related to abnormal presurgical mandibular morphology in this sample.