Should Mandibular Symphyseal Distraction Osteogenesis be considered in OSA Surgery?

Introduction: Surgical maxillary expansion for the treatment of obstructive sleep apnea (OSA) has become common place. To maximize airway improvement, over-expansion of the maxilla can occur, resulting in an excessively widened maxilla that creates a mismatch to the mandible. Therefore, mandibular symphyseal distraction osteogenesis (MSDO) to widen the mandible along with maxillary expansion is being increasingly advocated in OSA surgery.

Methods: The authors discuss their 20-year experience with MSDO and surgical maxillary expansion. They also analyze the airway impact between Distraction Osteogenesis Maxillary Expansion (DOME) and Endoscopically-Assisted Surgical Expansion (EASE) based on currently available computational fluid dynamic (CFD) data, which has implications in whether MSDO needs to be considered.

Results and conclusion: The goal of surgical maxillary expansion is to enlarge the nasal cavity and reduce the airway resistance. CFD data demonstrates that EASE results in a much greater reduction in airway resistance as compared to DOME. EASE achieved a 12-fold reduction in nasal airway resistance compared to 3-fold reduction by DOME; a 12-fold reduction of retropalatal airway resistance as compared to 3-fold reduction by DOME; a 10-fold reduction of oropharyngeal airway resistance as compared to a 3-fold reduction by DOME, and an 8-fold reduction of hypopharygeal airway resistance as compared to a 3-fold reduction by DOME. Because there is no physiologic basis or data that demonstrates mandibular widening improves OSA, an airway centric surgical expansion technique such as EASE can achieve a much greater airway impact without needing excessive maxillary widening, thus eliminating the necessity MSDO.