clinical symptoms and overall quality of life.

Traditional approaches have focused on bimaxillary surgery or single mandibular surgery, specically man­dibular advancement to improve retrolingual airway space. However, recent studies have sought to under­stand the role of improving OSA via maxillary orthog­nathic surgery procedures. Orthopedic procedures such as rapid maxillary expansion (RME) [29–35] in children and surgical assisted rapid palatal expansion (SARPE) [14, 36–39] or segmental Lefort surgery in adults dem­onstrate improvements in OSA. The mechanism by which AHI is improved is likely due to widening of the nasal oor which widens the nasal cavity [29, 30, 33]. This decreases the nasal resistance to airow reducing obligate mouth breathing which has been shown to be a contributing factor to abnormal dentofacial develop­ment [40]. Additionally, a pathologically constricted maxillary arch does not allow for a normal tongue pos­ture contributing to a posterior and inferior tongue position [41]. Normalizing maxillary arch width and increasing the horizontal dimension of the dentoalveo­lar framework, allows the tongue enough space within the dentoalveolar process. This new tongue posture improves pharyngeal airway [35] and even improves the airway dimension in the lower airway near the epiglottis [14]. In addition to tongue position, correction and wid­ening of the skeletal landmarks, the surrounding soft tissue anatomy of the airway responds in kind. Maxillary advancement pulls the velum and velopharyngeal mus­cles forward which results in less tension [7, 19, 27].