Knowledge of the pathophysiology of obstructive sleep apnea (OSA) in patients undergoing orthognathic surgery for correction of Class III skeletal malformations and compensatory mechanisms has been studied to achieve greater progress with the advent of computerized axial tomography providing three-dimensional elements previously described two-dimensional changes in lateral skull radiographs, the studies have not evaluated the volumetric changes of intraoral and pharyngeal airspace and it is possible that the narrowing of one of these planes is compensated by the extension of another or who are variations in the vertical or to reduce one of these spaces also reduce the other planes, directly compromising the ability of the airspace. Objective to correlate volumetric changes of upper airway before and after the Mandibular orthognathic surgery and Jaw for the correction of skeletal Class III malocclusion with the presence or exacerbation of respiratory disorders associated with sleep.

Design: Descriptive population: Adult patients, interfere to bimaxillary surgery (maxillary advancement and mandibular setback) or Monomaxilar Dismorfosis for the correction of skeletal Class III type in the Hopital Universitario San Vicente de Paul.

Evaluation by ENT patients, review pre-operative diagnostic aids, examination for signs and symptoms of increased resistance of the airway such as snoring, mouth breathing, treatment for acute or chronic diseases of the airways, breathing habits individuals, etc., application Epworth scale and severity of snoring.

Conflict of interest: None declared.