CEPHALOMETRIC PREDICTORS FOR ORTHOPEDIC MANDIBULAR ADVANCEMENT IN OBSTRUCTIVE SLEEP-APNEA

The cephalometric analysis of two groups: 30 sleep apnoea patients, an d 30 age- and sex-matched control patients, established predictors for the orthopaedic mandibular advancement by means of the Esmarch device (ED) in treating obstructive sleep apnoea (OSA). Polysomnographic sle ep and ventilation data gathered for each patient with and without man dibular advancement by means of the ED were compared. Cephalometric da ta and treatment efficacy for each patient were submitted to a regress ion analysis. Maximal efficacy is predicted by: 1. The combination of an orthognathic to prognathic maxilla (SNA larger than or equal to 83 degrees) with an orthognathic to retrognathic mandible (SNB less than or equal to 77 degrees) 2. An anterior superior displacement of the ma ndible, with the supramentale situated at a distance from the anterior part of second cervical vertebra (B-HWK 2 longer than or equal to 95. 5 mm) and a narrow angle between the skull and the mandibular ramus (S NIB-Go equal to or less than 1.5 degrees) 3. Short oral height (TB-PNS equal to or less than 35.5 mm), with the uvula not extending beyond t he tongue base (UT-PNS, equal to or less than 30 mm). 4. A narrow orop harynx (PAS equal to or less than 3.4 mm). The narrower the SNB-angle, the wider the SNA-angle, and the shorter the uvula, the more effectiv e the device.