Effects of an anteriorly titrated mandibular position on awake airway and obstructive sleep apnea severity.

The objective of this study was to investigate whether a reduction of obstructive sleep apnea (OSA) severity was associated with significant upper airway (UA) changes after an anterior titration of the mandibular position. Eighteen OSA patients with a mean (SD) apnea hypopnea index (AHI) of 32.5 (12.3) were recruited. Baseline supine cephalometry was obtained before the initial insertion, and follow-up supine cephalometry was undertaken after titration with a titratable oral appliance in place. The mean AHI before treatment was significantly reduced to 9.7 (7.4) (P <.001) after titration. In 13 responders with AHI reduced to < or =15/h, a significant forward displacement of the anterior wall of the velopharynx (P <.05) was observed. In addition, there was a significant forward displacement of the posterior wall of the oropharynx and the hypopharynx (P <.05). In the 5 nonresponders, no significant changes in the position of the anterior and posterior wall were observed. There was no significant difference in the total amount of mandibular advancement between responders and nonresponders. We conclude that treatment success with oral appliance therapy appears to depend not only on anterior titration of the mandibular position to enlarge the UA, but also on the amount of change in the size of the UA in response to mandibular advancement.