Effect of Mandibular Advancement Surgery on Tongue Length and Height and Its Correlation with Upper Airway Dimensions.

Abstract

The spatial position and dimensions of oral and pharyngeal soft tissues change post-mandibular advancement (MA) surgery which involves changes in position of soft palate, tongue and associated musculature. There is no study which simultaneously evaluates changes in tongue length and height post-MA surgery and correlates these changes with changes in upper airway dimensions and the amount of MA. Treatment records of 18 patients that underwent MA with bilateral sagittal split ramus osteotomy were evaluated at T1 (01week before surgery) and T2 (06months post-surgery). Linear airway and tongue measurements were done on lateral cephalogram. Mean volume and mean pharyngeal area values were recorded from the acoustic pharyngometry (AP) records of patients. A statistically significant increase in tongue length (P value < 0.001) and nonsignificant change in tongue height were observed at T2 (P value > 0.05). A statistically significant increase in airway parameters recorded on both lateral cephalogram and AP was observed at T2 (P value < 0.001). Correlation analysis did not show a statistically significant correlation of change in tongue length and tongue height at T2 with the amount of MA, change in airway parameters on lateral cephalogram and AP (P value > 0.05). Mandibular advancement surgery is a viable option for improvement in pharyngeal airway in skeletal Class II patients with retrognathic mandible. Changes in tongue length observed in our study may correspond to the stretch of protruders of tongue, especially genioglossus, and may point toward possible relapse on a long-term follow-up.