Anatomical analysis to establish the optimal positioning of an osteotomy for genioglossal advancement: a trial in cadavers.

Genioglossal advancement, which is one of the treatments for obstructive sleep apnoea, can be effective only if it contains enough genial tubercle for an osteotomy. The aim of this study was to establish the position of the genial tubercle and of the optimal osteotomy during genioglossal advancement. Twenty-four adult cadavers with intact bony mandibular structures were included. Five variables were measured: the width and height of the genial tubercle (GTW); the distance from its inferior border to the inferior border of the mandible (IGT-IBM); the distance from the superior border of the genial tubercle to the inferior border of the mandible (SGT-IBM); and the width of the intermental foramen (IMFW). The following mean (SD) (range) measurements were obtained: GTW 7.38 (1.43) (4.5-10.0); GTH 7.94 (1.45) (5.0-10.0); IGT-IBM 7.96 (2.29) (4.0-12.0); SGT-IBM 15.90 (2.29) (12.0-20.0); and IMFW 56.65 (6.44) (43.0-67.0) mm. Of the 24 cadavers, 22 showed evidence of optimal positioning when the osteotomy was placed 2mm higher than the SGT-IBM measured on the inner table. This suggests that an optimal osteotomy, which includes the genial tubercle, may be possible in most patients when the osteotomy is positioned 2mm higher at the SGT-IBM.