LAUSR

Purpose This study aims to evaluate the morphology of the genial tubercle (GT) and lingual foramen (LF) between obstructive sleep apnea (OSA) and non-OSA patients for considerations of mandibular advancement surgery. Methods Cone beam CT records of 198 patients were retrospectively collected and analyzed. Five variables were measured for genial tubercle; anterior mandible thickness (AMT), the distance from the lower incisors to the superior border of the genial tubercle, the distance from the inferior border of the genial tubercle to inferior border of the mandible, the height of GT, and genial tubercle width. Lingual foramen were classified according to the genial tubercle. The frequencies, distances of lingual foramen to alveolar crest, lower border of mandible (LVDL) and diameter of LF were also measured. Results Significant differences was found for genial tubercle width, anterior mandible thickness, and the distance of lower mandibular border to the midline lingual foramina between OSA and non-OSA patients ( p  < 0.05). AMT gets thicker and GT gets narrower in OSA patients ( p  < 0.05). A linear regression analysis on the apnea hypopnea index with measured anatomical variables showed the LVDL ( R   =  − 0.355*), body mass index ( R   =  0.254), and age ( R   =  0.33) showed a statistically significant association ( p  < 0.05). None of the other variables reached formal significance. Conclusion LVDL is linearly associated with sleep apnea severity. The variable dimensions and anatomy of genial tubercle as well as lingual foramen for OSA patients suggest the need of 3D preoperative radiological evaluation before genioglossus advancement surgery. Cone beam CT can be a powerful low radiation dose tool both for evaluating the anatomy of the upper airway and mandibular structures at the same time for OSA patients.