Outcomes of multilevel upper airway surgery, including tongue base resection, in patients with torus mandibularis

By affecting the tongue position and oropharyngeal airway volume, torus mandibularis is an anatomical factor associated with obstructive sleep apnea (OSA). This study aimed to investigate the influence of torus mandibularis on the surgical outcomes of multilevel upper airway surgery with tongue base resection (TBR) in patients with OSA. Patients with OSA who underwent palatal surgery and TBR were retrospectively analyzed. The patients were divided into two groups according to the presence or absence of torus mandibularis upon physical examination or on computed tomography images. The anatomical characteristics of the upper airway and pre/postoperative polysomnography were analyzed. The control and torus mandibularis groups comprised 69 and 35 patients, respectively, with all of them showing improved sleep quality after surgery. Apnea-hypopnea index (AHI) scores decreased from 42.1 ± 22.2 preoperatively to 23.9 ± 21.4 postoperatively in the control group (p 0.001), and from 45.2 ± 19.9 to 22.5 ± 13.5 in the torus mandibularis group (p 0.001). Comparing the postoperative changes in AHI, the AHI of the torus mandibularis group improved by 22.7 ± 23.4, whereas that of the control group improved by 18.1 ± 19.6 (p = 0.296). Sleep efficiency improved from 90.0 ± 7.5 to 92.8 ± 6.8 in the control group, and from 90.3 ± 8.7 to 93.6 ± 6.5 in the torus mandibularis group; however, there was no statistical difference between the two groups (p = 0.816). The presence of torus mandibularis did not appear to significantly affect the surgical results in OSA patients, but it did elicit significant changes in polysomnographic parameters compared with the control group. Therefore, following the identification of torus mandibularis in OSA patients, TBR should be considered as part of planning, as it may help to predict surgical outcomes.