Cranial Base Characteristics in Adults with Obstructive Sleep Apnoea and Matched Controls: A Retrospective CBCT Study

This study aimed to investigate cranial base and clival morphology using cone-beam computed tomography (CBCT) in patients with obstructive sleep apnoea (OSA) and matched controls, with particular emphasis on angular measurements and anatomical variations of the clivus and surrounding structures.

CBCT scans of 73 OSA patients and 73 age- and sex-matched controls were retrospectively evaluated. The skull base angle (SBA) and clivus angle (CA) were measured, and anatomical variants, including sphenoid sinus pneumatization types, sella turcica morphology, fossa navicularis magna (FNM), canalis basilaris medianus (CBM), and craniopharyngeal canal (CPC), were assessed. Group comparisons and regression analyses were performed to identify associations between these parameters and apnoea-hypopnea index (AHI).

Compared with controls, patients with OSA exhibited a significantly smaller SBA and a significantly larger CA (both p < 0.001). The distribution of sphenoid sinus pneumatization patterns differed significantly between the groups (p = 0.018). Presellar sphenoid sinus pneumatization was more frequent in the OSA group. Post-sellar pneumatization was the predominant pattern in both groups and was more frequent in controls. No significant differences were observed in sella turcica morphology, CBM, or FNM between groups. The CPC was not detected in any participant.

CBCT-based evaluation demonstrated that adults with OSA had a smaller cranial base angle, a larger clivus angle, and more frequent sphenoid sinus pneumatization anterior to the sella turcica compared with matched controls. Although these findings should be interpreted within a multifactorial framework, their assessment may provide complementary anatomical information in the radiologic evaluation of OSA.

This study presents a CBCT-based assessment of cranial base characteristics in adults with OSA, identifying angular features and anatomical variants that may be associated with upper airway narrowing. These findings suggest a potential role for cranial base configuration in OSA risk assessment, particularly in patients without overt maxillofacial abnormalities.