Comparative Assessment of Nasal, Nasopharyngeal and Pharyngeal Dimensions as Correlates of Obstructive Sleep Apnea in Adults: A Cross-Sectional Cone-Beam Computed Tomography Study Tomography Study

Abstract Background/Objectives: Studies of craniofacial contributors to obstructive sleep apnea (OSA) have focused predominantly on pharyngeal volume and minimum cross-sectional area, while the anterior upper airway has received little attention. We aimed to determine whether nasal base width, measured at the horizontal plate of the palatine bone, is associated with OSA status in adults. Methods In this cross-sectional study, 92 consecutive adults (49 with OSA, 43 without) presenting to a private orthodontic practice between January 20246 and June 2026 were evaluated. Nasal base width, minimum and maximum nasal width, PNS-PPW, UPPW, minimum cross-sectional area, upper airway length and the SN-GoMe angle were measured on cone-beam computed tomography volumes. OSA status was established by two nights of seven-channel home sleep apnea testing incorporating electroencephalographic recording. OSA severity was quantified using the apnea-hypopnea index (AHI, all apneas plus hypopneas with ≥ 3% oxygen desaturation/hour). Multivariable logistic regression was adjusted for sex, age and body mass index. Results Nasal base width was not associated with OSA status (OR 1.07 per mm, 95% CI 0.91–1.26, p = 0.386), nor was minimum cross-sectional area (OR 1.00, p = 0.988). In exploratory analyses, PNS-PPW was inversely associated with OSA (OR 0.83 per mm, 95% CI 0.73–0.95, p = 0.008; marginal effect − 3.5 percentage points per mm), with an area under the curve of 0.77. The association persisted after exclusion of influential observations and under bootstrap resampling. No other dimension was associated with OSA status. Conclusions Nasal base width did not discriminate OSA status in this sample. Sagittal nasopharyngeal depth at the posterior nasal spine warrants prospective evaluation.