Three-dimensional analysis of upper airways in Class II malocclusion children with obstructive sleep apnea

Morphometric evaluation of upper airways helps in identifying potential craniofacial anatomy that may predispose to pediatric obstructive sleep apnea (OSA). This study evaluated upper airway parameters three-dimensionally in children with OSA, with Class II malocclusion and a retrognathic mandible, to identify cutoff values for cone-beam computed tomography measurements that may predict the presence and severity of pediatric OSA.

The study comprised 47 growing children with OSA with Class II malocclusion and 47 low-risk OSA-matched controls. Upper airway was segmented into nasopharynx, oropharynx, and hypopharynx using cone-beam computed tomography and MIMICS16.0 software. Parameters included volume, minimum cross-sectional area (CSA_min), anterioposterior and lateral distances of CSA_min, and upper airway length.

The volume, cross-sectional area (CSA_min), and anteroposterior and lateral distances of CSA_min were significantly decreased at the level of the oropharynx in patients with OSA. At the level of the hypopharynx, CSA_min was significantly narrower and upper airway length was significantly increased in patients with OSA. OSA predictive cutoff values were proposed as 41.36 mm² CSA_min at the level of oropharynx, 52.45 mm² CSA_min at the level of hypopharynx, and 55.47 mm upper airway length. Only CSA_min at the level of the oropharynx had an independent association with OSA severity (P = 0.021).

Significant differences were found in the upper airway parameters of children with OSA compared with corresponding controls. CSA_min may represent part of the issues that play a role in the pathogenesis of OSA and may serve as a predictive of disease severity.