Prevalence of maxillary sinus hypoplasia and association with variations in the sinonasal complex: a cone beam CT study.

Objective: Understanding of maxillary sinus hypoplasia (MSH) and associated sinonasal variants is paramount to the diagnostic and therapeutic success of maxillary sinus and maxillary dental implant surgery. The purpose of this work was to explore the prevalence of MSH, frequency of mucosal thickening, and anatomical variations in the sinonasal complex.

Methods: Retrospective case-control design based on cone beam CT images of dental patients with MSH and matched for age and gender. MSH type and sinonasal variables were recorded.

Results: One thousand three hundred seventy cone beam CT scans were analyzed for MSH. MSH prevalence was 6% (n=82), matched with 82 controls= 100 females and 64 males, mean age 37.1±14.1 years. Most MSH were type I, 69.5%, 80.5% unilateral, 65.9% associated with no or mild mucosal thickening. Associated sinonasal anatomical variations were <27% except for deviated/hyperplastic (DH) meatus, 48.8%. Within the MSH group, significant associations were presented between MSH type, mucosal thickening, and DH nasal meatus. MSH group vs controls showed a significant difference in mucosal thickening (OR 5.2, 95% CI 2.0-17.3) and DH meatus (OR 1.6, 95% CI 1.4-2.1).

Conclusions: A hypoplastic maxillary sinus with abnormal or absent uncinate process is associated with advanced mucosal thickening and may present with altered anatomy of the lateral wall of the nasal cavity causing its approximation to the orbital floor.

Clinical Relevance: Pre-surgical knowledge of altered anatomy in the sinonasal complex is crucial in dental implant or sinus surgery.