Correlation of transverse mandibular dimension with naso-pharyngeal and oro-pharyngeal airway using computed tomographic analysis – A retrospective observational study

Abstract

Purpose: The aim of the study was to investigate changes in the naso-pharyngeal and oro-pharyngeal airway with varying degrees of mandibular flare. Methods: The investigators implemented a retrospective, observational study including CT data from patients fitting the inclusion criteria. Linear and angular measurements were used to assess the flare and transverse dimension of the mandible, while standard reference planes were used for assessment of airway dimensions. The primary outcome measures were to correlate and quantify the naso-pharyngeal and oro-pharyngeal volumes with mandibular flare. Secondary outcome measures were to study the intra-variable correlation. Significance level was fixed at 5% (α = 0.05). Results: The sample included CT data from 30 individuals with apparently normal craniofacial skeleton (53% males and 46.7% female with a mean age of 29.53 years). Both nasopharyngeal and oropharyngeal volumes demonstrated moderate positive correlations with inter-condylar width (p = 0.020 and p = 0.038) and inter-condylar angles (p = 0.041 and p = 0.005) respectively. Linear regression modelling demonstrated that for every millimetre increase of the Inter-condylar width, the naso-pharyngeal and oro-pharyngeal airway volume increased by 0.423 cm3 (p = 0.020) and 0.381 cm3 (p = 0.038) respectively, and every degree increase of inter-condylar angle produced an increase the nasopharyngeal and oropharyngeal volumes by 0.376cm3 (p = 0.041) and 0.496cm3 (p = 0.005) respectively. Conclusion: Parameters of mandibular flare demonstrate statistically significant correlation to pharyngeal airway volume, which may be a relevant predictor to evaluate airway in patients undergoing corrective skeletal surgery.