Related Experiment Video
Updated: Jan 9, 2026
Author Spotlight: Three-Dimensional Cephalometric Landmark Annotation Demonstration on Human Cone Beam Computed Tomography Scans
Published on: September 8, 2023
Association Between Morphological Variations of Mandibular Bone and Pharyngeal Airways: A Morphometric Cone-Beam
Gerardo Martínez-Suarez1, Luis Pablo Cruz-Hervert2,3, S Aída Borges-Yáñez2
1Dentistry, Master's and Doctoral Program in Medical, Dental, and Health Sciences, Universidad Nacional Autónoma de México, Mexico City, MEX.
None:
The 3D relationship between mandibular morphology and the upper pharyngeal airway (UPA) configuration remains unclear. Precise anatomical classification can improve risk stratification for obstructive sleep apnea (OSA) and guide orthodontic or surgical interventions.
Objective:
To identify the association between form variations of the mandibular bone and pharyngeal airways using cone-beam computed tomography (CBCT).
Methods:
This cross-sectional study included 282 CBCT records (aged 9-50 years). Thirty-two mandibular and 20 UPA landmarks were digitized in 3D. Raw landmark coordinates were analyzed without Procrustes adjustment and re-centered at mandibular landmark 2 to preserve the size and spatial position. Exploratory factor analysis (EFA) with VARIMAX rotation was performed, and three latent dimensions were retained for each structure. Based on these factors, hierarchical cluster analysis identified three mandibular and three UPA phenotypes. Multinomial logistic regression adjusted for age, sex, and skeletal class was used to quantify the associations between the mandibular and airway groups.
Results:
Mandibular factors explained 95.7% of the morphological variance, and UPA factors explained 99.3%. Md-G1 and Md-G2 exhibited vertical growth with narrow basal widths, whereas Md-G3 showed a broad horizontal pattern. The UPA groups differed mainly at the oropharyngeal level: UPA1 displayed mid-level transverse constriction, UPA2 showed generalized anteroposterior narrowing, and UPA3 maintained a wide and nearly circular lumen. Compared to Md-G3, Md-G1 was associated with a higher probability of UPA1 (relative risk ratio (RRR)=2.60; 95% CI: 0.94-7.23; p=0.066) and UPA2 (RR=2.96; 95% CI: 1.18-7.45; p=0.021). Md-G2 also correlated with UPA1 (RR=2.81; 95% CI: 1.02-7.78; p=0.045). Age contributed to an increased likelihood of UPA2 in older groups, while skeletal class II showed no significant association with UPA2 (RR=1.83; p=0.214). Sex differences were not statistically significant.
Conclusions:
3D morphometric and cluster analyses suggested an association between mandibular and UPA phenotypes. Vertical and narrow mandibular patterns (Md-G1, Md-G2) were linked to airway narrowing (UPA1, UPA2), whereas broad horizontal morphologies (Md-G3) corresponded to a wider airway (UPA3). These findings suggest that mandibular morphology may serve as a structural indicator of airway risk.
