Tridimensional analysis of the normal upper airways in non-dentofacial deformity patients

Abstract

Objectives

To establish normative three-dimensional airway measurements in patients without dentofacial deformities (DDFs) or obstructive sleep apnea (OSA), and to identify anatomical and epidemiological factors associated with airway volume.

Methods

This retrospective cross-sectional study analyzed 200 CT scans from patients aged 18–80 years, with no diagnosis of DDF, OSA, or craniofacial syndromes. Scans were processed using artificial intelligence software (NEMOFAB) for automatic segmentation and volumetric analysis. Variables assessed included age, sex, neck circumference, and craniofacial linear distances (Menton–Hyoid, Menton–3rd Vertebrae, PNS–Hyoid, Soft Palate–Hyoid). Airway volume and Minimum Axial Area (MAA) were measured and compared using ANOVA.

Results

The mean airway volume was 24,724.8 mm³. Younger individuals exhibited greater airway volumes, especially among males. Patients with a neck circumference < 40 cm had a 28.04% reduction in airway volume. Longer PNS–Hyoid, SPH, and M3 V distances were positively associated with increased airway volume, while Menton–Hyoid showed minimal impact. A low MAA (< 110 mm²) correlated with a significant volume decrease. Key predictors identified were age, neck circumference, PNS–Hyoid, SPH, and M3 V distances.

Conclusions

In patients without DDF or OSA, airway volume is significantly influenced by demographic and anatomical variables. These normative data provide a baseline for comparison in orthognathic surgical planning and respiratory risk assessment.

Clinical Relevance

Understanding normal airway morphology and its anatomical determinants enhances screening for patients at risk of airway compromise and may guide individualized treatment strategies in oral and maxillofacial surgery.