Associations of tongue and hyoid position, tongue volume, and pharyngeal airway dimensions with various dentoskeletal growth patterns

Objective: This study investigated the association between tongue and hyoid position, tongue volume, and pharyngeal airway dimensions with craniofacial growth patterns in the sagittal, vertical, and transverse planes. Methods: Cone beam computed tomography was used to assess 185 non-growing subjects (mean age, 28.7 ± 9.5 years). Multivariate linear regression analyses evaluated relationships between tongue and airway variables, and cephalometric/dental arch measurements. Results: Class III skeletal patterns—reflected by lower ANB and higher APDI—were significantly correlated with anteriorly positioned hyoids (ANB: β = 0.249; APDI: β = –0.291), and lower tongue positions at the tongue tip (ANB: β = –0.231; APDI: β = 0.166) and in the posterior area (ANB: β = –0.186; APDI: β = 0.196), and greater tongue volume (APDI: β = 0.174). Hyperdivergent vertical patterns—indicated by a lower ODI—were significantly correlated with a lower tongue tip position (β = –0.311) and posterior tongue position (β = –0.230). Regarding transverse dimensions, tongue volume showed positive correlations with upper intermolar width (β = 0.349), lower intercanine width (β = 0.130), lower intermolar width (β = 0.311), and a negative correlation with upper intercanine width (β = –0.299). Conclusions: Sagittal and vertical craniofacial patterns are interrelated and show associations with tongue and hyoid position, as well as tongue volume. Transverse dental arch dimensions are correlated not only with tongue position and volume but also with pharyngeal airway volume.