A CBCT Morphometric Study of Hyoid Bone According to Skeletal and Breathing Patterns Using Multi-Factor Robust ANOVA

Area of Science:

• Anatomy
• Craniofacial Development
• Biometrics

Background:

• The hyoid bone is crucial for swallowing, speech, and airway maintenance.
• Hyoid bone morphology can be influenced by various anatomical and functional factors.
• Understanding these influences is key to understanding craniofacial development and function.

Purpose of the Study:

• To investigate how skeletal class, respiratory mode, age, and sex affect hyoid bone morphometrics.
• To utilize cone-beam computed tomography (CBCT) for precise hyoid bone analysis.
• To identify specific morphometric variations linked to different influencing parameters.

Main Methods:

• Retrospective analysis of 560 CBCT scans (295 female, 265 male; ages 8-73).
• Measurement of hyoid angle, horizontal length, and vertical height using Dolphin 3D software.
• Categorization by skeletal class (I, II, III), breathing pattern (nasal/oral), and age group; statistical analysis via ANOVA and post hoc tests.

Main Results:

• In females, nasal breathers showed significantly larger hyoid angles and vertical heights than oral breathers (p < 0.001).
• In males, age and breathing mode significantly impacted hyoid angle and vertical length (p < 0.001).
• Skeletal Class I had significantly greater vertical height than Class III (p = 0.008); significant respiration-skeletal class interaction noted in females (p = 0.029).

Conclusions:

• Hyoid bone morphology is significantly influenced by age, breathing pattern, and skeletal class, with notable sex-specific differences.
• Nasal breathing and younger age are associated with more favorable hyoid bone positioning for airway stability.
• These findings have implications for understanding craniofacial development and potential airway issues.