Influence of occlusal plane inclination on static position and dynamic behavior of the hyoid bone

The relationship between occlusal plane inclination and the position and dynamic behavior of the hyoid bone remains unclear despite the hyoid bone's critical role in oral and airway functions.

This study aimed to investigate the influence of occlusal plane inclination on both the static position and dynamic behavior of the hyoid bone.

Cephalometric analysis evaluated the spatial relationship between the hyoid bone and the cranial base in the intercuspal position and mouth-opening positions. Correlations between occlusal plane inclination and hyoid-related parameters were analyzed using the Pearson or Spearman correlation coefficients, with partial correlation adjusted for age and number of missing posterior teeth.

In the static evaluation, the occlusal plane inclination correlated positively with the cranial base-hyoid angle (∠CB-Hy), indicating that steeper planes were associated with a more posterior hyoid position. In dynamic evaluation, changes in the mandibular base hyoid angle (∠MB-Hy) showed a significant negative correlation with occlusal plane inclination (P=.007). Occlusal plane morphology also corresponded with differences in mandibular and hyoid movement.

Occlusal plane inclination affected both static alignment and dynamic movement of the hyoid bone, potentially influencing airway patency and oral function. Integrating these findings should contribute to prosthodontic diagnosis, treatment planning, and clinical practice.