Position of the Hyoid Bone in Anteroposterior Skeletal Patterns

Abstract

Introduction. Hyoid bone plays a vital role in the craniofacial dynamics. From the maintenance of pharyngeal airway to phonation, deglutition, and mandibular movements, it has multifactorial roles to fulfill. The hyoid bone has a spatial relationship with cranial base, mandible, and cervical vertebrae. This study was performed to determine the position of the hyoid bone in different anteroposterior growth patterns. Materials and Methods. 75 lateral cephalograms belonging to all three sagittal skeletal patterns were evaluated in the study. The angular and linear measurements using 10 variables were made to determine the relationship of the hyoid bone with different craniofacial structures. SPSS was used to calculate the descriptive statistics, mean, and standard deviation of all the linear and angular variables. The analysis of variance (ANOVA) and post hoc test were used to compare the means of linear and angular measurement and multiple comparisons, respectively, at $p<0.05$ significance level. Results. There was no significant difference in the mean angular measurements (NSH and MPH) between the 3 groups ( $p>0.05$ ). Also, the multiple comparisons showed no significant difference between the linear measurements (H-FH, H-MP, H-H′, and H-N). However, there was a significant difference in three linear measurements: H-Rgn, RGN-C3, and C3-H. The values were more in class III subjects, compared to class I and class II. Conclusion. The linear millimetric distance between points H-RGN, RGN-C3, and C3-H which determine the relationship and spatial position of the hyoid bone with the mandible and third cervical vertebrae was statistically significant among groups. The values were more in class III subjects inferring the anterior position of the hyoid bone.