Assessment of Hyoid bone position in different anteroposterior skeletal relationships: A Cross Sectional study

Abstract

Introduction: Hyoid bone plays an important role in vital biological functions such as deglutition, breathing and phonation. The relative head and neck position is established by this unique anatomical landmark. The purpose of this study was to assess the position of hyoid bone in different anteroposterior jaw relationships (Class-I / Class-II/ Class III) in patients presenting to orthodontics department of Rehman College of dentistry.

Material and Methods: A total of 50 lateral cephalograms of patients were randomly selected from patient’s records of department. Measurements were taken on software IC Measure version 1.3. After importing the radiographs, the images were digitized on five points for linear and angular measurements. The main outcome measure was the ―hyoid bone position in anteroposterior and vertical dimensions‖ in 3 skeletal classes. The relationship between the variables was assessed by one- way ANOVA test.

Results: Patients in class II had significantly higher mean distance of L1(H-MP) than patients in class III. Moreover, the mean distance L2(H-PP) in class I and III was greater compared to class II. The mean distance L3(H-C3) was greatest in group III (P <0.05). Males had a larger distance L1 (H-MP), (P <0.05) than females. Angular measurements of hyoid bone were not significant among the three classes.

Conclusions: More posterior position of hyoid bone was found in class II, as shown by the smallest horizontal distance (H-C3). The hyoid bone is positioned more superiorly and posteriorly in females compared to males.