A study on the position of tongue and hyoid bone in relation to vertical facial patterns in skeletal Class III malocclusion / 대한치과교정학회지

ABSTRACT

The purpose of this study was to evaluate the position of tongue and hyoid bone in relation to vertical facial patterns in the adult and child. Lateral cephalograms taken in adults(63 cases, 11.7 years in average age) and children(69 cases, 22.6 years in average age) were traced and measured about position and posture of tongue and hyoid bone using the horizontal and vertical reference lines. The angle of mandibular plane to SN plane was employed to classify the samples into groups of hypodivergent and hyperdivergent. The comparison of the tongue/hyoid bone measurements between hypodivergent group and hyperdivergent group in the adult and child were statistically executed with Student's t-test. The results were as follows; 1. The tongue height was lower in the hyperdivergent group than in hypodivergent group, and higher in children than in adults. 2. The vertical height of hyoid bone was higher in hypodivergent group than in hyperdivergent group and also higher in children than in adults. 3. The anteroposterior position was of no significant difference in relation to age or vertical facial pattern. 4. The inclination of hyoid bone in relation to cranial base was steeper in children than in adults.