Abstract

CARVALHO, Elizete Nejm; NOUER, Darcy Flávio; GARBUI, Ivana Uglik  and  NOUER, Paulo Roberto Aranha. Relationship of the hyoid bone and posterior surface of the tongue for class II division 1 orthodontic patients. RGO, Rev. gaúch. odontol. (Online) [online]. 2013, vol.61, n.1, pp. 61-68. ISSN 1981-8637.

Objective The objective of this study was to evaluate the hyoid bone position in the sagittal and vertical planes, on dolichoprosopic, brachyprosopic and mesoprosopic facial types. Methods Individuals with Angle Class II Division 1 malocclusion were compared with a control group (Class I). Lateral teleradiographs of 45 dark-skinned individuals (experimental group) were selected from the scientific archives of the São Leopoldo Mandic College of Dentistry. The control group comprised 22 dark-skinned individuals with Angle Class I malocclusion, selected from the same archives. The cephalometric distances ANS-PNS, ANS-PH, PT-PoPh, BV-PoPh, AH-PoPh were used for evaluation of hyoid bone position in the sagittal plane; in the vertical plane, the cephalometric distances evaluated were H-SN; H-FH; H-MP; H-PP; H-OP. The intraclass correlation coefficient (ICC) calculated from control group data to evaluate observer reliability was 0.91. Statistical analysis performed using one-way ANOVA and Tukey's test at a 5% level of significance. Results No significant statistical differences were found for the position of the hyoid bone in individuals with Angle Class II Division 1 malocclusion, in both sagittal and vertical planes, when comparing all the facial types. When the groups of individuals with Angle Class I and II malocclusion were compared, differences were statistically significant in relation to the following vertical measurements H-SN; H-FH; H-PP; H-OP. However, there was no significant statistical difference for the H-MP cephalometric distance. Considering the sagittal measurements, only the distance ANS-PNS differed statistically between the groups. Conclusion In accordance with the absence of statistical differences among the facial types, it appears that an adaptation of the tegumentary tissue exists around the hyoid bone.

Keywords : Cephalometry; Hyoid bone; Malocclusion; Angle Class II; Orthodontics; Tongue.