Author Description

This dissertation, "Functional Appliance Therapy and Upper Airway Dimensions" by Min, Gu,, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: The aim of this study was to investigate the effects of functional appliance therapy on the upper airway dimensions of Chinese children. Firstly, associations between craniofacial characteristics and daytime sleepiness (a symptom of sleep disordered breathing [SDB]) were identified in an orthodontic clinic. The extra- and intra-oral craniofacial characteristics, and a self-completed Paediatric Daytime Sleepiness Scale were recorded in a group of 265 Chinese adolescents aged 11-17 years. The data demonstrated that a bilateral Class II molar relationship, increased overjet, hypertrophic tonsils and a relatively large tongue were positively associated with daytime sleepiness. The results implied that Class II malocclusion was a risk factor of SDB. Secondly, to derive upper airway cephalometric norms for Chinese children, lateral cephalograms of 425 randomly selected 12-year-old Chinese children from 10 schools in Hong Kong were used to establish sex-specific cephalometric norms for the upper airway. Ethnic and age differences were determined by comparing the norms with the results of 108 12-year-old Caucasian children and 74 Chinese adults, respectively. Thirdly, a retrospective study was conducted to investigate the effects of Herbst appliance therapy on the upper airway of different sexes. Pre- and post-treatment lateral cephalograms from 44 Herbst-treated adolescents were analysed. Longitudinal cephalometric data of 34 untreated adolescents were used as gro