Analysis of Bolton's tooth size discrepancy for a referred UK population

R Medicine > RK Dentistry

Muqbil, Insigam ; Rock, Peter

University:University of Birmingham

Department:School of Dentistry

关键词: R Medicine;    RK Dentistry;   

Others  :  http://etheses.bham.ac.uk//id/eprint/539/5/Muqbil10MPhil_A1a.pdf

来源: University of Birmingham eTheses Repository

【 摘 要 】

Objectives The aims of this study are: • To study the incidence of tooth size discrepancy in a UK population • To establish whether there are differences between males and females. • To assess racial differences for tooth size discrepancies in different malocclusion categories. Malocclusion groups included: Class I, Class II division 1, Class II division II, Class III Racial groups included: Caucasian, Asian, Afro-Caribbean Method A retrospective study using dental casts of patients in the orthodontic departments of Birmingham Dental Hospital and Kings College Hospital, London. 30 sets of casts were assessed from each malocclusion group for each race. i.e 30 Class I Caucasian, 30 Class I Asian, 30 Class I Afro-Caribbean, with an equal male to female ratio. In total 360 dental casts were used. Mesiodistal tooth dimensions were measured from right first molar to left first molar in the maxillary and mandibular arches. Measurements were taken using HATS digital callipers accurate to 0.1mm. Anterior and overall Bolton discrepancies were calculated for each model. Results Gender Significant differences between males and females for the overall ratio only existed for the Class II/I Afro-Carribean group. There were significant differences in the anterior ratio for all the racial groups with Class III malocclusion, and for Class I Asian and Class II/II Afro-Carribeans. Malocclusion group There were significant differences between the means of the malocclusion groups for the combined overall and anterior ratios. These differences arose because of the differences between the Class III subjects and the remaining malocclusion groups. There was also a significant difference in the anterior ratio in the Asian subjects due to the difference between the Class I and Class III groups. Race Significant differences only arose in the anterior ratio of the Class I group due to the differences between the Asian and the Caucasian groups. No significant differences were found in the combined overall or anterior ratios. Conclusion Differences between males and females existed mainly in the anterior ratio for the Class III groups. The Class III groups showed significantly higher combined overall and anterior ratios, compared to the other malocclusion groups. In addition the anterior ratio of the Asian group was higher in Class III than Class I subjects, indicating mandibular tooth size excess in Class III subjects. No significant differences were found when comparing racial groups, except the anterior ratio of the Class I Caucasian group was significantly greater than the Class I Asian group.