Full text
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| Author(s): |
Karina Santana Cruz
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Bauru. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Odontologia de Bauru (FOB/SDB) |
| Defense date: | 2000-04-10 |
| Examining board members: |
Guilherme dos Reis Pereira Janson;
Pedro Paulo Costa Gondim;
Jose Fernando Castanha Henriques
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| Advisor: | Guilherme dos Reis Pereira Janson |
| Abstract | |
The objective of this work was to evaluate the dentoskeletal changes consequent to orthodontic treatment in subjects with Angle's Class II subdivision malocclusions, treated with asymmetric extractions, as compared to a normal occlusion control group. The sample consisted of three groups, with 30 subjects in each: group 1 consisted of untreated Class II, subdivision subjects; group 2 had Class II, subdivision subjects after treatment with asymmetric extractions and group 3 consisted of normal occlusion subjects. All possessed a full complement of permanent teeth including first molars, at the beginning of treatment. The average age of subjects was 15.76, 18.57 and 22.42 years in the untreated, in the treated Class II, subdivision groups and in the normal occlusion group, respectively. Measurements of relative difference in spatial position of dental and skeletal bilateral landmarks were obtained from the submentovertex and posteroanterior cephalometric radiographs. The t test for independent samples was used to compare groups 1 and 2 with group 3 at different times. Group 2 was considered to have experienced an improvement if the variables of group 1 that had a statistically significant difference with group 3 were not statistically different from the normal occlusion control sample. Results in the submentovertex radiograph demonstrated that asymmetric extractions in Class II, subdivision malocclusions will accentuate the differences in the anteroposterior positions of right and le ft, upper and lower first molars, as would be expected with this treatment protocol. There were no significant skeletal changes that could be attributed to the treatment approaches investigated nor transversal colateral effects with the asymmetric mechanics employed. It was also demonstrated that treatment of Class II, subdivision malocclusions with asymmetric extractions produced corrections of upper and lower dental midline deviations with the midsaggital line, without canting the occlusal plane as well as any other investigated horizontal plane, in the PA radiograph. Therefore, it was concluded that treatment of Class II, subdivision malocclusions with asymmetric extractions constitute a beneficial approach to this problem. (AU) | |