O objetivo desse estudo foi avaliar cefalometricamente a estabilidade do tratamento sem extração da mordida aberta anterior realizado na dentadura permanente, após um período médio de 5 anos do término do tratamento. O grupo experimental consistiu de 21 pacientes que foram tratados com aparelho fixo, técnica de Edgewise, e que foram radiografados em três períodos: no início do tratamento (T1); imediatamente após o término do tratamento (T2); e após 5 anos, em média, do término do tratamento (T3). Foram utilizados dois grupos controle. O primeiro, em idade compatível ao grupo experimental no início do tratamento, serviu apenas para caracterizá-lo. O segundo grupo controle, de oclusão normal, apresentava um acompanhamento longitudinal, compatível ao período pós-tratamento, que foi utilizado para comparação das alterações entre ambos, nesse intervalo de tempo. As diferenças ocorridas entre as fases intra-grupo experimental foram analisadas pelo teste t pareado e as alterações pós-tratamento foram comparadas com as alterações do segundo grupo controle pelo teste t independente. Os resultados demonstraram uma recidiva estatisticamente significante da mordida aberta ao final do período pós-tratamento. Os principais fatores que contribuíram para a recidiva foram o menor desenvolvimento vertical dos incisivos superiores e inferiores, no período póstratamento. Entretanto, 61,9% dos casos tratados apresentaram resultados da correção da mordida aberta “clinicamente estáveis". Nem a magnitude inicial da mordida aberta anterior, nem a quantidade total de correção da má oclusão, mostraram-se correlacionadas com a recidiva do tratamento. / The purpose of this study was to cephalometrically evaluate the longterm stability of anterior open bite non-extraction treatment in the permanent dentition after a mean period of 5 years. The experimental group consisted of 21 patients who had undergone orthodontic treatment with fixed appliances from whom cephalometric headplates were obtained at the pretreatment (T1), posttreatment (T2) and postretention (T3) stages. Two control groups were employed. The first, with a compatible age to the experimental group before treatment, was used only to characterize it. The second control group, with normal occlusion, was longitudinally followed, in a time period compatible to the posttretention period and was used for comparison of the changes between them, during this period. The differences between the observation stages in the experimental group were analyzed with paired t tests and the postretention changes were compared to the changes of the second control group with independent t tests. Results demonstrated a statistically significant relapse of the open bite at the end of the postretention period. The primary factors that contributed for the relapse were the smaller vertical development of the maxillary and mandibular incisors in the postretention period. However, 61,9% of the sample presented a “clinically stable" open bite correction. Neither the pretreatment anterior open bite amount or the magnitude of correction were associated with the long-term stability of the final treatment results.

Introduction: The hyperdivergent facial form is typically characterized by a long lower anterior facial height (LAFH), steep mandibular plane angle, and skeletal open bite. The purpose of our study was to further explore morphologic variation within long LAFH subjects using geometric morphometric methods. Methods: Cephalograms of 147 individuals (n= 147; 87 female, 60 male; age range: 16-68 years) with LAFH to total anterior facial height (TAFH), ratio (LAFH/TAFH), at or above 57.4% were studied. Cluster analysis and canonical variate analysis captured phenotypic variation and identified homogenous groups. Results: Cluster analysis resulted in three discrete long LAFH phenotypes that varied along vertical and anteroposterior dimensions. Conclusions: We found significant morphologic variation within the sample population of long LAFH individuals. Three phenotypes with varied vertical and anteroposterior discrepancies were revealed through the cluster analysis. Within our sample, we found both convergent and divergent facial patterns with concomitant cranial base rotation and posterior ramal border displacement. Vertical variation was largely independent of anteroposterior discrepancies.

Thesis (M.S.)--University of Michigan, 1978.

Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (leaves 184-204).

Thesis (M.S.)--University of Michigan, 1967.

Thesis (M.S.)--University of Michigan, 1983.

Thesis (M.S.)--University of Michigan, 1973.

Thesis (M. Sc.)--University of Alberta, 1996. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--University of Michigan, 1983.

Thesis (M.S.)--University of Michigan, 1978.