Thesis (M.S.)--University of Michigan, 1990.

Thesis (M.S.)--University of Michigan, 2006. / Includes bibliographical references (leaves 86-93).

Thesis (M.S.)--West Virginia University, 2010. / Title from document title page. Document formatted into pages; contains x, 107 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 87-96).

Introduction: In order to properly diagnose and treatment plan, an orthodontist needs to be knowledgeable about the changes that occur to the maxillary and mandibular dental arches throughout growth. The purpose of this study is to provide an analysis of morphological shape differences seen in the maxillary and mandibular dental arches individually, as well as together, from birth to 3 years of age. Methods: Dental casts from the Iowa Infant Growth study ranging from 2 months to age 4 were photographed in the occlusal plane. The images were landmarked with 3 standard landmarks and 10 sliding semi-landmarks along the curvature of the maxillary and mandibular arches. TpsRelW was used to slide the semi-landmarks and superimpose the date to facilitate shape analysis. MorphoJ was used to determine the degree to which size influences dental arch shape. Once the effects of allometry had been removed, a principal component analysis was run on the residuals to display major features of shape variation in the dataset. Finally, a two block partial least squares analysis was run to determine the degree to which the maxillary and mandibular arches were integrated throughout early growth. Results: Allometry accounts for 9.63% of symmetric shape variation in the maxilla, while it accounts for 56% of symmetric shape variation in the mandible. Asymmetric shape variation is independent of allometry as it only affects 0.34% of the maxillary and 1.46% of the mandibular shape variation. Principal component one accounts for over 60% of all shape variation seen in maxillary and mandibular residuals. Principal component one of symmetric residuals results in a longer, wider dental arch or a shorter, narrower one. Principal component one of asymmetric residuals results in a dental arch with one posterior side being longer and wider while the contralateral side is shorter and narrower. The first three time points (2 months- 1 year) do not display significant integration between the maxillary and mandibular arches. Integration increases with age, displaying significant integration at the last three time points, with the most integration being displayed at 2.5 years. Conclusions: Allometry affects some of the symmetric shape variation in the maxilla, but over half of the symmetric shape variation in the mandible. The asymmetric components are independent of allometry. Integration of the maxillary and mandibular arches increase with age from 2 months to 3 years, peaking at a time point of 2.5 years.

Orientador: Francisco Antônio Bertoz / Banca: Eduardo César Almada Santos / Banca: Marcos Rogério de Mendonça / Banca: Terumi Okada Ozawa / Banca: Daniela Gamba Garib / Resumo: Introdução: O objetivo do presente estudo clínico foi avaliar as dimensões transversais do arco dentário inferior com o uso da placa lábio-ativa aberta e fixa associada à extensão lingual de canino decíduo a primeiro molar permanente. Métodos: A amostra constou de 14 pacientes no estágio de dentadura mista e com idade média de oito anos e seis meses. Todos os pacientes realizaram expansão rápida da maxila e expansão lenta do arco inferior com a placa lábio-ativa. Modelos de gesso foram obtidos nas fases de pré-tratamento e pós-tratamento e digitalizados com auxílio do scanner 3Shape R700 3D (3Shape A/S, Copenhagen, Dinamarca). Medições transversais foram realizadas para as distâncias entre as pontas de cúspide dos caninos decíduos, pontas de cúspide mesiovestibulares dos molares decíduos e primeiro molar permanente e pontos médio cervical da face vestibular. O teste t foi utilizado para determinar se o aumento nas larguras transversais foi significativo. Resultados: Observou-se um aumento transversal estatisticamente significativo (p<0,05) que variou de 4,11mm a 4,51mm nos referenciais utilizados no nível das pontas de cúspide. Conclusão: A placa lábio-ativa aberta e fixa apresentou um efeito transversal significativo em aproximadamente seis meses de tratamento / Abstract: Introduction: The aim of the current clinical study was to evaluate the transverse dimensions of the lower dental arch with the use of the fixed and expanded lip bumper associated to the lingual extension from the deciduous canine to the permanent first molar. Methods: The sample was comprised of 14 patients in the mixed dentition with a mean age of 8 years 6 months. All patients were submitted to rapid palatal expansion and dentolaveolar expansion of the lower dental arch with a lip bumper. Pre-teatment and post-treatment cast models were obtained and digitized with the 3Shape R700 3D (3Shape A/S, Copenhagen, Denmark) scanner. Transverse distances between the cusp tips of the canines, the mesial buccal cusps of the deciduous molars and of the permanent first molars and between the cervical middle points of the buccal aspects of these teeth were measured. The t tests were performed to determine whether an increase in transverse distances was significant. Results: A statistically significant transverse increase (p<0,05) ranging from 4.11 mm to 4.51 mm was observed in the cusp tips. Conclusion: The fixed and expanded lip bumper presented a significant transverse effect within approximately 6 months of treatment / Doutor

OBJECTIVES: The objective of this research is to evaluate variation of mandibular arch forms at different heights and to determine if there is any correlation between occlusal arch and sub-gingival arch forms. METHODS: 44 subjects were selected based on the inclusion criteria and their CBCTs then were imported to Mimics software (Materialise NV, Belgium) and traced. Each tooth was sliced midsection at 4 different heights: Occlusal, CEJ, Apex and 5mm apical to the apex. At occlusal level the midpoint of the crown was calculated mesiodistally as well as buccolingually. Subsequently, midpoints between the buccal and lingual plates were located for every tooth between and including the first molars. The points were connected forming 4 splines, which then were exported to Geomorph software (cran.r-project.org, Geomorph package, Dean Adams author, Iowa State 2015) for shape statistical analysis. RESULTS: The variation in the arch form among subjects is significantly smaller in the Occlusal and CEJ level. The variation at apical and basal bone levels are higher than the variation at CEJ and occlusal levels. However, variation between apical and basal bone levels are minimal. CONCLUSIONS: Mandibular dental arch form demonstrate more variation apically. It may be concluded that dental arch form variation should be considered when using standardized arch forms for different patients. The subgingival arch forms cannot be predicted from occlusal arch form. Occlusal arch shape and form may not be an indication of basal bone arch form. More information needed for detection of correlation between occlusal arch and sub-gingival arch forms.

No description available.

Thesis (M.D.S.)--University of Hong Kong, 1990. / Includes bibliographical references. Also available in print.

Thesis (M.D.S.)--University of Adelaide, Dept. of Dentistry, 1991. / Includes bibliographical references (leaves 121-129).

Thesis (M.S.)--University of Michigan, 1981.