published_or_final_version / Dentistry / Master / Master of Dental Surgery

Orientador: Vânia Célia Vieira de Siqueira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-17T06:12:45Z (GMT). No. of bitstreams: 1 Negreiros_PauloEduardo_M.pdf: 4232544 bytes, checksum: e8434e2474207fec3d2143a9d7c9541f (MD5) Previous issue date: 2000 / Resumo: Em 1884, os craniologistas adotaram o plano horizontal de Frankfurt, determinado pelos pontos Pório esquerdo, Pório direito e pelo ponto Infra-orbitário esquerdo, como sendo a referência que define a posição da cabeça enquanto paralela ao solo. Quando do surgimento da cefalometria, adotaram-se inúmeros pontos, linhas e planos de referência utilizados em craniometria, dentre os quais o plano horizontal de Frankfurt, porém somente com o desenvolvimento do cefalostato, em 1931, a validade do emprego dessas referências passou a ser questionada devido à dificuldade de localização dos pontos Pório e do Orbitário e à grande variabilidade interindividual de inclinação desse plano o que gera interpretações duvidosas nas análises cefalométricas nele baseadas. Dessa maneira a Posição Natural da Cabeça (PNC) associada a uma linha de referência extracraniana tornou-se objeto de interesse tanto para a antropologia quanto para a ortodontia por ser um posicionamento estável para as avaliações da estética facial, para o diagnóstico e para o estudo longitudinal do crescimento craniofacial. Este trabalho objetivou estudar as alterações das grandezas cefalométricas angulares e lineares mais comumente utilizadas em cefalometria, quando a posição natural da cabeça (PNC) é modificada durante a tomada da telerradiografia, sua influência no diagnóstico ortodôntico e a confiabilidade e reprodutibilidade da PNC em tomadas radiográficas sucessivas. Analisou-se 180 telerradiografias tomadas em norma lateral de 30 pacientes do sexo feminino com idade média de 21,3 anos obtidas em duas séries de tomadas radiográficas com intervalo de 15 dias entre as séries. Registrou-se em cada série, a posição natural da cabeça (PNC), a PNC acrescida de 5 graus (PNC+5°) e a PNC com flexão de 5 graus (PNC-5°) de cada paciente. Os resultados obtidos demonstraram que as grandezas lineares S-N, ENA-ENP, CO-Gn, Go-Gn, e as grandezas angulares SNA, ANB, PP.GoGn, l.PP, IMPA, 1.1, SN.VER e HF.VER não apresentaram alterações estatisticamente significantes entre as posições estudadas e entre as séries de tomadas radiográficas. As grandezas angulares SNB, SN.GoGn, FMA, SN.PP, Ângulo Z e a grandeza linear Co-Go apresentaram alterações estatisticamente significantes tanto entre as posições quanto entre séries de tomadas radiográficas, porém sem significância do ponto de vista clínico. Concluiu-se que as medidas angulares e lineares avaliadas não apresentaram alterações significantes quando a posição natural da cabeça modificou-se dentro da faixa de variação angular estudada, o que não conduziu a diagnósticos ou interpretações duvidosas. Devido a baixa variação das angulações dos ângulos SN.VER e HF.VER demonstrou-se que a metodologia empregada com a utilização da Unidade Orientadora de Posicionamento, apresentada neste trabalho, permite a reprodutibilidade da posição natural da cabeça com grande confiabilidade dentro de uma faixa de variação da PNC em ± 5°. / Abstract: Em 1884, craniologists adopted the Frankfurt horizontal plane, determined by the left Porion, right Porion and left Orbitale points, as being the reference that defines the head position while parallel to the soil. When of the appearance of the cephalometry, countless points, lines and reference planes were used in craniometry, among them the Frankfurt horizontal plane. However, only with the development of the cephalostat, in 1931, the validity of the employment of those references became questioned due to the difficulty of location of the Porion and Orbitale points and to the great variability of individual inclination of that plane which lead to doubtful interpretations when used for cephalometric analyses. Therefore, the Natural Head Position (NHP) associated with an extracranial reference line became object of so much interest for the anthropology as for the orthodontics due to a stable positioning for the evaluations of the facial aesthetics, diagnosis and for the longitudinal study of the craniofacial growth. This work aimed to study the alterations of angular and linear cephalometrics measurements more commonly used in cephalometry, when the natural head position (NHP) is modified during the taking of cephalometric radiography, its intluence in the orthodontic diagnosis, and the reliability and reproducibility of NHP for successive radiographs. One hundred and eighty cephalometrics radiographs were taken in lateral norm of 30 female patients with age range of 21,3 years old. The X-ray were obtained in two series within 15 days interval among them. In each of the series, the natural head position (NHP), the NHP added of 5 degrees (NHP+5°) and NHP with 5 degrees of flexion (NHP-5°) were registered from each patient. The obtained results demonstrated that the linear measurements S-N, ENA-ENP, CO-Gn, Go-Gn, and the angular measurements SNA, ANB, PP. GoGn, I.PP, IMP A, 1.1, SN. VER and HF. VER did not present statistically significant alterations among the studied positions and the two series of radiographic taken as well. The angular measurements of SNB, SN.GoGn, FMA, SN.PP, Z Angle and the linear measurements Co-Go presented statistically significant alterations even between the positions themselves as in the two series of radiographs taken, however, without significance on the clinical point of view. It was concluded that the angular and linear measurements appraised did not present significant alterations when the natural head position modified within of the angular variation strip studied, which did not lead to doubtful diagnosis or interpretations. Due to low variation of the angulations of the SN.VER and HF.VER angles, it was demonstrated that the methodology used with the employment of the Guiding Unit of Positioning presented in this work, allows the reproducibility of the natural head position with great reliability within at 5° variation strip of NHP. / Mestrado / Mestre em Ortodontia

Please read the abstract in the section 00front of this document / Dissertation (MChD (Orthodontics))--University of Pretoria, 2007. / Orthodontics / unrestricted

Made available in DSpace on 2016-08-03T16:30:59Z (GMT). No. of bitstreams: 1 SABRINA ROCHA RIBEIRO.pdf: 1398760 bytes, checksum: a6be3e289c3ef7a5a5b2cfa76b4e0008 (MD5) Previous issue date: 2011-12-07 / The objective of this retrospective study was evaluate the prevalence of anomalies in tooth position (palatal ectopic eruption of the maxillary canine, dental transposition, distal angulation of mandibular second premolars, mesial angulation of mandibular permanent second molar and infra-occlusion of deciduous molars), number (supernumerary teeth) and size (microdontia) in patients with permanent tooth agenesis, by comparing them with the rates expected for the general population; in addition, the hypothesis was tested that patients with agenesis of permanent teeth have increased prevalence of enamel hypoplasia. To that end, the sample of this study consisted of 351 patients with agenesis of at least one permanent tooth, ranging between 8 and 30 years of age and with full clinical records. The sample was collected by examining orthodontic records belonging to the archives of a professional institution of specialization in Orthodontics, a dental radiology clinic and private orthodontic practices. Study materials included panoramic and periapical view radiographs, plaster cast models, intra- and extraoral photographs and filled-out medical records. First, the reproducibility of evaluations was analyzed through the rate of concordance using the Kappa test, at a 95% confidence interval. The Chi-square test was used to compare the prevalence of agenesis and anomalies in the sample to the expected rates according to scientific literature, considering a 5% level of significance. The study also analyzed the degree of the associations using the odds ratio and the respective 95% confidence interval. The prevalence of dental agenesis in the sample, excluding third molars, was 88.6%. Of the 351 patients, 128 (36.4%) had agenesis in the maxillary arch, 108 (30.8%) in the mandibular arch, and 115 (32.8%) in both arches. A total of 52.4% had agenesis in the maxillary left hemiarch, 55.0% in the maxillary right hemiarch, 48.7% in the mandibular left hemiarch and 47.3% in the mandibular right hemiarch. With regard to the associated anomalies evaluated, 28.5% microdontia, 28.2% had enamel hipoplasia, 7.4% had palatal ectopic eruption of the canine, 6.6% had distal angulation, 4.3% infra-occlusion, 3,9% transposition of canine/premolar, 3.7% supernumerary teeth, 3.7% medial angulation, 0,6% transposition of incisive/canine, and, when compared to the general population, they were 96.1 times more likely to feature mesial angulation of the mandibular second molar; 34.6 times more likely to have distal angulation; 15,9 times more likely to show transposition of canine/premolar; 14,3 times more likely to show transposition of incisive/canine; 9 times more likely to show hipoplasia; 8,1 times more likely to show microdontia of the lateral incisor; 5,2 times more likely to have palatal ectopic eruption of the canine; and with regard to infra-occlusion, there was a lower likelihood than the general population. From the obtained results, a strong association was observed between agenesis of permanent teeth with significant dental anomalies. It was detected that permanent tooth agenesis showed an increased prevalence of enamel hypoplasia, and that agenesis and other associated anomalies are genetically interlinked. / O objetivo deste estudo retrospectivo foi avaliar a prevalência de anomalias de posição (irrupção ectópica de canino superior para palatino, transposição dental, distoangulação de segundos pré-molares inferiores, mesioangulação de segundo molar inferior permanente e infraoclusão de molares decíduos), de número (supranumerários) e de tamanho (microdontias) em pacientes com agenesias de dentes permanentes, comparando-as com as prevalências esperadas para a população em geral, além de testar a hipótese de que pacientes com agenesia de dentes permanentes apresentem uma prevalência aumentada de hipoplasia de esmalte. Para tanto, a amostra deste estudo foi composta por 351 pacientes, com a presença de agenesia de no mínimo um dente permanente, na faixa etária entre 8 e 30 anos e com prontuários clínicos preenchidos. A amostra foi coletada a partir do exame das documentações ortodônticas pertencentes aos arquivos de uma escola de aperfeiçoamento profissional em Ortodontia, de uma clínica radiológica odontológica e de consultórios particulares de ortodontistas. O material de estudo englobou radiografias panorâmicas e periapicais, modelos de gesso, fotografias intra e extraorais e prontuários clínicos devidamente preenchidos. Inicialmente foi analisada a reprodutibilidade das avaliações pela porcentagem de concordância utilizando Kappa, com intervalo de confiança de 95%. O teste de qui-quadrado foi utilizado para comparar as prevalências de agenesias e anomalias na amostra com as prevalências esperadas segundo a literatura científica, considerando o nível de significância de 5%. Analisou-se, ainda, o grau das associações pela razão de chances ( odds ratio ) e o respectivo intervalo de confiança de 95%. A prevalência de agenesias dentais na amostra, excluindo os terceiros molares, foi de 88,6%. Dos 351 pacientes, 128 (36,4%) apresentavam agenesia no arco maxilar, 108 (30,8%) no mandibular e 115 (32,8%) nos dois arcos. Em relação ao hemiarco maxilar esquerdo, 52,4% apresentavam agenesia, no direito 55,0%, no mandibular esquerdo 48,7% e no direito 47,3%. Das anomalias associadas avaliadas, 28,5% microdontia, 28,2% hipoplasia de esmalte, 7,4% apresentavam irrupção ectópica de canino superior por palatino, 6,6% distoangulação, 3,9% transposição de canino/pré-molar superior, 4,3% infraoclusão, 3,7 supranumerário, 3,7% mesioangulação, 0,6% transposição de incisivo/canino inferior, e, quando comparadas com a população em geral, observou que 96,1 vezes mais chance de apresentar mesioangulação do segundo molar inferior; 34,6 vezes mais chance de apresentar distoangulação; 15,9 vezes mais chance de apresentar transposição canino/pré-molar superior; 14,3 vezes mais chance de apresentar transposição de incisivo/canino inferior; 9 vezes mais chance de hipoplasia; a microdontia do incisivo lateral apresentou 8,1 vezes mais chance; 5,2 vezes mais chance de apresentar irrupção ectópica do canino superior por palatino, e, em relação à infraoclusão, apresentando uma menor chance do que a população geral. A partir dos resultados obtidos, verificou-se uma forte associação entre a agenesia de dentes permanentes, correlacionando com outras anomalias dentais importantes. Foi constatado de que pacientes com agenesia de dentes permanentes apresentam uma prevalência aumentada de hipoplasia de esmalte e de que agenesias e outras anomalias associadas apresentam-se interligadas geneticamente entre si.

Indiana University-Purdue University Indianapolis (IUPUI) / Quantification of treatment outcomes (tooth displacement and bony changes) is the key to advance orthodontic research and improve clinical practices. Traditionally, treatment outcome were quantified by using two-dimensional (2D) cephalometric analysis. However, there are problems inherent in 2D analysis, such as tracing errors and inability to detect side-effects. Thus, a reliable three-dimensional (3D) image analysis method for treatment outcome quantification is of high interest. Systematic 3D image analysis methods were developed for digital dental cast models and Cone-Beam Computed Tomography (CBCT) models. A typical analysis procedure includes image reconstruction, landmarks identification, coordinate system setup, superimposition, and displacement or change calculation. The specified procedures for maxillary teeth displacements and anatomical landmarks movements were presented and validated. The validation results showed that these procedures were accurate and reliable enough for clinical applications. The 3D methods were first applied to a human canine retraction clinical study. The purposes of this study were to quantify canines and anchorage tooth movements, and to compare two commonly used canine retraction strategies, controlled tipping and translation. The canine results showed that (1) canine movements were linear with time; (2) the initial load system was not the only factor that controlled the canine movement pattern; and (3) control tipping was significantly faster than translation. The anchorage tooth results showed that (1) anchorage losses occurred even with transpalatal arch (TPA); (2) there was no significant difference in anchorage loss between the two treatment strategies; and (3) compared with removable TPA, fixed TPA appliance can significantly reduce the amount of anchorage loss in the mesial-distal direction. The second clinical application for the 3D methods was a mandibular growth clinical trial. The purposes of this study were to quantify skeletal landmark movements, and compare two widely used appliances, Herbst and MARA. The results showed that (1) the Herbst appliance caused mandibular forward movement with backward rotation; and (2) the treatment effects had no significant differences by using either Herbst or MARA appliances. The two clinical applications validated the methods developed in this study to quantify orthodontic treatment outcomes. They also demonstrated the benefits of using the 3D methods to quantify orthodontic treatment outcomes and to test fundamental hypotheses. These 3D methods can easily be extended to other clinical cases. This study will benefit orthodontic patients, clinicians and researchers.