OBJECTIVES: The aim of this project is to develop a novel 3D cephalometric analysis using anatomical landmarks that cannot be easily viewed on a planar film but on a CBCT image and study the reliability of these measurements between different examiners. METHODS: Fifty CBCT images of patients with normodivergent, Class I skeletal patterns and without any noticeable craniofacial deformities were screened and included in the study based on the lateral cephalograms generated from CBCT data using the Roth/Jarabak Analysis. Fifteen predetermined landmarks that found to be reliable in another associated study were used to define six planes. Measurements were also completed on a human dry skull to confirm accuracy. Eleven different cephalometric measurements were performed by three operators three times using landmarks and planes in 3D. Descriptive statistics (mean and standard deviation) and intra-class correlation coefficient for intra- and inter-examiner reliability was performed. RESULTS: The measurements showed that the means and standard deviations of all three measurers are: for Mandibular A/P: 14.49mm ±2.26; Mandibular deviation: 1.63mm, ±1.19; Maxilla/Mandibular divergence: 24.51°, ±3.85; Maxillary deviation: 0.94mm ±0.5; Pitch (Mandibular Plane), 50.38° ±2.8; Pitch (Maxillary Plane): 74.66° ±3.53; Roll (Mandibular Plane): 87.66° ±2.38, 0.05; Roll (Maxillary Plane): 87.70° ±1.85; Yaw (Maxillary Plane): 4.41°± 2.11; Yaw (Mandibular): 3.61°± 2.43; Maxillary A/P: 2.96mm ±2.26. An interclass correlation was calculated at a range from 0.53 to 0.95. CONCLUSIONS: The means and standard deviations of the measurements can be used as a reference to study. Amongst the operators, we indicate between moderate and excellent reliability. The highest reliability was with measurement mandibular pitch. Lowest reliability was with measurement mandibular roll.

Introdução: Este estudo comparou os efeitos cefalométricos promovidos por dois aparelhos distalizadores de molares superiores distintos, o aparelho extrabucal cervical e o aparelho Jones Jig de caráter intrabucal, associados ao aparelho ortodôntico fixo. Objetivos: O objetivo do presente trabalho foi obter e comparar os valores entre os distalizadores , afim de saber quais as diferenças que ocorrem entre os protocolos de tratamento. Material e Métodos: O grupo AEB consiste de 25 pacientes apresentando má oclusão de Classe II, com idade média inicial de 13,00 anos, tratados por meio do aparelho extrabucal cervical associado ao aparelho ortodôntico fixo. O grupo Jones Jig foi de 21 pacientes possuindo má oclusão de Classe II, com idade média inicial de 12,88 anos, tratados com o aparelho Jones Jig seguido do aparelho ortodôntico fixo. Foram avaliadas as telerradiografias em norma lateral no início e no final do tratamento ortodôntico. Os grupos foram compatibilizados em relação à idade inicial, gênero da amostra, severidade da má oclusão de Classe II, características cefalométricas iniciais e finais. A partir das telerradiografias foram obtidos os traçados cefalométricos, utilizando-se o programa Dentalfacial Planner 7.02 para avaliação das grandezas esqueléticas e dentoalveolares. Foi realizado o teste estatístico teste t de Student não paramétrico para dados normais e o Man Witney para os dados não normais. Resultados: Houve um redirecionamento do crescimento maxilar no grupo AEB, resultando na restrição do vetor de crescimento maxilar para anterior, o que promoveu a melhora da relação maxilomandibular esquelética. No grupo Jones Jig, verificou somente efeitos dentoalveolares. Em ambos os protocolos de tratamento, não houve diferenças na mandíbula a não ser as diferenças que ocorrem naturalmente com o crescimento craniofacial. Não houve diferença nas repercussões de ambos os tratamentos no perfil facial tegumentar. Conclusão: Ambos os aparelhos corrigiram a má oclusão de Classe II, de forma semelhante, com a estabilização sagital do complexo dentoalveolar superior proporcionada pelos aparelhos distalizadores, enquanto que o complexo dentoalveolar inferior avançava em direção anterior, devido ao crescimento mandibular. / Introduction: This study compared the effects of two cephalometric promoted by two different molar distalizers, the cervical headgear and intraoral Jones Jig appliance, associated with fixed orthodontic appliances. Objectives: The aim of this study was to obtain and compare values between two different types of distalizer devices in order to know what the differences that occur between the treatment protocols. Material and Methods: The headgear group consists of 25 patients with Class II malocclusion, with an initial mean age of 13,00 years, treated by cervical headgear associated with fixed orthodontic appliance. The Jones Jig group is 21 patients having Class II malocclusion, with an initial mean age of 12,88 years, treated with the Jones Jig appliance followed by fixed orthodontic appliance. We evaluated the lateral cephalograms at the beginning and end of orthodontic treatment. The groups were matched for initial age, sample gender, severity of Class II malocclusion, initial and final cephalometric features. The radiographs were obtained from the cephalometric, using Dentalfacial Planner 7.02 program to evaluate the skeletal and dentoalveolar magnitudes. The nonparametric statistical t test and Man Witiney was performed. Results: There was a redirection of maxillary growth in the headgear group resulting in the restriction of maxillary growth vector for earlier, which allowed improvement of skeletal maxillomandibular relationship. Jones Jig group, there were only dentoalveolar effects. In both treatment protocols, there were no differences in the jaw unless the differences that naturally occur with craniofacial growth. Conclusion: Both appliances have corrected the Class II malocclusion, similarly, with the sagittal stabilization of the upper dentoalveolar complex provided by the distalizers, while the lower dentoalveolar complex advanced in an anterior direction due to mandibular growth. There was no difference in the effects of both treatments in soft facial profile.

Introdução: Este estudo comparou os efeitos cefalométricos promovidos por dois aparelhos distalizadores de molares superiores distintos, o aparelho extrabucal cervical e o aparelho Jones Jig de caráter intrabucal, associados ao aparelho ortodôntico fixo. Objetivos: O objetivo do presente trabalho foi obter e comparar os valores entre os distalizadores , afim de saber quais as diferenças que ocorrem entre os protocolos de tratamento. Material e Métodos: O grupo AEB consiste de 25 pacientes apresentando má oclusão de Classe II, com idade média inicial de 13,00 anos, tratados por meio do aparelho extrabucal cervical associado ao aparelho ortodôntico fixo. O grupo Jones Jig foi de 21 pacientes possuindo má oclusão de Classe II, com idade média inicial de 12,88 anos, tratados com o aparelho Jones Jig seguido do aparelho ortodôntico fixo. Foram avaliadas as telerradiografias em norma lateral no início e no final do tratamento ortodôntico. Os grupos foram compatibilizados em relação à idade inicial, gênero da amostra, severidade da má oclusão de Classe II, características cefalométricas iniciais e finais. A partir das telerradiografias foram obtidos os traçados cefalométricos, utilizando-se o programa Dentalfacial Planner 7.02 para avaliação das grandezas esqueléticas e dentoalveolares. Foi realizado o teste estatístico teste t de Student não paramétrico para dados normais e o Man Witney para os dados não normais. Resultados: Houve um redirecionamento do crescimento maxilar no grupo AEB, resultando na restrição do vetor de crescimento maxilar para anterior, o que promoveu a melhora da relação maxilomandibular esquelética. No grupo Jones Jig, verificou somente efeitos dentoalveolares. Em ambos os protocolos de tratamento, não houve diferenças na mandíbula a não ser as diferenças que ocorrem naturalmente com o crescimento craniofacial. Não houve diferença nas repercussões de ambos os tratamentos no perfil facial tegumentar. Conclusão: Ambos os aparelhos corrigiram a má oclusão de Classe II, de forma semelhante, com a estabilização sagital do complexo dentoalveolar superior proporcionada pelos aparelhos distalizadores, enquanto que o complexo dentoalveolar inferior avançava em direção anterior, devido ao crescimento mandibular. / Introduction: This study compared the effects of two cephalometric promoted by two different molar distalizers, the cervical headgear and intraoral Jones Jig appliance, associated with fixed orthodontic appliances. Objectives: The aim of this study was to obtain and compare values between two different types of distalizer devices in order to know what the differences that occur between the treatment protocols. Material and Methods: The headgear group consists of 25 patients with Class II malocclusion, with an initial mean age of 13,00 years, treated by cervical headgear associated with fixed orthodontic appliance. The Jones Jig group is 21 patients having Class II malocclusion, with an initial mean age of 12,88 years, treated with the Jones Jig appliance followed by fixed orthodontic appliance. We evaluated the lateral cephalograms at the beginning and end of orthodontic treatment. The groups were matched for initial age, sample gender, severity of Class II malocclusion, initial and final cephalometric features. The radiographs were obtained from the cephalometric, using Dentalfacial Planner 7.02 program to evaluate the skeletal and dentoalveolar magnitudes. The nonparametric statistical t test and Man Witiney was performed. Results: There was a redirection of maxillary growth in the headgear group resulting in the restriction of maxillary growth vector for earlier, which allowed improvement of skeletal maxillomandibular relationship. Jones Jig group, there were only dentoalveolar effects. In both treatment protocols, there were no differences in the jaw unless the differences that naturally occur with craniofacial growth. Conclusion: Both appliances have corrected the Class II malocclusion, similarly, with the sagittal stabilization of the upper dentoalveolar complex provided by the distalizers, while the lower dentoalveolar complex advanced in an anterior direction due to mandibular growth. There was no difference in the effects of both treatments in soft facial profile.

Magister Scientiae Dentium - MSc(Dent) / The Tip-Edge and edgewise techniques are the main techniques that are mostly used in orthodontics, and are applicable to the treatment of any type of malocclusion from the most simple to the most complex. The edgewise bracket wire combination produces bodily tooth movement simultaneously or separately in all three planes of space and hence permits correction of the most extreme tooth malpositions. On the other hand Tip-Edge offers a differential tooth movement (just like the previously used Begg technique) within an edgewise based bracket system (Parkhouse 2003). When treating patients using the Tip-Edge technique, it is recommended that a specialized archwire i.e. Australian stainless steel wire be used. This wire can be described as a round austenitic stainless steel wire that is heat-treated and cold-drawn to its proper diameter. This was done in order to produce its special and needed properties such as toughness, resiliency and tensile strength (Kesling, 1985). It is used in conjunction with light (2oz) class II elastics. The aim of this study was to compare cephalometric changes in skeletal and dento-alveolar parameters in cases treated by these two different orthodontic techniques. This was to be established by calculating and comparing the pre- and post-treatment cephalometric variables of cases treated with these techniques by looking at the skeletal and dento-alveolar measurements. Thirty Tip-Edge and thirty edgewise treated cases that had class II malocclusion, had extraction of four premolars and were treated with Class II elastics were selected. The gender distribution between the Tip-Edge and the edgewise techniques were 47% and 60% respectively for females. For males it was 53% in Tip-Edge and 40% in the edgewise techniques.

The domain of medical imaging analysis has burgeoned in recent years due to the availability and affordability of digital radiographic imaging equipment and associated algorithms and, as such, there has been significant activity in the automation of the medical diagnostic process. One such process, cephalometric analysis, is manually intensive and it can take an experienced orthodontist thirty minutes to analyse one radiology image. This thesis describes an approach, based on genetic programming, neural networks and machine learning, to automate this process. A cephalometric analysis involves locating a number of points in an X-ray and determining the linear and angular relationships between them. If the points can be located accurately enough, the rest of the analysis is straightforward. The investigative steps undertaken were as follows: Firstly, a previously published method, which was claimed to be domain independent, was implemented and tested on a selection of landmarks, ranging from easy to very difficult. These included the menton, upper lip, incisal upper incisor, nose tip and sella landmarks. The method used pixel values, and pixel statistics (mean and standard deviation) of pre-determined regions as inputs to a genetic programming detector. This approach proved unsatisfactory and the second part of the investigation focused on alternative handcrafted features sets and fitness measures. This proved to be much more successful and the third part of the investigation involved using pulse coupled neural networks to replace the handcrafted features with learned ones. The fourth and final stage involved an analysis of the evolved programs to determine whether reasonable algorithms had been evolved and not just random artefacts learnt from the training images. A significant finding from the investigative steps was that the new domain independent approach, using pulse coupled neural networks and genetic programming to evolve programs, was as good as or even better than one using the handcrafted features. The advantage of this finding is that little domain knowledge is required, thus obviating the requirement to manually generate handcrafted features. The investigation revealed that some of the easy landmarks could be found with 100\% accuracy while the accuracy of finding the most difficult ones was around 78\%. An extensive analysis of evolved programs revealed underlying regularities that were captured during the evolutionary process. Even though the evolutionary process took different routes and a diverse range of programs was evolved, many of the programs with an acceptable detection rate implemented algorithms with similar characteristics. The major outcome of this work is that the method described in this thesis could be used as the basis of an automated system. The orthodontist would be required to manually correct a few errors before completing the analysis.

As análises cefalométricas computadorizadas baseiam-se na marcação de pontos anatômicos sobre imagens radiográficas digitalizadas. Estudos têm questionado o desempenho dos executores, tendo em vista a falta de reprodutibilidade dos exames. Tal fato, gera preocupação com a formação do profissional para a prática da cefalometria radiográfica. Desta forma, se faz necessária a criação de novas abordagens no ensino que permitam promover e consolidar conhecimentos e intervenções neste domínio. Dentro deste contexto, foram desenvolvidos um objeto virtual chamado Ceph-Learning para aprendizagem e um software intitulado Cyclops Cephalometry para treinamento e calibragem em cefalometria radiográfica. Especialistas em tecnologia educativa, ortodontia, alunos de graduação e pós-graduação testaram os produtos criados. Os resultados mostraram que estes apresentam-se como ferramentas úteis, eficientes e facilitadoras do processo de aprendizagem e calibragem, servindo de suporte para o aprendizado e prática da cefalometria. Conclui-se que a tecnologia virtual aplicada ao aprendizado assistido por computador é eficiente e melhora o desempenho acadêmico e profissional nos exames cefalométricos. / Computed cephalometric analysis is based on the identification of anatomical landmarks marked on digitized radiographic images. Some studies have been enquiring the performance of the examiner, considering the analysis lack of reproducibility. This outcome generates a concern regarding the academic training of the professionals responsible for the cephalometric analysis. Therefore, the creation of new educational approaches which could allow the promotion and consolidation of interventions within this domain is necessary. This context has lead to the development of a virtual object directed to teaching denominated Ceph-Learning and a calibrating and training software named Cyclops Cephalometry. Technology education and orthodontics specialists, undergraduate and graduate students have tested the developed products. Results show that these tools have facilitated the teaching and calibrating process proven to be useful and efficient, therefore, standing as a cephalometric practice and learning support. As a conclusion, virtual technology applied to computer-aided learning is efficient and improves the professional and academic performance regarding cephalometric analysis.

As análises cefalométricas computadorizadas baseiam-se na marcação de pontos anatômicos sobre imagens radiográficas digitalizadas. Estudos têm questionado o desempenho dos executores, tendo em vista a falta de reprodutibilidade dos exames. Tal fato, gera preocupação com a formação do profissional para a prática da cefalometria radiográfica. Desta forma, se faz necessária a criação de novas abordagens no ensino que permitam promover e consolidar conhecimentos e intervenções neste domínio. Dentro deste contexto, foram desenvolvidos um objeto virtual chamado Ceph-Learning para aprendizagem e um software intitulado Cyclops Cephalometry para treinamento e calibragem em cefalometria radiográfica. Especialistas em tecnologia educativa, ortodontia, alunos de graduação e pós-graduação testaram os produtos criados. Os resultados mostraram que estes apresentam-se como ferramentas úteis, eficientes e facilitadoras do processo de aprendizagem e calibragem, servindo de suporte para o aprendizado e prática da cefalometria. Conclui-se que a tecnologia virtual aplicada ao aprendizado assistido por computador é eficiente e melhora o desempenho acadêmico e profissional nos exames cefalométricos. / Computed cephalometric analysis is based on the identification of anatomical landmarks marked on digitized radiographic images. Some studies have been enquiring the performance of the examiner, considering the analysis lack of reproducibility. This outcome generates a concern regarding the academic training of the professionals responsible for the cephalometric analysis. Therefore, the creation of new educational approaches which could allow the promotion and consolidation of interventions within this domain is necessary. This context has lead to the development of a virtual object directed to teaching denominated Ceph-Learning and a calibrating and training software named Cyclops Cephalometry. Technology education and orthodontics specialists, undergraduate and graduate students have tested the developed products. Results show that these tools have facilitated the teaching and calibrating process proven to be useful and efficient, therefore, standing as a cephalometric practice and learning support. As a conclusion, virtual technology applied to computer-aided learning is efficient and improves the professional and academic performance regarding cephalometric analysis.

As análises cefalométricas computadorizadas baseiam-se na marcação de pontos anatômicos sobre imagens radiográficas digitalizadas. Estudos têm questionado o desempenho dos executores, tendo em vista a falta de reprodutibilidade dos exames. Tal fato, gera preocupação com a formação do profissional para a prática da cefalometria radiográfica. Desta forma, se faz necessária a criação de novas abordagens no ensino que permitam promover e consolidar conhecimentos e intervenções neste domínio. Dentro deste contexto, foram desenvolvidos um objeto virtual chamado Ceph-Learning para aprendizagem e um software intitulado Cyclops Cephalometry para treinamento e calibragem em cefalometria radiográfica. Especialistas em tecnologia educativa, ortodontia, alunos de graduação e pós-graduação testaram os produtos criados. Os resultados mostraram que estes apresentam-se como ferramentas úteis, eficientes e facilitadoras do processo de aprendizagem e calibragem, servindo de suporte para o aprendizado e prática da cefalometria. Conclui-se que a tecnologia virtual aplicada ao aprendizado assistido por computador é eficiente e melhora o desempenho acadêmico e profissional nos exames cefalométricos. / Computed cephalometric analysis is based on the identification of anatomical landmarks marked on digitized radiographic images. Some studies have been enquiring the performance of the examiner, considering the analysis lack of reproducibility. This outcome generates a concern regarding the academic training of the professionals responsible for the cephalometric analysis. Therefore, the creation of new educational approaches which could allow the promotion and consolidation of interventions within this domain is necessary. This context has lead to the development of a virtual object directed to teaching denominated Ceph-Learning and a calibrating and training software named Cyclops Cephalometry. Technology education and orthodontics specialists, undergraduate and graduate students have tested the developed products. Results show that these tools have facilitated the teaching and calibrating process proven to be useful and efficient, therefore, standing as a cephalometric practice and learning support. As a conclusion, virtual technology applied to computer-aided learning is efficient and improves the professional and academic performance regarding cephalometric analysis.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

O objetivo nesta pesquisa foi o de avaliar quantitativamente as variações na determinação de 7 pontos cefalométricos e analisar o quanto que estes erros podem influenciar no planejamento e progressão da terapêutica ortodôntica. Foram utilizados 14 crânios macerados onde fora colocadas esferas metálicas para a demarcação dos pontos cefalométricos escolhidos. Estes crânios foram radiografados com e sem as esferas metálicas, e as grandezas cefalométricas avaliadas estatisticamente. Os resultados mostraram que a média de erro na localização dos pontos foi de 57,5% e que este desvio em termos numéricos podem levar a equívocos de planejamento que podem comprometer seriamente o resultado do tratamento com desvios em algumas medidas cefalométricas de até 4mm. As mensurações relacionadas aos pontos espinha nasal anterior, pogonio e gônio foram as que tiveram maior reprodutibilidade, porém, as medidas cefalométricas relacionadas ao ponto A mostraram que as diferenças encontradas então em torno de 4,3mm, e que a avaliação do comprimento mandibular obtida pela localização do ponto condílio, também gerou diferenças de 2,8mm em média, alterando assim substancialmente as avaliações para diagnóstico e tratamento ortodôntico e cirúrgico. / The aim of this study were to evaluate quantitatively the variations on the determination of 7 cephalometric landmarks and to analyze how these differences may influence the planning and outcome of the orthodontic treatment. Small steel balls were glued on specific sites of 14 dry skulls to represent the true anatomical landmarks. The skulls were radiographed with and without the steel balls, and the cephalometric values were submitted to statistical analysis. Results showed that the error in the localization of the landmarks was in average 57,5%. This high deviation, that reaches up to 4mm in certain cephalometric measurements, could lead to errors in treatment planning and compromise the result of any orthodontic treatment. Measurements of the Anterior Nasal Spine, Pogonion and Gonion showed the highest reproducibility, while point A showed the lowest (4,3mm). The evaluation of the mandibular length through the identification of Condyle also showed high discrepancies (2,8mm), which may alter the evaluations for orthodontic and/or surgical diagnosis and treatment.