Magister Scientiae Dentium - MSc(Dent) / This paper has attempted to describe the prenatal development of the mandible in humans and ita postnatal growth. The various theories of how this growth occurs have been described including the historical work by Brash, the' classical theory', .. which includes a section on the controversy regarding the term' growth centre' and its application to the mandibular condyle. Bjork's investigations using the implant method have been covered. This method allowed him to superimpose the mandibles in a longi tudinal growth study with more ease and accuracy than was formerly possible.Note that no mention is made in this paper of the error due to magni~cation changes in the radiographs resul~ing from the growth itself. Enlow's theory ,including his ideas on relocation,cortical drift,reversal etc. based on the morphology of the mandible are covered. The functional theory of Moss'which has many supporters and is perhaps one of the strongest theories is included with a further section on the role function plays The other main theory described is the theory of arcial growth is covered by Ricketts. The chin is a characteristic of Man and a short section will be found about its development Nowadays we are using prediction of the growth of an individual as an intgral part of our treatment plan in orthodontics .I have attempted to describe the structural features of acephalo metric radiograph which are our guidelines for prediction I have included at the end a short part about investigations using hormones to study their role in development.This only scratches the surface of the many hormonal studies carried out but serves to show another side of research concerning the development of the mandible.

Computed tomography (CT) is an established diagnostic modality for evaluation of canine elbow dysplasia. However, diagnostic sensitivity for elbow abnormalities may be affected by variations in CT image quality. Currently there are no data-based recommendations for elbow CT image display parameters. The purpose of this study was to test the effect of CT display parameters on observers' diagnostic certainty for CT abnormalities reportedly associated with canine elbow dysplasia. Fifty dysplastic elbows and ten clinically normal elbows were selected for imaging. Computed tomographic image data from selected elbows were filmed in transverse, sagittal and dorsal planes, with each plane filmed in window widths of 1500, 2500, and 3500 HU. Two veterinary radiologists independently evaluated each set of images for the presence or absence of hypoattenuating MCP subchondral defects, in situ MCP fissures, discrete MCP fragments, irregularity of the radial incisure of the ulna, subchondral sclerosis of the trochlea humeri, osteochondrosis or kissing lesions, and joint incongruity. Level of diagnostic certainty for each CT abnormality was recorded for each observer using a visual analog scale system. The effect of elbow status, plane, and window on the degree of observer certainty was tested. Overall, observers demonstrated higher diagnostic certainty for normal elbows than dysplastic elbows. Observer certainty for the presence of altered subchondral density (presumed osteomalacia or sclerosis) was primarily affected by window width, whereas certainty for structural defects of the MCP, radial incisure, trochlea humeri, and joint incongruity was primarily affected by image plane. / Master of Science

A hiperplasia do processo coronóide (HPC) é uma variação morfológica que causa limitação na abertura de boca interferindo na mastigação. Normalmente não apresenta sintomatologia dolorosa e o paciente só vai procurar tratamento quando houver dor ou problemas funcionais causados pela compressão do processo coronóide hiperplásico no osso zigomático. Muitos clínicos desconhecem esta alteração e adotam tratamento para disfunção da articulação temporomandibular (ATM). Neste trabalho propôs-se mostrar que a hiperplasia do processo coronóide pode ser observada em radiografias panorâmicas de forma a suspeitar da existência dessa alteração e, aliado aos dados clínicos, o cirurgião-dentista generalista possa encaminhar o paciente ao especialista para que sejam providenciados exames mais complexos que permitam a conclusão do diagnóstico. A amostra constituiu-se de 150 radiografias panorâmicas dentre as quais estavam incluídas imagens sugestivas da hiperplasia do processo coronóide (HPC). Estas radiografias foram submetidas à análise de 3 Radiologistas com um mínimo de 5 anos de experiência na especialidade. Ficou concluído que a radiografia panorâmica é um meio auxiliar para o diagnóstico inicial dessa alteração e o clínico deve estar atento aos possíveis indicativos que esta técnica radiográfica fornece para a sugestão do diagnóstico. / The Coronoid Process Hyperplasia is a morphologic variation, which reduces mouth opening and interferes on mastication. Normally, it doesn\'t have pain symtomatology, and the patient will only look for treatment when there is pain or functional problems caused by compression of the Hyperplasic Coronoid Process on the zygomatic bone. Many practitioners ignore this alteration, and do treatment for termporomandibular joint disorder. This work proposes to show that is possible to suspect the presence of Coronoid Process Hyperplasia on panoramic radiography, and allied with clinical information, general practitioners can forward their patients to a specialist, to make more complex exams which will allow the conclusion of the diagnosis. The sample was composed by 150 panoramic radiographys, where included some suggestive radiographs of Coronoid Process Hyperplasia. These radiographs were analyzed by 3 Radiologists with at least 5 years of experience on this activity. It was concluded that panoramic radiography is an auxiliary way for initial diagnoses of this alteration and practitioners should attent the possible indicatives that this radiograph technique brings for diagnoses suggestion.

A hiperplasia do processo coronóide (HPC) é uma variação morfológica que causa limitação na abertura de boca interferindo na mastigação. Normalmente não apresenta sintomatologia dolorosa e o paciente só vai procurar tratamento quando houver dor ou problemas funcionais causados pela compressão do processo coronóide hiperplásico no osso zigomático. Muitos clínicos desconhecem esta alteração e adotam tratamento para disfunção da articulação temporomandibular (ATM). Neste trabalho propôs-se mostrar que a hiperplasia do processo coronóide pode ser observada em radiografias panorâmicas de forma a suspeitar da existência dessa alteração e, aliado aos dados clínicos, o cirurgião-dentista generalista possa encaminhar o paciente ao especialista para que sejam providenciados exames mais complexos que permitam a conclusão do diagnóstico. A amostra constituiu-se de 150 radiografias panorâmicas dentre as quais estavam incluídas imagens sugestivas da hiperplasia do processo coronóide (HPC). Estas radiografias foram submetidas à análise de 3 Radiologistas com um mínimo de 5 anos de experiência na especialidade. Ficou concluído que a radiografia panorâmica é um meio auxiliar para o diagnóstico inicial dessa alteração e o clínico deve estar atento aos possíveis indicativos que esta técnica radiográfica fornece para a sugestão do diagnóstico. / The Coronoid Process Hyperplasia is a morphologic variation, which reduces mouth opening and interferes on mastication. Normally, it doesn\'t have pain symtomatology, and the patient will only look for treatment when there is pain or functional problems caused by compression of the Hyperplasic Coronoid Process on the zygomatic bone. Many practitioners ignore this alteration, and do treatment for termporomandibular joint disorder. This work proposes to show that is possible to suspect the presence of Coronoid Process Hyperplasia on panoramic radiography, and allied with clinical information, general practitioners can forward their patients to a specialist, to make more complex exams which will allow the conclusion of the diagnosis. The sample was composed by 150 panoramic radiographys, where included some suggestive radiographs of Coronoid Process Hyperplasia. These radiographs were analyzed by 3 Radiologists with at least 5 years of experience on this activity. It was concluded that panoramic radiography is an auxiliary way for initial diagnoses of this alteration and practitioners should attent the possible indicatives that this radiograph technique brings for diagnoses suggestion.

A hiperplasia do processo coronóide é uma afecção que causa uma limitada mobilidade mandibular e conseqüente limitação de abertura da boca. Não apresenta sintomatologia dolorosa, e tem progressão lenta, levando o paciente a procurar por tratamento somente se a limitação de abertura for severa a ponto de prejudicar as funções mastigatórias normais. Muitos casos levam clínicos a tratarem o paciente como portador de disfunção da articulação têmporo mandibular (DTM). Este trabalho se propõe a avaliar a tomografia computadorizada (TC) como método para auxiliar na elaboração do diagnóstico e no planejamento cirúrgico desta anomalia, estudando a presença da hiperplasia do processo coronóide pela observação de imagens obtidas por meio da Tomografia Computadorizada Helicoidal, considerando as imagens volumétricas multiplanar e 3D, e as suas associações. Foram utilizadas imagens de arquivo dos exames de tomografia computadorizada helicoidal de 152 pacientes que apresentavam sinais e sintomas de Disfunção Têmporo Mandibular (DTM) encaminhados para a Unidade de Diagnóstico Dento-Maxilo-Facial da Clínica Félix Boada, na cidade de Caracas - Venezuela, para exame tomográfico da ATM. Dos 152 pacientes, foram selecionados 20 casos, que eram de portadores de sinais e/ou sintomas de Disfunção Têmporo Mandibular, mas que, ao exame realizado, constatou-se a presença da hiperplasia do processo coronóide. Os dados dos 20 pacientes foram comparados, de maneira a identificar as possíveis diferenças entre as opiniões de 5 cirurgiões dentistas radiologistas e de 5 cirurgiões dentistas buco-maxilo-faciais. Utilizou-se a técnica da Análise de Médias (Analysis of Means - ANOM), que calcula uma média geral entre os 5 observadores de cada especialidade, e um intervalo que indica quais observadores tiveram opiniões semelhantes e quais tiveram opiniões diversas. Depois foi feita a comparação entre os dois grupos, utilizando o teste das proporções. Em conclusão, os observadores acharam as imagens MPR mais esclarecedoras que as reconstruções volumétricas 3D, na maioria dos casos de hiperplasia do processo coronóide, quando esses recursos foram avaliados separadamente. Contudo, acharam imprescindível a utilização de ambas as imagens, em associação ou não, indicando-as para o estudo da hiperplasia do processo coronóide. A hipomobilidade foi observada na articulação temporomandibular, no lado acometido pela hiperplasia do processo coronóide, em 55,2% dos casos / The Coronoid Process Hyperplasia is an affection that causes a limited mandibular mobility and a consequent limitation in mouth opening. It doesn’t present any painful symptomatology and has a slow progression, leading the patient to look for treatment only when the opening limitation is severe to the point of impairing regular masticatory functions. Many cases lead clinicians to treat the patient as he had a temporomandibular dysfunction. This work proposed an evaluation of the CT as an auxiliary method in the elaboration of the diagnosis and in the surgical planning of that anomaly by studying the presence of the Coronoid Process Hyperplasia through the observation of images obtained by means of the Helicoidal Computerized Tomography, considering the volumetric multiplane and 3D images and their associations. Filed images of Helicoidal Computerized Tomography were used, belonging to the examination of 152 patients who presented symptoms of temporomandibular dysfunction and were all directed to the Dento-Maxillo-Facial Diagnosis Unit of the Clinica Felix Boada in the city of Caracas – Venezuela for TMA tomographic examination. Of the 152 patients 20 were selected who showed signs or symptoms of TMA dysfunction and Coronoid Process Hyperplasia was detected. Data of the 20 patients were compared in order to identify possible differences among the opinions of 5 radiologist specialists and 5 buco-maxillo -facial specialists. The Analysis of Means – ANOM was used to calculate a general average among the 5 specialists in each specialty and a gap that opinions and which ones had different opinions. Afterwards the comparison between the 2 groups was made using the Proportion Test. The observers concluded that the MPR images were more clarifying than the 3D images in most of the cases of coronoid process hyperplasia, especially when those resources were evaluated separately. Although they found vital the utilization of both images in association or not and indicated them to the study of the Coronoid Process Hyperplasia. Hypo mobility was observed in the TMA in the affected side in 55,2% of the cases

A hiperplasia do processo coronóide é uma afecção que causa uma limitada mobilidade mandibular e conseqüente limitação de abertura da boca. Não apresenta sintomatologia dolorosa, e tem progressão lenta, levando o paciente a procurar por tratamento somente se a limitação de abertura for severa a ponto de prejudicar as funções mastigatórias normais. Muitos casos levam clínicos a tratarem o paciente como portador de disfunção da articulação têmporo mandibular (DTM). Este trabalho se propõe a avaliar a tomografia computadorizada (TC) como método para auxiliar na elaboração do diagnóstico e no planejamento cirúrgico desta anomalia, estudando a presença da hiperplasia do processo coronóide pela observação de imagens obtidas por meio da Tomografia Computadorizada Helicoidal, considerando as imagens volumétricas multiplanar e 3D, e as suas associações. Foram utilizadas imagens de arquivo dos exames de tomografia computadorizada helicoidal de 152 pacientes que apresentavam sinais e sintomas de Disfunção Têmporo Mandibular (DTM) encaminhados para a Unidade de Diagnóstico Dento-Maxilo-Facial da Clínica Félix Boada, na cidade de Caracas - Venezuela, para exame tomográfico da ATM. Dos 152 pacientes, foram selecionados 20 casos, que eram de portadores de sinais e/ou sintomas de Disfunção Têmporo Mandibular, mas que, ao exame realizado, constatou-se a presença da hiperplasia do processo coronóide. Os dados dos 20 pacientes foram comparados, de maneira a identificar as possíveis diferenças entre as opiniões de 5 cirurgiões dentistas radiologistas e de 5 cirurgiões dentistas buco-maxilo-faciais. Utilizou-se a técnica da Análise de Médias (Analysis of Means - ANOM), que calcula uma média geral entre os 5 observadores de cada especialidade, e um intervalo que indica quais observadores tiveram opiniões semelhantes e quais tiveram opiniões diversas. Depois foi feita a comparação entre os dois grupos, utilizando o teste das proporções. Em conclusão, os observadores acharam as imagens MPR mais esclarecedoras que as reconstruções volumétricas 3D, na maioria dos casos de hiperplasia do processo coronóide, quando esses recursos foram avaliados separadamente. Contudo, acharam imprescindível a utilização de ambas as imagens, em associação ou não, indicando-as para o estudo da hiperplasia do processo coronóide. A hipomobilidade foi observada na articulação temporomandibular, no lado acometido pela hiperplasia do processo coronóide, em 55,2% dos casos / The Coronoid Process Hyperplasia is an affection that causes a limited mandibular mobility and a consequent limitation in mouth opening. It doesn’t present any painful symptomatology and has a slow progression, leading the patient to look for treatment only when the opening limitation is severe to the point of impairing regular masticatory functions. Many cases lead clinicians to treat the patient as he had a temporomandibular dysfunction. This work proposed an evaluation of the CT as an auxiliary method in the elaboration of the diagnosis and in the surgical planning of that anomaly by studying the presence of the Coronoid Process Hyperplasia through the observation of images obtained by means of the Helicoidal Computerized Tomography, considering the volumetric multiplane and 3D images and their associations. Filed images of Helicoidal Computerized Tomography were used, belonging to the examination of 152 patients who presented symptoms of temporomandibular dysfunction and were all directed to the Dento-Maxillo-Facial Diagnosis Unit of the Clinica Felix Boada in the city of Caracas – Venezuela for TMA tomographic examination. Of the 152 patients 20 were selected who showed signs or symptoms of TMA dysfunction and Coronoid Process Hyperplasia was detected. Data of the 20 patients were compared in order to identify possible differences among the opinions of 5 radiologist specialists and 5 buco-maxillo -facial specialists. The Analysis of Means – ANOM was used to calculate a general average among the 5 specialists in each specialty and a gap that opinions and which ones had different opinions. Afterwards the comparison between the 2 groups was made using the Proportion Test. The observers concluded that the MPR images were more clarifying than the 3D images in most of the cases of coronoid process hyperplasia, especially when those resources were evaluated separately. Although they found vital the utilization of both images in association or not and indicated them to the study of the Coronoid Process Hyperplasia. Hypo mobility was observed in the TMA in the affected side in 55,2% of the cases

Magister Scientiae (Medical Bioscience) - MSc(MBS) / Some African mole-rats of the family Bathyergidea have dramatically different ecological niches which may cause selective anatomical adaptations. Bathyergus suillus lives in sandy soil and eats a wide range of food whereas Georychus capensis is restricted to the mountainous hard soil and eats mainly geophytes. Georychus capensis is considered a chisel-tooth digger in that it uses its incisors to dislodge soil while Bathyergus suillus is a scratch-digger that uses both its incisors and large front paws to dislodge soil. The purpose of this study was to compare certain aspects of the masticatory anatomy of Bathyergus suillus and Georychus capensis. In particular the question that drives this study is: Do the differences in ecology of the two species reflect in the anatomical adaptation of their masticatory apparatus? Nine whole body specimens of each species were obtained for this study. The masticatory apparatus of each specimen was dissected, examined and analysed.Selected bones of their skulls were investigated to determine their gross morphology. Digitalized images were captured by a high-resolution Olympus digital camera and were analysed by DOCU analysis software, in order to determine the morphometric parameters. In addition, the cleaned skulls of each species were weighed with a chemical balance. In order to make the comparison of the four muscles of mastication more effective than when using only their linear measurements, the mass (in grams) of each skull was divided by the length of each metric traits squared in order to yield their respective indices. Various statistical tests were used.This study has thus revealed some dissimilarities between the two species.Comparison of the two species reveals that one of the more distinguishing differences between the two is their upper incisors. There are also significant differences in the morphology and dimensions of their angular plates. And the external pterygoid muscle is significantly larger in Georychus capensis than in Bathyergus suillus, there are no significant differences between the others of the masticatory muscles of the two species.The feeding and foraging activities of Bathyergus suillus as well as Georychus capensis have close relationship with their lifestyles (digging abilities and adaptations). Bathyergus suillus is predisposed to dig with its incisors as well as its large front paws, and the range of food is large, whereas Georychus capensis uses its incisors only to dig, and the range of food is limited. Subsequently the skull of Bathyergus suillus is bigger than Georychus capensis. But, due to the environment of the latter, strong incisors are needed to perform its feeding and digging activities. The investigation thus reveals that the two selected species have successfully adapted their anatomical masticatory elements to their environments.

The use of computational modeling is an effective and inexpensive way to predict the response of complex systems to various perturbations. However, not until the early 1990s had this technology been used to predict the behavior of physiological systems, specifically the human skeletal system. To that end, a computational model of the human elbow joint was developed using computed topography (CT) scans of cadaveric donor tissue, as well as the commercially available software package SolidWorks™. The kinematic function of the joint model was then defined through 3D reconstructions of the osteoarticular surfaces and various soft-tissue constraints. The model was validated against cadaveric experiments performed by Hull et al and Fern et al that measured the significance of coronoid process fractures, lateral ulnar collateral ligament ruptures, and radial head resection in elbow joint resistance to varus displacement of the forearm. Kinematic simulations showed that the computational model was able to mimic the physiological movements of the joint throughout various ranges of motion including flexion/extension and pronation/supination. Quantitatively, the model was able to accurately reproduce the trends, as well as the magnitudes, of varus resistance observed in the cadaveric specimens. Additionally, magnitudes of ligament tension and joint contact force predicted by the model were able to further elucidate the complex soft-tissue and osseous contributions to varus elbow stability.