Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (leaves 260-272).

Orientador: Rosilene Fernandes da Rocha / Banca: Francisco Haiter Neto / Banca: Darcy de Oliveira Tosello / Banca: Yasmim Rodarte Carvalho / Banca: Mônica Fernands Gomes / RESUMO: Neste trabalho estudou-se a ação da calcitonina no processo de regeneração óssea em mandíbulas de ratas normais e ovariectomizadas, com e sem a administração de calcitonina. Para este estudo foram utilizadas cem ratas com idade aproximada de sessenta dias. Dessas, cinquenta foram ovariectomizadas formando o grupo Ov e, um mês após esta cirurgia, em todos os cem animais foi realizado defeito ósseo cirúrgico, na região do ângulo da mandíbula, criando uma lesão óssea de aproximadamente 4mm, recoberta com uma barreira de PTFE. Os animais Ovforam divididos em dois grupos iguais: Ov (ovaricctomizados) e OvM(ovariectomizados com administração de calcitonina). Os outros cinquenta animais, somente com a lesão óssea, também foram divididos em dois grupos: C (controle) e CM (controle com administração de calcitonina). Os grupos tratados receberam a primeira dose da substância imediatamente após a cirurgia, na dose de 2 UI/kg, i.m., três vezes por semana. Os animais foram sacrificados após três, sete, 14, 21 e 28 dias, sendo suas mandíbulas removidas e encaminhadas para preparação histológica. Análises densitométrica, histológica e histomorfométrica foram realizadas verificando-seque foi possível observar que os animais Ov apresentavam diminuição da densidade óssea e um processo regenerativo muito mais lento, quando comparados com os animais controle. A calcitonina mostrou-se efetiva tanto nos animais ovariectomizados quanto naqueles apenas com lesão óssea / ABSTRACT: In This work we studied the action of calcitonin on bone regeneration in the jaws of normal and ovariectomized rats with and without administration of calcitonin. One hundred rats aged approximately sixty days were used for this study. Of these fifty were ovariectomizedOv forming group and one month after the surgery, animals in all a hundred surgical bone defect was made in the angle of the mandible, creating a bone lesion of approximately 4 mm, covered with a PTFE barrier. OvThe animals were divided into two equal groups: Ov (ovaricctomizados) and LMO (ovariectomized with calcitonin). The other fifty animals, only with the bone lesion were also divided into two groups: control (C) and CM (control with calcitonin). Treated groups received the first dose of the substance immediately after surgery, the dose of 2 IU / kg IM three times per week. The animals were sacrificed after three, seven, 14, 21 and 28 days, with their jaws removed and sent for histological preparation. Densitometric analyzes were performed histological and histomorphometric verifying that it was observed that the Ov animals showed decreased bone density and a much slower regenerative process, when compared with control animals. Calcitonin proved effective in both ovariectomized animals and in those with only bone injury / Doutor

Made available in DSpace on 2014-11-10T11:10:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2000-12-13Bitstream added on 2014-11-10T11:57:21Z : No. of bitstreams: 1 000145913.pdf: 3866536 bytes, checksum: 79d6d371ef5d2113f46b8313c0805ea5 (MD5) / Neste trabalho estudou-se a ação da calcitonina no processo de regeneração óssea em mandíbulas de ratas normais e ovariectomizadas, com e sem a administração de calcitonina. Para este estudo foram utilizadas cem ratas com idade aproximada de sessenta dias. Dessas, cinquenta foram ovariectomizadas formando o grupo Ov e, um mês após esta cirurgia, em todos os cem animais foi realizado defeito ósseo cirúrgico, na região do ângulo da mandíbula, criando uma lesão óssea de aproximadamente 4mm, recoberta com uma barreira de PTFE. Os animais Ovforam divididos em dois grupos iguais: Ov (ovaricctomizados) e OvM(ovariectomizados com administração de calcitonina). Os outros cinquenta animais, somente com a lesão óssea, também foram divididos em dois grupos: C (controle) e CM (controle com administração de calcitonina). Os grupos tratados receberam a primeira dose da substância imediatamente após a cirurgia, na dose de 2 UI/kg, i.m., três vezes por semana. Os animais foram sacrificados após três, sete, 14, 21 e 28 dias, sendo suas mandíbulas removidas e encaminhadas para preparação histológica. Análises densitométrica, histológica e histomorfométrica foram realizadas verificando-seque foi possível observar que os animais Ov apresentavam diminuição da densidade óssea e um processo regenerativo muito mais lento, quando comparados com os animais controle. A calcitonina mostrou-se efetiva tanto nos animais ovariectomizados quanto naqueles apenas com lesão óssea. / In This work we studied the action of calcitonin on bone regeneration in the jaws of normal and ovariectomized rats with and without administration of calcitonin. One hundred rats aged approximately sixty days were used for this study. Of these fifty were ovariectomizedOv forming group and one month after the surgery, animals in all a hundred surgical bone defect was made in the angle of the mandible, creating a bone lesion of approximately 4 mm, covered with a PTFE barrier. OvThe animals were divided into two equal groups: Ov (ovaricctomizados) and LMO (ovariectomized with calcitonin). The other fifty animals, only with the bone lesion were also divided into two groups: control (C) and CM (control with calcitonin). Treated groups received the first dose of the substance immediately after surgery, the dose of 2 IU / kg IM three times per week. The animals were sacrificed after three, seven, 14, 21 and 28 days, with their jaws removed and sent for histological preparation. Densitometric analyzes were performed histological and histomorphometric verifying that it was observed that the Ov animals showed decreased bone density and a much slower regenerative process, when compared with control animals. Calcitonin proved effective in both ovariectomized animals and in those with only bone injury.

Abstract The study was undertaken to determine effects of unilateral masticatory function on craniofacial growth and temporomandibular joint structures in young rabbits. Right-side maxillary and mandibular molars were ground out of occlusion under general anesthesia. Macroscopic measurements were made using the skulls and mandibular halves. Articular surface inclinations were determined using photographs. Positions of articular eminences on crania were determined using machine-vision technique. Changes to extracellular matrix of condylar cartilage were studied histochemically and biochemically. Unilateral masticatory function resulted in changes in the shapes and dimensions of the mandible, maxilla and glenoid fossa. Maxillary widths, lengths of half-mandibles, and angles between the ramus and corpus were lower on the right than on the left side of each animal that had been subjected to right-side molar grinding, and in comparison with controls. As the rabbits grew, there was no recovery from the changes that had been brought about by the asymmetric function, even after occlusal function was reversed or left unmodified after a period of unilateral function. Inclinations of articular surfaces became shallower and positions of articular eminences and glenoid fossae more anterior in animals that had been subjected to molar grinding than in controls. Proteoglycan contents of condylar cartilage extracellular matrix were also affected by molar grinding: amounts of the aggregated proteoglycans in particular were low. We concluded, that the shape and the sagittal and vertical position of the articular eminence is highly adaptive to the function of the condyle process, and that there were associated alterations in the dimensions and shapes of mandible and maxilla. Unilateral masticatory function resulted in significant changes in condylar cartilage extracellular matrix. Normal occlusion and bilaterally symmetric masticatory function during early phases of growth is important for normal development of the maxilla, mandible and articular cartilage.

Magister Scientiae Dentium - MSc(Dent) / Aim: The aim of the study was to compare immediate and delayed surgical management of septic mandibular fractures. Introduction: Infected mandible fractures can be treated via diverse protocols. Two recognized protocols are the so-called delayed approached and the immediate approach. In the delayed approach, sepsis is resolved first, followed by surgery. With the immediate approach, the sepsis is first drained, followed by open reduction and internal fixation of the jaw fracture in one continuous surgical procedure. Material and methods: 20 clinical cases where included in the study. Patients were randomly selected and assigned to the two treatment protocol groups. Pain, vital signs, fracture union, fracture stability, surgical time, hospital time, follow-up visits and patients’ demographics were recorded. Results: No statistically significant findings were made in the analysis of the demographic data and clinical parameters relating to the sepsis. The only significant data were related to the surgical time and hospital time. It was found that the advantages of the immediate approach versus the delayed approach related only to shorter surgical time and less days spent in hospital for the immediate approach. Conclusion: Septic mandibular fractures can be managed either by an immediate or a delayed approach. The immediate surgical approach seems to have an advantage over the delayed approach regarding the surgical time and hospital admission days.

Orientador: Rosilene Fernandes da Rocha / Banca: Darcy de Oliveira Tosello / Banca: Antonio Olavo Cardoso Jorge / Resumo: O objetivo deste trabalho foi avaliar os efeitos da sinvastatina na reparação óssea guiada de mandíbulas de ratas ovariectomizadas e observar o nível de colesterol sangüíneo nesses animais. Foram utilizadas setenta ratas, divididas em quatro grupos: controle normal, controle ovariectomizado, tratado normal e tratado ovariectomizado. Após um mês da ovariectomia foi confeccionado um defeito ósseo bicortical na mandíbula, que foi recoberto por uma membrana de politetrafluoretileno. Imediatamente após a cirurgia os grupos tratados receberam 20mg/Kg/dia de sinvastatina via oral, durante 15 ou trinta dias. As ratas foram sacrificadas 15, trinta e sessenta dias após a cirurgia, tendo o sangue retirado para dosagem do colesterol e a mandíbula removida para análise densitométrica, histológica e morfométrica. Todos os espécimes foram submetidos à análise de variância (ANOVA) e teste de Tukey. Os grupos ovariectomizados apresentaram nível de colesterol superior ao grupo tratado normal e não foram encontradas diferenças estatisticamente significantes entre os diferentes tempos de tratamento e sacrifício. As análises densitométrica, histológica e morfométrica demonstraram que o grupo tratado ovariectomizado apresentou maior quantidade de tecido ósseo neoformado em relação ao controle ovariectomizado, mas não foram observadas diferenças estatisticamente significantes entre os tempos de tratamento. Concluiu-se que a deficiência de estrógeno promoveu um aumento do nível de colesterol sangüíneo e que a sinvastatina favoreceu a reparação óssea guiada nos animais ovariectomizados / Abstract: The purpose of this study was to evaluate the effects of the simvastatin on guided bone regeneration of mandibles of ovariectomized rats and to observe the blood cholesterol level in these animais, 70female rats were divided into four groups; normal control, ovariectomized control, normal treated and ovariectomized treated. A month after the ovariectomy a bone defect was created in the mandible, which was covered by a polytetrafluoroethylene membrane. Immediately after surgery the treated groups received 20 mg/K/day of simvastatin orally for 15 or 30 days. The rats were sacrificed 15, 30 and 60 days after the surgery, a blood sample was extracted to observe the cholesterol levels and the mandible was extracted to densiometric, histological and morphometric analyses. All specimens were submitted to analysis of variance (ANOVA) and to Tukey's method. The ovariectomized groups presented higher cholesterol level than the treated normal group and no significant statistical difference was found between the different treatment periods and the sacrifice times. The densiometric, histological and morphometric analyses showed that the treated ovariectomized group presented more quantity of new bone formation when compared to the control ovariectomized, but no statistica1 difference was observed between the treatment periods. It can be concluded that the deficienty of estrogen increased the level of blood cholesterol and that the simvastatin helped the new bone formation in the ovariectomized animals / Mestre

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.

This inquiry investigated the suitability of the jaw of domestic sheep as an animal model for dental implantology research. Initially, parameters for osseous healing of critical size defects (CSD) in the sheep mandible were established. Pilot studies were conducted using machined-surface implants and a surgical protocol established for dental implant placement in ovine mandibular sites. Subsequent experiments considered the utility of this animal model for examination of techniques designed to enhance osseointegration. Hydroxyapatite-coated implants were compared with titanium plasma-sprayed (TPS) implants, either alone or combined with autogenous bone grafts or a bone graft/collagen vehicle loaded with transforming growth factor-beta (TGF-β). Immunofluorescent bone labelling gave information on the mineral apposition rate (MAR). Implant survival and "acceptability" (likelihood of clinical success) were major output variables, along with histomorphometric analysis of percent bone-implant contact (%BIC) and percent peri-implant bone density (%density). Naturally-occurring "broken-mouth" periodontitis in sheep was identified as a potential confounder. Subsequent experiments considered implants with different surfaces. The model was also extended from a two-stage surgical protocol to include single-stage implants. The effect of pre-existing ovine peridontitis was also examined. A systematic review and meta-analysis of published animal implant experiments was conducted in order to validate the candidate sheep model. Major findings were as follows. The size of non-healing sheep mandibular unicortical CSD is >12mm. Attempts to establish a chronic non-healing CSD were unsuccessful. The sheep diastema proved unsuitable for implant placement. The model was modified to a post-extraction protocol. Implant "acceptability" rates after 3 months integration in the sheep mandible (defined as implant survival with %BIC >10%) ranged from 50% - 100% for different implant surface treatments and placement protocols. Histomorphometriic analyses revealed that %BIC ranged from 11 � 17% to 81 � 29 % for different titanium surfaces and up to 85 � 11% for hydroxyapatite surfaces. Implants with TGF-β plus autogenous bone grafts had %BIC of 36 � 30% compared with 43 � 30% for implants with grafts alone. Bone per unit area (%density) adjacent to, but outside of the implant threads, ranged from 63 � 16% to 86 � 3% and was markedly lower for titanium plasma-sprayed surfaces and for one-stage implants. Within the implant threads, %density varied from 31 � 33% to 73.4 � 8.3%, and was markedly lower for machined titanium surfaces. Sheep periodontitis had little effect on the protocols investigated. The sheep mandibular model was found to be comparable to similar models in other species and merits further development.

The mandible is able to move in a complex fashion, with variable combinations of both translation and rotation in three dimensions (six degrees of freedom), at any given time during function. Research into the process of accurately capturing three-dimensional functional movement of the mandible has many broad clinical applications in dentistry and medicine alike. Anatomical kinematics of the craniofacial skeleton that includes motion analysis has potential scope for clinicians in the areas of diagnostics, treatment planning and treatment outcome assessment. The aims of this study were to describe mandibular motion during opening-closing tasks of two adult subjects and one growing subject with a Class II malocclusion, undergoing growth modification with a Clark Twin Block appliance. Motion analysis recordings were taken with the use of a twelve-camera motion analysis system (Motion Analysis Corporation). The values of the kinematic variables (translation [millimeters] and rotation [degrees]) of mandibular opening-closing that were obtained were consistent and repeatable for both adult subjects throughout this study. In contrast, those values obtained from the subject who wore a functional appliance show noticeable changes in the motion patterning during the initial stages (recordings taken at four and at eight weeks) of appliance wear. These are most apparent in the translation data recorded along the anterior-posterior axis. Mandibular motion however, seemed to return to near pre-treatment patterning in this individual following one year following the initiation of the appliance wear. These observations were seen in one experimental individual. Further research is needed to elucidate whether such changes in motion patterning are seen normally in the growing individual, or, are accountable due to the clinical intervention with an orthodontic appliance. This study piloted the use of two different splint designs for the purposes of recording mandibular motion in the two adult subjects. There were no significant differences in the recording of mandibular motion between the two different splint designs. One design has been recommended for future studies due to its overall ease of fabrication and intra-oral comfort for the subjects.

Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (leaves 40-49).