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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Effects of premolar extraction on airway dimensions: A retrospective cephalometric appraisal

Van Zyl, Luzaan January 2020 (has links)
Magister Scientiae Dentium - MSc(Dent) / Aim: The aim of this study was to assess the effect of retraction of anterior teeth on pharyngeal airway dimensions, after orthodontic treatment of bimaxillary protrusion cases by means of the extraction of four premolars. Method: A total of 88 lateral cephalometric radiograph pairs, consisting of a pre-treatment and post-treatment radiograph taken for orthodontic treatment of bimaxillary protrusion by means of extraction of four premolars, was used. The pharyngeal airway space, measured across three different levels, as well as the length of the maxilla and mandible were assessed for changes from pre-treatment to post-treatment. Pearson’s correlation coefficient was used to determine the degree to which the change in pharyngeal airway space was associated with the change in maxilla or mandible length. Results: The pre-treatment average pharyngeal airway space measurements were recorded as 15.23mm for the Superior Pharyngeal Airway Space, 11.63mm for the Middle Pharyngeal Airway Space and 13.56mm for the Inferior Pharyngeal Airway Space. The average reduction in the pharyngeal airway space was noted as 1.21mm, 1.64mm and 2.23mm respectively. All with statistically significant P values of <0.001.
2

Utilising radiographic incisor crown markers to determine incisor inclination on lateral headfilms - and experimental study on extracted teeth

Dippenaar, Alfred Meyer 02 March 2004 (has links)
Inaccuracy in landmark identification is regarded as the most important source of error in cephalometry. Better definition of landmarks should therefore contribute to better clinical decisions and research validity. This study primarily comprised of an ex vivo investigation on 50 extracted lower incisor teeth to determine whether radiopaque markers could be utilised to accurately assess lower incisor inclination. Fifty extracted lower incisor teeth were mounted onto a Perspex sheet. Radiopaque markers, manufactured from 1mm wide strips of lead film from used peri-apical radiographs, were attached to the crowns of the mounted teeth. A lateral cephalometric radiograph was taken in accordance to standard radiographic procedures (radiograph A). This showed the true inclination of the teeth. A second radiograph was taken with the roots obscured (radiograph B). Three observers traced the inclinations of the teeth on radiograph B (from incisor edge through the middle of the labio-lingual crown-root junction). The determination was done on two different occasions and the assessments compared with the true inclination. Comparative statistical analysis was applied to the readings and the results indicated that this method compared favourably with other methods to determine incisor inclination. In addition, clinical application of opaque markers to the teeth of patients demonstrated the following: it indicated exactly which tooth was being assessed, provided clear definition of the anatomical crown in the sagittal plane and served as a constant reference point for clinical, study model and cephalometric measurements. decisions and research validity. Opaque radiographic markers on teeth can contribute to more accurate cephalometric measurements in orthodontics, leading to better diagnoses, treatment planning and research validity. / Thesis (MChD (Orthodontics))--University of Pretoria, 2005. / Orthodontics / unrestricted
3

A importância de uma documentação radiográfica como método auxiliar de diagnóstico, planejamento e proservação na reabilitação com prótese total / The importance of radiographic documentation as an auxiliary method of diagnosis, planning and proservation in the rehabilitation with complete dentures

Ramalli, Lílian Tedeschi 04 May 2012 (has links)
As modificações provocadas pelo edentulismo no padrão fonético, mastigatório e estético dos pacientes, implicam em alterações do comportamento social, emocional e psicológico. A fim de que a saúde bucal dos pacientes seja preservada, uma adequada reabilitação oral deve ser realizada, respeitando-se os princípios biomecânicos para a confecção das próteses. Para tanto, o cirurgião dentista pode contar com um aparato de imagens radiográficas que podem auxiliar em várias etapas do processo reabilitador. O objetivo do trabalho foi avaliar a contribuição de diferentes técnicas radiográficas no diagnóstico, planejamento e proservação na reabilitação com prótese total, propondo o emprego de uma documentação radiográfica. Foram utilizadas radiografias das articulações têmporo-mandibulares (ATMs), para avaliação dos espaços articulares anterior, posterior e superior, antes e após o tratamento reabilitador; radiografias panorâmicas e carpais, para avaliação de índices radiomorfométricos mentual, goníaco e metacarpal, para a pesquisa da presença de osteoporose; e telerradiografias laterais cefalométricas antes e após a colocação das próteses totais, verificando a presença da proporção áurea nas medidas craniofaciais. Foram feitas análises estatísticas para correlacionar os dados obtidos das análises radiográficas. Para as radiografias das ATMs, encontrou-se um aumento bilateral do espaço anterior, e uma conseqüente diminuição do espaço posterior, enquanto que o espaço superior aumentou levemente na articulação esquerda e diminuiu levemente na articulação direita. Nas radiografias panorâmicas e carpais observou-se uma diminuição dos valores dos índices radiomorfométricos conforme o aumento da idade. Nas telerradiografias laterais observou-se melhora do perfil com a colocação da prótese, e proximidade de algumas razões com a proporção áurea. Concluiu-se que: as radiografias de ATMs trazem informações importantes acerca da anatomia e relacionamento da cabeça da mandíbula com a fossa articular; os índices radiomorfométricos panorâmicos são importantes para detecção da diminuição da massa óssea, podendo contribuir para a detecção de sinais precoces de osteoporose e propiciar o encaminhamento desses pacientes para cuidados médicos adequados; o índice metacarpal propiciou informações muito semelhantes aos índices panorâmicos, não havendo, portanto, necessidade dessa radiografia compor a documentação, uma vez que a panorâmica pode contribuir com um maior número de informações; e que as telerradiografias laterais mostrou que, além de auxiliar no diagnóstico, através de medidas da dimensão vertical, posicionamento dos dentes artificiais, entre outros, ainda possibilitou avaliação da estética facial, tornando-se uma ferramenta da qual o cirurgião dentista pode lançar mão utilizando a proporção áurea como instrumento auxiliar na busca e favorecimento de planos de tratamento eficazes. / The changes caused by tooth loss in the standard phonetic, chewing and aesthetic of the patients, result in changes in social behavior, emotional and psychological. In order that the oral health of patients is preserved, adequate oral rehabilitation must be performed respecting the biomechanical principles for the manufacture of prostheses. Thus, the dentist may have an apparatus of radiographic images that can help in various stages of rehabilitation. The objective of this study was to evaluate the contribution of different radiographic techniques in the diagnosis, planning and proservation in the rehabilitation with dentures, proposing the use of a radiographic documentation. The TMJ radiographs were used for assessment of joint spaces anterior, posterior and upper before and after rehabilitation treatment, panoramic and carpal radiographs for evaluation radiomorphometric index mental, gonial and metacarpal, for the detection of the presence of osteoporosis, and radiographs lateral cephalometric before and after placement of dentures, verifying the presence of the golden ratio in craniofacial measures. Statistical analysis was made to correlate the data obtained from the radiographic analysis. For Radiographs of the ATMs, found a bilateral increase in anterior space, and a consequent reduction of the posterior space, while the upper space in the joint increased slightly left and slightly decreased in the right joint. In the panoramic radiographs and carpal observed a decrease in values of radiomorphometric index increase with age. In the lateral cephalometric radiographs showed improvements of the profile with the placement of the prosthesis, and proximity to some reasons with the golden ratio. Was concluded that: the TMJs radiographs provide important information about the anatomy and relationship of the condyle with the glenoid fossa; radiomorphometric index are important for detection of low bone mass and may contribute to the detection of early signs of osteoporosis and to facilitate the referral of patients to proper medical care, and the index metacarpal provided information very similar to the panoramic indices, and there is therefore need for such radiography compose documentation, since the panoramic can contribute to a greater amount of information, and that the lateral cephalometric radiographs showed that in addition to aid in the diagnosis, through measures of the vertical dimension, positioning of artificial teeth, among others, has enabled evaluation of facial aesthetics, becoming a tool from which the dentist can resort to using the the golden ratio as an aid in search and favoring effective treatment plans.
4

A importância de uma documentação radiográfica como método auxiliar de diagnóstico, planejamento e proservação na reabilitação com prótese total / The importance of radiographic documentation as an auxiliary method of diagnosis, planning and proservation in the rehabilitation with complete dentures

Lílian Tedeschi Ramalli 04 May 2012 (has links)
As modificações provocadas pelo edentulismo no padrão fonético, mastigatório e estético dos pacientes, implicam em alterações do comportamento social, emocional e psicológico. A fim de que a saúde bucal dos pacientes seja preservada, uma adequada reabilitação oral deve ser realizada, respeitando-se os princípios biomecânicos para a confecção das próteses. Para tanto, o cirurgião dentista pode contar com um aparato de imagens radiográficas que podem auxiliar em várias etapas do processo reabilitador. O objetivo do trabalho foi avaliar a contribuição de diferentes técnicas radiográficas no diagnóstico, planejamento e proservação na reabilitação com prótese total, propondo o emprego de uma documentação radiográfica. Foram utilizadas radiografias das articulações têmporo-mandibulares (ATMs), para avaliação dos espaços articulares anterior, posterior e superior, antes e após o tratamento reabilitador; radiografias panorâmicas e carpais, para avaliação de índices radiomorfométricos mentual, goníaco e metacarpal, para a pesquisa da presença de osteoporose; e telerradiografias laterais cefalométricas antes e após a colocação das próteses totais, verificando a presença da proporção áurea nas medidas craniofaciais. Foram feitas análises estatísticas para correlacionar os dados obtidos das análises radiográficas. Para as radiografias das ATMs, encontrou-se um aumento bilateral do espaço anterior, e uma conseqüente diminuição do espaço posterior, enquanto que o espaço superior aumentou levemente na articulação esquerda e diminuiu levemente na articulação direita. Nas radiografias panorâmicas e carpais observou-se uma diminuição dos valores dos índices radiomorfométricos conforme o aumento da idade. Nas telerradiografias laterais observou-se melhora do perfil com a colocação da prótese, e proximidade de algumas razões com a proporção áurea. Concluiu-se que: as radiografias de ATMs trazem informações importantes acerca da anatomia e relacionamento da cabeça da mandíbula com a fossa articular; os índices radiomorfométricos panorâmicos são importantes para detecção da diminuição da massa óssea, podendo contribuir para a detecção de sinais precoces de osteoporose e propiciar o encaminhamento desses pacientes para cuidados médicos adequados; o índice metacarpal propiciou informações muito semelhantes aos índices panorâmicos, não havendo, portanto, necessidade dessa radiografia compor a documentação, uma vez que a panorâmica pode contribuir com um maior número de informações; e que as telerradiografias laterais mostrou que, além de auxiliar no diagnóstico, através de medidas da dimensão vertical, posicionamento dos dentes artificiais, entre outros, ainda possibilitou avaliação da estética facial, tornando-se uma ferramenta da qual o cirurgião dentista pode lançar mão utilizando a proporção áurea como instrumento auxiliar na busca e favorecimento de planos de tratamento eficazes. / The changes caused by tooth loss in the standard phonetic, chewing and aesthetic of the patients, result in changes in social behavior, emotional and psychological. In order that the oral health of patients is preserved, adequate oral rehabilitation must be performed respecting the biomechanical principles for the manufacture of prostheses. Thus, the dentist may have an apparatus of radiographic images that can help in various stages of rehabilitation. The objective of this study was to evaluate the contribution of different radiographic techniques in the diagnosis, planning and proservation in the rehabilitation with dentures, proposing the use of a radiographic documentation. The TMJ radiographs were used for assessment of joint spaces anterior, posterior and upper before and after rehabilitation treatment, panoramic and carpal radiographs for evaluation radiomorphometric index mental, gonial and metacarpal, for the detection of the presence of osteoporosis, and radiographs lateral cephalometric before and after placement of dentures, verifying the presence of the golden ratio in craniofacial measures. Statistical analysis was made to correlate the data obtained from the radiographic analysis. For Radiographs of the ATMs, found a bilateral increase in anterior space, and a consequent reduction of the posterior space, while the upper space in the joint increased slightly left and slightly decreased in the right joint. In the panoramic radiographs and carpal observed a decrease in values of radiomorphometric index increase with age. In the lateral cephalometric radiographs showed improvements of the profile with the placement of the prosthesis, and proximity to some reasons with the golden ratio. Was concluded that: the TMJs radiographs provide important information about the anatomy and relationship of the condyle with the glenoid fossa; radiomorphometric index are important for detection of low bone mass and may contribute to the detection of early signs of osteoporosis and to facilitate the referral of patients to proper medical care, and the index metacarpal provided information very similar to the panoramic indices, and there is therefore need for such radiography compose documentation, since the panoramic can contribute to a greater amount of information, and that the lateral cephalometric radiographs showed that in addition to aid in the diagnosis, through measures of the vertical dimension, positioning of artificial teeth, among others, has enabled evaluation of facial aesthetics, becoming a tool from which the dentist can resort to using the the golden ratio as an aid in search and favoring effective treatment plans.

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