Thesis (M.S.) --University of Texas Graduate School of Biomedical Sciences at San Antonio, 2008. / Vita. Includes bibliographical references.

A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Master of Medicine, Johannesburg, 2018 / Introduction: The hallux valgus interphalangeus (HVI) deformity has a common association with hallux valgus and hallux rigidus. The radiographic measurement of the hallux valgus interphalangeus is formed by the angle between the long axes of the proximal and distal phalanges. The normal value for this angular deformity in the coronal plane is less than 10 degrees. The reliability of measuring the hallux interphalangeal angle has not been verified as yet .The purpose of this study is to analyse the intra- and inter-observer reliability of measurements of the interphalangeal angle by orthopaedic surgeons. This study is going to be the first study to evaluate the reliability and reproducibility of the hallux valgus interphalangeal angle. Methods: Twenty one X-ray prints (images) of the weight bearing foot constituted a set. Three such sets were sent to each evaluator at four week intervals. Sixteen qualified orthopaedic surgeons were asked to measure the hallux interphalangeal angle of all twenty one X-ray images at three different occasions. After all three sets were measured, data was retrieved and statistically analysed to determine the incidence of inter- and intra-observer variability and reliability in the measurement of the hallux interphalangeal angle. Results: Reproducibility of the hallux interphalangeal angle measurement was assessed using three categories which included the ability to measure the same angle three times and achieve: three degrees or less, five degrees or less, more than five degrees. The intra-observer reliability was found to be 5 degrees and less in 75.2% of participants and for the inter-observer reliability was 61.2%. The researcher did not find significant correlation between the surgeons’ level of experience with respect to the reliability of measurement of the hallux interphalangeal angle. Conclusion: The reliability and reproducibility of measurement of the hallux interphalangeal angle is low. The level of experience of the surgeon does not improve this reliability. / XL2018

No description available.

Objectives: This project explores the demographic and clinical presentation of cemento-osseous dysplasia (COD), and their pathognomonic radiographic features. Methods: Demographic and clinical data were collected from the charts of 118 subjects with COD from the Oral Radiology archives. Using a systematic objective survey instrument, 3 general dentists (GP) and 3 oral radiologists (RG) reviewed 50 image sets of COD and similarly-appearing entities. Participants were asked to identify radiographic features and to make a diagnosis based on the images provided. Results: The majority of cases occurred in clinically asymptomatic females in their fifth decade. RGs identified a well-defined border, radiolucent periphery, bilateral occurrence, mixed radiolucent/radiopaque internal structure, and association with anterior and posterior teeth as key features, correctly interpreting 79.3% of COD cases. The absence of root resorption and an association with anterior and posterior teeth were the only key features that guided GPs to correctly interpret 38.7% of COD cases.

Objectives: This project explores the demographic and clinical presentation of cemento-osseous dysplasia (COD), and their pathognomonic radiographic features. Methods: Demographic and clinical data were collected from the charts of 118 subjects with COD from the Oral Radiology archives. Using a systematic objective survey instrument, 3 general dentists (GP) and 3 oral radiologists (RG) reviewed 50 image sets of COD and similarly-appearing entities. Participants were asked to identify radiographic features and to make a diagnosis based on the images provided. Results: The majority of cases occurred in clinically asymptomatic females in their fifth decade. RGs identified a well-defined border, radiolucent periphery, bilateral occurrence, mixed radiolucent/radiopaque internal structure, and association with anterior and posterior teeth as key features, correctly interpreting 79.3% of COD cases. The absence of root resorption and an association with anterior and posterior teeth were the only key features that guided GPs to correctly interpret 38.7% of COD cases.

Resumo: A reabsorção severa da raiz diagnosticada tardiamente pode acarretar a perda dentaria, e sendo a técnica de subtração radiográfica digital (SDR) um importante recurso para detecção precoce de alterações minerais, este estudo avaliou a eficiência no diagnóstico precoce da reabsorção radicular externa simulada apical e lingual, pela técnica de subtração radiográfica digital (SRD) e radiografia digital (RD). Foram utilizados 14 dentes incisivos de mandíbulas humanas maceradas com reabsorções de diferentes dimensões, simuladas na região apical e lingual, e radiografados com variação de ângulos de projeção. As radiografias foram subtraídas pelo programa Regeemy®, e para avaliação do desempenho dos métodos de diagnóstico, pares de radiografias periapicais e imagens subtraídas foram apresentadas a 2 radiologistas. De acordo com os resultados, não foram observadas diferenças estatisticamente significativas entre os métodos na detecção de reabsorções linguais, independentemente do tamanho da lesão, assim como não houve diferença entre os métodos na detecção de reabsorções apicais, com exceção do examinador 2 com relação a variação angular vertical e horizontal de 100 utilizando o maior nível de desgaste, que apresentou a radiografia digital como método superior na avaliação em relação a subtração radiográfica. E o aumento no nível de desgastes e a menor variação dos ângulos verticais e horizontais permitiram melhor avaliação nas regiões de reabsorções apicais e linguais, para detecção das reabsorções apicais e linguais. Com estes resultados podemos concluir que a subtração radiográfica digital é um exame indicado para detecção de pequenas perdas minerais em radiografias que apresentem pouca ou nenhuma variação nas angulações verticais e horizontais / Abstract: The severe root resorption diagnosed late can lead to tooth loss, and being the technique of digital subtraction radiography (SDR) as an important resource for early detection mineral changes, this study evaluated the efficiency in the early diagnosis simulated external root resorption apical and lingual by the technique of digital subtraction radiography (SRD) and digital radiography (DR). We used 14 human incisors jaw macerated with resorption different sizes, simulated in the apical and lingual, and radiographed with a range of projection angles. The radiographs were subtracted by the program Regeemy ®, and performance evaluation diagnostic methods, pairs intraoral radiographs and subtracted images were presented to two radiologists. According to the results, there were no statistically significant differences between methods in the detection lingual resorption, regardless of lesion size, as there was no difference between the methods in the detection of apical resorption, except the second examiner with respect to variation vertical and horizontal angle of 100 using the highest level of wear, which lodged the digital radiography as a method superior in the evaluation for subtraction radiography. And the increase in the level of wear and less variation vertical and horizontal angles allowed a better assessment resorption in the regions apical and lingual to detect and lingual apical resorption. With these results we conclude that the digital subtraction radiography is a test for the detection of small mineral loss in radiographs showing little or no variation in vertical and horizontal angles / Orientador: Mari Eli Leonelli de Moraes / Coorientador: Jefferson Luis Oshiro Tanaka / Banca: Rodrigo Dias Nascimento / Banca: Edmundo Médicci Filho / Banca: Milton Soares Gonçalves / Banca: Warley David Kerbauy / Doutor

No

This purpose of this work was to investigate the patient radiation doses and image quality of a Philips/Agfa computed radiographic (CR) system and a Philips indirect-capture digital radiographic (DR) system in a paediatric setting. A CDRAD digital radiographic contrast-detail phantom was used to assess radiographic image quality. Perspex slabs of three different thicknesses (6, 11 and 16 cm) were used to simulate paediatric patients of three arbitrary ages. These phantoms, in conjunction with the CDRAD digital radiographic contrast-detail phantom, were imaged under three different conditions. The CDRAD Analyser software package was used to assess the quality of each image. The first experiment conducted was a comparison of the two systems under standard conditions, with beam filtration of aluminium and copper, as recommended in European Guidelines on Quality Criteria for Diagnostic Radiographic Images in Paediatrics (European Commission 1996b). Image quality was compared for each phantom size at three doses with the same entrance exposure used for both systems. A visual comparison of the resulting contrast detail curves showed the DR system generally outperformed the CR system, especially at the lowest two doses. A chi-square analysis of the targets detected generally confirmed this visual impression. The second experiment performed was to compare the two systems under the conditions used in routine clinical practice at PMH. As a result of additional beam filtration not generally being employed, the image quality of the CR system was similar to the DR system for the two smaller phantom sizes but with a major dose cost - effective doses higher by between 38% and 100%. A chi-square analysis of the targets detected showed the CR system to be significantly better than the DR system at two of three doses for the thinnest phantom and no significant difference at any doses for the intermediate phantom size. For the largest phantom size, additional filtration - although different - was used for the CR and DR systems and so the X-ray beam spectra were more similar. Consequently, the results for this phantom size reflected those from the experiment conducted under standard conditions, ie the effective doses for both systems were similar and the image quality of the DR system superior. The chi-square analysis s howed the DR system to be significantly better than the CR at all three dose levels. A third experiment was undertaken to compare doses between the two systems at 'equal' image quality. The CDRAD Analyser software specific image quality parameter, IQFinv, was held constant for both systems. The entrance exposures required to achieve this image quality were measured and then converted to effective doses using the dose calculation software package PCXMC 1.5. The DR system offered effective dose savings of between 28 and 42% for the three phantom sizes. Overall, this work suggests that a Philips flat-panel system is superior to an Agfa CR system in paediatric radiography. This result generally reflects the findings of other authors who have conducted similar studies in adult patient settings.

Diss. (sammanfattning) Linköping : Univ., 2001. / Härtill 5 uppsatser.

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