Gnathic changes after head and neck radiotherapy have not been thoroughly characterized radiographically. The objectives of this study are to characterize changes to the teeth and jaws on panoramic images following intensity modulated radiotherapy (IMRT), and to determine whether subject comorbidities and radiation dose affect these changes. This retrospective analysis reviews the charts and panoramic images of 126 head and neck cancer patients who received IMRT at Princess Margaret Hospital between January 1, 2005 and December 31, 2008. Of the 126 subjects, 75 (60%) showed changes on panoramic radiographs; 66 (88%) of which consisted of widened periodontal ligament spaces (WPLS). The median time to WPLS was 29 months after IMRT. Female sex and dose correlated with decreased time to WPLS. These results suggest that WPLS is a common radiographic sign following IMRT that may not require endodontic intervention as post-IMRT WPLS is unrelated to the pulpal status of the tooth.

Gnathic changes after head and neck radiotherapy have not been thoroughly characterized radiographically. The objectives of this study are to characterize changes to the teeth and jaws on panoramic images following intensity modulated radiotherapy (IMRT), and to determine whether subject comorbidities and radiation dose affect these changes. This retrospective analysis reviews the charts and panoramic images of 126 head and neck cancer patients who received IMRT at Princess Margaret Hospital between January 1, 2005 and December 31, 2008. Of the 126 subjects, 75 (60%) showed changes on panoramic radiographs; 66 (88%) of which consisted of widened periodontal ligament spaces (WPLS). The median time to WPLS was 29 months after IMRT. Female sex and dose correlated with decreased time to WPLS. These results suggest that WPLS is a common radiographic sign following IMRT that may not require endodontic intervention as post-IMRT WPLS is unrelated to the pulpal status of the tooth.

This retrospective clinical study aimed: (1) to establish and validate a reproducible geometrical measurement strategy in quantifying peri-implant alveolar bone changes based on CBCT images taken before and one year after implantation; (2) to quantify and compare the bone changes of Type 1 and Type 4 implant placement in the patient cohort that requested implant placement at premolar and molar sites; (3) to analyse the bone changes in relation to the two implant protocols in aspects of buccal and lingual, maxilla and mandible, within the cohort and combined cohorts. 3D imaging analysis in this study had used a software package - OnDemand3D. The evaluation of the measurement strategy was based on a simulation model which was made of human dry skull with and without a standard implant (Straumann Standard Plus, Ø3.3 mm diameter, L12 mm) to simulate before and after the implant placement. The recruited cases were 69 (44 Type 1 cases and 25 Type 4 cases); all data sets were provided by Shanghai 9th people's hospital, China. Each case had two CBCT data sets at before and one year after implant placement. With 69 cases, bone grafting was applied to all Type 1 cases, and the flap surgery was applied to Type 1 cases when buccal bone recession greater than 3 mm. The measurements were made in bone height (HL) and bone thickness (L0O0, L1O1, L2O2, L3O) at lingual side, while the same at buccal side (HB, B0O0, B1O1, B2O2, B3O3). The four sections of bone thickness were at 0, 1 mm, 4 mm and 7 mm from the top of the implant. Additionally, six special cases were reported, as they provided extra information. They were two spilt-mouth control cases, three 2-year follow-up cases and one 3-year follow-up case. The evaluation of the measurement strategy showed the error of the measurement strategy was -0.06 mm and the measurement uncertainty was ±0.05 mm. The main measurement outcomes from the clinical cases were as follows: (1) at buccal side, the mean value of bone changes in height was a positive value of +0.18±1.64 mm for Type 1, which was significantly more than +0.01±0.86 mm for Type 4 (p < 0.05). However the standard deviation over the 44 and 25 patient cohorts were as large as 1.64 mm and 0.86 mm; (2) at buccal side, the bone changes in thickness showed significantly more loss at B0O0 (p < 0.01) and B1O1 (p < 0.05) sections in Type 1 (-0.38±1.49 mm and -0.25±1.15 mm) compared with Type 4 (-0.19±0.34 mm and -0.16±0.76 mm); (3) in Type 1 cases, the bone thickness at buccal side showed significantly more absorption at L1O1B1 (p < 0.05), L2O2B2 (p < 0.01), L3O3B3 (p < 0.01) section (-0.25±1.15 mm, -0.19±0.99 mm, -0.12±0.57 mm) compared to lingual side (-0.13±0.85 mm, -0.16±0.28 mm, -0.05±0.28 mm); and the bone height (+0.18±1.64 mm) increased significantly more at buccal side than lingual side (-0.25±0.79 mm) with bone augmentation procedure (p < 0.01). However, within Type 4 cases, no significant difference in bone changes between buccal and lingual sides could be found. In conclusion, the measurement strategy established in this study was reproducible and provided valid quantifiable data of bone changes in relation to implant placement based on 3D CBCT images. The data analysis from these two patient cohorts suggested that Type 1 implant placement protocol could re-build the bone height at buccal side better than Type 4.

Introduction. Osteoporosis is a chronic disease characterized by the loss of bone mass and the deterioration of bone micro-architecture leading to a subsequent increase in fracture risk. High-resolution peripheral quantitative computed tomography (HR-pQCT) provides non-invasive measures of bone micro-architecture and strength in live humans but its ability to monitor small skeletal changes is yet poorly understood. The objectives of this thesis were to 1) determine HR-pQCT precision for volumetric density, geometry, cortical and trabecular micro-architecture, as well as estimates of bone strength; 2) determine the monitoring time interval (MTI) and least significant change (LSC) metrics; and 3) to characterize annual changes in bone area, density, and micro-architecture at the distal radius and tibia using HR-pQCT in postmenopausal women. Methods. To determine precision error as well as monitoring and change metrics of the distal radius and tibia, 34 postmenopausal women (mean age 74, SD±7 years) from the Saskatoon cohort of the Canadian Multicentre Osteoporosis Study (CaMos) were measured using HR-pQCT. To characterize the annual change in bone outcomes of this same cohort, 51 women (mean age±SD: 77±7 years) were measuring at baseline and again 1 year later. Precision errors were calculated as coefficient of variation (CV% and CV%RMS). The LSC was determined from precision errors and then divided by the median annual percent changes to define MTIs for bone area, density, and micro-architecture. Repeated measures analysis of variance (ANOVA) with Bonferroni adjustment for multiple comparisons were used to characterize the mean annual change in total density, cortical perimeter, trabecular and cortical bone area, density, content, and micro-architecture. Significant changes were accepted at P<0.05. Results and Discussion. HR-pQCT precision errors were <10% for bone densitometric, geometric, and mechanical properties; while precision errors were <16% for cortical and trabecular micro-architectural outcomes. Further, the use of either automatic or modified contour methods for the dual-threshold technique for cortical micro-architectural analysis provided similar precision. Densitometric and geometric outcomes had longer monitoring times (>3 years), while micro-architecture had monitoring times of ~2 years. The observed annual changes were statistically significant for several outcomes; however, only cortical and trabecular area, as well as cortical density at the distal tibia changed beyond the LSC. Overall, thesis findings will assist design and interpretation of prospective HR-pQCT studies in postmenopausal women.

Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-08-30T11:31:00Z No. of bitstreams: 1 isabelamaddalenadias.pdf: 1933858 bytes, checksum: dd1558f677feb5cfa8ac31d154731a13 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-08-30T11:44:47Z (GMT) No. of bitstreams: 1 isabelamaddalenadias.pdf: 1933858 bytes, checksum: dd1558f677feb5cfa8ac31d154731a13 (MD5) / Made available in DSpace on 2017-08-30T11:44:47Z (GMT). No. of bitstreams: 1 isabelamaddalenadias.pdf: 1933858 bytes, checksum: dd1558f677feb5cfa8ac31d154731a13 (MD5) Previous issue date: 2011-03-28 / O presente estudo teve como objetivo avaliar por meio de imagens de ressonância magnética a prevalência e os tipos de deslocamentos de disco e alterações ósseas degenerativas que podem acometer a articulação temporomandibular (ATM) de indivíduos adultos portadores de sinais e sintomas de desordens temporomandibulares (DTM), verificando a correlação entre estes achados. Foram avaliadas 224 articulações de112 pacientes, de ambos os gêneros, com indicação para o exame de ressonância magnética. A possibilidade de visualizar simultaneamente o disco articular e estruturas de tecido duro da ATM por meio de um único exame permitiu verificar estas condições e a correlação entre ambas. Para isso um examinador calibrado avaliou as imagens atribuindo escores em relação ao deslocamento do disco articular e alterações ósseas degenerativas. O deslocamento do disco articular foi verificado em 58,42% das ATM avaliadas no corte sagital. O deslocamento anterior de disco com redução foi o mais frequente, ocorrendo em 67,18% dos casos de articulações com deslocamento do disco. Nos cortes coronais, o deslocamento do disco articular foi verificado em 56,65% das ATM avaliadas, sendo o deslocamento medial visto em 96% dos casos. Com relação às alterações ósseas degenerativas as mesmas foram verificadas em 53,94% das ATM analisadas. Houve correlação significativa entre o deslocamento de disco com redução e o aplainamento condilar; deslocamento de disco sem redução e o aplainamento condilar; deslocamento de disco sem redução e alterações degenerativas associadas (aplainamento e erosão; aplainamento, osteófito e erosão; aplainamento e osteófito; erosão e esclerose, aplainamento e esclerose; aplainamento, osteófito e esclerose) e deslocamento lateral do disco articular e osteófitos. A associação entre casos avançados de deslocamento de disco e a ocorrência de alterações degenerativas, enfatizam a importância das imagens por ressonância magnética tanto para um diagnóstico preciso e elaboração de um correto plano de tratamento, quanto para fins prognósticos, nos casos que o exame clínico não é suficiente para estes objetivos. / The aim of this study is evaluate by means of magnetic resonance images the prevalence and types of disc displacements and degenerative bone changes that can affect the temporomandibular joint (TMJ) of patients with signs and symptoms of temporomandibular disorders (TMD),checking the correlation between these findings. Two hundred twenty-for temporomandibular joints of 112 patients of both genders, with an indication for MRI, were evaluated The possibility to simultaneously view the disc and hard tissue structures of the TMJ by a single examination has shown these conditions and the correlation between them. For this purpose a calibrated examiner evaluated the images by assigning scores in relation to the disc displacement and degenerative bone changes. The disc displacement was found in 58.42% of TMJ evaluated on sagittal sections. The anterior displacement of the disc with reduction was the most common, occurring in 67.18% of cases of joints with disc displacement. In coronal sections, disc displacement was observed in 56.65% of TMJ evaluated, and the medial displacement seen in 96% of cases. With respect to degenerative bone changes, the same were observed in 53.94% of TMJ analyzed. There was significant correlation between disc displacement with reduction and condylar flattening, disc displacement without reduction and condylar flattening, disc displacement without reduction and degenerative changes associated (flattening and erosion, flattening, osteophyte and erosion; flattening and osteophytes, erosion and sclerosis, flattening and sclerosis, flattening, osteophytes and sclerosis) and lateral displacement of the disc and osteophytes. The association between advanced cases of disc displacement and the occurrence of degenerative changes, emphasize the importance of magnetic resonance imaging to an accurate diagnosis and development of an appropriate treatment plan, and for prognosis in cases than clinical examination is not sufficient for these purposes.

A articulação temporomandibular (ATM) é considerada a articulação mais complexa do corpo humano. Assim como outras articulações do sistema músculo-esquelético ela pode ser acometida pelas mesmas doenças e desordens, como por exemplo, deslocamentos de disco (DD), doenças articulares degenerativas (osteoartrite OA), artrites inflamatórias e sinovites. Baseado nos laudos obtidos por meio das análises das imagens em norma sagital das ATMs de pacientes sintomáticos encaminhados para a realização de exame por ressonância magnética (RM) foram avaliadas a presença de alterações ósseas das cabeças de mandíbula, eminências articulares e fossas articulares do osso temporal e a presença de derrame articular (DA), decorrentes do posicionamento do disco articular. A amostra foi constituída por 148 ATMs de 74 pacientes sintomáticos. As alterações ósseas ocorreram com mais frequência nas cabeças de mandíbula, com destaque para o aparecimento de osteófitos e erosões nos casos de deslocamento de disco sem redução (DDSR). Os resultados dos testes estatísticos revelaram que as alterações ósseas da cabeça de mandíbula do tipo erosão e osteófito e da eminência articular anterior, assim como a presença do DA estão associadas ao posicionamento do disco articular. / The temporomandibular joint (TMJ) is considered the most complex articulation of the human body. Like other joints of the musculoskeletal system it can be affected by the same diseases and disorders, such as disc displacement, degenerative joint disease (osteoarthritis - OA), inflammatory arthritis and synovitis. Based on reports obtained by the analysis of images in standard sagittal TMJs of symptomatic patients referred for magnetic resonance exam were evaluated the presence of bone changes in the condyle, articular eminence and glenoid fossa, and the presence of joint effusion arising from the positioning of the disc. The sample consisted of 148 TMJs in 74 symptomatic patients. The bone changes occurred more frequently in the condyles, especially the appearance of osteophytes and erosions in cases of disc displacement without reduction. The results of statistical tests revealed that the bone changes of the condyle type erosion and osteophyte and anterior articular eminence, as well as joint effusion are associated with the disc position.

A articulação temporomandibular (ATM) é considerada a articulação mais complexa do corpo humano. Assim como outras articulações do sistema músculo-esquelético ela pode ser acometida pelas mesmas doenças e desordens, como por exemplo, deslocamentos de disco (DD), doenças articulares degenerativas (osteoartrite OA), artrites inflamatórias e sinovites. Baseado nos laudos obtidos por meio das análises das imagens em norma sagital das ATMs de pacientes sintomáticos encaminhados para a realização de exame por ressonância magnética (RM) foram avaliadas a presença de alterações ósseas das cabeças de mandíbula, eminências articulares e fossas articulares do osso temporal e a presença de derrame articular (DA), decorrentes do posicionamento do disco articular. A amostra foi constituída por 148 ATMs de 74 pacientes sintomáticos. As alterações ósseas ocorreram com mais frequência nas cabeças de mandíbula, com destaque para o aparecimento de osteófitos e erosões nos casos de deslocamento de disco sem redução (DDSR). Os resultados dos testes estatísticos revelaram que as alterações ósseas da cabeça de mandíbula do tipo erosão e osteófito e da eminência articular anterior, assim como a presença do DA estão associadas ao posicionamento do disco articular. / The temporomandibular joint (TMJ) is considered the most complex articulation of the human body. Like other joints of the musculoskeletal system it can be affected by the same diseases and disorders, such as disc displacement, degenerative joint disease (osteoarthritis - OA), inflammatory arthritis and synovitis. Based on reports obtained by the analysis of images in standard sagittal TMJs of symptomatic patients referred for magnetic resonance exam were evaluated the presence of bone changes in the condyle, articular eminence and glenoid fossa, and the presence of joint effusion arising from the positioning of the disc. The sample consisted of 148 TMJs in 74 symptomatic patients. The bone changes occurred more frequently in the condyles, especially the appearance of osteophytes and erosions in cases of disc displacement without reduction. The results of statistical tests revealed that the bone changes of the condyle type erosion and osteophyte and anterior articular eminence, as well as joint effusion are associated with the disc position.