Cone beam computed tomography for dental implants : influence of the mandibular positioning on the bone height and widht

Orientador: Solange Maria de AlmeidaTese (doutorado) - Universidade Estadual de Campinas. Faculdade de Odontologia de PiracicabaResumo: A utilização de implantes dentários para a reabilitação de regiões edêntulas é uma das atividades mais crescentes da Odontologia e a utilização de imagens é um fator essencial para se alcançar o almejado sucesso. Vários métodos de imagem vêm sendo utilizados com esse propósito e a tomografia computadorizada de feixe cônico (TCFC) vem se estabelecendo como um dos métodos promissores nesse sentido, pois se trata de um método confiável, capaz de produzir imagens em tamanho real, sem sobreposição e com dose de radiação menor que a tomografia computadorizada fan beam. Neste trabalho teve-se como objetivo avaliar a influência da posição da mandíbula na realização de medidas da altura e da espessura de sítios implantares em cortes ortorradiais de TCFC. Para tanto, foram utilizadas 10 mandíbulas maceradas, sendo obtidas imagens utilizando-se o tomógrafo de feixe cônico i-CAT. Foi realizada uma única imagem de cada mandíbula e a partir dessa imagem, os cortes ortorradiais foram obtidos considerando-se 3 diferentes posições: 1: base da mandíbula paralela ao plano horizontal (Posição Normal - PN); 2: base com inclinação de +10° (Posição Superior - PS) e 3: com inclinação de -10° (Posição Inferior - PI). A altura e a espessura óssea de cada região foram mensuradas por um único examinador e os dados obtidos nos grupos experimentais (PS e PI) foram comparados com os dados obtidos do grupo controle (PN) usando a análise de variância two-way (a=0,05). Os valores médios de altura e de espessura ósseas não variaram significativamente entre as posições inclinadas (PS e PI) e a posição padrão (PN), o que permite concluir que nas inclinações avaliadas, a direção do plano axial não influenciou nas medidas obtidasAbstract: Dental implants have became part of routine treatment plans in many cases of edentulous patients and an important part of preimplant examination is provided by images of the existing bone structures in addition to the clinical findings. Several imaging modalities have been used for preimplant assessment and the cone-beam computed tomography may indeed be the next major advancement, since provides clinicians with accurate images of high diagnostic quality with relatively short scanning times and a reported radiation dose lower than fan beam computed tomography. The aim of this present study was to investigate the influence of mandibular inclination on the measured height and width of the cortical bone in reformatted cross-sectional cone beam computed tomography. Ten human dry mandibles were scanned with dental CBCT (i-CAT). It was performed only one scan of any mandible and reformatted cross-sectional scans were obtained at three different positions: (1) parallel to the lower border of the mandible (standard position); (2) with a inclination of +10° (Upper Position) and (3) with a n inclination of -10°(Lower Position). The alveolar bone height and width were measured for one examiner and data subjected to two-way analysis of variance and to compare the means obtained for the experimental groups (UP and LP) with the control group (standard position) (a=0,05). Mean values of bone height and width did not varied significantly between the inclined (UP and LP) and the standard positions. It could be concluded that in the positions analyzed, the direction of the axial planes did not influence the measurements obtainedDoutoradoRadiologia OdontologicaDoutor em Radiologia Odontológic

Dental maturity as an indicator of chronological age: radiographic assessment of dental age in a brazilian population

OBJECTIVE: The purpose of this investigation was to evaluate the applicability of the methods proposed by Nolla and by Nicodemo and colleagues for assessing dental age and its correlation to chronological age. METHODS: Panoramic radiographs of 360 patients from the city of Fortaleza (CE, Brazil) aged 7-15 years were used to assess the associations between dental and chronological age. Data were submitted to statistical analysis using the BioEstat 2.0 (2000) software. Student-Neuman-Keuls test was performed and Pearson's correlation coefficients were calculated at 5% significance level. RESULTS: When the Nolla method was applied, the mean difference between true and estimated age for males and females was underestimated. The use of the method proposed by Nicodemo and colleagues also resulted in underestimation, although it was more evident in male subjects. The correlation coefficients between chronological age and estimated dental age were high, with mean values ranging between 0.87 and 0.91 for males and between 0.84 and 0.93 for females. CONCLUSION: Although both methods proved to be reliable in estimating age, the use of correction factors is recommended

The relationship between temporomandibular dysfunction and head and cervical posture

OBJECTIVE: This study aimed to evaluate the possibility of any correlation between disc displacement and parameters used for evaluation of skull positioning in relation to the cervical spine: craniocervical angle, suboccipital space between C0-C1, cervical curvature and position of the hyoid bone in individuals with and without symptoms of temporomandibular dysfunction. MATERIAL AND METHODS: The patients were evaluated following the guidelines set forth by RDC/TMD. Evaluation was performed by magnetic resonance imaging for establishment of disc positioning in the temporomandibular joints (TMJs) of 30 volunteer patients without temporomandibular dysfunction symptoms and 30 patients with symptoms. Evaluation of skull positioning in relation to the cervical spine was performed on lateral cephalograms achieved with the individual in natural head position. Data were submitted to statistical analysis by Fisher's exact test at 5% significance level. To measure the degree of reproducibility/agreements between surveys, the kappa (K) statistics was used. RESULTS: Significant differences were observed between C0-C1 measurement for both symptomatic (p=0.04) and asymptomatic (p=0.02). No statistical differences were observed regarding craniocervical angle, C1-C2 and hyoid bone position in relation to the TMJs with and without disc displacement. Although statistically significant difference was found in the C0-C1 space, no association between these and internal temporomandibular joint disorder can be considered. CONCLUSIONS: Based on the results observed in this study, no direct relationship could be determined between the presence of disc displacement and the variables assessed

Patologias atuais: a compulsão e a sociedade dos excessos: Current pathologies: compulsion and the society of excesses

O artigo em tela tem por objetivo analisar os aspectos biopsicossociais da conduta compulsiva de consumo. Propõe-se a apresentar os elementos psicológicos contidos nesse comportamento, além de verificar quais são os resultados decorrentes dessa compulsão. O consumo compulsivo, também chamado de oniomania, é um transtorno causado pela ansiedade despertada pela necessidade de comprar e saciada, somente, quando é materializada a aquisição daquilo que se deseja comprar. O estudo em questão pode ser classificado como sendo de cunho bibliográfico, a partir da análise de documentos publicados em forma de artigos científicos e livros em formato digital

Skeletal Age Assessment: A Comparison Of 3 Methods.

The aim of this study was to evaluate the applicability of 3 methods of skeletal age assessment. The skeletal assessment methods of Greulich and Pyle (GP), Tanner et al (TW3), and Eklöf and Ringertz (ER) were used to analyze the dorsopalmar hand-wrist radiographs of 360 Brazilian children and adolescents (180 boys, 180 girls; ages, 7-15 years). The standard error of the mean and confidence intervals of the 3 assessment methods as well as the mean chronologic ages of both sexes and the age ranges studied were calculated. Skeletal age means obtained with the GP and TW3 methods were close to chronologic age for both sexes. The ER method tended to overestimate skeletal age for the lower age groups, to correspond for the intermediate age groups, and to underestimate for the higher age groups in both sexes. The confidence interval confirmed that these data did not represent a statistically significant difference between chronologic and assessed skeletal ages; this means there is a high relationship between the studied sample data and the 3 standard methods. Determinate correction factors (regression equation) make each method more useful for the studied population. Although all methods reliably assessed age, correction factors are recommended for better adaptability to the studied population.130435.e15-2

Computed tomography findings of periostitis ossificans

Periostitis ossificans (PO) is a type of chronic osteomyelitis, an inflammation of cortical and cancellous bone. In the maxillofacial region, the mandible is most frequently affected. The cause of inflammatory subperiosteal bone production in PO is spread of infection from a bacterial focus (e.g.: odontogenic disease, pulpal or periodontal infection, and extraction wounds). This pathology is most common in younger people (mean age of 13 years). Conventional radiographs are one of the most useful tools for diagnosis, but in some cases computed tomography (CT) has a key role in both diagnosis and identification of the tissues involved. This paper reports two cases of PO in which CT helped establishing the suspicious etiology: a 12-year-old boy with PO of pulpal origin and a 14-year-old boy with PO of periodontal origin

The relationship between temporomandibular dysfunction and head and cervical posture

OBJECTIVE: This study aimed to evaluate the possibility of any correlation between disc displacement and parameters used for evaluation of skull positioning in relation to the cervical spine: craniocervical angle, suboccipital space between C0-C1, cervical curvature and position of the hyoid bone in individuals with and without symptoms of temporomandibular dysfunction. MATERIAL AND METHODS: The patients were evaluated following the guidelines set forth by RDC/TMD. Evaluation was performed by magnetic resonance imaging for establishment of disc positioning in the temporomandibular joints (TMJs) of 30 volunteer patients without temporomandibular dysfunction symptoms and 30 patients with symptoms. Evaluation of skull positioning in relation to the cervical spine was performed on lateral cephalograms achieved with the individual in natural head position. Data were submitted to statistical analysis by Fisher's exact test at 5% significance level. To measure the degree of reproducibility/agreements between surveys, the kappa (K) statistics was used. RESULTS: Significant differences were observed between C0-C1 measurement for both symptomatic (p=0.04) and asymptomatic (p=0.02). No statistical differences were observed regarding craniocervical angle, C1-C2 and hyoid bone position in relation to the TMJs with and without disc displacement. Although statistically significant difference was found in the C0-C1 space, no association between these and internal temporomandibular joint disorder can be considered. CONCLUSIONS: Based on the results observed in this study, no direct relationship could be determined between the presence of disc displacement and the variables assessed