Thesis (Ph. D.)--Simon Fraser University, 2007. / Senior Supervisor: Jerald Zaslove. Includes bibliographical references (leaves 291-310). Also issued in digital format and available on the World Wide Web.

Quality control on panoramic radiography units, calculation of effective dose, principles of function of panoramic units, QC protocols, radio-protection issues. / Έλεγχος ποιότητας οδοντιατρικών πανοραμικών συστημάτων ακτινογράφησης, υπολογισμός ενεργού δόσης, αρχές λειτουργίας πανοραμικών συστημάτων, πρωτόκολλα ποιοτικού ελέγχου, ζητήματα ακτινοπροστασίας.

Made available in DSpace on 2014-06-11T19:29:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-07-01Bitstream added on 2014-06-13T18:07:38Z : No. of bitstreams: 1 bissoli_cf_me_sjc.pdf: 1658392 bytes, checksum: 87521fc116b48dbe7d8b1a4b112dee4e (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O propósito deste trabalho é analisar e verificar as medidas verticais de dentes humanos in vitro por meio de radiografias panorâmicas. O estudo foi baseado na montagem de uma boca com 28 dentes em um manequim de borracha, sendo utilizado para a realização das radiografias dois aparelhos ortopantomográficos (Rotograph plus e Panoura-10). O manequim, com o auxílio de suportes de madeira, foi radiografado com o plano oclusal paralelo ao horizontal, e também com seu plano oclusal à +5 graus e à -5 graus em relação ao plano horizontal. Os resultados obtidos indicaram que para a região de incisivos para o aparelho Rotograph plus a ampliação foi de 18,97% na maxila e 17,91% na mandíbula; para a região de pré-molares foi de 16,38% na maxila e 16,30% na mandíbula; e para a região de molares foi de 14,90% na maxila e 14,24% na mandíbula. Já para o aparelho Panoura-10 foi na região de incisivos 19,70% na maxila e 19,31% na mandíbula, na região de pré-molares 18,49% na maxila e 17,88% na mandíbula e para molares 16,66% na maxila e 16,17% na mandíbula. Conclui-se que houve ampliações diferentes nas regiões anatômicas estudadas. Posteriormente foi feito o teste estatístico ANOVA, e não houve diferenças estatisticamente significantes entre as inclinações de +5 graus e -5 graus em relação ao plano oclusal paralelo ao horizontal nos dois aparelhos (p>0,05). Também foi concluído que o aparelho Panoura-10 obteve 18,03% de ampliação vertical geral média e que o Rotograph plus obteve 16,45% de ampliação vertical geral média. / The aim of this work is to analyze and to verify the vertical measurements of the human teeth in vitro by panoramic radiographs. The study was based in set up of 28 teeth in rubber manikin. The radiographs were made with two orthopantomographs (Rotograph plus and Panoura - 10). The manikin with wood supports was radiographic with oclusal plane parallel to horizontal plane and oclusal plane 5 degrees positive and 5 degrees negative to horizontal plane. The results has showed that in incisors region, in Rotograph plus, has enlarged 18,97 % for the maxilla and 17,91% for the mandible; in bicuspid region, 16,38% for the maxilla and 16,30%for the mandible; and molar region, 14,90% for the maxilla and 14,24% for the mandible. The Panoura - 10 has enlarged in incisor region, 19,70% for the maxilla and 19,31% for the mandible, mandible, in bicuspid region, 18,49 % for the maxilla and 17,88 % for the mandible and molar region 16,66 % for the maxilla and 16,17 % for the mandible. The conclusions were that different enlargements in anatomic regions studied occurred. The ANOVA test has known that significance statistical differences between the inclinations of +5 degrees and -5 degrees and oclusal plane parallel the horizontal plane in both (p>0,05) didn t happen. The Panoura - 10 has enlarged 18,03% in total vertical average and the Rotograph plus has enlarged, 16,45 % in total vertical average.

Orientador: Plauto Christopher Aranha Watanabe / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-13T08:02:53Z (GMT). No. of bitstreams: 1 Pedrosa_EsioFortalezaNascimentoChaves_M.pdf: 2734521 bytes, checksum: ab04697c2441e91af05be90051625d6d (MD5) Previous issue date: 2009 / Resumo: Existem diversos métodos para avaliar a qualidade óssea através de sua densidade. Estes métodos variam no custo, disponibilidade e na dose de radiação. O cirurgião-dentista atua nos elementos dentários e nas estruturas de suporte dos maxilares e mandíbula, componentes do sistema estomatognático. Nas últimas décadas têm se pesquisado muito a respeito da qualidade óssea das estruturas de suporte dos elementos dentários, principalmente na mandíbula, com convincentes evidências de perda óssea bucal associada com a osteoporose, particularmente um aumento da porosidade cortical do osso alveolar e corpo mandibular. O Objetivo deste estudo foi avaliar a correlação de três aspectos da qualidade óssea mandibular, em radiografias panorâmicas, correlacionando-os com medidas de densidade óssea mineral (DOM) do DEXA realizados no radio, coluna e fêmur. Os resultados apresentaram correlação significante entre a classificação morfológica do córtex (CC) e a espessura da cortical basal mandibular com a DOM. Não houve correlação entre os fatores dimensão fractal (DF) e porcentagem de pixels pretos (ET) com a DOM. Pode-se concluir que é possível referenciar pacientes para o DEXA com a finalidade de pesquisar a baixa massa óssea mineral pelas análises da cortical inferior da mandíbula. / Abstract: There are several methods to evaluate the bone quality by the density. These methods vary in cost, availability and the radiation dose. The dentist works on teeth and in the maxilla and mandible support structures, components of the stomatognathic system. Recently, it has been searched too much about the bone quality of the teeth support structures, especially in the jaw with evidences of oral bone loss associated with osteoporosis, particularly an increase in cortical porosity of the alveolar bone and mandibular body. The aim of this study was to evaluate the interrelationship of three aspects of mandibular bone quality on panoramic radiographs, correlating them with measures of bone mineral density (BMD) of DEXA performed in radio, spine and femur. The results showed a significant correlation between the cortex morphological classification and cortex thickness with lower BMD. There was no correlation between the fractal dimension (FD) factors and black pixels (ET) percentage with the BMD. It could be concluded that it is possible to refer patients for DEXA in order to search for low bone mineral analysis of the lower mandibular cortex. / Mestrado / Radiologia Odontologica / Mestre em Radiologia Odontológica

A hiperplasia do processo coronóide (HPC) é uma variação morfológica que causa limitação na abertura de boca interferindo na mastigação. Normalmente não apresenta sintomatologia dolorosa e o paciente só vai procurar tratamento quando houver dor ou problemas funcionais causados pela compressão do processo coronóide hiperplásico no osso zigomático. Muitos clínicos desconhecem esta alteração e adotam tratamento para disfunção da articulação temporomandibular (ATM). Neste trabalho propôs-se mostrar que a hiperplasia do processo coronóide pode ser observada em radiografias panorâmicas de forma a suspeitar da existência dessa alteração e, aliado aos dados clínicos, o cirurgião-dentista generalista possa encaminhar o paciente ao especialista para que sejam providenciados exames mais complexos que permitam a conclusão do diagnóstico. A amostra constituiu-se de 150 radiografias panorâmicas dentre as quais estavam incluídas imagens sugestivas da hiperplasia do processo coronóide (HPC). Estas radiografias foram submetidas à análise de 3 Radiologistas com um mínimo de 5 anos de experiência na especialidade. Ficou concluído que a radiografia panorâmica é um meio auxiliar para o diagnóstico inicial dessa alteração e o clínico deve estar atento aos possíveis indicativos que esta técnica radiográfica fornece para a sugestão do diagnóstico. / The Coronoid Process Hyperplasia is a morphologic variation, which reduces mouth opening and interferes on mastication. Normally, it doesn\'t have pain symtomatology, and the patient will only look for treatment when there is pain or functional problems caused by compression of the Hyperplasic Coronoid Process on the zygomatic bone. Many practitioners ignore this alteration, and do treatment for termporomandibular joint disorder. This work proposes to show that is possible to suspect the presence of Coronoid Process Hyperplasia on panoramic radiography, and allied with clinical information, general practitioners can forward their patients to a specialist, to make more complex exams which will allow the conclusion of the diagnosis. The sample was composed by 150 panoramic radiographys, where included some suggestive radiographs of Coronoid Process Hyperplasia. These radiographs were analyzed by 3 Radiologists with at least 5 years of experience on this activity. It was concluded that panoramic radiography is an auxiliary way for initial diagnoses of this alteration and practitioners should attent the possible indicatives that this radiograph technique brings for diagnoses suggestion.

>Magister Scientiae - MSc / Different pathology associated with impacted wisdom teeth in the oral cavity showed that it is prevalent and may lead to varied dental complications. This study adopted a descriptive cross-sectional retrospective analytical design in order to examine hard tissue features associated with the presence of impacted third molars in a random sample of 2998 digital panoramic radiographs (DPRs) of patients' records in Tygerberg Oral Health Centre, Faculty of Dentistry, University of Western Cape. The specific objectives of the study were to categorize the type of impactions in the DPRs of patients and to determine the prevalence of distal cervical caries (DCC) in second molars, any radiolucent (RL) /radiopaque (RO) lesions or external root resorption (ERR) complications associated with impacted wisdom teeth. Results of the pantomographs and clinical records of patients indicated that the most prevalent type of impaction (TOI) is Mesioangular (MA) Impaction (65%) followed by Horizontal (H) Impaction (17%), Vertical (V) Impaction (15%), Transverse (TVS) Impaction (2 %) and Distoangular (DA) Impaction (1.2 %), respectively. The least prevalent type was Inverted (INV) Impaction with a frequency count of 0.5%. The results further indicated varied dental complications resulting from impaction, ranging from ERR with a frequency of 3% of which 66.70% was associated with MA type of impaction, followed by H with a frequency of 26.7%. The association of Gender and RL/ RO lesions was significant (p-value=0.04) while association between DCC and types of impaction was also significant (p-value =0.0017). The study concluded that the high prevalence of MA among all populations and genders over the years may be related to the anatomical normal inclination of the third molars to the mesial surface. The low prevalence of DA observed in the study sample on the other hand might be attributable to gender and demographic factors. Lastly, this study has only one radiopaque lesion and the high prevalence of RL lesions in males and in the older age group suggests that these complications take a while to develop. Future research is needed to raise more awareness and encourage patients to seek treatment of symptomatic and asymptomatic third molars before complications arise.

Syftet med studien är att undersöka fem olika mätmetoders noggrannhet för bestämning av positionen hos en ej erupterad överkäkshörntand på panoramabilder. Då allt fler panoramabilder exponeras på barn och ungdomar kan dessa användas för positionsbestämning av överkäkens hörntänder. Materialet omfattar panoramaröntgenbilder på 70 överkäkshörntänder på 47 barn och ungdomar, 9-19 år gamla. Fem mätmetoder för positionsbestämning av hörntanden med panoramabilden jämförs samt valideras med CBCT "Gold standard". 1. Vinkelmetod (Ang1); 2. Vinkelmetod (Ang2); 3. Canine Incisive Index (CII); 4. Sektormetod; 5. Vertikalmetod. Studien visade att de bästa metoderna för positionsbestämning av hörntanden är Ang1 och Ang2, samt CII, med en accuracy på 74 % -72 %, medan sektormetoden hade en accuracy på 64 %. Ingen statistiskt signifikant skillnad förelåg mellan Ang1, Ang2, CII och sektormetoden. Panoramabilden kan användas för bedömning av hörntandens position innan vidare utredning med CBCT görs.

Magister Scientiae Dentium - MSc(Dent) / Background: Dental age is an indicator of the physiological maturity of growing children. Different methods for estimating the dental age in comparison to the chronological age were proposed in the literature. Objective: The aim of this study was to compare the accuracy of two methods i.e. the Phillips and Proffit methods in estimating the dental age in a sample of South African children at the Tygerberg dental faculty. Methods: A retrospective study was conducted by randomly selecting 100 panoramic radiographs with known chronological age. The sample contained an equal number of girls and boys (50 in each group) and the chronological age ranged between 6 and 11 years. Dental age for each radiograph was estimated using the Phillips and the Proffit methods respectively. The mean difference between dental and chronological age was calculated. Dental and chronological ages were compared using overall bias and random errors. Results: The results showed that for the girls’ sample, the Phillips method underestimated the age by 4 months which is statistically significant (p-value =0.03). The Proffit method underestimated the age by 2 days which is not statistically significant (p-value =0.97). Both methods however have the same frequency of random errors. For the boys’ sample, Phillips’ method underestimated the age by 6 months which is statistically significant (p-value <0.0001). Proffit’s method underestimated the age by 2 months which is not statistically significant (p-value= 0.15). The Phillips method was shown to have fewer random errors in boys. Discussion: The above mentioned results showed that for dental age estimation for girls, Proffit’s method would be more appropriate. This rationale is explained by the conclusion that it only underestimates the age by 2 days and has the same frequency of random errors as Phillips’ method. However, if one had to choose between the two methods for boys, the situation should be evaluated carefully. For boys, the Phillips method has fewer random errors but a larger overall bias (6 months) whereas Proffit’s method has more random errors but less overall bias (2 months). The choice between the two methods should therefore depend on the purpose of the estimation. If the method is used for estimating the age in a single individual with an unknown chronological age, Phillips’ method would be more preferable. However, if the method is used for age estimation in populations with a known mean chronological age, Proffit is preferred. Conclusion: Proffit’s description for dental development has been shown to be accurate in estimating the DA. It may therefore be considered to be a legitimate DA estimation method and not just a developmental description for the dentition.

Orientador: Deborah Queiroz de Freitas França / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-27T00:38:46Z (GMT). No. of bitstreams: 1 Lopes_LucianaJacome_M.pdf: 2079743 bytes, checksum: df9b484145571a9011ec6e478289e4c6 (MD5) Previous issue date: 2015 / Resumo: Diversos fatores influenciam o crescimento e desenvolvimento de crianças e adolescentes, dentre eles fatores ambientais e étnicos, o que faz com que distintas populações apresentem diferentes padrões de desenvolvimento. O escasso conhecimento da relação entre o desenvolvimento dentário e a maturação esquelética na população brasileira até o momento justifica a realização de pesquisas que avaliem a referida relação em indivíduos brasileiros. Portanto, o presente estudo teve como objetivo investigar a relação entre os estágios de mineralização dos dentes e os estágios de maturação esquelética da mão e punho na população brasileira. Foram selecionadas radiografias panorâmicas e carpais de 491 indivíduos (222 do sexo masculino e 269 do sexo feminino) com idades entre 7 e 17 anos. Dois radiologistas avaliaram as imagens juntos, chegando a um consenso final. Os estágios de mineralização dentária nas radiografias panorâmicas foram determinados de acordo com Demirjian e a maturação esquelética nas radiografias carpais de acordo com Grave & Brown. A média e o desvio padrão das idades cronológicas foram determinados para as três fases do surto de crescimento puberal (SCP) e a associação entre os estágios foi obtida através da análise de regressão logística multinominal ordinal. O percentual de distribuição dos dentes estudados dentre as fases de maturação também foi calculado. O segundo molar (Odds Ratio (OR) = 4,34, 95% intervalo de confiança (IC): 2,64-7,68) e primeiro pré-molar (OR = 2,45, 95% IC: 1,40-4,28) foram os melhores preditores de crescimento para o sexo feminino. Para o sexo masculino, que apresentou a mineralização dos dentes em estágios mais avançados, o segundo molar (OR = 6,80, 95% IC: 3,48-13,27), o segundo pré-molar (OR = 2,41, 95% IC: 1,24-4,43) e o canino (OR = 3,21, 95% IC: 1,38-7,50) foram os melhores indicadores. Os estágios D e E para o sexo feminino e os estágios E e F para o sexo masculino do segundo molar corresponderam aos eventos que ocorrem no início do surto de crescimento puberal. O estágio F para o sexo feminino e G para o sexo masculino do segundo molar corresponderam aos eventos que ocorrem durante o pico do SCP. No final do SCP, a maior parte dos dentes apresentaram os ápices fechados, com exceção do segundo molar no sexo feminino em que a maioria estava no estágio G. Foi possível concluir que existe associação entre os estágios de mineralização dentária e as fases de maturação esquelética em indivíduos na população brasileira e que a avaliação desses estágios é útil para estimar em que fase do SCP o paciente se encontra / Abstract: Several factors influence the growth and development of children and adolescents, including environmental and ethnic factors, so different populations show different patterns of development. The poor knowledge of the relationship between tooth development and skeletal maturity in the Brazilian population justify the need for studies to evaluate this relationship in Brazilian subjects. Panoramic and carpal radiographs of 491 subjects (222 males and 269 females), between 7 and 17 years of age were selected. Two radiologists jointly evaluated the images and reached a final consensus. The stages of tooth mineralization in the panoramic radiographs were determined according to Demirjian, while the skeletal maturity in carpal radiographs was evaluated according to the method described by Grave and Brown. The mean and standard deviations of chronological ages were determined for the three periods of pubertal growth spurt (PGS), and the association between the stages was obtained by ordinal multinomial logistic regression. The percentage distribution of the studied teeth was also calculated. The second molar (odds ratio (OD) = 4.34, 95% confidence interval (CI): 2.64-7.68) and first premolar (OD = 2.45, 95% CI: 1.40-4.28) were the best predictors of growth for females. For males with a more advanced trend in tooth mineralization, the second molar (OD = 6.80, 95% CI: 3.48-13.27), second premolar (OD = 2.41, 95% CI: 1.24-4.43), and canine (OD = 3.21, 95% CI: 1.38-7.50) proved to be the best predictors. Stages D and E for females, and stages E and F for males, of the second molar corresponded to the events that occur at the beginning of PGS. Stage F, for females, and stage G, for males, of the second molar corresponded to events that occur during the peak of the PGS. At the end of the PGS, most teeth had closed apices, with the exception of the second molar in females in which the majority was in stage G. It could, therefore, be concluded that there is an association between dental mineralization stages and skeletal maturity periods in the Brazilian population and the evaluation of these stages is useful to estimate the period of skeletal maturity / Mestrado / Radiologia Odontologica / Mestra em Radiologia Odontológica

Dental age estimation techniques have great importance in dental evaluation, specifically in the orthodontic, academic, and forensic areas. The aim of this study was to compare the dental age according to the Demirjian, Nolla and Cameriere methods with the chronological age in a Peruvian population. This is an observational, descriptive, retrospective and cross-sectional study, which had a total population of 578 panoramic radiographs of subjects aged 6 to 14 years, where the difference in means from a previous study was calculated, and 193 subjects were finally randomly selected. The chronological ages (CA) and dental ages (DA) were compared using the Wilcoxon and Kruskall Wallis Range Tests. The means were 8.77 ± 2.34 and 8.90 ± 2.04 years of the CA for the female and male genders, respectively. The difference in means of the CA and DA according to the Nolla, Demirjian and Cameriere methods were-0.38, 0.96 and-0.21 years, respectively, for the total study sample. A positive correlation was found for the three methods studied; however, the Demirjian method showed a statistically significant difference with an underestimation of-0.91 years in the total sample. Also, the method of Cameriere was the closest to the chronological age. / Las técnicas de estimación de edad dental tienen gran importancia en la evaluación odontológica, específicamente en el área de ortodoncia, académica y forense. El objetivo de este estudio fue comparar la edad dental según los métodos de Demirjian, Nolla y Cameriere con la edad cronológica en una población peruana. El diseño del estudio es de tipo observacional, descriptivo, de corte transversal y retrospectivo; tuvo una población total de 578 radiografías panorámicas de sujetos de 6 a 14 años, en las cuales se calculó la diferencia de medias de un estudio previo y, finalmente, fueron seleccionadas 193 de forma aleatoria. Se compararon la edad cronológica (EC) y la edad dental (ED) según los métodos de Nolla, Demirjian y Cameriere, utilizando las Pruebas de Rangos de Wilcoxon y Kruskall Wallis. Las medias de la EC fueron de 8,77±2,34 y 8,90±2,04 años para el género femenino y masculino, respectivamente. Las diferencias de medias de la EC y ED, de acuerdo con los métodos Nolla, Demirjian y Cameriere, fue de -0,38, 0,96 y -0,29 años, respectivamente, para la muestra total de estudio. Se encontró una correlación positiva para los tres métodos estudiados; sin embargo, el método de Demirjian mostró una diferencia estadísticamente significativa con una subestimación de -0,91 años en la muestra total. Asimismo, el método de Cameriere fue el que tuvo más cercanía a la edad cronológica. / Revisión por pares