Magister Scientiae Dentium - MSc(Dent) / A number of dental age estimation methods have been developed over the years ranging from the frequently used age estimation of Demirjian et al (1973) and Moorrees et al (1965) to the less frequently used age estimation methods of Haavikko (1970) and Nolla (1960). Different dental age estimation methods have been used with variable success. These were developed using mainly children of Central and Northern European descent and white North Americans. The results of the above-mentioned dental age estimation methods, when used on South African children, show that the need for adaptation of these methods exists. Phillips has thus developed a dental age estimation table for Nguni children of South Africa, to assist in correcting this discrepancy. OBJECTIVE: To establish if the Phillips dental age estimation developed for Nguni children of South Africa is applicable to children in the region of Mpumalanga. METHOD: Cross sectional study using a stratified random sampling method involving 100 panoramic radiographs of black children up to the age of 14 years, in the region of Mpumalanga. CONCLUSION: This study will determine if Phillips dental age estimation tables developed for South African Nguni children is applicable and accurate in estimating the age of black Mpumalanga children.

The age estimation method as described by Demirjian is the most frequently used tool to estimate the sub-adult dental age in forensic dentistry. This technique has been shown to over or under estimate the chronological age of sub-adults when applied to specific population groups. The aim of this study was to compare a black South African population sample with the original French-Canadian model to determine if Demirjian’s method accurately reflects the true chronological age of this population group. A sample of panoramic radiographs from 279 boys and 325 girls between the ages of 6 and 16 was obtained from the School of Dentistry University of Pretoria, and from orthodontists in private practice in the Pretoria region. The panoramic radiographs were used to score the seven left mandibular teeth. The calculated maturity score was used to determine the Demirjian dental age. All panoramic radiographs were scored by one examiner. A subset of 20 panoramic radiographs was scored by a second examiner and reliability tested using a Wilcoxon Matched Pairs Test. This research showed that black South African children have a more advanced dental age compared to French-Canadian children. Demirjian overestimated the age for boys by 0.8 years and for girls by 0.5 years. The dental age assessment provided by Demirjian is not suitable for black South African children. As a result, new standards of dental age assessment should be established for this population. Copyright / Dissertation (MSc(Odont))--University of Pretoria, 2011. / Oral Pathology and Oral Biology / unrestricted

Though applied in bioarchaeology, dental wear is an underexplored age indicator in the biological anthropology of contemporary populations, although research has been conducted on dental attrition in forensic contexts (Kim et al. 2000, Prince et al. 2008, Yun et al. 2007). The purpose of this study is to apply and adapt existing techniques for age estimation based on dental wear to a modern American population, with the aim of producing accurate age range estimates for individuals from an industrialized context. Methodologies following Yun and Prince were applied to a random sample from the University of New Mexico (n=583) and Universidade de Coimbra (n=50) cast and skeletal collections. Analysis of variance (ANOVA) and linear regression analyses were conducted to examine the relationship between tooth wear scores and age. Application of both Yun et al. (2007) and Prince et al. (2008) methodologies resulted in inaccurate age estimates. Recalibrated sectioning points correctly classified individuals as over or under 50 years for 88% of the sample. Linear regression demonstrated 60% of age estimates fell within ±10 years of the actual age, and accuracy improved for individuals under 45 years, with 74% of predictions within ±10 years. This study demonstrates that age estimation from dental wear is possible for modern populations, with comparable age intervals to other established methods. It provides a quantifiable method of seriation into “older” and “younger” adult categories, and is a more reliable method than cranial sutures in instances where only the skull is available. / 2019-07-11T00:00:00Z

Philosophiae Doctor - PhD / Age estimation of the skeletal remains of children can be accomplished by examination of the ossification centres and the fusion of the epiphyseal plates of long bones. Dental age estimation is done by examining the eruption of the deciduous and permanent teeth. Both these methods are inaccurate and are subject to the nutritional status of the individual. A more accurate method of age estimation is by the examination of radiographic images of the developmental stages of the tooth crown and root formation. Two methods of dental age estimation used are those of Moorrees, Fanning and Hunt (1963) (MFH) and that of Demirjian, Goldstein and Tanner (1973) (DGT). These methods were tested on a sample of 913 Tygerberg dental patients; a random mixture of Caucasoid and Khoisanoid children. The MFH method under-estimated the ages of the sample by an average of 0.91 years and the DGT method over-estimated the ages by an average of 0.89 years. Samples of Indian and Negroid children from Kwa-Zulu Natal were tested in a similar manner and the results showed similar under and over-estimation of the ages by these methods. The Negroid children were labelled the Zulu sample. Correction factors were derived for the MFH and DGT methods of dental age estimation when used on Tygerberg, Indian and Zulu children. These correction factors were tested on the samples and found to improve the accuracy of the age estimation methods of MFH and DGT significantly.A second sample group of Tygerberg, Indian and Zulu children were then tested firstly using the standard method of MFH and DGT and the using the correction factors. The results showed that the correction factors improved the age estimation on these samples except in the case of the DGT method on Zulu children. A sample of Xhosa speaking children were added to the two Zulu samples and made an Nguni sample. The Tygerberg samples were combined as were the Indian samples to form data bases for the construction of dental age related tables for Tygerberg, Indian and Nguni children. These tables show that there are distinct differences in the ages at which the teeth develop in the different sample groups and that dental age related tables are necessary for children of different population origins. Statistical analysis of the age related tables from this study (Phillips Tables) show these tables are more accurate in the age estimation of South African children.

Made available in DSpace on 2014-12-17T14:13:35Z (GMT). No. of bitstreams: 1 MariaCGM_DISSERT.pdf: 783345 bytes, checksum: 2bbd27cd96c8b3b35673be95266c5187 (MD5) Previous issue date: 2010-09-17 / Since Demirjian's system of estimating dental maturity was first described, many researchers from different countries have tested its accuracy among diverse populations. Some of these studies have pointed out a need to determine population-specific standards. In Brazil, the Northeast region is the one that most suffers the negative impact of exodus, specially related to the increase of abandoned children in the cities. The aim of this study was to test the accuracy of Demirjian's system for assessing the dental maturity of northeastern Brazilian children, so as to present a scale for maturity score conversion into dental age developed specifically for this population. This could be used for forensic, anthropological and legal matters, and also as a model for other countries attempting to formulate their own conversion scales. Panoramic radiographs of 1,491 children (821 females and 670 males), aged 7 to 13 years, from Cear? state, northeast Brazil, were assessed by a single observer to determine dental age (DA) according to Demirjian's system. The mean percentage of intra-observer agreement was 86.6%, with a mean Cohen's Kappa coefficient of 0.67 (substantial agreement). The DA was compared by paired t-test to subjects' chronological age (CA). The differences between CA and DA in all age groups were statistically significant (p<0.0001), demonstrating a great advancement in DA among Brazilians. Scatter plots were drawn for both genders, and the data were fitted to a growth curve, y = 100/ (1 + e-a(x b)). Graphs corresponding to the 50th percentile curves were produced. A table with new values for the conversion of maturity score into dental age for northeastern Brazilian children is presented. The great advancement in DA, as obtained by Demirjian's system in this population, justified the determination of specific scores for dental maturity assessment / A estimativa da maturidade dent?ria tem sido descrita na literatura basicamente atrav?s de dois m?todos, a observa??o direta do processo de erup??o do dente na cavidade oral ou por meio de radiografias. A radiografia panor?mica, obtida por t?cnica extra-oral de uso dos raios X, ? um elemento essencial para o diagn?stico por imagens em Radiologia odontol?gica. Este trabalho apresenta dois estudos quantitativos anal?tico-descritivos utilizando o m?todo de determina??o da idade dental atrav?s de radiografia panor?mica em crian?as brasileiras nordestinas. Um estudo piloto realizado com 325 crian?as (191 meninas e 134 meninos) de 7 a 16 anos, da cidade de Fortaleza, objetivando determinar as interrela??es entre as suas idades cronol?gica (data de nascimento), ?ssea (pelo m?todo de Grewlich & Pyle) e dental (segundo Demirjian et al.). Outro estudo, j? publicado, conduzido com 1.491 crian?as (821 meninas e 670 meninos) cearenses, de 7 a 13 anos, visando avaliar a aplicabilidade do m?todo de Demirjian na popula??o estudada. Em ambos os estudos, mostra-se que a estimativa de idade dental utilizando as tabelas de convers?o de maturidade dental propostas por Demirjian et al. n?o se ad?qua ? popula??o pesquisada. Assim, uma escala de valores de convers?o de maturidade dental em idade dental foi desenvolvida especificamente para crian?as nordestinas e ? agora apresentada, visando ? sua aplica??o n?o s? na cl?nica, mas em quest?es forenses, antropol?gicas, legais e/ou criminais. As pesquisas de car?ter interdisciplinar envolveram pesquisadores das ?reas de Odontologia (Odontopediatria, Ortodontia e Radiologia); Medicina (Endocrinologia e Metabologia); e F?sica, preenchendo os requisitos de multidisciplinaridade do Programa de P?s-Gradua??o em Ci?ncias da Sa?de

A utilização de Células-tronco e técnicas da Engenharia Tecidual representa um grande avanço tecnológico e beneficiará muitos pacientes com suas conquistas. A descoberta de germes dentários como uma fonte confiável de células-tronco possibilitou diversas pesquisas nesta área. Duailibi et al. (2011) sugeriram uma nova classificação de desenvolvimento dentário baseada pela quantidade de material biológico coletado indicando a necessidade de métodos de diagnóstico por imagem para esta nova classificação. Na literatura diversos trabalhos indicam métodos de classificação dentária e métodos para estimar a idade fisiológica de indivíduos. O presente estudo tem o objetivo de adaptar alguns destes métodos para estimar o estágio de desenvolvimento proposto por Duailibi et al. (2011) consequentemente indicando a quantidade de células-tronco esperadas nas amostras. Para tanto, submeteu-se uma coleção de 67 dentes previamente classificados por Duailibi et al. (2011) à técnica rpcl e à tcfc para a obtenção de imagens e a aplicação de técnicas de estimativas por proporções lineares e volumétricas. Os resultados por análises lineares indicaram valores de R2 para o método de proporção de comprimento CDCP de 0,14050; CCCP de 0,65369; CCCR de 0,5408; CDCR de 0,54074; o método de proporção de área APAD de 0,23925; e método de proporção de volume VPVD de 0,08553, com valor de p menor ou igual à 0,05. Concluindo este estudo indica-se o método de rpcl utilizando a análise do comprimento entre coroa e polpa como o mais indicado para estimar o estágio de desenvolvimento. / The usage of human dental stem cells and tissue engineering technics represents a huge tecnological development and it may benefits many patients in a promissing future. The discovery of suitable source of human dental stem cells were made using tooth buds. Duailibi et al. 2011 indicated a new tooth classification on a stem cell harvesting based research, sugesting new methods for diagnosis these stages. Several method were developed for dental age assesement. The presente study aims to evaluate some of these dental age technics and make adaptations for estimating Duailibi et al. 2011 tooth stages. A 67 tooth sample previoulsy classificated by Duailbi et al. 2011 were submited through periapical parallel long cone X-rays and CBCT analysis. Age estimation ratio methods were applied by measuring tooth/root lenth, crown/root lenth, tooth/pulp lenth, crown/pulp lenth, tooth/poulp área and tooth/pulp volume. Results indicated by linear regression analisys a R2 value of tooth/pulp lenth 0,14050; crown/pulp lenth 0,65369; crown/root lenth 0,5408; tooth/root lenth 0,54074; pulp/tooth volume 0,23925; e tooth/pulp volume de 0,08553, with p value of 0,005. In conclusion , the best method for estimating Duailibi et al. 2011 tooth classification techinic is made by using periapical long cone X-rays using crown/pulp lenth ratio.

A utilização de Células-tronco e técnicas da Engenharia Tecidual representa um grande avanço tecnológico e beneficiará muitos pacientes com suas conquistas. A descoberta de germes dentários como uma fonte confiável de células-tronco possibilitou diversas pesquisas nesta área. Duailibi et al. (2011) sugeriram uma nova classificação de desenvolvimento dentário baseada pela quantidade de material biológico coletado indicando a necessidade de métodos de diagnóstico por imagem para esta nova classificação. Na literatura diversos trabalhos indicam métodos de classificação dentária e métodos para estimar a idade fisiológica de indivíduos. O presente estudo tem o objetivo de adaptar alguns destes métodos para estimar o estágio de desenvolvimento proposto por Duailibi et al. (2011) consequentemente indicando a quantidade de células-tronco esperadas nas amostras. Para tanto, submeteu-se uma coleção de 67 dentes previamente classificados por Duailibi et al. (2011) à técnica rpcl e à tcfc para a obtenção de imagens e a aplicação de técnicas de estimativas por proporções lineares e volumétricas. Os resultados por análises lineares indicaram valores de R2 para o método de proporção de comprimento CDCP de 0,14050; CCCP de 0,65369; CCCR de 0,5408; CDCR de 0,54074; o método de proporção de área APAD de 0,23925; e método de proporção de volume VPVD de 0,08553, com valor de p menor ou igual à 0,05. Concluindo este estudo indica-se o método de rpcl utilizando a análise do comprimento entre coroa e polpa como o mais indicado para estimar o estágio de desenvolvimento. / The usage of human dental stem cells and tissue engineering technics represents a huge tecnological development and it may benefits many patients in a promissing future. The discovery of suitable source of human dental stem cells were made using tooth buds. Duailibi et al. 2011 indicated a new tooth classification on a stem cell harvesting based research, sugesting new methods for diagnosis these stages. Several method were developed for dental age assesement. The presente study aims to evaluate some of these dental age technics and make adaptations for estimating Duailibi et al. 2011 tooth stages. A 67 tooth sample previoulsy classificated by Duailbi et al. 2011 were submited through periapical parallel long cone X-rays and CBCT analysis. Age estimation ratio methods were applied by measuring tooth/root lenth, crown/root lenth, tooth/pulp lenth, crown/pulp lenth, tooth/poulp área and tooth/pulp volume. Results indicated by linear regression analisys a R2 value of tooth/pulp lenth 0,14050; crown/pulp lenth 0,65369; crown/root lenth 0,5408; tooth/root lenth 0,54074; pulp/tooth volume 0,23925; e tooth/pulp volume de 0,08553, with p value of 0,005. In conclusion , the best method for estimating Duailibi et al. 2011 tooth classification techinic is made by using periapical long cone X-rays using crown/pulp lenth ratio.