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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A Cephalometric Study of the Mesio-Distal Axial Inclinations of the Teeth

Burns, Richard D. January 1968 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Eighteen adult human skulls with "normal occlusion" were examined with oriented lateral, 15, 25, 45, 75, and 90 degree cephalograms from which the mesio-distal axial inclinations of the teeth were measured. This study indicates that a large variation of the mesio-distal axial inclinations of the teeth may occur and still have a "normal occlusion". The standard deviations varied from a maximum of 11.0 degrees for the maxillary third molar to a minimum of 3.4 degrees for the maxillary cuspid. Rotation of the midsagittal plane of the head with the film effected the measurements of the maxillary first molars and cuspids, and the mandibular bicuspids by producing divergence of their roots on the film image. No relationship was found between measurements of this sample and measurements of mandibular plane, A-B plane, Y-axis, facial angle, angle of convexity, Down's occlusal plane, lower incisor - A-Pg, and interincisal angle. A positive relationship was found between the measurements of this sample and the posterior one-half of nasal floor, posterior occlusal plane, and the labiolingual axial inclination of the lower incisor.
2

Maxillary central incisor crown-root relationships in class I normal occlusions and class III open and deep malocclusions

Fuller, Jessica Kay 01 May 2015 (has links)
MAXILLARY CENTRAL INCISOR CROWN-ROOT RELATIONSHIPS IN CLASS I NORMAL OCCLUSIONS AND CLASS III OPEN AND DEEP MALOCCLUSIONS By Jessica Fuller M.S. Thesis Research Project Introduction: The purposes of this thesis were several: (1) to examine a new crown-to-root angle based on anatomic points, the labial crown-root angle (LCRA), that was proposed in a recent University of Iowa thesis by Bauer, T.J. (2014) and correlate it with the collum angle (CA) values for Class I normal occlusions and Class III malocclusions; (2) to establish mean values for CA and LCRA for Class I normal occlusions and Class III open and deep bite malocclusions and statistically compare the groups; (3) to compare the significance of the correlation between overbite measures and CA and LCRA in the Class III sample. Only one study addressed the increased CA in Class III malocclusions however, the study did not include a normal occlusion control sample. Methods: 46 Class I normal samples, 20 Class III open bite samples and 22 Class III deep bite samples who met the inclusion criteria were measured cephalometrically. Relevant landmarks were placed, analyzed for reliability, and recorded for the measurements of interest. Results: A strong increasing correlation was found between CA and LCRA for all samples (Pearson's correlation coefficient = 0.82, p < .0001). The mean CA for the Class III deep bite group (9.32±4.46) was significantly different from the Class I normal core (3.38±1.70), Class I expanded (3.60±1.94) and Class III open bite (5.24±3.99) groups (ANOVA). The mean LCRA for the Class III deep bite group (39.67±5.64) was also significantly different from Class I normal core (31.97±4.25), Class I expanded (33.53±5.65) and Class III open bite (35.55±5.65) groups (ANOVA). There was no significant correlation between CA and overbite within Class III open (p=0.8029) and Class III deep bite groups (p=0.2089) or LCRA and overbite within Class III open (p=0.7529) and Class III deep bite groups (p=0.1864). Conclusions: LCRA and CA were highly correlated in Class III patients. Patients with Class III deep bites had statistically higher means for CA and LCRA than patients with Class I normal occlusions and Class III open bite malocclusions. There was no significant correlation between the measures for overbite and either CA or LCRA values in Class III patients.
3

Estudo in vitro da anatomia dos canais radiculares de molares permanentes de humanos / In vitro study of the anatomy of the root canals of permanent human molar teeth

Lima, Fernando Jose Camello de 19 July 2005 (has links)
Orientador: Brenda P. F. A. Gomes / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-04T21:56:23Z (GMT). No. of bitstreams: 1 Lima_FernandoJoseCamellode_M.pdf: 4661786 bytes, checksum: 585044641889708ea8ca89cc73fd7064 (MD5) Previous issue date: 2005 / Resumo: O presente estudo teve como objetivo investigar a moriologia dos canais radiculares dos molares permanentes de humanos, identificando a configuração dos canais radiculares (classificação de WEINE modificada), os istmos, canais em C, e a correlação entre anatomia externa e interna. Foram utilizados 131 dentes: primeiros e segundos molares superiores (1°Se 2°SMS) e primeiros e segundos molares inferiores (1°Se 2°8 MI), obtidos em Maceió, AL. Os dentes tiveram as suas características externas registradas, para aí serem seccionados na junção amelo-cementária (JAC), para a visualização dos soalhos e das entradas dos canais radiculares. As raízes foram seccionadas transversalmente a 1; 2,5; 4; 5,5 e 7 mm do ápice e examinadas pelo lado apical no estereomicroscópio. Os dados obtidos foram submetidos ao teste do qui-quadrado com significância de 5%. Encontraram-se todos os tipos estudados de canais radiculares nas raízes mésiovestibulares (MV) dos MS. As raízes palatinas (P) dos 1°SMS e distais (O) de 2°S MI só tiveram um canal, enquanto que esta configuração não foi encontrada nas raízes mesiais (M) de 1°SMI. Os istmos estiveram presentes nas raízes MV dos MS em 98,5%, disto-vestibulares (OV) de MS em 10,4% e nos MI, em 91,1% das raizes mesiais (M) e 46,4% das raizes (O). Seis dentes tiveram canais em C, desses, só um não apresentava fusionamento radicular. O soalho da câmara pulpar nos 1°SMS foi trapezoidal em 75% dos casos e triangular no 2° MS em 53,6% dos casos. Os MS com projeções de cúspides MV apresentaram 81,3% de casos nos 1°SMS e 60,7% nos 2°SMS com mais de um canal na raiz MV. Pode-se concluir que as raizes MV de MS e M de MI têm maior probabilidade de possuírem dois canais. Quanto aos istmos, exceto as raízes P e eventuais raízes V dos MS, todas as outras raízes apresentaram istmos nos canais radiculares, porém a maior incidência apareceu nas raizes MV dos 1°SMS, e nas raízes M dos MI. Quanto ao canal em C, todos os molares, exceto os 1°SMI, mostraram esta configuração anatômica ao nível de raiz, sendo isto mais encontrado nas raízes fusionadas. Os MS, principalmente os primeiros molares, com projeções de cúspides MV apresentam maior possibilidade de ter mais de um canal na raiz MV / Abstract: The aim of this study was to investigate the root canais morphology of permanent human molars, to identify the root canal configuration (Weine modified), to verify the presence of isthmus and C-shapes configuration in root canais, and to establish a correlation between internal/external anatomies. One hundred and thirty-one first and second upperllower molars obtained from Maceio, AL, Brazil, were used. Teeth were sectioned in the enamel- cement junction to investigate pulp canal chamber floar and orifice shapes. Then, the roots were transversally sectioned at 1; 2,5; 4; 5,5 and 7 mm from the apex. Afterwards, they were investigated in stereomicroscopy from an apex side view. Data obtained were submitted to chi-square test. The major diversity of root canal types was found in mesial-buccalroots of the uppermolars. Palatal roots of 1st upper molar and distal roots of 2nd lower molars presented only one root canal, while it did not happen in mesial roots of 1st lower molars. Isthmus were presentin mesial-buccalrootsof the upper molars (98,5%), distal-buccal roots of the upper molars (10,4%), mesial root of the lower molars (91,1%) and distal root of the lower molars (46,4%) of the cases. C-shape root canais were found in 6 teeth, in which, only one did not show root-fusion. Most chamber floar shapes were trapezoidal in 1st (75%) and triangle in the 2nd upper molars (53,6%). First upper molars presented in 81,3% a projection of the mesial-buccal cusps, and 60,7% of the 2nd upper molars showed greater possibility of presenting more than one canal in the mesial-buccal root. In conclusion, mesial-buccal roots in upper molars and mesial roots in lower molars presented more often two root canais. Isthmus was found in ali root canais, except from palatine and eventually buccal roots of upper molars. C-shape root canal morphology were found in ali molars besides first lower ones; being frequently found in teeth with fusioned roots. First upper molars with an overprojected mesial buccal cusp showed more frequently two root canais / Mestrado / Endodontia / Mestre em Clínica Odontológica
4

Comparison of the Incidence of Bolton Tooth Mass Discrepancy in African-American and Caucasian Populations

Adelsperger, M. Jayme January 1998 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Tooth mass discrepancies have been studied extensively in Caucasian populations, but little has been done to compare differences between Caucasian and African-American populations. The objective of this study was to determine whether the incidence of tooth mass discrepancies between the maxillary and mandibular arches was greater in African-American populations than Caucasian populations. Pretreatment plaster orthodontic models of 100 African-American and 100 Caucasian patients from the Indiana University Orthodontic Clinic and from one private practitioner were measured with a Mitutoyo Digimatic® caliper accurate to 0.01 mm. Mesiodistal widths of all teeth from first molar to first molar were measured with the mesio-buccal and disto-buccal contact areas normally being the widest area. The investigator was blinded to the gender and ethnicity of the subject by assigning each model a random number which was matched to the patient profile only following statistical analysis. Anterior ratios and total (posterior+ anterior) ratios were calculated according to the methods described by Bolton and were compared to the Bolton means and standard deviations. Incidence of tooth mass discrepancy was also investigated according to gender and dental malocclusion classification of the individuals. Tooth mass discrepancies present a hurdle to the clinician in achieving an ideal occlusion. Reports of the incidence of significant discrepancies in defined populations alerts the practitioner to problems in finishing their patients' occlusions. Results of the study show nearly double the incidence of overall Bolton tooth mass discrepancy in the African-American sample than in the Caucasian. The overall tooth mass discrepancy was more severe in the African-American sample, while anterior tooth mass discrepancies were nearly identical in both populations.
5

Porovnání orálního zdraví 12-15letých adolescentů v okresech Jihlava a Havlíčkův Brod / Comparison of oral health of 12-15 years old adolescents in the district of Jihlava and the district of Havlíčkův Brod

VAŇKÁTOVÁ, Denisa January 2015 (has links)
"Oral health is important for general state of health and also for quality of life". This is how treatise on problems of oral health WHO starts. This sentence was an inspiration for this dissertation called "Comparison of oral health of 12-15 year old adolescents in the region of Jihlava and Havlíčkův Brod". All over the world 60-90 % of school age children have a dental caries. It is a localised patological process of microbiological origin which affects hard tooth tissue. It can lead to the loss of vitality of a tooth marrow and other patological phenomena. It is a very frequent disease in children´s age. One of the indicators of level of oral health is DMF index. It is a sum of permanent teeth with decay, with filling and teeth already extracted due to tooth decay. This thesis traditionally consists of theoretical part, which is a compiled information from specialized literature and practical part, where a method of cross-sectional study was used. The practical part consists of a cross-sectional study. The aim of this part was to map the occurence of tooth caries at 12-15 year old adolescents in chosen regions. It focuses on comparison of differences in oral health between these two regions and between boys and girls in both regions measured by DMF index. Part of this study is also a comparison of oral health of chosen population with recommended parameters of WHO for 12 years old. To fulfil this target, selected dentists were contacted and asked for cooperation. Collection of data was done with help of nurses in the dentists' offices. Data were recorded from health cards of the patients to a prepared record keeping sheet. Anonymity was preserved during collection and processing of data. To validate the data the corectness of inserted data was randomly rechecked. Data were entered into Microsoft Office Excel data sheet and were backed up. Three hypotheses were rised in this thesis: H1: There exists statistically significant difference in teeth defectiveness in chosen regions. The difference at defectiveness of teeth has been demonstrated. Higher level of oral health is in Jihlava region study population. H2: There exists statistically significant difference in teeth defectiveness between girls and boys. This hypothesis was rejected. Alternative hypothesis was accepted: Statistically significant difference in teeth defectiveness between girls and boys does not exist. H3: Oral health of 12-15 year old adolescents in chosen regions has got parameters recommended by WHO. This hypothesis was rejected. Alternative hypothesis was accepted: Oral health of 12-15 year old adolescents in chosen regions does not have parameters recomMended by WHO. Results of this study will be communicated with all participating dentists. Results of the study has also shown a significantly higher defectiveness of teeth in the studied population in comparison with foreign study in a similar age sample of young people from New South Wales. On the other hand, young people from Jihlava and Havlíčkův Brod more often attend dentists and their results are much better at this point. In comparison with national studies from years 1998, 2003 and 2010 our results are more positive. It is possible to see gradual increase of percentage of young people with intact teeth and also slow decrease of average DMF value. In comparison of these two regions Jihlava and Havlíčkův Brod, the results from Jihlava were more positive. Statistically significant difference in defectiveness of teeth between girls and boys was not notified. Average DMF in studied population was 1,7. WHO recommended DMF 3 for the year 2000 and 1,0 for the year 2010. DMF index in our study did not reach the level recommended by WHO for the year 2010.

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