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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.
11

Utilising radiographic incisor crown markers to determine incisor inclination on lateral headfilms - and experimental study on extracted teeth

Dippenaar, Alfred Meyer 02 March 2004 (has links)
Inaccuracy in landmark identification is regarded as the most important source of error in cephalometry. Better definition of landmarks should therefore contribute to better clinical decisions and research validity. This study primarily comprised of an ex vivo investigation on 50 extracted lower incisor teeth to determine whether radiopaque markers could be utilised to accurately assess lower incisor inclination. Fifty extracted lower incisor teeth were mounted onto a Perspex sheet. Radiopaque markers, manufactured from 1mm wide strips of lead film from used peri-apical radiographs, were attached to the crowns of the mounted teeth. A lateral cephalometric radiograph was taken in accordance to standard radiographic procedures (radiograph A). This showed the true inclination of the teeth. A second radiograph was taken with the roots obscured (radiograph B). Three observers traced the inclinations of the teeth on radiograph B (from incisor edge through the middle of the labio-lingual crown-root junction). The determination was done on two different occasions and the assessments compared with the true inclination. Comparative statistical analysis was applied to the readings and the results indicated that this method compared favourably with other methods to determine incisor inclination. In addition, clinical application of opaque markers to the teeth of patients demonstrated the following: it indicated exactly which tooth was being assessed, provided clear definition of the anatomical crown in the sagittal plane and served as a constant reference point for clinical, study model and cephalometric measurements. decisions and research validity. Opaque radiographic markers on teeth can contribute to more accurate cephalometric measurements in orthodontics, leading to better diagnoses, treatment planning and research validity. / Thesis (MChD (Orthodontics))--University of Pretoria, 2005. / Orthodontics / unrestricted
12

A radiographic comparison of the proclination of mandibular incisors between Class II extraction and non-extraction cases using the Damon® self-ligating system

Walton, Leeren January 2021 (has links)
Magister Chirurgiae Dentium - MChD / The stable position of the mandibular incisors, and the extent to which their spatial position may be changed in the sagittal plane, represents a key point in determining orthodontic treatment goals and objectives. According to the equilibrium theory, the mandibular incisors lie in a narrow zone of stability that is governed by pressure from the lips, cheek, tongue and periodontium. Proclining the mandibular incisors more than 2 mm leads to instability because of an increase in lip pressure. The magnitude of incisor proclination therefore determines aesthetics, stability and function.
13

ESTHETIC PREFERENCES OF MAXILLARY INCISOR LABIOLINGUAL INCLINATION ACROSS RACES

Barcoma, Elvi M 01 January 2015 (has links)
Abstract ESTHETIC PREFERENCES FOR MAXILLARY INCISOR LABIOLINGUAL INCLINATION ACROSS RACES by Elvi Marie Barcoma, D.D.S. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Dentistry at Virginia Commonwealth University Virginia Commonwealth University, 2015 Major Director: Bhavna Shroff, D.M.D., M.Dent.Sc, Program Director, Orthodontics Objective: To determine if people of different racial backgrounds prefer different amounts of maxillary incisor labiolingual inclination from a smiling profile view. Materials and Methods: An electronic survey was created with smiling profile images of an African-American female and a White female with varying degrees of maxillary incisor labiolingual inclination. Images were ranked from most attractive to least attractive. Results: There was no statistically significant difference in the overall preference for maxillary incisor labiolingual inclination between African-American and White evaluators or between genders. The estimated optimal incisal inclination across races was -8.1°. Conclusions: There was no clinically significant difference in the estimated optimal inclination across races or between genders. The average of the top three maxillary incisor inclinations ranged between -10° and -5°. The majority of evaluators preferred retroclined maxillary incisors over proclined maxillary incisors.
14

Comparação pela análise de vigorito da posição do incisivo inferior na sínfise em jovens brasileiros leucodermas, melanodermas e feodermas com oclusão normal / Comparative study of mandibular incisor position in the symphysis by vigorito analysis in white, black and afrocaucasian brazilian adolescents with normal occlusion

Yarlequé, María Pía Seminario 08 February 2019 (has links)
Introdução: A grande miscigenação populacional no Brasil tem influência nas características cefalométricas, faciais e dentárias e variam significantemente entre as diferentes raças. A Ortodontia não pode mais aceitar valores absolutos ou padrões de normalidade rígidos, pois cada indivíduo apresenta arquitetura facial própria, sendo necessário respeitar as diferenças de cada raça e conhecer as individualidades de cada tipo étnico e racial. O conhecimento da posição do incisivo inferior na sínfise é importante para o correto diagnóstico e o tratamento a oferecer para o paciente. Proposição: Comparar o posicionamento do incisivo inferior na sínfise em jovens brasileiros leucodermas, melanodermas e feodermas para obter os valores médios de normalidade e comparar os valores obtidos entre esses grupos raciais. Material e Métodos: A amostra foi constituída de 115 telerradiografias em norma lateral de indivíduos brasileiros jovens com oclusão normal, divididos em três grupos de ambos os gêneros: grupo I: 38 indivíduos leucodermas, sendo 19 do gênero feminino e 19 do gênero masculino; grupo II: 39 indivíduos melanodermas, 19 do gênero feminino e 20 do gênero masculino e grupo III: 38 indivíduos feodermas, sendo eles 19 do gênero feminino e 19 do gênero masculino. A partir das telerradiografias, foram obtidos os traçados e medidas cefalométricas para comparação das grandezas mediante a análise de Vigorito. Resultados: Os indivíduos melanodermas apresentaram a sínfise mais inclinada para vestibular, a maxila e o incisivo inferior mais protruido e o perfil mais convexo que os leucodermas e feodermas. Conclusões: Pode se concluir que os melanodermas apresentam diferentes características em relação aos leucodermas e feodermas, portanto é importante reconhecer os valores para obter um perfil harmonioso. / Introduction: The great miscegenation of the population in Brazil have a direct influence on the cephalometric, facial and dental characteristics. All of these vary between different races. Orthodontics does not accept absolute values to evaluate normality, because each individual have their own facial pattern. Therefore, it is important to study the differences of the cephalometric values for each ethnic group. The lower incisor position is considered essential to make diagnosis and design a correct treatment plan. The objective of these research is to compare the linear measurements of the position of the mandibular incisor in White, Black and Afrocaucasian Brazilian adolescents. Materials and Methods: The sample was comprised by 115 lateral headfilms of Brazilian individuals with normal occlusion, divided in three groups: 38 White-Brazilian (19 females and 19 males), 39 Black- Brazilian (19 females and 20 males) and 38 Afrocaucasian-Brazilian (19 females and 19 males). The Lateral headfilms were digitalized and the variables were measured performed by the Vigorito analysis. Black- Brazilian sample showed significantly differences than the other groups. Results: Black- Brazilian subjects presented the most inclined symphysis for vestibular, the maxilla and the lower incisor more protruded and the profile more convex than the leucodermas and feodermas. Conclusion: The results of these research allow us to concluded that Black-Brazilian presented different characteristics than White and Afrocaucasian Brazilian and it is important to recognize each value to reach a harmonious profile.
15

Comparação pela análise de Vigorito da posição do incisivo inferior na sínfise, em jovens brasileiros leucodermas, xantodermas e mestiços nipo-brasileiros, com oclusão normal / Vigorito comparative cephalometric analyses of mandibular incisor related to symphysis in brazilian adolescent: whites, xanthoderms and japanese-brazilians, with normal occlusion

Guerra, Jose Gregorio Pelayo 08 February 2019 (has links)
Introdução: O objetivo desse estudo foi comparar as medidas angulares, lineares, utilizando a análise de Vigorito como parâmetro em Leucodermas, Xantodermas e Nipo-brasileiros para obter os valores médios de normalidade, comparar os valores obtidos e as diferenças entre os grupos raciais e o dimorfismo entre os sexos. Métodos: A amostra retrospectiva foi constituída de 103 telerradiografias em norma lateral de indivíduos brasileiros jovens com oclusão normal, divididos em três grupos: grupo I com 38 indivíduos Leucodermas, sendo 19 de cada gênero; grupo II, com 33 indivíduos Xantodermas, sendo 17 do gênero feminino e 16 do masculino; grupo III, com 32 indivíduos mestiços Nipo-Brasileiros, sendo 17 do gênero feminino e 15 do masculino. Estas radiografias foram digitalizadas utilizando o scanner Scan Maker i800, e as variáveis cefalométricas próprias da análise foram medidas através do software Cephx 4.5.14. e comparadas entre as diferentes raças. A compatibilidade das idades foi analisada utilizando o teste ANOVA seguido de teste de Tukey. O dimorfismo sexual foi avaliado com teste t independente e a comparação entre grupos foi realizado pelo teste ANCOVA seguido de teste de Tukey. Resultados: Os indivíduos femininos dos grupos Leucoderma e Nipo-Brasileiros apresentaram diferenças estatisticamente significantes para o dimorfismo sexual mostrando um perfil facial mais convexo, e incisivo inferior menos protruído. Além disso, os indivíduos Nipo-Brasileiros apresentaram uma protrusão maxilar significantemente menor quando comparados com Xantodermas e Leucodermas, que também apresentaram uma menor protrusão do incisivo comparados com Nipo-Brasileiros respectivamente. Conclusões: Os indivíduos Leucodermas, Xantoderma e Nipo-Brasileiros com oclusão normal apresentaram algumas diferenças dentoesqueléticas, dentárias, faciais e entre os sexos em relação à sínfise mandibular. Assim se justifica a individualização dos padrões cefalométricos destes diferentes grupos raciais. / Introduction: The aim of this study was to compare the linear and angular measurements, using the Vigorito analysis as parameter in White, Xanthoderm and Japanese-Brazilian adolescents for the average normal values, comparing the values and differences obtained between racial groups and the sex dimorphism. Methods: The sample included 103 lateral films, divided into three groups: Group I with 38 white subjects, 19 males and 19 females; Group II, with 33 Japanese subjects, 17 females and 16 males; Group III, with 32 Japanese-Brazilian subjects, 17 females and 15 males with normal occlusion. Lateral films were scanned using San Maker i800 scanner, and CephX 4.5.4. was used for measure the cephalometric variables and were compared Intragroup sexual dimorphism was evaluated with t tests. Intergroup comparisons were performed with ANCOVA followed by Tukey tests. Results: White and Japanese- Brazilian female group presented statistically significant differences for sexual dimorphism, showing a higher facial convexity and lower mandibular incisor protrusion. In addition, Japanese-Brazilian subjects presented a significant lower maxillary protrusion when compared with Japanese and White subjects, which also presented a lower mandibular incisor protrusion compare with Japanese-Brazilian respectively. Conclusions: Whites, Japanese and Japanese-Brazilian subjects with normal occlusion presented dentoskeletal and facial soft tissues profile differences when analyzed through cephalometric Vigorito´ analysis. Thus, the individualization of cephalometric norms in different racial groups is justified.
16

Maxillary incisor crown form and crowding in adolescent orthodontic patients

Frederick, Kortne King, January 2008 (has links) (PDF)
Thesis (M.S. )--University of Tennessee Health Science Center, 2008 / Title from title page screen (viewed on July 30, 2008). Research advisor: Edward F. Harris, Ph.D. Document formatted into pages (xvi, 154 p. : ill.). Vita. Abstract. Includes bibliographical references (p. 148-154).
17

Colour comparison of two composite materials to natural tooth structure: an in vitro study

Grundlingh, Andries Adam January 2013 (has links)
Magister Chirurgiae Dentium (MChD) / This in vitro study compares the ability of two composite materials Filtek Supreme XTE™ (3M, ESPE) and CeramX™ Duo (Dentsply) against extracted tooth structure using the modern two layering concept. Fifty six extracted anterior maxillary central incisor teeth were selected which were caries free, had no surface defects and within the colour range A3, B3, C3 or D2. The teeth were randomly divided into four colour groups (A3, B3, C3 and D2), each containing 14 teeth. A class IV cavity was prepared on all the teeth and the two composite materials were used alternately with no bonding agent to restore the cavity. The colour of both composites was assessed immediately after restoration, 24 hours and after two weeks using the SpectroShade™ (MHT) spectrophotometer. The MHT SpectroShade™ version 3.3 software was used with the CIE L*a*b* colour system to evaluate the colour of the teeth and restorations. The Kruskal-Wallis One- Way analysis of variance was used to compare the differences between the medians of the two composite materials. The significance was set at z>3.1237. The Spearman’s rank correlation coefficient was set at a significance of p<0.01 to evaluate colour change (_E*ab) in the restorations over three time intervals (immediate restoration, 24 hours and two weeks).
18

Prevalence, Clinical Presentation, and Associated Sociodemographic Characteristics of Molar Hypomineralization in Indiana, USA

Ahmed, Azza Tagelsir Mohamed 05 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Molar Hypomineralization (MH) of the first permanent molars (FPMs) and the second primary molars (SPMs) is a common developmental defect of enamel, with global prevalence of 14% and 5% respectively. Children with MH represent a special pediatric population because their affected molars have extreme susceptibility to enamel breakdown, decay and tooth sensitivity. Although the problem of MH has been described almost twenty years ago mainly through reports from Europe, there is very little information about the problem from the USA. In this dissertation, MH was explored both from the perspectives of pediatric dentists’ (PDs) and at population level. The majority of the survey respondents perceived MH prevalence to be <10% in their clinical practice (62%). The most cited clinical challenge in managing MH teeth was “long-term success of restorations” (79%). When analyzed individually, responses differed significantly for different demographics and educational characteristics of the respondents (p<0.05). At population level, MH of the FPMs (Molar Incisor Hypomineralization (MIH) cohort: 337 schoolchildren, average age 9 years) and of the SPMs (Hypomineralized Second Primary Molar (HSPM) cohort: 423 schoolchildren, average age 7 years) had prevalence estimates of 13% and 6% respectively. In the MIH cohort, water fluoridation or non-Hispanic Black race/ethnicity was significantly associated with higher collective prevalence of enamel defect (EDs) (P<0.05), but not with the prevalence of MH of the FPMs. In the HSPM cohort, race/ethnicity was significantly associated with higher overall prevalence of EDs of SPMs, but not with the HSPM prevalence. Older age group (>10 years), living in central Indiana, and water fluoridation were significantly associated with higher overall prevalence of EDs (P<0.01), but not with the HSPM prevalence. Caries experience was significantly higher in children with MH of FPMs and/or SPMs than in the group without MH. We concluded that USA pediatric dentists’ respondents were well aware of the MH problem, but demonstrated discrepancies in different aspects of the MH problem. At population level, MIH and HSPM were common presentation with prevalence estimates similar to the global figures. Certain demographic characteristics were significantly associated with the overall prevalence of the enamel defects of the examined teeth.
19

Is eye color related to dental injection pain?

Hyde, Jason C., Hyde January 2017 (has links)
No description available.
20

Mandibular Incisor Proclination Variability During Class II Correction

Redford, James 06 May 2014 (has links)
Background: Lower incisor proclination has been shown to increase during Class II correction with appliances such as the Forsus. This lower incisor flaring shows great variability among patients. The purpose of this study was to evaluate the effects of Class II severity, mandibular growth, and occlusal plane rotation on lower incisor flaring in patients treated with the Forsus appliance. Materials and Methods: 121 records of Class II patients treated with the Forsus appliance were analyzed retrospectively. Cephalograms were traced at three time points. ANOVA was used to compare changes in cephalometric measurements over time. Pearson’s correlation was used to test for relationships between variables. Multiple regression tested for correlation between multiple variables. Results/Conclusions: Lower incisor flaring during Class II correction with the Forsus appliance was only weakly associated with sex, molar relationship change, and occlusal plane steepening. There was no correlation between the change in lower incisor proclination and mandibular growth.

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