• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • Tagged with
  • 5
  • 5
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 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

The Prevalence of the Need for Esthetic Crown Lengthening in Post Orthodontically Treated Subjects

Konikoff, Bryan Marc 01 January 2006 (has links)
Prevalence information on excessive gingival display in post-orthodontic patients is limited. By studying one aspect, namely the size relationship of the clinical crowns of teeth, in an orthodontic population, we can begin to quantify their need for periodontal plastic surgery. In this two part study, 200 plaster models were used as subjects, followed by a clinical exam of 31 of those subjects. These models represented patients before and directly after orthodontic therapy, and the Part 2 clinical exams were performed at least five years later. The lengths and widths of the six anterior teeth were measured and these values were compared to known ideals. This study revealed a significant increase in the length of the maxillary anterior teeth over the three examinations, yet these values were still approximately 1.5mm shorter than ideal. The mean tooth width-to-length ratio was 87-88% for maxillary central incisors, clearly below the accepted "ideal." As well, 61-71% of maxillary central incisors exceeded allowable tooth width-to-length ratios, and 61% of subjects displayed asymmetry in gingival architecture. Although this study only examined one aspect of excessive gingival display, it is the first study to show that in a predominantly young, post-orthodontic population, the prevalence of non-ideal width-to-length ratios is greater than 65%, and that the presence of asymmetry is greater than 60%. Therefore, close interaction between the periodontist and the orthodontist is necessary to diagnose these conditions in order to provide patients with all options for improving their smile.
2

The Prevalence of the Need for Esthetic Crown Lengthening in Post Orthodontically Treated Subjects

Johnson, David Clark 01 January 2004 (has links)
The problem of excess gingival display is difficult to diagnose and treat. By studying one aspect of excess gingival display, namely the size relationships of the clinical crowns of teeth, we can begin to quantify reasonable goals of therapy. In this study, two hundred plaster models were used as subjects. These represented two hundred patients before and after orthodontic therapy. The six anterior teeth were measured for length and width and compared to known ideals. Teeth that did not meet ideal standards may require treatment. It was found that the mean tooth length after orthodontic therapy was approximately two millimeters shorter than ideal. The length of maxillary central incisors did not increase over the course of therapy. Eighty-five to ninety percent of maxillary central incisors exceeded allowable tooth width-to-length ratios. Twenty-nine to thirty percent of central incisors exceeded one hundred percent in their width-to-length ratio. Sixty-eight percent of patients displayed asymmetry in gingival architecture.
3

Avaliação retrospectiva de dentes submetidos à plastia radicular durante aumento de coroa clínica / Retrospective evaluation of teeth submitted to odontoplasty during clinical crown lengthening

Cruz, Márcio Klug da 22 May 2009 (has links)
Made available in DSpace on 2014-08-20T14:30:06Z (GMT). No. of bitstreams: 1 Dissertacao_Marcio_Klug_da_Cruz.pdf: 2303507 bytes, checksum: 0c9ba7ada6929a20db9ac2db96817b28 (MD5) Previous issue date: 2009-05-22 / The aim of this study was to retrospectively evaluate the clinical outcome of teeth submitted to odontoplasty during clinical crown lengthening surgery (CCLS), when compared to their contralateral non-operated teeth. Fourteen patients submitted to odontoplasty during CCLS were evaluated according to plaque index, bleeding on probing, probing depth and final restoration outcome (total success, relative success and failure). The mean follow-up period was 14.28 ( 7.72) months, and ranged from 6 to 24 months. Total success of the final rehabilitation was observed for all cases and no differences, regarding periodontal parameters, were observed between operated and contralateral non-operated teeth. It can be concluded that odontoplasty during CCLS is a feasible procedure that does not affect periodontal health and the long-term prognosis of restorative procedures / O objetivo deste estudo foi avaliar retrospectivamente o resultado clínico de dentes submetidos à odontoplastia durante cirurgia de aumento de coroa clínica (CACC), comparando-os a seus respectivos dentes contralaterais não operados. Quatorze pacientes submetidos à odontoplastia durante CACC foram avaliados segundo os seguintes parâmetros: índice de placa, sangramento à sondagem, profundidade de sondagem e resultado final da restauração (sucesso total, sucesso relativo e fracasso). O período médio de acompanhamento foi de 14,28 ( 7,72) meses, variando de 6 a 24 meses. Todas as reabilitações obtiveram sucesso e não foram observadas diferenças entre os dentes operados e não-operados em relação aos parâmetros periodontais. Pode-se concluir que a odontoplastia durante as CACC é um procedimento viável que não afeta a saúde periodontal e o prognóstico em longo prazo dos procedimentos restauradores
4

The effect of esthetic crown lengthening on perceptions of a patient’s attractiveness, friendliness, trustworthiness, intelligence, and self-confidence

Malkinson, Samuel Lyon 23 April 2012 (has links)
BACKGROUND: Smile esthetics play a major role in the perception of a person’s attractiveness, as well as other social parameters. The study aim was to see if altering the gingival display of patients would affect perceptions of the aforementioned social parameters. METHODS: Smiling photographs were taken and then digitally altered so as to lengthen the teeth and reduce the amount of gingiva. These photographs were shown to a group of senior dental students, and a group of evaluators with no formal dental training. Groups were asked to rate each picture’s attractiveness, friendliness, trustworthiness, intelligence, and self-confidence. RESULTS: The digitally altered photographs were rated higher for all five social parameters than were their unaltered counterparts (p<0.0001). There were no statistically significant differences between the two groups of evaluators. CONCLUSIONS: Excessive gingival display positively affected how attractive a person’s smile is judged, and also how friendly, trustworthy, intelligent, and self-confident they are.
5

CARACTERIZAÇÃO E MODELAGEM DO CRESCIMENTO DA COPA E DO INCREMENTO DE ÁRVORES ISOLADAS DE Cedrela fissillis Vell. / CARACTERIZATION AND MODELING OF CROWN AND INCREMENT OF Cedrela fissilis (Vell.) OPEN-GROWN TREES

Cavalli, Jean Pierre 01 March 2013 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / On the growth evaluation of the open-grown trees was selected 57 samples, of which were mensuration many morphometric variables from digital photographs in software AutoCAD and dendrometrics variables in bole increment extracted in diameter breast height (DBH). The development of this research was to described the singular dimensions and recover crown and bole growth from open-grown Cedrela fissilis, corresponding to period 2007-2011, and build mathematical equations to described the growth of variable crown diameter (CD), mantle of the crown (MC), crown diameter in relative heights (CDrh) and periodic annual increment in basal area (PAIb). In the annual lengthening (AL) were observed minimum, maximum and median annual values of 3.0, 91.0 and 32.4 cm, respectively. As well as, serie correlations, determined by Pearson (r = 0.76 a 0.86; Pr<.0001), with higher lengthening connected to the lower orders of branching. In periodic lengthening (PL), corresponding to the period of 2007-2011 there were values of up to 1.82 m, found in diameter class 30-40, with a coefficient of variation (CV) up to 67.67%, checked in diametric class > 60. To model growth construction 35 trees were selected from 57 initially sampled considering it crown and bole conditions, having been discarded sample of the > 60 diametric class. To the mantle of the crown variable the model NLMC=b0+b1*(1/DBH)+b2*(DBH²) has good adjust (R²adj.=0.92; VC=6.12%). The equation to annual lengthening of the crown, ALC=b0+b1*(NLCAI)+b2*(DBH) showed adjustment and precision (R²adj.=0.50; VC=35.95%), it explaining until 50% total variance, but with higher percent residual. With similar precision, the model adjusted to crown growth in diameter, CGD=b0+b1*(NLCAI), had statistical precision defined to R²adj= 0.44 and VC=36.25%, with higher VC resulted from the higher variance in samples. To the CDrh the adjust was represented to R²adj.=0.58 and VC=52.41%, had been defined the model NLCDrh=b0+b1*(NLDBH)+b2*(1/hi²)+b3*(DBH²), with the results of residual evaluations didn t submit normality distribution and homogeny variance. The adjust to CAIb equation showed good statistical precision (R²adj.=0.66; VC=11%), it explaining until 66% total variance from model NLCAIb=b0+b1*(DBH)+b2*(h/d). On the increment descriptive analyses it observed high periodic annual increment in diameter (PAId) and PAIb in the 25, 35 and 45 cm diameter class. The PAId medium, minimum and maximum values correspond to 3.6 cm, 0.7 cm and 7.3 cm. At the 35 and 45 cm class it observed 95.6 and 75.5 PAIb average, respectively. All of the diameter classes it was observed current annual increment in diameter (CAId) higher 2.5 cm. The crown growth reviews from the open-grown trees demonstrated that the crown growth rhythmic and its correlation with the bole increments it turn possible to build growth models characterized to good adjust and statistical efficiency, wherever, it should be stratification methods based in site informations. The methodology analyses with digital photography also showed good precision and practicality, it can be widely used to review singular and open-grown trees. / Na avaliação do crescimento de árvores isoladas foram selecionadas 57 amostras, das quais se mensurou variáveis morfométricas em fotos digitalizadas no software AutoCAD e dendrométricas a partir de rolos de incremento coletados na altura do DAP. O desenvolvimento desta pesquisa teve como objetivo descrever as dimensões individuais e reconstituir o crescimento da copa e fuste de árvores isoladas de Cedrela fissilis, avaliado de 2007 a 2011, e construir equações matemáticas para descrever o crescimento da variável diâmetro da copa (DC), manto de copa (MC), diâmetro da copa em alturas relativas (DChi) e incremento periódico anual em área basal (IPAg). Nos alongamento anuais (ALG) foram verificados valores mínimo, máximo e médio anual de 3,0, 91,0 e 32,4 cm, respectivamente. Assim como correlações em série, determinada por r = 0,76 a 0,86 (Pr<.0001), tendo sido observados maiores alongamentos nas menores ordens de ramificação. Nos alongamentos periódicos (ALGP), correspondente ao período 2007-2011, verificaram-se valores médios de até 1,82 m, observado na classe diamétrica 30-40 cm, com coeficiente de variação (CV) máximo de 67,67%, verificado na classe > 60 cm. Para a construção dos modelos de crescimento foram selecionadas 35 árvores de acordo com sua condição de copa e fuste, sendo descartada a classe diamétrica > 60 cm devido a pouca amostragem. Para o manto de copa o modelo LNMC = b0+b1*(1/DAP)+b2*(DAP²) apresentou bom ajuste (R²aj.= 0,92 e CV = 6,12%). A equação da variável alongamento anual da copa, ALG=b0+b1*(LNICA)+b2*(DAP), apresentou o ajuste comprometido pelo alto erro percentual (R²aj. = 0,50; CV = 35,95%), descrevendo até 50% da variância total. Com precisão semelhante à ALG, o modelo ajustado para a variável crescimento da copa em diâmetro, CCD=b0+b1*(LNICA), apresentou altas taxas de erro percentual, com precisão estatística definida por CV = 36,25%; R²aj. = 0,44. Para o modelo DChi o ajuste foi descrito por R²aj.=0,58 e CV=52,41%, tendo sido definido o modelo LNDChi=b0+b1*(LNDAP)+b2*(1/hi²)+b3*(DAP²), tendo o mesmo não apresentado distribuição normal e heterogeneidade na variância dos resíduos. O ajuste da equação apara o IPAg apresentou boa precisão estatística (R²aj.=0,66; CV=11%), descrevendo até 66% da variância total a partir do modelo LNIPAg=b0+b1*(DAP)+b2*(h/d). Na avaliação descritiva dos incrementos observaram-se elevadas taxas de incremento periódico anual em diâmetro (IPAd) e IPAg nas classes diamétricas 25, 35 e 45 cm. Os valores de IPAd médio, mínimo e máximo foram de 3,6 cm, 0,7 e 7,3 cm, respectivamente. Nas classes 35 e 45 cm verificou-se taxa de IPAg média de 95,6 e 75,5 cm², respectivamente. Em todas as classes de diâmetro foram encontradas taxas de incremento corrente anual em diâmetro (ICAd) superior a 2,5 cm. As análises do crescimento da copa de árvore isoladas demonstraram que o crescimento rítmico da mesma e sua correlação com os incrementos do fuste possibilitam a construção de modelos de crescimento com boa eficiência estatística, porém, devendo se aperfeiçoar a estratificação fazendo uso de informações que descrevam as condições dos sítios. A metodologia de avaliação a partir de fotos digitalizadas também apresentou boa precisão e praticidade, podendo ser amplamente utilizada na avaliação de árvores singulares ou isoladas.

Page generated in 0.056 seconds