Dissertations / Theses on the topic 'Orthodontic devices'

Thesis (MScEng)--Stellenbosch University, 2013.
ENGLISH ABSTRACT: Orthodontics is the eld of dentistry concerned with the treatment of maloc- clusion and anomalies of the dento-facial complex. This thesis is concerned with studying the underlying biomechanical principles of orthodontic tooth movement. It aims to develop a novel treatment approach and an orthodontic appliance to facilitate said approach by employing advanced technologies. A thorough review of the literature is used to form a comprehensive knowledge base pertaining to the factors a ecting orthodontic tooth movement. It is hypothesised that an electromechanical orthodontic appliance could improve treatment by characterising orthodontic cases based on the relationship be- tween the applied mechanical stimulus and the resulting changes to the af- fected structures, which can then be sensed by the appliance. A prototype is built using electronically controllable linear actuators and a custom built force transducer system for measuring orthodontic forces. Electronic circuits are de- veloped to connect the appliance to a USB port and allow it to be controlled from a graphical user interface (GUI). This further facilitates real-time viewing of important orthodontic parameters. Experiments are carried out to evaluate the appliance functionality with regard to the proposed hypothesis. To con- clude, the relevance of the results to the orthodontic eld is highlighted and recommendations for further development of an electromechanical orthodontic appliance are provided.
AFRIKAANSE OPSOMMING: Ortodonsie is die vakgebied in tandheelkunde gemoeid met die behandeling van wanpassing en abnormaliteit van die tand- en gesig-area. Hierdie tesis bestudeer die onderliggende biomeganiese beginsels van ortodontiese tandbeweging om sodoende 'n nuwe benadering sowel as 'n ortodontiese apparaat te ontwikkel om die genoemde benadering te fasiliteer deur gebruik te maak van gevorderde tegnologie. 'n Deeglike oorsig van die literatuur word gebruik om 'n omvattende kennisbasis op te bou rondom die faktore wat ortodontiese tandbeweging a ekteer. Die hipotese word gestel dat 'n elektromeganiese ortodontiese apparaat behandeling kan verbeter deur ortodontiese gevalle te identi seer/- karakteriseer gebaseer op die verhouding tussen die toegepaste meganiese stimulus en die gevolglike veranderinge aan die gea ekteerde strukture wat deur die apparaat aangevoel word. Elektronies-beheerbare lineêre aandrywers en 'n pasgemaakte krag-oordraerstelsel vir die meet van ortodontiese kragte word gebruik om 'n prototipe te vervaardig. Elektroniese stroombane word ontwikkel om die apparaat te koppel aan 'n USB poort sodat dit beheer kan word d.m.v. 'n gra ese gebruikerskoppelvlak. Eksperimente poog om die apparaat funksioneel te evalueer volgens die voorgestelde hipotese. Ter afsluiting: die toepaslikheid van die verwerfde resultate in die ortodontiese vakgebied word beklemtoon en aanbevelings word gemaak vir toekomstige/verdere ontwikkelings m.b.t. 'n elektromeganiese ortodontiese apparaat.

O objetivo deste estudo foi avaliar a influência do padrão de crescimento craniofacial na espessura da cortical óssea alveolar e correlacioná-lo com a estabilidade dos mini-implantes ortodônticos. A amostra constituiu de 30 pacientes com 56 mini-implantes inseridos na região posterior vestibular da maxila como recurso de ancoragem na retração anterior. Inicialmente, os pacientes foram divididos de acordo com a média do ângulo FMA, em padrão de crescimento horizontal (grupo GH) e vertical (grupo GV). As espessuras das corticais ósseas foram mensuradas nos cortes axiais das imagens de tomografia computadorizada de feixe cônico. As médias econtradas em cada grupo foram comparadas pelo teste t. A correlação de Pearson foi realizada entre os valores do ângulo FMA e as espessuras das corticais ósseas. Posteriormente, para avaliar a influência do padrão de crescimento sobre a estabilidade dos mini-implantes, estes foram divididos em dois grupos também de acordo com o padrão de crescimento: GMI(H) horizontal e GMI(V) vertical. Os grupos foram comparados quanto ao grau de mobilidade e a proporção de sucesso dos mini-implantes pelos testes de Mann-Whitney e o teste Exato de Fisher. Através desses testes e do teste Qui-quadrado foi avaliada a influência das seguintes variáveis sobre o grau de estabilidade: características do tecido mole na região de inserção, sensibilidade, a quantidade de placa, o período de observação e a técnica utilizada para cada dispositivo. Os resultados obtidos demonstraram que a espessura da cortical óssea alveolar anterior (superior e inferior) e posterior (inferior) vestibulares foram maiores no grupo GH do que o grupo GV. Houve correlação negativa significante entre o FMA e as espessuras nas regiões anteriores inferiores (vestibular e lingual) e superior (vestibular). Não houve diferença significante nos resultados para o grau de mobilidade e proporção de sucesso dos mini-implantes nos grupos GMI(H) e GMI(V). O tempo médio de observação foi de 8,77 meses. A proporção de sucesso total foi de 89,29% e nenhuma variável mostrou estar relacionada com o sucesso dos mini-implantes. No entanto, observou-se maior sensibilidade nos pacientes cujo mini-implante apresentava mobilidade e a falha desses dispositivos de ancoragem ocorria logo após sua inserção.
This study aimed the assessment of the craniofacial growth pattern influence on the alveolar bone cortical thickness as well as the evaluation of the stability of orthodontic mini-implants. The sample comprised 56 mini-implants inserted on the posterior buccal region of the maxilla of 30 patients with the purpose of orthodontic anchorage for the anterior retraction. Initially, patients were divided by FMA mean according to the growth pattern as: horizontal group (GH group) and vertical group (GV group). The alveolar cortical bone thicknesses were measured in the axial sections of the images of cone-beam computed tomography. The means found for each group were compared with the t test. Pearson´s correlation was performed for the values of growth pattern (FMA) and for the thicknesses of cortical bone. In order to evaluate the influence of growth pattern on the stability of mini-implants, these devices were divided in two other groups, according to the growth pattern as: GMI(H), horizontal and GMI(V), vertical. The mobility degree and success rate of mini-implants shown by these two groups were compared using Mann-Whitney tests and Fisher Exact test. Through these tests and the Chi-square test the influence of the following variables on the degree of stability were evaluated: soft tissue characteristics of the insertion site, sensibility degree, plaque retention around miniimplant, observation period and technique used. The results demonstrated that the thickness of the anterior buccal cortical bone (upper and lower) and the posterior cortical bone (lower) were greater for the GH group than for the GV group. There was a significant negative correlation between the FMA and the thicknesses of the lower anterior regions (buccal and lingual) and upper regions (buccal). No significant difference was found regarding the mobility degree and the success rate of miniimplants between the groups GMI(H) and GMI(V). Total success rate found was 89.29% and no variable showed to be related to the success of mini-implants. Nevertheless, a greater sensibility was observed in patients whose mini-implants presented mobility and the failure of these anchorage devices occurred in a short time after insertion.

Enamel demineralisation or white spot lesions (WSLs) is a risk for all patients undergoing fixed appliance orthodontic treatment (FAOT) with no consensus with regards to prevalence, risk factors, prevention and treatment. Slow-release fluoride glass devices (SRFGDs) have been shown to clinically prevent caries without relying on patient’s compliance, therefore their effectiveness in preventing WSLs during FAOT was investigated. An in-vitro exploratory study investigated fluoride (F) and phosphate (PO4) release from different types of powder from SRFGDs incorporated into a composite resin bonding material. Samples were stored in artificial saliva and assessed with ion chromatography for up to six months. Three types of powder showed high F release to maximise caries prevention and low PO4 release to minimise degradation of powder. A questionnaire was emailed to orthodontists’ members of the British Orthodontic Society. For majority of responders the key factors to the problems related to WSLs are clinical examination, photographs, F, oral hygiene, diet and duration of FAOT. A double-blind, randomised clinical study with orthodontic patients randomly allocated to SRFGDs or placebo devices threaded onto the orthodontic wire was conducted. Cross-polarised digital photographs of the maxillary permanent central and lateral incisors and canines were taken for 63 subjects at the start and for 40 subjects at the end of the study. One examiner assessed photographs for presence and severity of WSLs. Majority of volunteers and the smallest number of refusals lived in the most deprived areas according to the Multiple Deprivation Index. Use of SRFGDs would decrease severity by preventing 2.88 times more teeth compared to use of 225 ppm F mouth-rinse once daily and 1,450 ppmF tooth-paste twice daily. Duration of FAOT and increased gingival index at the start of FAOT increased significantly the risk of developing WSLs. SRFGDs were effective in preventing teeth with WSLs during the course of FAOT.

Orientador: Cecília Amélia de Carvalho Zaváglia
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
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Resumo: Os bráquetes são suportes utilizados pelos ortodontistas para controlar o posicionamento dos dentes nos tratamentos ortodônticos. Por eles, mais precisamente por seus slots, passam os fios ortodônticos e ambos são responsáveis pela biomecânica dos movimentos. O bráquete pode ser confeccionado por diversos materiais, sendo o mais comum o metal pela praticidade, preço e resistência. Recentemente, com a maior demanda por aparelhos estéticos, devido ao aumento de adultos utilizando estes dispositivos, aumentou o uso de bráquetes estéticos, feitos geralmente de polímeros ou cerâmicas. As maiores dificuldades encontradas estão relacionadas a estética, resistência, capacidade de coloração por alimentos e maior atrito com o fio. O propósito deste estudo foi a obtenção de compósitos cerâmicos de alumina e zircônia (ZTA) a partir de pós finamente cominuídos em diferentes proporções 70/30, 80/20 e 90/10 provenientes de materiais cerâmicos de alumina e zircônia separadamente. Os compósitos cerâmicos (ZTA) foram submetidos a processos de análises do tamanho de partículas, moagens, prensagens, conformações de corpos de provas (c.p.), difração de raio X, ensaios de compressão diametral, análises das propriedades mecânicas, avaliações das microestruturas e análises de propagação de trincas. Os resultados demonstraram tamanhos de partículas de 0,3µ, os valores da compressão diamentral de 296,64 MPa, 262,60 MPa, 220,30 MPa, os valores de microdureza de 13,12 GPa, 13,42 GPa, 13,81 GPa, os valores de tenacidade à fratura de 8,91 MPa m½, 9,37 Mpa m½, 9,65 Mpa m½, os tamanhos de grãos em torno de 0,6µ e uma redução significativa nas propagações das trincas em relação à alumina. Estes compósitos cerâmicos de alumina e zirconia (ZTA) demonstraram resultados superiores em seus valores de tenacidade à fratura de aproximadamente 68% em relação a alumina, atualmente utlizados em bráquetes comerciais. Ocorreu uma redução do tamanho de grãos e modificações no comportamento de propagação das trincas resultando na diminuição da ocorrência de trincas. A conclusão, diante dos resultados apresentados nas análises, foi que os materiais compósitos cerâmicos de alumina e zircônia (ZTA), nos quesitos avaliados, foram adequados para serem aplicados em bráquetes estéticos de Ortodontia, porém novos trabalhos foram sugeridos para avaliação desses materiais em relação ao desgaste, a fricção e a coloração. Palavras-chave Aparelhos ortodonticos estéticos, bráquetes cerâmicos, compósitos cerâmicos, compósitos ZTA
Abstract: The brackets are used by orthodontists to control the tooth positions on orthodontic treatments. Inside the brackets, in the slots, are the orthodontic wire and both are responsible for the biomechanical movement. The brackets can be made of different materials and the most common is the metallic by practically, price and resitance. Recently, with the greatest demand of aesthetic devices, because a adult demand, increased use of aesthetic brackets made of polymers and ceramics. The greatest aesthetic difficulties are the resitence, staining for food and the wire friction. This work aims to contribute to the development of new aesthetic orthodontic brackets. Thereby was proposed in this study the obtainment of ceramic composites alumina and zirconia (ZTA) powder finely comminuted in different proportions 70/30, 80/20 and 90/10 from alumina and zirconia separately. These ceramic composites alumina and zirconia (ZTA) were submitted to particle analysis, milling process, pressing, specimens conformations, X ray diffraction, diametral compression, mechanical properties analysis, evaluation of microstructured and crack propagation analysis. The results showed particle size 0,3µ, the diametral compression values of 296,64 MPa, 262,60 MPa, 220,30 Mpa, the hardness values of 13,12 GPa, 13,42 GPa, 13,81 GPa, the fracture toughtness values of 8,91 MPa m½, 9,37 Mpa m½, 9,65 Mpa m½, the grain size of 0,6µ and a significant reduction in crack propagation compared to alumina. These ceramic composites alumina and zirconia (ZTA) demonstrated superior results in their fracture toughness values of approximately 68% compared to alumina, currently used in commercial brackets. There was a reduction in grain size and changes in the behavior of propagation of cracks resulting in a decrease of occurance of cracks. The conclusion on the results presented was that ceramic composites alumina and zirconia (ZTA), on the variables evaluated, were suitable for application in Orthodontic aesthetic brackets however new studies have been suggested for the evaluation of these materials in relation to wear, friction and staining. Key Words Aesthetic orthodontic devices, ceramic brackets, ceramic composites, ZTA composites
Doutorado
Materiais e Processos de Fabricação
Doutor em Engenharia Mecânica

A thesis submitted to the College of Dental Medicine of Nova Southeastern University of the degree of Master of Science in Dentistry. Objectives. The purpose of this study was to determine the effect of pitch and thread depth of orthodontic miniscrew implants(MSI's) on stress generation. Methods. Quasi-three dimensional photoelastic models were created with MSI's embedded and then loaded with 60 and 104 grams respectively and evaluated under a full field reflection polariscope. The control MSI's (1.0mm pitch / 0.25mm thread depth) were compared to 3 experimental groups (n=10) which varied with only one design characteristic: Group 1 (0.75mm pitch), Group 2 (1.25mm pitch) and Group 3 (0.40 thread depth). The maximum shear stress (τmax) was calculated at 5 predetermined and standardized points. A two-way ANOVA was conducted to compare the means of τmax followed by a Tukey's post hoc (p<0.05). Results. No statistical differences were found for τmax between the control group and each of the 3 experimental groups except at point 4. At point 4, the control group was higher by an average of 5.05 and 7.1 MPa for the 60 and 104 gram loads respectively (p<0.05). No statistically significant differences were found for points 1, 2, and 5 for the 60 gram load and for points 1, 2, 3, and 5 for the 104 gram load. The mean τ max from highest to lowest was located at points 5<1< 2<4 <3 in both the 60 and 104 load steps. The variability in τmax at point 4 may have been due to its proximity to the neutral zone of the present loading conditions. Conclusions. As the orthodontic load was increased, maximum shear stress also increased for each of the four MSI designs used in this study. The results of this study suggest that, within limits, variation of pitch and thread depth of MSI's may not have a significant influence on the stress generation when loaded for orthodontic purposes. Photoelastic analysis has shown to be a viable option to evaluate mechanical properties of MSI'S.

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O objetivo do trabalho foi avaliar tridimensionalmente as mudanças dentárias após avanço mandibular com o aparelho de Herbst bandado em indivíduos classe II divisão 1, após surto de crescimento. A amostra deste trabalho constituiu-se de modelos ortodônticos pré (T1) e pós tratamento (T2) de 34 pacientes (21 indivíduos masculinos e 13 femininos, idade média 16,2) portadores de má oclusão de Classe II divisão 1, que receberam na média terapia de avanço mandibular durante 8 meses. Estes modelos de estudo foram digitalizados (R700, 3Shape®) em oclusão habitual e analisados tridimensionalmente através do software VistaDent®. Em função de objetivos específicos, dividiu-se o trabalho em dois estudos. O primeiro estudo foi desenvolvido com o intuito de detectar efeitos acontecidos após 8 meses de avanço mandibular com aparelho de Herbst bandando, sobre a Curva de Spee (CDS) mandibular, índice de irregularidade de Little e inclinação vestíbulo-lingual dos incisivos inferiores. A análise estatística foi realizada por meio do teste t de Student, com nível de significância de 5%, precedido do teste de Levene, para analisar a hipótese de igualdade das variâncias. Incremento na profundidade da CDS (média -1,47 mm, P <0,00005), aumento no índice de irregularidade (média-1,89 mm; P <0,00005), e foi encontrada uma diferente proclinação entre incisivos laterais (32: média, 3,01, P <0,05; 42: média, 3,83, P <0,005) e incisivos centrais mandibulares (31: média, 1,80°, P <0,05; 41: média, 2,43°, P <0,05). Resultados sugeriram uma mudança negativa clinicamente significativa na profundidade da CDS, incremento no índice de irregularidade e proclinação diferenciada dos incisivos inferiores, após 8 meses de terapia com aparelho de Herbst bandado. O segundo estudo teve como objetivo de avaliar os efeitos dentários transversais imediatos após 8 meses de avanço mandibular com aparelho de Herbst bandando, na distância intercaninos, interpré-molares e intermolares assim como a rotação dos primeiros molares maxilares e mandibulares. Comparação estatística das varáveis pré e pós-tratamento e dimorfismo de gênero foi feita através do teste t de Student com um nível de significância de 5% precedido do teste de Levene, para analisar a hipótese de igualdade das variâncias. Diferenças na homogeneidade de gênero dentro da amostra (T1) provocou a separação do grupo para avaliação individual (masculino/feminino) em algumas das variáveis estudadas. Incremento nas distâncias interpré-molares da maxila (15-25: média 1,66 mm; 14-24: média 1,36 mm), mudanças insignificantes nas distâncias intercaninos (Mandibular: média 0.02 P=947; Maxilar: média 0.36 mm; P =0,177), ausência de rotações nos molares e um leve incremento nas distâncias intermolares (maxilar: média 0,80 mm; mandibular: média 0,06 mm) foram os resultados mais relevantes do trabalho. Resultados sugeriram mudanças transversais significativas nas distâncias interpré-molares maxilares, intermolares maxilar e mandibular com ausência de rotações e uma estabilidade das distâncias intercaninos.
The aim of this study was to evaluated three-dimensional mandibular dental effects with a banded Herbst appliance on Class II division 1 individuals, post growth spurt. The sample of this work constituted with pre-treatment (T1) and post-treatment (T2) orthodontic models of 34 patients (21 male, 13 female, average of 16,2 years-old) with Class II division 1 malocclusion, who received a mandibular advanced therapy during 8 months, were digitalized (R700, 3Shape®) in habitual occlusion and three-dimensionally analyzed through VistaDent® software In function of specific objectives this investigation was divided in 2 different studies. The first one with the intention of detecting dental effects of mandibular advancement with a Banded Herbst appliance over the Curve of Spee during 8 months; irregularity index of Little and vestibular-lingual inclination of the mandibular incisors. Statistical analysis was done through the T student test, with a level of significance of 5%, preceded by the Levene test, to analyze the equality of variances. Increase in depth of CDS (average-1,47 mm, P <0,00005), as well as the index of irregularity (average- 1,89 mm; P <0,00005); a different proclination was found in between lateral incisors (32: average, -3,01, P <0,05; 42: average, -3,83, P <0,005) and mandibular central incisors (31: average, -1,80°, P <0,05; 41: average, -2,43°, P <0,05). (31: average: -1,80°, P <0,05; 41: average, -2,43°, P <0,05). The results reflected a clinically significant negative effect in CDS depth, increase in the index of irregularity and differentiated proclination of mandibular incisors, after an 8-month therapy with Herbst banded appliance. The objective of the second study was to evaluate the immediate transversal dental effects after 8 months of mandibular advancement with a banded Herbst appliance, on inter-canine, inter-premolar and inter-molar distance; as well as the rotation of the mandibular and maxillary first molars. The statistical comparison between pre-treatment and post-treatment variances and gender dimorphism was made through the Student t test, with a level of significance of 5%, preceded by the Levene test, to analyze the hypothesis of variances equality. Differences in gender homogeneity in the sample (T1) provoked a group separation, becoming an individual evolution (male/female) in some of the studied variables. Increase in maxillary inter-premolar distances (15-25: average 1,66 mm; 14-24: average 1,36 mm), insignificant statistical changes within inter-canine distances (Mandibular: average 0.02 P=947; Maxillary: average 0.36 mm; P =0,177), absence of rotation in molars and slight increase in inter-molar distances (maxillary: average 0,80 mm; mandibular: average 0,06 mm) were the most relevant increases in this research. The results suggested significant transversal changes in maxillary inter-premolar distances, maxillary and mandibular inter-molar rotation absence and instability of inter-canine distance.

O objetivo deste trabalho foi avaliar a influencia da proximidade entre miniimplantes autoperfurantes e as raizes dentarias sobre a estabilidade destes dispositivos de ancoragem. A amostra consistiu de 40 mini-implantes inseridos entre as raizes do primeiro molar e segundo pre-molar superiores de 21 pacientes, como recurso de ancoragem para retracao anterior. A largura do septo no local de insercao (LSI) e a menor distancia da cabeca do mini-implante a raiz dentaria (MDR) foram mensuradas nas 40 radiografias pos-cirurgicas. Sob este aspecto, os miniimplantes foram divididos em duas categorias de grupos: de acordo com a largura do septo no local de insercao, grupos G1L (LSI3mm) e G2L (LSI>3mm), e de acordo com a proximidade do mini-implante a raiz adjacente, grupos G1P (MDR0mm) e G2P (MDR>0mm). A estabilidade dos mini-implantes foi avaliada mensalmente pela quantificacao do grau de mobilidade, e a partir desta variavel foi calculada a proporcao de sucesso. Tambem foi avaliada a influencia das seguintes variaveis sobre o grau de estabilidade: caracteristica do tecido mole no local de insercao, o grau de sensibilidade, a quantidade de placa, a altura de insercao e o periodo de observacao. As duas categorias de grupos foram comparadas quanto ao grau de mobilidade e proporcao de sucesso por meio do teste de Mann-Whitney e do teste Exato de Fisher, respectivamente. Adicionalmente, avaliou-se a influencia das demais variaveis sobre a estabilidade deste sistema de ancoragem atraves do teste t e do teste do Qui-quadrado. Os resultados obtidos demonstraram que não houve diferenca estatisticamente significante para o grau de mobilidade e proporção de sucesso entre os mini-implantes inseridos em septos do grupo G1L e G2L. A proximidade entre os mini-implantes avaliados e as raizes dentarias adjacentes (grupos G1P e G2P) tambem nao influenciou na estabilidade e proporcao de sucesso deste sistema de ancoragem. A proporcao de sucesso total encontrada foi de 90% e nenhuma variavel demonstrou estar relacionada ao insucesso dos miniimplantes. No entanto, observou-se maior sensibilidade nos pacientes cujos miniimplantes apresentavam mobilidade, e que a falha destes dispositivos de ancoragem ocorria logo apos sua insercao.
The purpose of this study was to evaluate the influence of the proximity between self-drilling miniscrews and dental roots on the stability degree. The sample consisted of 40 miniscrews inserted in the interradicular septum between maxillary second premolars and first molars to provide skeletal anchorage for anterior retraction. The forty post-surgical radiographs were used to measure the septum width in the insertion site (SWI) and the smallest distance between miniscrew head and dental root (SDR). In this regard, the miniscrews were divided in two categories of groups: according to the septum width in the insertion site, groups G1W (SWI 3mm) and G2W (SWI>3 mm), and according to the miniscrew dental root proximity, groups G1P (SDR0mm) and G2P (SDR>0mm). The mobility degree (MD) was monthly quantified to determine miniscrew stability, and the success rate of these devices was calculated. This study also evaluated the influence of following variables on the stability degree: soft tissue characteristics in the insertion site (attached gingiva, mucogingival junction and alveolar mucosa), sensitivity degree during miniscrew load, plaque amount around miniscrew, insertion height, and total evaluation period. All the groups were compared regarding mobility degree and success rate using t test and Fisher exact test, respectively. The results showed no significant difference in mobility degree and success rate between groups G1W and G2W. The miniscrew dental root proximity did not influence the stability and success rate of this anchorage system when G1P and G2P were compared. The total success rate found was 90% and no variable was associated with the miniscrew failure. Nevertheless, the results showed that greater patient sensitivity degree was associated to the miniscrews mobility and the failure of these anchorage devices happened in a short time after their insertion.

O objetivo deste estudo longitudinal foi comparar as alterações dentoesqueléticas e tegumentares de jovens com má oclusão de Classe II não tratados e tratados com distalizador First Class em ancoragem convencional ou esquelética, ou com o aparelho extrabucal cervical (AEB), seguidos do aparelho fixo. A amostra foi composta por 44 pacientes com má oclusão de classe II e divididos em quatro grupos de 11 cada: pacientes tratados com distalizador First Class com ancoragem convencional no botão de Nance (G1), tratados com distalizador First Class com ancoragem esquelética apoiado em 2 mini-implantes no palato (G2), tratados com o aparelho extrabucal (AEB) (G3) e o grupo controle, com pacientes não tratados (G0). Foram obtidas as telerradiografias ao início (Ti) e final (Tf) do tratamento para a realização das análises cefalométricas e avaliação das alterações dentárias, esqueléticas e tegumentares e compará-los com o grupo controle (G0). A análise estatística foi realizada pelo teste t pareado com a finalidade de verificar as alterações ocorridas dentro de um mesmo grupo e pelo teste ANOVA a um critério e teste de Tukey para verificar as diferenças entre os grupos. Observou-se restrição e redirecionamento do crescimento maxilar ao final do tratamento no G1 e G3. Os efeitos esqueléticos na mandíbula só foram significantes no G0. As medidas da relação maxilomandibular diminuíram significantemente no G1 e G3 com significante diminuição das medidas que avaliaram o perfil tegumentar. Quanto ao componente vertical todas as medidas aumentaram no G3. Os primeiros molares superiores angularam distalmente no G2 e os inferiores mesialmente no G3. Os quatro grupos apresentaram extrusão dos dentes superiores e inferiores. Os três grupos experimentais apresentaram diminuição significante nas relações dentárias (relação molar, trespasse horizontal e vertical). Conclui-se que os grupos experimentais corrigiram a má colusão de Classe II de maneira satisfatória, sendo que o uso do AEB mostrou efeitos esqueléticos e dentários na correção e os grupos com distalizadores somente efeitos dentários. O tempo de tratamento no grupo com AEB foi significantemente menor.
The aim of this prospective study was to compare the dental, skeletal and soft tissue changes in youngsters with Class II malocclusion untreated and treated with First Class distalizer in conventional or skeletal achorage or with cervical headgear followed by fixed orthodontic appliances. The sample consisted of 44 patients with Class II malocclusion and divided into four groups of 11: patients treated with First Class distalizer with conventional anchorage (Nance button)(G1), treated with First Class distalizer with skeletal anchorage supported in two palatal mini-implants (G2), treated with cervical headgear (G3) and follow-up group with untreated patients (G0). Lateral cephalometrics radiographs were taken before treatment and after treatment in order to cephalometric analysis and evaluate the dental, skeletal and soft tissue changes and to compare with follow-up group (G0). Statistical analysis was performed by dependent t test to verify the changes occurred in the same group and by one-way ANOVA and Tukey test to verify the changes occurred between the groups. It was observed restriction and redirection of maxillary growth after treatment in G1 and G3. Mandibular skeletal effects were significant in G0. The values of skeletal maxilomandibular relationship decreased significantly in G1 and G3 with significant decrease of measurements that evaluated soft facial profile. All measurements of vertical component increased in G3. Maxillary first molars were distal tipping in G2 and lower first molars were mesial tipping in G3. The four groups showed extrusion in the upper and lower teeth. The three experimental groups showed significant decreased in the molar relationship, overjet and overbite. It concluded that experimental groups corrected the Class II malocclusion efficiently, cervical headgear showed skeletal and dental effects and the groups with distalizers showed only dental effects. The mean treatment period was significant lower with cervical headgear.

O objetivo deste estudo prospectivo foi avaliar as alterações dentoesqueléticas e tegumentares de jovens com má oclusão de Classe II tratados com distalizador First Class em dois tipos diferentes de ancoragem. Foram selecionados 30 pacientes e divididos, aleatoriamente, em dois grupos de 15: G1 (5 masculino e 10 feminino) que recebeu o distalizador com ancoragem convencional no botão de Nance e G2 (10 masculino e 5 feminino) que recebeu o distalizador com ancoragem esquelética apoiado em 2 mini-implantes no palato, com médias de 13,00 e 13,28 anos de idade, respectivamente. As telerradiografias foram obtidas antes e após a distalização dos molares para a realização das análises cefalométricas. A análise estatística foi realizada pelo teste t dependente com a finalidade de verificar as alterações ocorridas dentro de um mesmo grupo e pelo teste t independente para verificar as diferenças entre os grupos. Foi calculado também o erro sistemático e casual. O tempo médio de tratamento foi de 4,51 e 6,28 meses para G1 e G2, respectivamente. Ambos os grupos apresentaram alterações dentárias significantes com distalização (G1=2,39 mm; G2=2,21 mm), angulação distal (G1=10,51º; G2=4,49º) e intrusão (G1=0,53 mm; G2=0,10 mm) dos primeiros molares superiores, sendo apenas sem significância a intrusão em G2. A perda de ancoragem foi semelhante entre os dois grupos, com significante mesialização (G1=2,78 mm; G2=3,11 mm) e angulação mesial (G1=4,95°; G2=4,69°) dos segundos pré-molares, protrusão (G1=1 ,55 mm; G2=1,94 mm) e vestibularização (G1=5,78°; G2=3,13°) significantes dos incisivos superiores e um aumento significante no trespasse horizontal (G1=1,07 mm; G2=0,81 mm). A mecânica de distalização não interferiu nos componentes esqueléticos e tegumentares dos pacientes. Em ambos os grupos, o distalizador First Class promoveu correção da relação molar, porém apresentou efeitos de perda de ancoragem verificada nos pré-molares e incisivos superiores mesmo quando associada à mini-implantes. Não houve diferença significante entre os grupos quanto às alterações dentárias lineares, porém as angulares foram significantemente menores no grupo com ancoragem esquelética.
The aim of this prospective study was to evaluate the dental, skeletal and soft tissue changes in youngsters with Class II malocclusion treated with First Class distalizer in two different types of anchorage. Thirty patients were included and divided, randomly, in two groups of 15. G1 (5 boys and 10 girls) that received distalizers with conventional anchorage (Nance button) and G2 (10 boys and 5 girls) that received distalizers with skeletal anchorage supported in two palatal mini-implants, average age of 13.00 and 13.28 years old, respectively. Lateral cephalometric radiographs were taken before and after molar distalization in order to the cephalometric analysis. Statistical analysis was performed by dependent t test to verify the changes occurred in the same group and by independent t test to verify the difference between the groups. The systematic and casual errors were calculated as well. The mean treatment period was 4.51 and 6.28 months for G1 and G2, respectively. Both groups showed significant dental changes with distalization (G1=2.39 mm; G2=2.21 mm), distal tipping (G1=10.51º; G2=4.49º) and intrusion (G1=0.53 mm; G2=0.10 mm) of maxillary first molars, just intrusion in G2 was not significant. Anchorage loss showed similar in both groups with significant mesialization (G1=2.78 mm; G2=3.11 mm) and mesial tipping (G1=4.95°; G2=4.69°) of maxillary second premolars, significant protrusion (G1=1.55 mm; G2=1.94 mm) and proclination (G1=5.78°; G2=3.13°) of maxillary incisors and significant increase in overjet (G1=1.07 mm; G2=0.81 mm). Distalization mechanic did not interfere in skeletal and soft tissue measurements of patients. In both groups, the First Class distalizer corrected the molar relationship, however it showed anchorage loss effects in maxillary premolars and incisors even when associated to mini-implants. There was no significant difference between the groups on dental linear changes, however the dental angular changes were significantly lower in skeletal anchorage group.

Thesis (M.S.)--West Virginia University, 2010.
Title from document title page. Document formatted into pages; contains viii, 101 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 83-92).

Objetivo: O objetivo deste estudo foi comparar as alterações cefalométricas de pacientes com má oclusão de Classe II divisão 1 tratados com os aparelhos Jasper Jumper e Forsus Fatigue Resistant Device, associados ao aparelho ortodôntico fixo. Material e métodos: A amostra foi constituída por 124 telerradiografias em norma lateral de 62 indivíduos, os quais foram divididos em 3 grupos: Grupo Experimental 1 (n=22, idade inicial=12,39 anos), tratados por meio do aparelho Jasper Jumper associado ao aparelho fixo, por um período médio de 2,43 anos; Grupo Experimental 2 (n=19, idade inicial=12,43 anos), tratados com o aparelho Forsus associado ao aparelho fixo, com tempo médio de tratamento de 3,54 anos; Grupo Controle (n=22, idade inicial 12,14 anos), observados por um período médio de 1,78 anos. As alterações de todas as variáveis cefalométricas dos grupos experimentais foram anualizadas e, posteriormente, comparadas às alterações das variáveis do grupo Controle, por meio da Análise de Variância e do teste de Tukey. Resultados: Observou-se que ambos os tratamentos apresentaram um efeito restritivo na maxila; não alteraram o desenvolvimento mandibular; melhoraram a relação maxilomandibular; promoveram rotação horária do plano oclusal e um suave aumento da altura facial anteroinferior. Os grupos experimentais apresentaram limitação do desenvolvimento vertical dos molares superiores; inclinação para vestibular e limitação do desenvolvimento vertical dos incisivos inferiores; e extrusão dos molares inferiores. Os incisivos inferiores exibiram maior protrusão no grupo 1 em relação aos demais grupos. Ambos os aparelhos melhoraram significantemente a relação maxilomandibular, os trespasses horizontal, vertical e a relação molar. Os protocolos de tratamento promoveram retrusão dos lábios superiores. O grupo 2 apresentou suave protrusão dos lábios inferiores e os grupos 1 e 3 apresentaram pequena retrusão. Conclusão: Conclui-se que ambos os aparelhos foram eficazes na correção da má oclusão de Classe II.
Objective: The aim of this study was to compare the cephalometric changes of Class II division 1 malocclusion patients treated with Jasper Jumper and Forsus Fatigue Resistant Device, associated with fixed appliances. Methods: The sample consisted of 124 lateral cephalograms of 62 individuals, divided into 3 groups: Group 1 (n=22,mean age=12.39 years), treated with the Jasper Jumper appliance associated with fixed appliances for a mean period of 2.43 years; Group 2 (n=19, mean age=12.43 years), treated with the Forsus appliance associated with fixed appliances, with a mean treatment time of 3.54 years; and the Control group (n=22, mean age=12.14 years), followed for a mean period of 1.78 years. The changes of all cephalometric variables in the study groups were annualized and then compared to the changes observed for the Control group, by analysis of variance and Tukey test. Results: It was observed that both treatments presented a restrictive effect on the maxila; did not change the mandibular development; improved maxillomandibular relationship; produced clockwise rotation of the occlusal plane; and a slight increase in lower anterior facial height. Study groups showed limitation on the vertical development of the maxillary molars; buccal tipping and limitation on the vertical development of the mandibular incisors; and extrusion of mandibular molars. The mandibular incisors exhibited greater protrusion in the group 1 compared to other groups. Both appliances provided significant improvement of maxillomandibular relationship, overjet, overbite and molar relationship. Treatment protocols promoted retrusion of the upper lip. Group 2 presented mild protrusion of the lower lip and groups 1 and 3 showed mild retrusion. Conclusion: Both the appliances were effective in the treatment of Class II malocclusion.

Over the past 5 years, the use of titanium implants as temporary anchorage devices (TADs) has become an important tool in clinical orthodontic practices. The use of TADs have provided orthodontists a way of moving teeth against fixed objects rather than against the surrounding teeth, which tend to counteract desired motion. At present, viable attachment of TADs involves direct insertion through gingival tissue and piercing of the bone. Surface modifications such as sandblasted and acid-etched treatment or bone morphogenetic protein surface treatment, however, can be applied to the TADs to promote enhanced osseointegration, thereby allowing the TADs to serve as stable anchors while avoiding bone puncture. In this study, a comparison was made between sandblasted/acid-etched TADs and sandblasted/acid-etched/recombinant human bone morphogenetic protein-2 (rhBMP-2) treated TADs to determine whether rhBMP-2 promotes enhanced osseointegration. A total of 10 rats (4 controls and 6 treated with rhBMP-2) were used in the study, with 1 TAD placed on the skull of each rat. At the end of 6 weeks, the animals were euthanized by carbon dioxide asphyxiation, and bone blocks, each containing a TAD, were prepared for histological examination and biomechanical characterization. The results of this study showed that TADs treated with rhBMP-2 had greater bone formation at the bone-implant interface and an increase in total implant stability.

December 2011. A thesis submitted to the College of Dental Medicine of Nova Southeastern University of the degree of Master of Science in Dentistry. Background: Temporary anchorage devices (TADs) provide a versatile means by which orthodontic anchorage can be established without the need for patient compliance and complex force systems. Their use is predicated on their ability to remain stable throughout the course of treatment in which they are needed. This has been shown to be the result of "primary stability" which is achieved through mechanical interlocking of the screw threads with the surrounding bone immediately upon placement. Therefore, evaluating the factors that can either enhance or detract from the primary stability of TADs can serve to improve the predictability of their success. Objectives: The objectives of this study were to describe how variations in synthetic cortical bone thickness and the angle of force applied in relation to the long axis of TADs affects their stability in terms of pull-out strength, and to ascertain the perspectives of practicing orthodontists in the state of Florida on their experiences with temporary anchorage devices with regards to success and failure. Methods: For the bench top study, 90 1.5x8mm long neck Orthotechnology Spider Screws were randomly allocated to 9 groups of 10 TADs each. The 9 groups were established based on both the thickness of synthetic cortical bone (1.0, 1.5, and 2.0mm) and the angle of force vector applied relative to the long axis of the TADs (45, 90, and 1800). Pull-out testing was carried out by applying a force to the TADs via a universal testing machine (Instron, Canton, MA) at a rate of 2.0mm/minute. Real-time graphical and digital readings were recorded, with the forces being recorded in Newtons (N). Each miniscrew was subjected to the pull force until peak force values were obtained. For the 450 and 1800 tests, the force registered at the time-point of pull-out, or screw head movement of 1.5mm within the synthetic bone blocks. The determination of 1.5mm of movement was made due the dramatically erratic deflection observed by the digital and graphical readouts at precisely this point. For the survey portion of this study, A customized survey was developed for this study. The survey was composed of 12 questions, some of which were obtained from a questionnaire that was created by Buschang et al.54 The additional questions were devised by the members of this research project, with the aim of answering questions regarding the clinical experiences that practicing orthodontists experienced with TADs. Results: For the bench top study: Implants placed in 2.0mm of synthetic cortical bone and pulled at an angle of 1800 had the highest pull-out strength among all groups (258.38N), while those placed in 1.0mm of synthetic cortical bone and pulled at an angle of 900 exhibited the lowest (67.11N). When evaluated separately, a cortical bone thickness of 2.0 mm displayed the highest pull-out forces for the three angles of force application, and 1800 angle of force displayed the highest-pull-out forces for the three cortical bone thicknesses. Conversely, 1.0mm of cortical bone thickness displayed the lowest pull-out forces for the three angles of force application, and 900 angle of force displayed the highest-pull-out forces for the three cortical bone thicknesses. For the survey: The most important factor associated with TAD failure was cited as placement location by 45.7% (n=16) of respondents, while root proximity was cited as the least important factor by 35.3% (n=12) of respondents. For the site from which practitioners indicated that they experience the greatest success, 81.8% cited the palate, while 51.9% responded that they experience the highest failure rates for the posterior maxilla (distal to the cuspids). Conclusions: A synthetic cortical bone thickness of 2mm and pull forces applied parallel to the long axis of TADs resulted in the greatest resistance to pull-out.

Titanium has been widely used for dental implants, and in particular, roughened titanium surfaces have provided a means for increasing bone apposition and strengthening the implant-to-bone interface. Finding a way to further increase osseointegration is important because there is a significant clinical benefit to patients if a stable anchor can be established instead of anchoring orthodontic hardware to the molars. In this study, the effect of recombinant human bone morphogenetic protein-2 (rhBMP-2) on the ability of temporary anchorage devices (TADs) to osseointegrate was investigated. The temporary anchorage devices (TADs) used in this study were manufactured from commercially pure titanium and divided into 2 types of treatments: (1) sandblasted and acid-etched (i.e. the control) and (2) sandblasted and acid-etched treated with Medtronic INFUSE® Bone Graft (recombinant human bone morphogenetic protein-2 placed on an absorbable collagen sponge). The implants were placed on the cranial bones of 10 adult male Sprague-Dawley rats. The rats were euthanized by carbon dioxide asphyxiation 6 weeks following surgery for histological examination and biomechanical testing. The results from visual inspection and biomechanical testing showed that the sandblasted and acid-etched TADs treated with rhBMP-2 promoted better osseointegration than TADs that were only sandblasted and acid-etched. Specifically, surface modified TADs treated with rhBMP-2 on bottom showed an increased surface coverage by bone and an increase in the adhesion strength at the TAD-to-bone interface.

Fixed retainer after orthodontic treatment is an increasing retention appliance. For the mandibular incisors there are two different fixed retainers that are commonly used, either a canine-to-canine retainer bonded only to the canines or a twistflex retainer bonded to each of the mandibular incisors and canines. Increased mandibular incisor irregularity seems to be a continuous process throughout life even in untreated patients. The natural physiological changes during aging causes changes like those that occur after orthodontic treatment and the removal of retainers. There are few long-term studies that have compared patients who have had a mandibular fixed retainer with patients without retention appliance after treatment, and then compared the treated patients with untreated subjects.The overall aim of this thesis was to compare and evaluate two different mandibular fixed retainers and also to compare orthodontically treated cases with untreated long-term. This thesis is based on two studies and a PAR Index evaluation was presented in the frame story:Paper I is a retrospective longitudinal study done on dental casts and lateral head radiographs from patients who had received either a canine-to-canine retainer or a twistflex retainer after treatment. Different variables were measured, were Little’s Irregularity Index was the main outcome measure. The measurements were done at four different occasions, were the last registration was 12 years after treatment, i.e. 9 years after removal of retainer. Paper II is also a retrospective longitudinal study with three different groups, one group received a fixed mandibular retainer, one group did not receive any retention appliance after treatment and the third group was untreated subjects. Measurements were done on dental casts and lateral head radiographs at four different occasions to analyze dental and skeletal changes 12 years after treatment. Also here Little’s Irregularity Index was the main outcome measure. PAR Index evaluation is done to evaluate the stability of orthodontic treatment outcome after treatment and long-term for two different retainer groups and one non-retention group. The following conclusions were drawn: Paper I•Both the canine-to-canine retainer and the twistflex retainer can be recommended since both are equally effective during retention period.•None of the retention types prevent long-term changes of mandibular incisor irregularity or available space for the mandibular incisors after removal of the retainers.•No differences in bonding failures between the two retainers were found. Paper II•There were no differences found 12 years after treatment in Little’s Irregularity Index for the mandibular incisors between the group that had a retainer and the group that had no retainer after treatment•In the untreated group, Little’s Irregularity Index was increased over time but not to the same extent as in the treated groups. •The crowding before treatment did not explain the crowding at the last registration.•The use of mandibular retainers for two to three years does not appear to prevent long-term relapse. •If the patient wants to constrain the changes that come with natural development, then lifelong retention is needed.•The overjet and overbite were stable long-term.PAR Index evaluation•Twelve years after treatment the mean reduction in PAR score was over 70 per cent only for the groups who had a mandibular retainer after treatment. However, the non-retention group had a PAR score of 66 per cent.•There were more cases in the retention groups that were ”greatly improved and/or improved” 12 years after treatment compared to the non-retention group. After treatment between 16 and 23.3 per cent of all the cases were ”worse or not improved”. Twelve years after treatment between 36 and 43.6 per cent of the total cases were ”worse or not improved”.

碩士
國立中正大學
機械工程所
96
A system of tooth arrangement and a force feedback interface are developed in this paper. The virtual tooth arrangement system that used the models of tooth with root and alveolar extracted from CT (computed tomography) data has the most difference between the other commercial software of orthodontics. The root and alveolar can be used to detect whether root’s location is out of alveolar or not. Based on this information, the tooth model after being arranged will be useful and more confident. That can’t be done as the system has only crown data scanned from impression or cast. Besides, the system is also integrated with haptic device. For this reason, user will feel the feedback force by haptic device as the tooth contacts other teeth or alveolar. The preview function simulates the process of the orthodontic treatment. Finally, output the teeth of all process that could be used to manufacture aligners.

博士
長庚大學
機械工程學系
102
Clinicians have experienced mini-implant loosening during treatment and have difficulty in placing a mini-implant at the optimal position as the anchorage source. For solving the above-mentioned problems, the purpose of this study was to design and develop an orthodontic dual-thread (DT) mini-implant with a revolving cap. There are four steps as follows: (1) First generation of the design: Solid dual thread mini-implant and revolving cap model were generated using a CAD system. A DT mini-implant (diameter, 1.6 mm and length, 9.5 mm) was designed with 0.25 mm pitch in the upper 2 mm region to provide cortical bone contact and has 0.8 mm pitch in the lower region. Revolving cap can be assembled on the mini-implant head, permits angular adjustments of 60 degrees as a switching unit and with an extended arm that can be used to provide orthodontic wire attachments from different positions at various distances. The proposed mini-implant and revolving cap were manufactured by the manufacturer with ISO 13485 quality management systems. (2) In vitro experiment and FEA: the section of in vitro experiment, the actual physical products of single thread (ST) and DT mini-implant were inserted into/ removed from/ pull-out from artificial bone with cortical bone thicknesses of 0 (control group), 1, and 2 mm. The maximum insertion/ removal torque (MIT and MRT), insertion/ removal angular momentum (IAM and RAM) and the peak load at extraction (Fmax) were recorded. To ensure whether the cap connection capability was sufficient to resist the detachment force from hand pullout disturbances by patients, finger-pulling forces and the cap removal forces were measured. The section of CEA, the simulated models, including the DT and ST bone/mini-implant system with cortical bone thicknesses of 0, 1, and 2 mm, and DT bone/ mini-implant with cortical bone thicknesses of 2 mm, with a concentrated lateral 4.9 N forces were observed. The micromotion at the implant/bone interface around the implant and maximum von Mises strain for cortical bone were recorded for all simulated models. (3) Second generation of the design: Three types of mini-implants (diameter 1.5 mm and length 8.0 mm) consisting of ST (0.75mm pitch in whole length), DT-A and DT-B with double-starts 0.375mm pitch (half of the macro-thread) and single-start 0.2mm pitch in upper 2mm micro thread region for DT-A and DT-B types, respectively, for performing insertion (90˚) and pull-out testing (30˚、60˚ and 90˚). Nine specimens were bi-sectioned to perform histomorphometrical analysis in evaluating peri-implant bone defect. A substantially equivalent (SE) test, according to ASTM F543 A1-A3, of orthodontic mini-implant between DT-A and Micro Implant AbsoAnchor (MIA). The results show that (1) the MRT, RAM, and Fmax tests show that DT screws exhibit higher retention than that of ST screws when cortical bone existed. Fmax increased with increasing cortical bone thickness for both screw types. The cap removal forces is larger than two times of finger-pulling forces (9.3 N). Simulation results showed that the maximum von Mises bone strain concentrated at the cervical regions around the mini-implant. The corresponding strain value in DT mini-implant assembled with cap was greater than those for DT and ST implants. That implant micro-motions were smaller than the critical bone remodeling threshold for all cases. (2) MIT in type DT-A was found smallest significantly. Largest value of Fmax in DT-A mini-implant were found significantly greater than those of ST mini-implant regardless of implant inserted orientations. Histomorphometric evaluation images showed that the mini-implant engaged the cortical bone well as observed in ST and DTA types but the DTB mini-implant thread ridge broke and damaged the cortical bone. (3) The twisting strength, MIT, and MRT of the DT-A mini-implants were larger than MIA, but no significant difference on Fmax between DT-A mini-implants and MIA. This study suggested that (1) DT mini-implant designs with correct micro thread pitch (parametrically relationship with macro-thread pitch) can provide better primary stability and enhanced mechanical retention than implants with single-thread. (2) An orthodontic DT mini-implant with revolving temporary cap in this study is feasible for clinical applications.

碩士
中國醫藥大學
醫學研究所碩士班
95
Improving facial esthetics of our patients is of great importance to orthodontists. An individual’s facial appearance is one of their most obvious characteristics and has profound social significance. Tooth movement and proper positioning of the teeth to ensure favorable facial changes and to avoid unfavorable changes should be the goal in the orthodontist’s mind. Standard color photographs and radiographic views (PA and cephalometric X-ray films) remain a principle adjunct to orthodontic care. Various methods of soft-tissue assessment have evolved; however, none of those method has been reported adequately enough to describe the face without depending upon anatomically variable intracranial landmarks as reference points or upon the facial soft tissues themselves. In addition, the most important problems are difficulties in standardizing these images. The main disadvantages are the poor resolution and the inconsistent magnification of the X-ray images and the fact that the landmarks identified on the soft tissue profile do not correspond with those identified from radiographic examination. These unavoidable disadvantages make it hard to analyze and compare the post-treatment outcomes directly. At present, 2-dimensional (2D) assessments of lateral cephalograms is the main method to investigate the effects of orthodontic treatment on the face. However, patients tend to assess their appearance from either a frontal or a three-quarter profile view, rarely from the sagittal view as recorded in the 2D lateral cephalograms. Three-dimensional (3D) imaging has developed greatly in the last two decades and has been applied to orthodontic treatment. In 3D imaging, a set of anatomical data are collected using diagnostic imaging equipment, processed by a computer and displayed on a 2D monitor to give the illustration of depth. Depth perception causes the image to appear in 3D. This study was to compare the 3D effects on the lower face immediate changes after the first step (direct bonding system, DBS) of orthodontic treatment. Laser scanner (Minolta VIVID 910) was used for capturing the facial images before and after DBS of each patient. The collected data were processed and compared with the Rapidforn 2006 (INUS Korea) reverse engineering software. The great immediate changes of the lower face after DBS were appeared over the peri-oral, chin area and could be measured by the variation directly from the superimposed images. But the immediate changes of the lower face after DBS were not in accordance with the thickness of the brackets. The 3D laser scanning for capturing the facial profiles is a simple and effective tool clinically, because the 3D images can be measured directly from the processing software and easily showed the results of orthodontic treatment to patients. Application of 3D data is expected to increase significantly soon and might eventually replace many conventional orthodontic records which are in use today.

Indiana University-Purdue University Indianapolis (IUPUI)
One of the most common concern among patients who need orthodontic treatment is treatment duration. The ability to accelerate orthodontic tooth movements would be bene cial to reduce the undesired side-effects of prolonged treatment. Methods have been used in conjugate with common orthodontic appliances to shorten the treatment. One of them is to use vibrational force (VF), which is non-invasive. The VF stimulates bone modeling and remodeling, which is essential to tooth movement. However, commercial devices used in the clinic failed to deliver consistent outcomes. The effects of the VF highly depend on its intensity the tooth receives. There must be a range of stimulation that optimizes the ffeects. The stimulation outside the range either have no effects or creates damages, which adversely affects the orthodontic treatment. Since these devices have generic mouthpiece and teeth are in di erent heights, hence some teeth cannot get force stimulation and others may be overloaded. The current designs also do not have ability to adjust the level of VF intensity that individual tooth needs, as in some cases orthodontists are required to move a tooth faster than others or even slower, which needs the device to be personalized. There- fore, the primary cause of inconsistent clinical outcomes is the inadequate design of the mouthpiece of the current device. The goal of this study is to design a better vibratory device that not only guarantees VF delivery but also enables orthodontists to control the level of VF on the individual tooth, which meets the patient's treat- ment needs. This is a preliminary study to understand the effects of different design parameters affecting the VF distribution on teeth. A nite element model, which consists of human upper and lower jaws in their occlusal positions and a mouthpiece, was created. The VF was from a vibratory source with a peak load of 0.3N and speci ed frequencies (30 and 120 Hz). The element size was determined through a convergence test and the model was validated experimentally. Results showed that the VF distribution among the teeth relies on the material property of the mouthpiece. The distribution is uneven, meaning some teeth bearing much more load than others. This means, with the current device design, teeth would be a ected with di erent level of force stimulation, which results in di erent clinical outcomes consequently. Dynamic load (VF) changes the force distribution on the teeth comparing to the dis- tribution from a static load. Frequency does not affect the peak load. Finally, the study demonstrated that the level of VF stimulation can be adjusted by introducing clearance or interference between the teeth and mouthpiece. It is feasible to control the level of the VF intensity for individual tooth based on treatment requirement.

O aparelho ortodôntico fixo tipo multibandas atual não permite medir ‘in-vivo’ as forças e torques aplicados ao dente individual. Para um tratamento ideal e para reduzir os efeitos iatrogênicos, o ‘Smart Bracket’ foi desenvolvido para uma próxima geração de aparelhos ortodônticos fixos fornecendo ao ortodontista uma medida quantitativa sobre as forças e torques aplicados a cada dente ao longo da terapia. O presente trabalho pretende ser uma revisão narrativa da literatura tendo como objetivo descrever o conceito de ‘Smart Bracket’, comparando-o com os aparelhos ortodônticos fixos atuais. Além disso, procura analisar e resumir o seu desenvolvimento e a evolução dos seus vários protótipos existentes. A pesquisa foi realizada entre Fevereiro e Agosto de 2020 por meio do motor de busca B-On (entre outros), para o período temporal 2005-2020, com o objectivo de sintetizar a literatura sobre o sistema, identificar seus limites e, eventualmente, recomendar novos temas de pesquisa. Adicionalmente, artigos de revisão e livros científicos foram consultados a partir de 2000 para apresentar os atuais aparelhos multibandas e seus efeitos iatrogênicos.
The current multi-bracket appliances do not allow to measure ‘in-vivo’ the forces and torques applied to the individual tooth. For an ideal treatment and to reduce iatrogenic effects, the ‘Smart Bracket’ has been developed for a next generation of fixed orthodontic appliances providing the orthodontist with quantitative measure of the forces and torques applied to each tooth throughout therapy. The present work intends to be a narrative review of the literature aiming to describe the concept of ‘Smart Bracket’, comparing it with the current fixed orthodontic appliances. In addition, it seeks to analyze and summarize its development and the evolution of its various existing prototypes. The literature research was carried out between February and August 2020 using the search engine B-On (among others), for the period 2005-2020, with the aim of synthesizing the literature on the system, identifying its limits and, eventually, recommend new research topics. In addition, review articles and scientific books were consulted from 2000 onwards to present the current multiband devices and their iatrogenic effects.

Trabalho final do 5º ano com vista à atribuição do grau de mestre no âmbito do ciclo de estudos de Mestrado Integrado em Medicina Dentária apresentado à Faculdade de Medicina da Universidade de Coimbra.
Introdução: Os microimplantes são os elementos de ancoragem esquelética mais frequentemente utilizados, uma vez que apresentam uma técnica cirúrgica de fácil execução, têm um baixo custo e são muito eficazes. Estes dispositivos de ancoragem temporária permitem a aplicação de forças contínuas com maior eficiência, levando à diminuição do tempo de tratamento. Como a ancoragem é esquelética e não dentária, a aplicação da força ortodôntica ao microimplante elimina os efeitos indesejados da força de reação que eventualmente se faria sentir sobre os dentes de ancoragem, havendo apenas movimentação dos dentes sujeitos à ação ortodôntica. Além disso, o seu tamanho é bastante reduzido, o que permite que sejam colocados nos mais diversos locais, tanto no maxilar como na mandíbula. Objetivos: Detalhar a nomenclatura, o design e as características dos microimplantes; selecionar os locais de inserção e os seus tamanhos; referir os locais mais perigosos e os ideais para a colocação destes dispositivos; explicar a técnica cirúrgica, as indicações e as complicações da sua utilização. Materiais e métodos: Foi efetuada uma pesquisa bibliográfica nas bases de dados: PubMed, EBSCO, Google Académico e consultados dois livros de texto. Conclusões: Os microimplantes apresentam uma série de vantagens que levam a que sejam utilizados com frequência na prática clinica. O sucesso da ancoragem com microimplantes no tratamento ortodôntico depende da criteriosa seleção de casos clínicos, bem como do correto planeamento da sua colocação e do controlo das forças ortodônticas a eles aplicadas.

Introdução: A Síndrome da Apneia/Hipopneia Obstrutiva do Sono (SAHOS) tem vindo a tornar-se uma constante em pacientes pediátricos, pelo que o interesse pela investigação deste tema tem vindo a crescer nos últimos tempos. O aumento de casos pediátricos poderá ser o espelho da evolução do diagnóstico da Síndrome. Na prática clínica, a escolha do tratamento ortodôntico intercetivo mais adequado deve basear-se num diagnóstico corretamente realizado e completo e fundamentado pelas evidências científicas disponíveis. Objetivos: O principal objetivo é comparar a eficácia entre as terapêuticas Expansão Maxilar Rápida, Dispositivo de Avanço Mandibular e Distração Osteogénica Mandibular no que toca à melhoria e/ou desaparecimento dos sinais e sintomas clínicos característicos da Síndrome da Apneia/Hipopneia Obstrutiva do Sono, em pacientes pediátricos. Material e Métodos: Criação de um protocolo de pesquisa, do qual faz parte a formulação da questão de investigação PICO (População, Intervenção, Comparação e Outcome) e definição dos objetivos de trabalho; recolha de dados utilizando a base de dados online da Medline (Pubmed®); filtros e termos de pesquisa e critérios de inclusão/exclusão aplicados de forma a obter os artigos mais relevantes sobre o tema; leitura integral dos artigos obtidos e utilização da meta-análise para analisar os dados obtidos. Resultados: Relativamente à Expansão Maxilar Rápida e à Distração Osteogénica Mandibular, não se observou a existência de diferenças significativas entre os tratamentos na diminuição média do IAH, nem no aumento médio do Lowest SaO2. No que toca à Expansão Maxilar Rápida e ao Dispositivo de Avanço Mandibular, não se observou a existência de diferenças significativas entre os tratamentos na diminuição do risco relativo de Apneas, Daily sleeping, Restless sleep e Snoring. Conclusões: Todas as opções terapêuticas se revelaram similares no que toca à eficácia na melhoria e/ou desaparecimento dos sinais e sintomas clínicos característicos da SAHOS.
Introduction: The Sleep Apnea has become common disease in pediatric patients and the interest in this Syndrome pathology as well as its research have increased enormously these days. This pediatric increase can be the mirror of the Syndrome evolution. In clinic practice, the most suitable interceptive orthodontic treatment should be practiced on an accurate based scientific evidence treatment. Aims: The major aim of this paper is to compare the efficiency between the rapid maxillary expansion, the mandibular advancement device and distraction osteogenesis in what concerns the improvement and/or disappearance of the characteristic clinical signs and symptoms of the sleep apnea. Material and methods: Creation of a research protocol which includes the formulation of the investigation question PICO (population, intervention, comparation and outcome) and work aims definition. Data collection using the online database of Medline (Pubmed®). Filters and research and inclusion/exclusion criteria applied in a way to obtain the most relevant articles about the subject. Integral reading of the articles obtained. Use of the meta-analysis to analyze the obtained data. Results: As far as the Rapid Maxillary Expansion and the Distraction Osteogenesis is concerned, there were no significant differences between the treatments to the medium decrease of the AHI or in the medium increase of Lowest SaO2. In what concerns the Rapid Maxillary Expansion and Mandibular Advancement Device, no significant existence was observed between the treatments in reducing the relative risk of Apneas, Daily Sleeping, Restless Sleep and Snoring. Conclusions: All the therapeutical options revealed themselves similar in terms of effectiveness, improvement and/or disappearance of sleep apnea sings and clinical characteristic symptoms.