Thesis (M.S.)--University of Florida, 2006. / Typescript. Title from title page of source document. Document formatted into pages; contains 34 pages. Includes Vita. Includes bibliographical references.

Thesis (M.S.)--University of Florida, 2004. / Typescript. Title from title page of source document. Document formatted into pages; contains 31 pages. Includes Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (leaves 115-138).

CAPES / O presente trabalho estudou por meio do Método dos Elementos Finitos e por testes experimentais o efeito da distância interbraquetes, ativação e geometria (variáveis independentes) sobre o sistema de forças (Fx, Fy e Mz) produzidos por alças delta após ativação. As amostras foram produzidas com titânio-molibdênio, com secção transversal 0.017 x 0.025 polegadas (0,43mm x 0,64mm) e separadas em dois grupos (G1 e G2), com dez alças cada um. O grupo de alças G1 apresenta hastes com inclinação em suas extremidades. O Grupo G2 hastes com extremidades arredondadas. Visando identificar diferenças entre as médias populacionais devidas a três possíveis causas ou fontes de variação (variáveis independentes) e as interações entre as mesmas (geometria, distância interbraquetes e ativação), utilizou-se a método de análise de variância a três critérios de classificação, modelo fatorial completo (ANOVA). O método de análise de variância aceita ou rejeita a(s) hipótese(s) H0 de igualdade das médias populacionais. Se H0 for rejeitada, admite-se que pelo menos uma das médias é diferente das demais. Nestas condições utilizou-se o teste proposto por Games-Howell para variâncias heterogêneas, visando estabelecer comparações entre os diferentes tratamentos. Para estimar a constante elástica para os dois tratamentos (G1 e G2), utilizou-se a análise de regressão para verificar o grau de relacionamento entre os valores da variável resposta (força Fx) e a variável independente (ativação da alça). Os Grupos G1 e G2 apresentaram magnitudes de força compatíveis com as descritas pela literatura (houve variação de 81,65gf até125gf para o grupo G1 e de 92,45gf até 133,10gf para G2, aos 3.0mm e 4.0mm de ativação, respectivamente para Fx). As forças verticais Fy foram de 50gf e 16gf para G1 e G2, aos 4.0mm, respectivamente, e 52,15gf e 26,95gf para G1 e G2 aos 3.0mm de ativação, respectivamente. A constante de mola encontrada para os grupos estudados mostrou estar dentro de limites apropriados para uso clínico, resultando 27,95gf/mm para G1 e 32,09 para G2. A relação M/F aumentou à medida que as alças desativavam. As alças mostraram ser adequadas para a retração de caninos desde que ativadas até aos 4,0mm e reativadas após 2,0mm de desativação. A relação M/F média foi de 9,2mm aos 4,0 mm de ativação e de 13mm aos 3,0mm para G1 enquanto que para G2 os valores médios foram de 9,3mm aos 4,0mm de ativação e13mm aos 3,0mm. Não houve diferença significativa entre os grupos. A variável independente ativação causou diferença estatística significativa nos resultados das variáveis dependentes (Fx, Fy e Mz). As diferentes distâncias interbraquetes não influenciaram de maneira significativa o sistema de forças. A variável grupo influenciou de maneira significativa os valores de Fy e Mz. / The present study tested experimentally and by Finite Element Method the effect of inter-bracket distance (IBD), activation and geometry (independent variables) on the force system (Fx, Fy, Mz) produced by delta springs after activation. The springs were produced with titanium-molybdenum 0.017 x 0.025 in (0,43mm x 0,64mm), and separated in two groups (G1 and G2) with ten springs each one. The springs in group G1 presented angulated legs and in the group G2 rounded legs. Analysis of factorial variance averages caused by three possible variation (inter brackets distance, geometry and activation) sources and the interactions between them. Regression analysis was also performed to obtain the spring rate. Groups G1 and G2 presented force magnitudes which are compatible with the ones mentioned in the literature related to the subject (varying from 81,65gf to 125gf for G1 and from 92,45gf to 133,10gf for G2, at 3.0mm and 4.0mm of activation, respectively for Fx). The vertical Fy forces were 50 gf and 16gf for G1 and G2, at 4.0mm, respectively, and 52,15gf and 16,95 gf for G1 and G2 at 3.0mm of activation, respectively. The spring constants have proved to be within the levels which are appropriate for clinical use, resulting 27,95gf/mm for G1 and 32,09 for G2 groups. The mean moment-to-force ratio (M/F) was M/F=9,2mm at 4,0 mm of activation and 13mm at 3,0mm of activation for G1 group, whereas for G2 the mean values were M/F=9,3mm at 4,0mm of activation and M/F=13mm at 3,0mm. The M/F ratio incresead as the springs deactivated. There was no statistical differences between groups. IBD and geometry does not cause significative influence on force systems resulting from activations, but activation that produced statistical difference on force system (Fx, Fy and Mz).

Orientador: Lídia Parsekian Martins / Banca: Dirceu Barnabé Raveli / Banca: Ana Cláudia de Mello / Resumo: O objetivo do presente trabalho foi avaliar in vitro, por meio de um ensaio mecânico, a força necessária para a remoção das bandas ortodônticas Grip Tite (C), Convencional (A) e banda Convencional com a superfície interna microjateada por óxido de alumínio (B). Também analisar visualmente a quantidade de cimento residual, e classificar usando uma escala de incrementos a 25%. Após, verificar, por meio de MEV, a superfície com melhores características para a retenção. Os resultados obtidos mostraram que a média de carga do Grupo B, bandas microjateadas internamente por óxido de alumínio, foi significantemente maior que as médias dos Grupos A, bandas Convencionais, e C, bandas Grip Tite. Quanto a quantidade de cimento remanescente nas bandas, o Grupo B apresentou 100% das bandas com índice 4, indicando a presença de mais de 75% de cimento residual nas bandas, enquanto que nos Grupos A e C, houve a predominância do índice 1, indicativo de menos de 25% de cimento residual nas bandas, sem diferença significativa entre esses dois grupos. Os resultados foram confirmados pela MEV, onde observou-se uma superfície com melhores características para a retenção do cimento nas bandas onde foi realizado o processo de microjateamento. Conclui-se que o processo de microjateamento por óxido de alumínio, na superfície interna das bandas convencionais, aumenta a força necessária para a remoção das bandas e aumenta a quantidade de cimento residual preso à superfície da banda. Quando analisada pela MEV, essa superfície apresenta-se como a mais áspera e rugosa, com a maior quantidade de cimento de ionômero de vidro aderido à banda. / Abstract: The purpose of this study was to evaluate in vitro, the necessary force for the removal of Grip Tite, Conventional and Sandblasted orthodontics molar bands, as well as, to analyze and to classify the amount of residual cement in the internal surface of these bands. After that, checking through scanning electron microscopy, the surface with better characteristics for the retention. The obtained results showed that the load average of the group B, Sandblasted bands, was significantly higher than the group A, Conventional bands, and C, Grip Tite bands. Observing the amount of remaining cement in the bands, group B presented 100% of the bands with index 4, indicating the presence of more than 75% of residual cement in the bands, while in the groups A and C, had the predominance of index 1, indicative of less than 25% of residual cement in the bands, without significant difference between these two groups. The results were confirmed by the scanning electronic microscopy, where the surface with better characteristics for the retention of the cement was observed, in the bands where the sandblasted process was carried through. It was concluded that the process of sandblasted, in the internal surface of the conventional bands, increases the necessary force for the removal of the bands and increases the amount of residual cement in the internal surface of the band. When analyzed by the scanning electronic microscopy, this surface appeared rougher and corrugated, with great amount of glass ionomer cement adhered to the band. / Mestre

Indiana University-Purdue University Indianapolis (IUPUI) / The force-moment systems of orthodontic T-loops have been widely described and investigated. A simpler triangular loop spring design has been employed in the graduate orthodontic clinic at Indiana University School of Dentistry. To date, no investigators have specifically examined and compared the force systems generated by these two loop configurations. The objective of this study was to compare the force systems generated by a T-loop and two different geometric shapes of triangular loops. A sample of 20 T-loops and 40 triangular loop springs were studied. The triangular loops were constructed in two different geometric configurations (n = 20 in each group) utilizing the same linear amount of wire as used in the T-loop fabrication. One set of triangular loops was the same height as the T-loop (isosceles shape); the other set was the same width as the T-loop (equilateral shape). Force and moment components along three mutually perpendicular axes (x, y, and z) were analyzed, with particular emphasis on the force system generated in the sagittal plane. The force-moment systems generated upon mesio-distal (x axis) activation were measured by a transducer connected to a computer for data collection and analysis. Statistical analysis utilized repeated measures of variance models (ANOVA). Multiple comparisons were made using Fisher's Protected Least Significant Differences at a 95-percent overall confidence level. On initial ligation, there were no significant differences between the loops in the M/F ratios in the sagittal plane (p = 0.75). For all other activation distances, the equilateral triangular loops produced greater M/F ratios than both the isosceles and T-loops (p = 0.0001), and the isosceles triangular loops generated greater M/F ratios than the T-loops (p < 0.0035).

Indiana University-Purdue University Indianapolis (IUPUI) / Understanding the factors that increase patients susceptibility to orthodontically induced root resorption is of the utmost importance to the practicing clinician. Numerous studies have been conducted that investigated contributing and etiological factors that tend to increase the amount of external apical root resorption a patient may incur during orthodontic treatment. However, there has been little research that has attempted to determine if patients treated with different slot size orthodontic brackets exhibit the same amount of external apical root resorption. The purpose of this research was to determine if patients treated with the 0.018 x 0.025 slot size bracket and patients treated with the 0.022 x 0.028 exhibited similar amounts of external apical root resorption during orthodontic treatment. Pre and Post treatment panoramic films from 91 consecutively treated orthodontic patients from a private orthodontic practice were used for this study. Each case that was included in the study had been treated with standard edgewise brackets using the Tweed-Merrifield philosophy of treatment. Forty-three cases from the 0.018 group and 48 from the 0.022 group were obtained. Each film that was analyzed was blinded prior to measuring to minimize observer bias. Mitutoyo Digimatic® calipers accurate to the nearest tenth of a millimeter were used for obtaining tooth measurements. Measurements were made from the Cemento-enamel junction and from incisal/occlusal to most apical portion of each incisor and all first molars. Statistical analysis was performed and the results showed no significant correlation between the size of the bracket and the amount of root resorption. No significant correlations existed between the groups for patient age, time in treatment, gender, and angle classification. Statistically significant differences were noted for cases in which extraction of four bicuspids was performed. Subjects belonging to the extraction group demonstrated significantly more external apical root resorption than those in which extractions were not done. This study demonstrated that the incidence of EARR that a patient may incur during treatment is independent of the size of the slot of the orthodontic bracket.

INTRODUKTION OCH SYFTE: Tidigare studier av kooperation och ortodonti har visat att ett av de bästa sätten att öka patienternas kooperation är genom att övervaka användningstiden och påminna patienten om att använda sin apparatur. Den här pilotstudiens syfte var att undersöka om någon utav två olika typer av påminnelser objektivt ökar användningstiden vid behandling med avtagbar apparatur eller inte.MATERIAL OCH METOD: 18 patienter i åldrarna 9-14 års ålder från en patientpopulation som behandlades vid avdelningen för Ortodonti, Odontologiska Fakulteten på Malmö Högskola, deltog i studien. Patienterna hade olika typer av bettavvikelser som gjorde dem behandlingsbara med antingen van Beek eller expansionsplåt. Patienterna placerades slumpmässigt in i en av tre grupper, alarm, kalender eller kontrollgrupp. Användningstid registrerades objektivt med en TheraMon®-timermodul som placerades inuti den ortodontiska apparaturens akrylbas.RESULTAT: Alarm-gruppen hade högst genomsnittlig användningstid. Kontrollgruppen hade något lägre användningstid än alarmgrupppen och kalendergruppen hade minst genomsnittlig användningstid. Det var skillnad på de olika behandlingstyperna, då behandlade med expansionsplåt hade bättre genomsnittlig användningstid än patienter behandlade med van Beek. Data testades för statistisk signifikans med Anova och t-test, ingen statistisk signifikans fanns.KONKLUSION: Den här studiens resultat tyder på att en påminnelse i form av ett alarm verkar vara bättre på att öka patienters kooperation än en kalender eller ingen påminnelse alls. Detta indikerar att det finns ett underlag för att i framtida studier vidare undersöka hur påminnelser via mobiltelefon påverkar compliance, till exempel påminnelse via en app. Patienter som behandlas med expansionsplåtar verkar ha en bättre compliance än patienter behandlade med van Beek-aktivatorer, därför bör framtida fokus läggas på att förbättra kooperationen hos patienter som behandlas med van Beek-aktivatorer. Framtida studier bör endast innefatta en typ av ortodontisk apparatur, till exempel van Beek. Fler patienter krävs i framtida studier för att säkerställa statistiskt signifikanta resultat. / INTRODUCTION AND PURPOSE: Earlier studies on compliance and orthodontics have shown that one of the best ways to increase compliance is by supervising the wearing time. Compliance can also be increased by reminding the patient to use the removable appliance. This pilot study aims to investigate if any of two kinds of reminders objectively increase the compliance during orthodontic treatment with removable appliances or not.MATERIALS AND METHODS: 18 patients between 9-14 years of age were selected from a patient population attending the department of Orthodontics, Faculty of Odontology, Malmö University. They presented different types of malocclusion which made them candidates for treatment with either van Beek-appliances or expansion plate. The patients were randomly placed in one of three groups; alarm, calendar or control group. Wearing time was objectively collected from the TheraMon®-module placed inside the acrylic base of the appliances. After the data collecting-phase was finished the data was tested with Anova and t-test to determine whether there was a significant difference between the groups.RESULTS: The alarm group had the highest average wear time. The control group had slightly lower average wear time than the alarm group, and the calendar group had the least amount of average wear time. There was a difference in average wear time between van Beek and expansion plate, with van Beek having a lower average wear time than expansion plate. Patients treated with expansion plates were more cooperative than patients treated with van Beek appliances. When data was tested for significance, no statistical significance was found.CONCLUSION: The study concludes that an alarm type of reminder appears to be better at improving wear time than a calendar or no reminder at all. This indicates that for future studies there might be a reason to develop a reminder for patients, for example an app. The study concludes that patients with expansion plates appear more cooperative than patients using van Beek appliance, so therefore focus should be on improving cooperation for patients using these types of appliances. This study shows that future studies should use one type of appliance, e.g. van Beek. More patients are needed in future studies to achieve statistical significant results.

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.

A dentição mista é suscetível a uma diversidade de fatores que podem alterar as dimensões do arco dentário, dificultando a erupção dos dentes permanentes. Este trabalho teve como objetivo avaliar as alterações nas dimensões do arco dentário superior, decorrentes do uso de aparelho parcial fixo 4 x 2. A amostra total foi composta por 48 pacientes, dos gêneros masculino e feminino, na faixa etária de 8 a 11 anos, com boa saúde periodontal, dentição mista no período intertransitório do desenvolvimento da oclusão, com presença dos incisivos centrais, laterais e primeiros molares permanentes, ausência dos segundos molares permanentes, que apresentavam falta de espaço para irromper caninos e pré-molares, relação classe II de molar, os quais foram divididos igualmente em dois grupos. No grupo experimental (G1), 24 pacientes foram tratados na clínica de Ortodontia Preventiva da Faculdade de Odontologia da Universidade de São Paulo, com aparelho parcial fixo 4 x 2, associado a fios ortodônticos expandidos de CuNiTi e molas abertas de NiTi. O grupo controle (G2) foi composto por 24 pacientes, os quais não foram tratados e foram avaliados quanto às alterações decorrentes do crescimento, sem intervenção ortodôntica, no mesmo período de tempo do grupo experimental. Foram realizadas moldagens em alginato no início, em cada consulta de ativação e no final do tratamento ortodôntico preventivo e os modelos em gesso foram escaneados e medidos. As telerradiografias laterais foram obtidas no início (T1) e ao final (T5) do tratamento com aparelho parcial fixo 4 x 2 e suas medidas avaliadas. No grupo controle (G2), os modelos e as radiografias foram escaneados e medidos no início (T1) e ao final (T2) do período de observação. Os resultados encontrados no grupo experimental (G1) mostraram aumento médio significativo no perímetro (p= 0) e na profundidade da arcada (p= 0), no entanto não houve alteração significativa na distância intermolares (p= 0.14). Ocorreu aumento não significativo (p= 0.37) da distância da coroa do incisivo central superior à linha Sela perpendicular (Sperp), e do ângulo 1 . Plano palatino, também não significativo (p= 0.13), entre os tempos (T1 e T5). Ocorreu diminuição média significativa da distância da coroa e da raiz do molar à linha Sperp, p= 0 e p= 0.004, respectivamente, assim como do ângulo 6 . Plano palatino (p= 0.03). Após análise dos resultados, concluímos que o aparelho parcial fixo 4 x 2 promoveu aumento no perímetro e na profundidade do arco dentário, distalização de corpo do molar superior (com distalização da coroa, da raiz e com controle da inclinação) e controlou a inclinação vestibular dos incisivos superiores. / The mixed dentition stage is susceptible to a number of factors that can change the dental arch dimensions, making it difficult for permanent teeth to erupt. The objective of this study was to evaluate the changes in the dimensions of an upper dental arch resulting from the use of 2 x 4 fixed partial appliance. In total, 48 male and female patients were selected, aged 8 to 11 years, of good periodontal health, mixed dentition in the intertransitional period of occlusion development, with presence of central and lateral incisors and first permanent molars, absence of permanent second molars, insufficient space for the eruption of canines and premolars, and class II molar relationship, which were equally divided in two groups. In the experimental group (G1), 24 patients were treated at the Preventive Orthodontics Clinic of the School of Dentistry of the University of São Paulo, with 2 x 4 fixed partial appliance, associated with expanded orthodontic CuNiTi wires and open NiTi springs. The control group (G2) consisted of 24 children who were not treated, but evaluated in terms of growth-related changes, without orthodontic intervention, in the same period as the experimental group. Alginate moldings were created in the beginning, at each visit, and at the end of the preventive orthodontic treatment, and the gypsum models were scanned and measured. Lateral teleradiographs were obtained in the beginning (T1) and at the end (T2) of the treatment with 2 x 4 fixed partial appliance, and the measurements were evaluated. In the control group (G2), the models and radiographs were scanned and measured in the beginning (T1) and at the end (T2) of the observation period. The results obtained in the experimental group (G1) showed a significant mean increase in the perimeter (p= 0) and depth (p= 0) of the arch; however, no significant change was observed in the intermolar distance (p= 0.14). An increase was observed, but not significant (p= 0.37), in the distance between the perpendicular Sella line (Sperp) and the crown of the maxillary central incisor, and between Sperp and 1 . Palatal plane angle, also not significant (p= 0.13), between T1 and T2. A significant mean reduction was observed in the distance between the Sperp line and the molar crown and root, p= 0 and p= 0.004, respectively, and between Sperp and 6 . Palatal plane angle (p= 0.03). After analyzing the results, this study concluded the 2 x 4 fixed partial appliance promoted an increase in the dental arch perimeter and depth, upper molar distalization (with distalization of the crown and root, and inclination control), and controlled buccal inclination of the upper incisors.