Dissertations / Theses on the topic 'Surgical orthodontics'

This study aimed to examine end-of-treatment outcomes of severe Class II Division I malocclusion patients treated with surgical or non-surgical approaches. This study tests the hypotheses that occlusal outcomes (ABO-OGS) at end of treatment will be similar while cephalometric outcomes will differ between these groups. A total of 60 patients were included: 20 of which underwent surgical correction and 40 of which did not. The end of treatment ABO-OGS and cephalometric outcomes were compared by Mann-Whitney U tests and multivariable linear regression models. Following adjustment for multiple confounders (age, gender, complexity of case, and skeletal patterns), the final deband score (ABO-OGS) was similar for both groups (23.8 for surgical group versus 22.5 for non-surgical group). Those treated surgically had a significantly larger reduction in ANB angle, 3.4 degrees reduction versus 1.5 degrees reduction in the non-surgical group (p=0.002). The surgical group also showed increased maxillary incisor proclination (p=0.001) compared to candidates treated non-surgically. This might be attributed to retroclination of incisors during treatment selection in the non-surgical group – namely, extraction of premolars to mask the discrepancy. Studies such as this are necessary because they begin to give practitioners view of not only the outcomes of a single treatment plan, but a comprehensive approach by providing evidence of the over-arching treatment used for successful treatment in both groups.

Background and objectives: The control of anchorage is integral to successful orthodontic treatment. The objective of this research was to undertake three related projects to evaluate methods of increasing anchorage with the aim of adding to orthodontic knowledge and improve methods of treatment delivery. Methods: Two Cochrane systematic reviews were undertaken according to the methods published in the Cochrane Handbook for Systematic Reviews of Interventions, version 5.1.0. The influence of functional appliances on tooth position and the extraction decision was performed as a retrospective study using participants from a completed multicentre randomized trial. Results: 1- Statistically and clinically significant differences were found between the mean values of distal molar movement when surgical anchorage and conventional anchorage were compared. 2- Statistically significant differences were found between the mean values of distal molar movement and mesial upper incisor movement when intraoral distalising appliances and cervical headgear were compared.3- Fixed and removable functional appliances are equally effective in anchorage preparation. The type of functional appliance and time spent in Phase I treatment influenced the amount of lower incisor proclination. Conclusions: 1- Surgical anchorage is more effective than headgear without the inherent risks and compliance issues. However, intraoral appliances used in adolescence for distalisation of upper molars do not appear to have any advantages over cervical headgear. 2- Functional appliances reduce the anchorage requirements of a case primarily by reduction of the overjet, both fixed and removable functional appliances are equally effective in obtaining this. However, fixed functional appliances result in greater lower incisor proclination than removable functional appliances. 3- The type of functional appliance (removable or fixed) does not influence the extraction decision, however, this is influenced by overall space requirements.

A expansão rápida da maxila assistida cirurgicamente (ERMAC) é o procedimento de eleição para o tratamento da deficiência transversa de maxila em pacientes esqueleticamente maduros. Controvérsias em relação ao procedimento ainda persistem principalmente relacionadas aos métodos de avaliação, técnica cirúrgica utilizada, morbidade, eficácia clínica e estabilidade de resultados. A utilização da tomografia computadorizada para a avaliação da eficiência da ERMAC é uma opção atual e ainda pouco divulgada. Consequentemente, os parâmetros anatômicos para a utilização deste método ainda não foram totalmente estabelecidos. Os objetivos do presente estudo foram avaliar a confiabilidade da metodologia proposta e as alterações esqueléticas maxilares decorrentes da ERMAC com a utilização do método de avaliação por tomografia computadorizada. No período de junho de 2004 a maio de 2005, 15 pacientes, sendo 10 do sexo feminino, foram submetidos a ERMAC. A técnica cirúrgica utilizada constou de osteotomia maxilar do tipo Le Fort I, sem osteotomia da sutura ptérigo-maxilar, associada a osteotomia sagital mediana do palato. O aparelho expansor utilizado foi do tipo Hyrax. Os pacientes foram submetidos a exames de tomografia computadorizada, em tomógrafos de múltiplos detectores, no pré-operatório e após 6 meses, utilizando-se metodologia idealizada para a avaliação específica deste procedimento cirúrgico. Para a determinação do padrão das alterações transversais e ântero-posteriores, medidas lineares e angulares foram realizadas diretamente na estação de trabalho dos aparelhos de tomografia. Através de imagens obtidas nas aquisições tomográficas axiais e em reconstruções coronais, as regiões anterior, média e posterior da maxila foram avaliadas separadamente. A área de secção transversa da maxila foi também calculada. Após a avaliação dos resultados observou-se que a confiabilidade do método foi estatisticamente comprovada. Um significativo aumento da área de secção transversa da maxila foi observado (p<0.05). Entretanto, o padrão de expansão transversa não se mostrou uniforme. O aumento das dimensões transversas nas regiões anterior e média foi estatisticamente comprovado. Não foi observada expansão transversa significativa na região posterior da maxila. Ao se avaliar a relação entre a abertura do parafuso expansor e a efetiva expansão esquelética da maxila, observou-se que esta foi menor que a abertura do parafuso, em termos absolutos. O aumento transverso relativo à expansão do parafuso foi estatisticamente maior nas regiões anterior e média da maxila do que em sua região posterior. Em conclusão, a avaliação por tomografia computadorizada para a análise das alterações esqueléticas da região maxilar, em pacientes submetidos à ERMAC é metodologia confiável e reprodutível. A expansão transversa da maxila decorrente do procedimento de ERMAC utilizado no presente estudo acarretou uma expansão não uniforme da maxila, com predomínio da expansão transversa nas regiões anterior e média.
Surgically assisted rapid palatal expansion is the procedure of choice for treating transverse maxillary deficiency in mature patients. Some controversies regarding surgically assisted rapid palatal expansion remain, mainly concerning technical aspects such as type and location of osteotomy sites, as well as surgical morbidity, clinical efficiency, and stability. The evaluation of transverse expansion is still a theme of discussion. On conventional anteroposterior radiographs, anatomical structures are superimposed, resulting in a high number of image artifacts, as well as hindering the tracing and evaluation. The use of computed tomography as a method of evaluating the efficiency of this procedure has not been widely reported. Consequently, few landmarks for use in evaluating maxillary expansion have been defined. The goals of the present study were to define parameters to assess skeletal changes after surgically assisted palatal expansion, to evaluate the reliability of the proposed method and to use computed tomography to assess those parameters. From June of 2004 to May of 2005, 15 patients underwent surgically assisted rapid palatal expansion (a modified Le Fort I maxillary osteotomy without pterygomaxillary separation, together with a sagital palatal osteotomy) according to a defined protocol, using a Hyrax appliance. To determine the pattern of transversal and anteroposterior expansion, linear and angular measurements were performed on multislice computed tomography, using computed software directly on the workstation. The anterior, intermediate and posterior portions of the maxilla were evaluated separately, using a specific method, in axial acquisition and coronal reconstructed views. The cross-sectional area of the maxilla was calculated to obtain general information about maxillary expansion. The reliability of the method was statistically confirmed. Significant maxillary overall expansion was observed. However, different patterns of expansion were seen in the three regions analyzed. In the anterior and intermediate portions of the maxilla, the increase in maxillary width was significantly greater than that observed in the posterior portion. The opening of the jackscrew was greater than skeletal expansion. Comparing jackscrew opening and transverse expansion, the same pattern of asymmetric expansion was verified. No change was observed in anteroposterior dimensions. The method of computed tomography evaluation is a useful tool for evaluation of surgically assisted rapid palatal expansion changes. The accurate evaluation of the postoperative changes was heavily dependent upon images acquired through computed tomography. An overall maxillary expansion was confirmed. However, transverse expansion of the maxilla achieved through surgically assisted rapid palatal expansion without pterygoid plate separation was less than uniform.

Background: The correction of Class II malocclusions is one of the most common treatments performed in the United States. Despite Class II malocclusions being one the most commonly presented problems for orthodontists, there is no consensus of which non-surgical treatment modality best impacts a patient’s quality of life long term. Purpose: This study examines the different non-surgical treatment approaches for patients with severe Class II division 1 and the impact of treatment outcomes on patient satisfaction and quality of life long term. Study Design: This study retrospectively analyzed the different treatment approaches and outcomes of class II division 1 with severe overjet, while prospectively assessing patient satisfaction and quality of life long term. Initial and final cephalometric and clinical variables for 83 patients (38 at Harvard School of Dental Medicine, 30 at the University of Iowa, and 15 in private practice in Iowa) treated non-surgically were recorded and analyzed. A retention clinical exam, at least 6 months post-debond, was done for final measurements, assessment of practitioner and patient satisfaction, and patient quality of life questionnaires. Results: Non-surgical treatment of severe Class II division 1 malocclusions yielded 5.54 mm overjet reduction and 0.51 mm of relapse in retention on average. Patients with more overjet at their long term retention check demonstrated significantly poorer satisfaction scores with the appearance of their bite (p<0.001), the appearance of their face (p<0.001), and with their overall orthodontic treatment (p<0.001). Extraction treatment was associated with significantly lower patient satisfaction scores of overall orthodontic treatment (p=0.023) and appearance of bite (p=0.018) but not facial appearance. Patients treated with extractions also showed higher QOL scores on the OHIP-14 (p=0.022) and CPQ (p=0.002) surveys, indicating that extraction therapy of severe Class II division 1 patients led to a significantly poorer quality of life. Conclusion: Non-surgical treatment of severe Class II division 1 malocclusions can yield excellent results and stability long term. Overjet can be dramatically reduced with non-surgical treatment but there is a tendency for overjet to relapse in retention. While treatment outcomes yielded high results of patient satisfaction, patients with more overjet in retention displayed significantly less satisfaction of the appearance of their bite, appearance of their face, and with their overall orthodontic treatment. Extraction treatment was associated with significantly lower patient satisfaction scores of overall orthodontic treatment and appearance of bite but not facial appearance. Patients treated with extractions showed poorer quality of life scores in retention compared to those treated nonextraction.

Introduction: Class II Division 1 malocclusions are characterized by a retrusive mandible and prominent upper incisors. Despite Class II malocclusions being one of the most frequently treated cases in orthodontists' office, there is no uniform consensus in the orthodontic community on the best treatment modality and biomechanical approach to use in treating patients with Class II malocclusions. Purpose: This paper examines the end-of-treatment outcomes of severe Class II Division I malocclusion patients treated with surgical versus non-surgical approaches. Study Design: This is a retrospective study of consecutively treated severe Class II Division I patients at the University of Iowa. Initial and deband lateral cephalometric radiographs were compared between 45 non-surgical and 21 surgical patients. All patients that were debanded between the ages of 13 to 19 years were included. Multivariable regression analyses were used to examine differences in outcomes between treatment groups. Results: Following adjustment for patient level confounders (age, gender, and race), those treated surgically had better end of treatment cephalometric outcomes. Those treated surgically had a more balanced skeletal profile, greater reduction in overjet, and improvement in ANB angle (p Conclusion: Orthodontic treatment in conjunction with orthognathic surgery is a more ideal treatment for patients with severe Class II Division I malocclusion. When treated surgically, a greater amount of overjet can be reduced while keeping lower incisors in a more stable position in bone.

Introduction: This vertical malocclusion has the potential of causing functional and esthetic impairment, impacting patients´ quality of life negatively. The long-term stability of anterior open bite surgical-orthodontic treatment is an important and controversial issue. A variety of factors such as surgery type, surgery fixation, and the anteroposterior discrepancy is related to and can influence long-term overbite stability. The controversy of stability arises in the inherent difficulty of collecting a homogeneous sample, with considerable sample size and adequate long-term followup, leading the current literature to an inconclusive status. Therefore this thesis aimed to test 2 null hypotheses: 1- There is no difference in the long-term stability of the surgical-orthodontic correction of anterior open bite when comparing Le Fort I to 4-piece segmental Le Fort I osteotomies. 2- To test the null hypothesis that there is no difference in the long-term stability of the surgical-orthodontic correction of anterior open bite when comparing Class II to Class III patients. Materials and Methods: The sample of the first investigation comprised the lateral cephs of 29 open bite subjects treated with 1-piece Lefort I osteotomy compared to the lateral cephs of 24 open bite subjects treated with 4-piece Lefort I osteotomy; in both groups Class I, II and III subjects were included. The groups were matched regarding age and were compared with t-tests. To test the second null hypothesis, lateral cephs of 21 Class II open bite subjects were compared to lateral cephs of 25 Class III open bite subjects. Overbite changes were compared at 3-time points: T1 (pretreatment), T2 (posttreatment) and T3 (follow-up) by using t-test. Overbite clinical stability percentage at T3 was assessed with the chi-square test. Results: In 1-piece Le Fort I Group 65.52% of patients presented with clinically significant overbite stability, while in 4-piece Group 83.33% remained stable in the long-term, however it was not statistically significant. In Class II Group 57.14% of patients presented with clinically significant overbite stability, while in Class III Group 88% remained clinically stable, and it was statistically significant. Conclusions: The first null hypothesis regarding maxillary segmentation was accepted because there was no significant intergroup difference regarding the percentage of clinically stable patients. The type of fixation seems to influence the long-term stability of open bite surgical-orthodontic correction more than maxillary segmentation. The second null hypothesis was rejected because clinical stability of Class II malocclusion open bite surgical-orthodontic treatment was significantly smaller than in Class III malocclusions.
Introdução: A estabilidade em longo prazo do tratamento orto-cirúrgico da mordida aberta anterior é um assunto relevante e controverso. Esta má oclusão vertical tem o potencial de causar importantes alterações tanto funcionais quanto estéticas, impactando negativamente a qualidade de vida dos pacientes. Vários fatores, como o tipo de cirurgia, a fixação cirúrgica e a discrepância ântero-posterior, estão relacionados e podem influenciar a estabilidade da sobremordida em longo prazo. A controvérsia na estabilidade surge na dificuldade inerente de coletar uma amostra homogênea, com um tamanho de amostra considerável e acompanhamento adequado em longo prazo, levando esse assunto na literatura atual a um status inconclusivo. Portanto, esta tese teve como objetivos testar 2 hipóteses nulas: 1- Não há diferença na estabilidade em longo prazo da correção orto-cirúrgica da mordida aberta anterior ao comparar as osteotomias tipo Le Fort I com e sem segmentação maxilar. 2- Não há diferença na estabilidade em longo prazo da correção orto-cirúrgica da mordida aberta anterior ao comparar pacientes com má oclusão de Classe II e Classe III. Materiais e Métodos: A amostra da primeira investigação compreendeu as telerradiografias de 29 indivíduos com mordida aberta tratados por osteotomia Lefort I sem segmentação maxilar, às quais foram comparadas às telerradiografias laterais de 24 indivíduos com mordida aberta tratados por osteotomia Lefort I com segmentação maxilar; pacientes Classe I, II e III foram incluídos. Os grupos foram compatibilizados pela idade e foram comparados com testes t e qui-quadrado. Para testar a segunda hipótese nula, telerradiografias laterais de 21 indivíduos com mordida aberta e má oclusão de Classe II foram comparadas às telerradiografias laterais de 25 indivíduos com mordida aberta e má oclusão de Classe III. As alterações do overbite foram comparadas em três tempos: T1 (pré-tratamento), T2 (pós-tratamento) e T3 (longo-prazo) usando o teste t. A taxa de estabilidade clínica em T3 foi avaliada com teste de qui-quadrado. Resultados: No Grupo Le Fort I sem segmentação maxilar 65,52% dos pacientes apresentaram estabilidade clínica da sobremordida, enquanto que no Grupo Le Fort I com segmentação maxilar, 83,33% mantiveram-se estáveis em longo prazo, porém essa diferença não se apresentou estatisticamente significante. No Grupo Classe II, 57,14% dos pacientes permaneceram clinicamente estáveis, enquanto que no Grupo Classe III, a porcentagem clínica de estabilidade foi de 88%, e a diferença apresentou significância estatística. Conclusões: A primeira hipótese nula em relação à segmentação maxilar foi aceita porque não houve diferença estatisticamente significante entre os grupos em relação à porcentagem de pacientes clinicamente estáveis. O tipo de fixação parece influenciar a estabilidade em longo prazo da correção orto-cirúrgica da mordida aberta mais do que a segmentação maxilar. A segunda hipótese nula foi rejeitada porque a estabilidade clínica do tratamento orto-cirúrgico da mordida aberta em pacientes com má oclusão de Classe II foi significativamente menor do que nos pacientes com má oclusão de Classe III.

Objetivo: Comparar os resultados cefalométricos obtidos com tratamentos compensatórios e tratamentos orto-cirúrgicos para pacientes que apresentam Classe III esquelética. Metodologia: Foram selecionadas de forma retrospectiva telerradiografias iniciais e finais de 97 pacientes Classe III esquelética. Os critérios de inclusão foram: dentição permanente completa até primeiros molares, relação molar de Classe III, ausência de extrações dentárias durante o tratamento, ausência de problemas periodontais severos, Wits menor que -2mm, telerradiografia em normalateral iniciais e finais, fotografias intra e extra-bucais iniciais e modelos de gesso iniciais. Os pacientes foram divididos em 3 grupos. Grupo C: pacientes que foram submetidos ao tratamento ortodôntico associado à cirurgia ortognática (uni ou bimaxilar) totalizando 30 pacientes (idade média inicial 25,07 [22,90-25,56]). Grupo R pacientes que foram submetidos ao tratamento ortodôntico compensatório usando a prescrição Roth totalizando 30 pacientes (idade média inicial 16,22 [15,68-23,90]). Grupo B pacientes que foram submetidos ao tratamento ortodôntico compensatório usando a prescrição Biofuncional para Classe III totalizando 37 pacientes (idade média inicial 19,97 [18,53–24,68]). A severidade da Classe III foi determinada pela relação posterior e dividida em ¼, ½, ¾ e completa. Todas as telerradiografias foram digitalizadas e seus traçados foram realizados pelo mesmo examinador no software Dolphin (Dolphin Imaging Versão 11.9). As variáveis estudadas foram divididas em grupos: Alterações Maxilares, Mandibulares, Maxilo-Mandibulares, Convexidade Facial, Padrão Facial, Posição dos dentes superiores, Posição dos dentes inferiores e Perfil Tegumentar. A análise estatística foi realizada utilizando o software SPSS, versão 18.0. [SPSS Inc. lançado 2009. PASW Statistics for Windows, Versão 18.0. Chicago: SPSS Inc.]. As variáveis contínuas simétricas foram expressas como média e erro padrão da média (± SEM) ou mediana e intervalo de confiança de 95% ([IC 95%]), definido pelo teste de Shapiro-Wilk. As variáveis categóricas foram descritas por frequências absolutas (n) e relativas (n%). Para comparação de meios entre grupos independentes, foi aplicada uma Análise de Variância Unidireccional (ANOVA) com teste post hoc de Tukey ou teste de Kruskal-Wallis com teste post hoc Dunn. Além disso, o teste de classificação assinado por Wilcoxon foi usado para dados emparelhados (por exemplo, medições pré e pós-tratamento). Por outro lado, as variáveis categóricas foram comparadas intragrupo pelo teste do Qui-Quadrado com análise residual ajustada padronizada. Todos os dados foram avaliados usando o SPSS, versão 18.0. O nível de significância foi fixado em 5%.Resultados: O grupo C apresentou uma severidade maior do 8 que os demais grupos tendo 73,3% dos pacientes com uma Classe III severa (3/4 e completa). Houve um avanço do ponto A (projeção da maxila) nos Grupos B e C e um recuo do mesmo no Grupo R. Já na mandíbula, apenas o Grupo C apresentou um recuo estatisticamente significativo. Os três grupos apresentaram uma melhora na relação Wits estatisticamente significativa. Contudo, apenas os grupos C e B apresentaram uma melhora significativa nas medidas ANB e NAP, mostrando que nestes grupos houve uma melhora no perfil dos pacientes. Em relação ao posicionamento dentário, o Grupo R apresentou uma vestibuloversão, extrusão e projeção dos incisivos superiores e uma linguoversão, retrusão e extrusão dos incisivos inferiores. Já o grupo Biofuncional apenas apresentou uma extrusão dos incisivos superiores e inferiores, sem alteração em relação à inclinação. O Grupo C apresentou uma descompensação com vestibuloversão dos incisivos inferiores e palatoversão dos incisivos superiores. Nos grupos C e B, os lábios superiores foram posicionados mais para anterior e os lábios inferiores mais para posterior, melhorando o perfil tegumentar. Já no grupo R, o lábio superior foi posicionado mais para posterior, deixando o perfil tegumentar mais côncavo. Conclusões: O grupo C e B apresentaram um avanço da maxila (Ponto A) semelhantes, enquanto que o Grupo R mostrou um recuo da mesma. Alterações mandibulares só ocorreram no grupo C. Houve uma melhora na convexidade facial e pefil tegumentar nos grupos C e B e houve uma piora no grupo R. O Grupo R apresentou maiores características de compensação dentária do que o grupo B, sendo que este último apresentou os melhores resultados quando opta-se pela camuflagem ortodôntica. Quando existe envolvimento de ambas as bases ósseas (maxila e mandíbula), o melhor tratamento é a associação de tratamento ortodôntico e cirurgia ortognática. Quando o envolvimento é apenas da maxila, o tratamento com a prescrição Biofuncional apresenta resultados semelhantes ao tratamento com ortodontia e cirurgia. A prescrição Biofuncional apresenta resultados de camuflagem melhores do que a prescrição Roth em todas as situações.
Objective: To compare cephalometric results obtained with compensatory treatments and ortho-surgical treatments for patients with skeletal Class III. Methods: Initial and final cephalograms of 97 skeletal Class III patients were retrospectively selected. Inclusion criteria were: complete permanent dentition until first molars, Class III molar relationship, absence of dental extractions during treatment, absence of severe periodontal problems, Wits less than -2mm, teleradiography at initial and final, intra and extra photographs and initial gypsum models. Patients were divided into 3 groups. Group C: patients who underwent orthodontic treatment associated with orthognathic surgery (uni or bimaxillary) totaling 30 patients (initial mean age 25,07 [22,90-25,56]). Group R patients who underwent compensatory orthodontic treatment using the Roth prescription totaling 30 patients (initial mean age 16,22 [15,68-23,90]). Group B patients who underwent compensatory orthodontic treatment using the Biofunctional prescription for Class III totaling 37 patients (Initial mean age 19,97 [18,53-24,68]). The severity of Class III was determined by the posterior relationship and divided into ¼, ½, ¾ and complete. All cephalograms were digitized and their tracings were performed by the same examiner in Dolphin software (Dolphin Imaging Version 11.9). The variables studied were divided into groups: Maxillary, Mandibular, Maxillo-Mandibular, Facial Convexity, Facial Pattern, Upper Teeth Position, Lower Teeth Position and Tegumentary Profile. Statistical analysis was performed using SPSS software, version 18.0. [SPSS Inc. released 2009. PASW Statistics for Windows, Version 18.0. Chicago: SPSS Inc.]. The symmetric continuous variables were expressed as mean and standard error of the mean (± SEM) or median and 95% confidence interval ([95% CI]), defined by the Shapiro-Wilk test. Categorical variables were described by absolute (n) and relative (n%) frequencies. For comparison of means between independent groups, a Univirectional Variance Analysis (ANOVA) was applied with Tukey post hoc test or Kruskal-Wallis test with Dunn post hoc test. In addition, the Wilcoxon-signed classification test was used for paired data (for example, pre- and post-treatment measurements). On the other hand, the categorical variables were compared intra-group by the chi-square test with standardized adjusted residual analysis. All data were evaluated using SPSS, version 18.0. The level of significance was set at 5%. Results: Group C had a higher severity than the other groups, with 73,3% of patients with a severe Class III (3/4 and complete). There was a progression of point A (projection of the maxilla) in Groups B and C and a retreat of the same in Group R. In the mandible, only Group C presented a statistically significant 10 decrease. The three groups showed a statistically significant improvement in the Wits ratio. However, only groups C and B showed a significant improvement in ANB and NAP measurements, showing that in these groups there was an improvement in the patients' profile. Regarding tooth positioning, Group R presented vestibuloversion, extrusion and projection of the upper incisors and a linguoversion, retrusion and extrusion of the lower incisors. On the other hand, the Biofunctional group presented only an extrusion of the upper and lower incisors, with no change in relation to the inclination. Group C presented a decompensation with vestibuloversion of the lower incisors and palatoversion of the upper incisors. In groups C and B, the upper lips were positioned more anteriorly and the lower lips more posteriorly, improving the tegumentary profile. In the Roth group, the upper lip was positioned posteriorly, leaving the tegmental profile more concave. Conclusions: Group C and B presented similar maxillary advancement (Point A), while Group R showed a decrease of the same. Mandibular changes occurred only in group C. There was an improvement in facial convexity and tegumentary skin in groups C and B and there was worsening in group R. Group R presented higher tooth compensation characteristics than group B, and the latter presented the best results when opted for orthodontic camouflage. When there is involvement of both bone bases (maxilla and mandible), the best treatment is the association of orthodontic treatment and orthognathic surgery. When the involvement is only of the maxilla, the treatment with the prescription Biofuncional presents results similar to the treatment with orthodontics and surgery. The Biofunctional prescription presents better camouflage results than the Roth prescription in all situations.

Surgically Assisted Rapid Maxillary Expansion (SARME) is frequently used to treat skeletal maxillary transverse deficiency (MTD) in skeletally mature and non-growing individuals. Despite previous research in the field, questions remain with respect to the long-term stability of SARME and its effects on hard and soft tissue. The overall aim of the present doctoral work was to achieve a greater understanding of SARME, using modern image technology and a multidisciplinary approach, with special reference to effects on the hard and soft tissues and respiration. A more specific aim was to evaluate the long-term stability in a retrospective sample of patients treated with SARME and orthodontic treatment and to compare the results with a matched, untreated control group. The studies in this doctoral project are thus based on two different samples and study designs. The first sample, Study I (Paper I), is a retrospective, consecutive, long-term follow-up material of study models from 31 patients (17 males and 14 females) treated with SARME and orthodontic treatment between 1991 and 2000. The mean pre-treatment age was 25.9 years (SD 9.6) with a mean follow-up time of 6.4 years (SD 3.3). Direct measurements on study models were made with a digital sliding caliper at reference points on molars and canines. To evaluate treatment outcome and long-term stability, the results were compared with study models from an untreated control group, matched for age, gender and follow-up time. The second sample, Study II (Papers II-IV), is a prospective consecutive, longitudinal material of 40 patients scheduled to undergo SARME and orthodontic treatment between 2006 and 2009. In Paper II, one patient was excluded because of a planned adenoidectomy. The final sample comprised 39 patients (16 males and 23 females). The mean age at treatment start was 19.9 years (range 15.9 – 43.9). Acoustic rhinometry, rhinomanometry and a questionnaire were used to assess the degree of nasal obstruction at three time-points; pre-treatment, three months after expansion and after completed treatment (mean 18 months). In Papers III–IV, three patients declined to participate and two had to be excluded because their CT-records were incomplete. The final sample comprised 35 patients (14 males and 21 females). The mean age at treatment start was 19.7 years (range 16.1 – 43.9). Helical CT-images were taken pre-treatment and eighteen months’ post-expansion. 3D models were registered and superimposed at the anterior cranial base. The automated voxel-based image registration method allows precise, accurate measurements in all areas of the maxilla. In Papers II–IV, the treatment groups constituted their own control groups. The main findings in the retrospective, long-term follow-up study were that SARME and orthodontic treatment normalized the transverse discrepancy and was stable for a mean of 6 years post-treatment. Pterygoid detachment did not entirely eliminate the side effect of buccal tipping of the posterior molars. Relapse is time-related and is most pronounced during the first 3 years after treatment. Thus the retention period should be extended and should be considered for this period. The main rhinological findings in the prospective longitudinal study were that SARME had a shortterm, favourable effect on nasal respiration, but the effect did not persist in the long-term. However, subjects with pre-treatment nasal obstruction reported a lasting sensation of improved nasal function. SARME and orthodontic treatment had a significant but non-uniform skeletal treatment effect, with significantly greater expansion posteriorly than anteriorly. The expansion was parallel anteriorly but not posteriorly. The lateral tipping of the posterior segment was significant, despite careful surgical separation. No correlation was found between tipping and the patient's age. Furthermore, SARME and orthodontic treatment significantly affected all dimensions of the external features of the nose. The most obvious changes were at the most lateral alar-bases. The difference in lateral displacement profoundly influenced the perception of a more rounded nose. There were no predictive correlations between the changes. Patients with narrow and constrained nostrils can benefit from these changes with respect to the subjective experience of nasal obstruction. It is questionable whether an alar-cinch suture will prevent widening at the alar-base. The 3D superimposition applied in Study II is a reliable method, circumventing projection and measurement errors. In conclusion, SARME and orthodontic treatment normalize the transverse deficiency, with long-term stability. SARME has a favourable effect on the subjective perception of nasal respiration. SARME significantly affects dental, skeletal and nasal structures.

Hörntänderna i maxillan är efter visdomständerna de tänder som oftast blir retinerade. Prevalensen varierar mellan 1-3%. En retinerad överkäkshörntand har ofta en ektopisk placering. Detta kan leda till att eruptionsriktningen blir felaktig och därmed kan tanden orsaka skador på de angränsande incisivernas rötter. För att minska risken för detta krävs tidig diagnostik, i 9-11 års ålder.Den vanligaste åtgärden för palatinalt displacerade hörntänder är extraktion av mjölkhörntänderna för att underlätta spontaneruption av de efterföljande permanenta hörntänderna. Om enbart denna behandling inte är tillräcklig eller om den permanenta hörntanden ligger för djupt måste kirurgisk friläggning ske. Detta sker i kombination med efterföljande ortodontisk behandling.I Sverige används idag två typer av kirurgisk friläggning; öppen och sluten. Vilken typ av friläggning som används tycks vara lokalt betingat. I Malmöregionen används oftast öppen friläggning medan i Jönköpingsregionen sluten friläggning är vanligast.I denna studie jämförs behandlingsutfallet hos patienter där öppna och slutna friläggningar gjorts. Framförallt utvärderas om det finns någon signifikant skillnad i behandlingstid, från friläggning till dess att den ortodontiska behandlingen är färdig. Hänsyn tas till typ av friläggning och om tanden ligger palatinalt eller buckalt retinerad. Det undersöks även vid vilken ålder friläggning gjorts samt vilken typ av retentionapparatur som använts.I gruppen med öppen friläggning var patienterna i genomsnitt 15,2 år respektive 12,9 år i gruppen med sluten friläggning. Den totala behandlingstiden från friläggning till avlägsnande av apparatur visade sig vara signifikant kortare i gruppen som fick öppen friläggning jämfört med gruppen som fick sluten friläggning.
The maxillary canines are after the third molars, the most frequently impacted teeth. The incidence varies between 1-3%. Impacted maxillary canines are often related to ectopic position, which can lead to an incorrect direction of eruption and thus cause damage to the adjacent incisors roots.The most common treatment for palatally displaced canines is extraction of the primary canines to facilitate spontaneous eruption of the succeeding permanent teeth. If this treatment is not sufficient or if the permanent canine lies too deep, surgical exposure is needed. This occurs in combination with orthodontic treatment.In Sweden two types of surgical exposures are practiced; open and closed. Which type of exposure is used seems to be locally induced. In Malmö the open exposure is most frequently practiced while in Jönköping the closed exposure is the treatment of choice.The aim of this study is to compare the treatment outcome in two groups of patients, treated either with an open or a closed exposure. It was evaluated whether any significant difference was found in the overall treatment time, from exposure until completed orthodontic treatment. Consideration was given to type of exposure and weather the tooth was palatally or buccally impacted. The age of the patients when the exposures occurred and the type of retention used in the different groups were also examined.The mean age for the patients treated with an open exposure was 15.2 years compared to 12.9 years in the other group. The total time of treatment from exposure to removal of the appliances was significantly shorter in the group with open exposure.

Objetivo: Analisar a técnica da corticotomia associada ao tratamento ortodôntico, discutindo o seu contexto histórico, príncipios biológicos e ortodônticos, protocolos cirúrgicos, as aplicações e limitações. Procurar-se-á avaliar as suas vantagens e desvantagens comparando as diversas técnicas utilizadas. Método: Foi realizada uma revisão bibliográfica recorrendo à motores de busca como Pubmes, B-on, Cochrane Library e Science Direct, incluindo Casos Clinicos, Metanalises, revisões bibliográficas e sistemática em Inglês, Português, Espanhol e Italiano. Resultados: Apresenta-se uma descrição detalhada das técnicas cirúrgicas usadas em corticotomia e as indicações ortodônticas. Conclusões: Através uma analise de dados è possível definir que a corticotomia é um procedimento cirúrgico seguro e predictível que consegue induzir uma aceleração do movimento dentário. O seu grau de invasividade varia de acordo do tratamento e técnica a efetuar. Posteriores estudos são necessários para avaliar os efeios ao longo prazo.
Objetive: To analyze the corticotomy technique associated with the orthodontic treatment, discussing its background, biological and orthodontic principlea, surgical protocols, apllications and limitations. Its advantages and disadvantages will be assessed by comparin the different techniques used. Methods: A literature review was carried out using search engines such as PubMed, B-on, Cochrane Library and Science Direct, including Clinical Cases, Metanalysis, bibliographical and systematic review in English, Portuguese, Spanish and Italian. Results: A detailed description of surgical techniques used in corticotomy and orthodontic indications is presented. Conclutions: Through a data analysis it is possible to define that corticotomy is a safe and predictable surgical procedure that can induce an acceleration of dental movement. The degree of invasiveness varies according to the treatment and technique performed. Further studies are needed to assess long-term effects.

Introdução: São inúmeras as mudanças a nível psicológico que podem ocorrer quando se realiza uma cirurgia ortognática. Revela-se de interesse social estudar, se realmente, pacientes com deformidade dento-facial apresentam na verdade uma menor qualidade de vida e baixa autoestima de maneira a complementar o tratamento ortodôntico-cirúrgico-ortognático. Até hoje este tema, que relaciona a medicina dentária e a psicologia, foi muito pouco estudado em Portugal. Objetivos: Avaliar o impacto psicossocial em pacientes com deformidade dento-facial e encontrar diferenças entre o género, idade e tipo de classe esquelético nesses pacientes. Materiais e Métodos: Realização de dois questionários para apreciação da qualidade de vida (WHOQoL-Bref) e autoestima (Escala de autoestima de Rosenberg) aplicados em pacientes com diagnóstico de deformidade dento-facial dado pelo médico-dentista e/ou cirurgião maxilo-facial e em pacientes com indicação para tratamento ortodôntico convencional. Resultados: Os pacientes com deformidade dento-facial não apresentaram valores estatisticamente diferentes de qualidade de vida relativamente a pacientes com indicação para tratamento ortodôntico convencional, mas por outro lado as diferenças revelaram-se significantes na autoestima, ditando que os primeiros exibem valores menores de autoestima. O género vê-se associado apenas no domínio psicológico da qualidade de vida, onde o género feminino surgiu com diferenças estatisticamente significativas. Já a Classe esquelética não originou diferenças significativas nas variáveis em estudo. Em relação à variável idade, esta surgiu estatisticamente associada à autoestima, de forma que paciente mais jovens possuem valores mais baixos. Conclusão: Pacientes com deformidade dento-facial apresentaram uma autoestima geral significativamente mais baixa que o grupo controlo. Foi verificado a existência de diferenças estatisticamente significativas entre o homens e mulheres no domínio psicológico da qualidade de vida, bem como entre as diferentes faixas etárias na autoestima geral. O conhecimento destas diferenças é imprescindível para conceder aos pacientes um tratamento mais personalizado, integrado e completo.
Introduction: There are countless psychological changes that can occur when orthognathic surgery is performed. Therefore, it is of social interest to study if in reality patients with DFD actually have a lower quality of life and low self-esteem in order to complement orthodontic-surgical-orthognathic treatment. Until today, this topic which relates dentistry and psychology, has been little studied in Portugal. Objectives: To evaluate the psychosocial impact in patients with dento-facial deformity and find differences between gender, age and type of skeletal class in these patients. Materials and Methods: Two questionnaires were carried out to assess quality of life (WHOQoL-Bref) and self-esteem (Rosenberg's self-esteem scale) applied to patients diagnosed with dentofacial deformity by the dentist and / or maxillofacial surgeon and in patients with indication for conventional orthodontic treatment. Results: Patients with dento-facial deformity did not present statistically different values of quality of life compared to patients with indication for conventional orthodontic treatment. On the other hand, the differences proved to be significant in self-esteem, dictating that the former exhibit lower values of self-esteem. Gender is associated only in the psychological domain of quality of life, in which the female gender has emerged with statistically significant differences. The Skeletal Class did not cause significant differences in the variables under study. Regarding the age variable, it appeared statistically associated with self-esteem, in which younger patients have lower values. Conclusion: Patients with facial-facial deformity showed lower general self-esteem than the control group. It was verified the existence of statistically significant differences between men and women in the psychological domain of quality of life, as well as between different age groups in general self-esteem. The knowledge of these differences is essential to grant patients a more personalized, integrated and complete treatment.

Corticotomies have been used to assist orthodontic treatment since the late 18th century. This review describes and compares different surgical techniques available to accelerate tooth movement: PAOO™, Corticision, Piezocision™ and Propel. All of the approaches described accelerate orthodontic tooth movement and may protect against root resorption. PAOO™ and Piezocision™ offer the option of bone and soft tissue grafting at time of surgery. Corticision, Piezocision™ and Propel are considered minimally invasive procedures thanks to the flapless approach, but the use of the mallet in Corticision could constitute a trauma for the patient. The piezoelectric knife creates a more intense Regional Accelleratory Phenomenon (RAP) at the site of injury due to the effect of high frequency vibrations. This suggests that Piezocision™ could create a greater effect on bone remodeling, hence producing faster tooth movement and extended RAP. The lack of randomized controlled clinical trials makes an effective comparison between these techniques difficult and future studies are needed to better evaluate the outcomes of each of these.

碩士
國立臺灣大學
臨床牙醫學研究所
102
Objectives: Most of the patients receiving surgical orthodontic treatments in National Taiwan University Hospital (NTUH) exhibit Class III skeletal pattern with mandibular prognathism. It is common that skeletal Class III patients have the feature of facial asymmetry. The objective of this research is to study the CBCT (Cone beam CT) image of skeletal Class III patients before and after surgical orthodontic treatments. This would help us to have more insight into the surgical treatment for Class III patients with facial asymmetry. Method: 38 patients underwent surgical orthodontic treatment in NTUH were included in this research. CBCT was taken before full mouth orthodontic treatment (T1) and within 3 months after debanding and debonding of brackets (T2) by using i-CAT CBCT scanner. Dolphin imaging system was utilized for image analysis. Ba was defined as the origin of the 3-dimensional coordinates and the image was oriented according to the following reference planes. The midsaggital plane was defined as the plane that passed through N, S, Ba and the horizontal reference plane was defined as the plane that was perpendicular to midsaggital plane and passed through the midpoint of bilateral Po, Or projecting to midsaggital plane. Coronal plane was defined the plane that was perpendicular to saggital and horizontal plane. After orientation of T1 image was performed, T2 image was superimposed to T1 image according to the best fit of cranial base structures. Thus, the differences of each landmark between T1 and T2 images could be measured by calculating the coordinates. To analyze the movement of proximal segments, the border of ascending ramus was projected onto coronal plane and analyzed sequentially at different levels from the level of mandibular notch to the level of gonial angle. The patients were grouped according to the relationship of Menton deviation and bilateral Ramus width difference to characterize the facial asymmetry. The criteria of grouping was as follows: Group 1: Menton deviation&;#8805; Ramus width difference&;#8805;0 Group 2: Ramus width difference> Menton deviation&;#8805;0 Group3: Menton deviation>0, Ramus width difference<0 Results: Average Menton deviation of the 38 patients was 4.07±3.13mm. 13 patients were classified into Group 1, and the average Menton deviation of Group 1 was 6.29±3.49 mm. Nine patients were classified into Group 2 ,and the average Menton deviation was 2.08±1.49mm. The asymmetry pattern of the Group 2 patients was associated with the differences between distances from ramus to midsaggital plane. 16 patients were classified into Group 3, and the average Menton deviation was 3.38±2.47 mm. In contrast to Group 1 and Group 2, Group 3 patients has more prominent gonial angle at non-deviated side. Besides, the position of mental foramen and mandibular foramen were more forward at the non-deviated side compared to the deviated side. For Group 1 patients, the Menton devaiton , Ramus width difference , and arch form discrepancy were improved after treatment. For Group 2 patients, Menton deviation and Ramus width difference improved after surgery. As to Group 3 patients, the treatment corrected Menton deviation, but not the Ramus width difference. Conclusion: CBCT 3 dimensional image is helpful in the analysis of skeletal Class III patients with facial asymmetry. The parameter of Menton deviation and bilateral Ramus width difference were feasible for diagnosis and surgical-orthodontic treatment plan of skeletal Class III patients. The asymmetry patterns were different among the three groups. Menton deviation and Ramus width difference may be corrected after treatment for Group 1 and Group 2 patients. However, for Group 3 patients, the treatment only corrected Menton deviation but not the Ramus width difference.

碩士
國立臺灣大學
臨床牙醫學研究所
100
Objective: The prevalence of Class III malocclusion is higher in Asians than in Caucasians. To improve the occlusal function and facial esthetics, orthodontic treatment combined with orthognathic surgery is often indicated in Class III malocclusion with severe skeletal discrepancy. The objectives of this research were to investigate the three-dimensional (3D) morphological changes of the soft and hard tissues in Class III facial asymmetry patients who were corrected with surgical orthodontic treatment. Method: The subjects included 15 adult skeletal Class III patients who had 3D cone beam computerized tomography (CBCT) taken before full mouth orthodontic treatment (T1) and within one month after debanding and debonding (T2). They were treated with orthodontic treatment combined with one-jaw surgery to setback mandible (bilateral sagittal split osteotomy, BSSO) or two-jaw surgery (Le Fort I maxillary advancement and BSSO mandibular setback). The 3D CBCT images were superimposed on the cranial base in Dolphin imaging system (best fit of cranial base). After superimposition, 3D changes of the soft and hard tissues were measured from the vertical, anteroposterior, and transverse directions, respectively. In addition, the soft to hard tissue movement ratios were calculated. Result: Asymmetry was more evident in the lower face in comparison with the middle face. Chin deviation was found in 13 of 15 subjects and 5 of them were deviated to the right side. Moreover, the mean deviation of bony pogonion at T1 was 4.32 mm. The mandibular prognathism were successfully corrected and facial asymmetry improved, but not fully corrected. In the vertical evaluation, the average occlusal plane canting changed from 1.73 mm to 1.04 mm. The vertical discrepancy of bilateral mandibular inferior border changed from 1.87 mm (T1) to 2.08 mm (T2). In the evaluations either before or after treatment, the vertical asymmetry of bilateral mandibular inferior borders was coincident with the direction of occlusal plane canting. In the anteroposterior (AP) evaluation of two-jaw surgery patients, the soft-to-hard tissue movement ratios (S/H ratios) of the maxilla gradually increased from midsagittal to paranasal area (0.295, 0.745, 1.19). The S/H ratios of the mandible were gradually increased from L1 CEJ to pogonion. Furthermore, marked individual variation of S/H ratios in transverse direction is noted. Conclusion: The CBCT 3D image is useful to evaluate the treatment effects of surgical orthodontic treatment in patients with mandibular prognathism and facial asymmetry. The S/H ratios of maxilla in AP direction gradually increased from midsagittal to paranasal area. The S/H ratios in mandible were close to one. The transverse movement of the soft tissue seemed difficult to predict from hard tissue because of marked individual variation.

碩士
國立陽明大學
醫學工程研究所
102
In recent years, mini-screw has been commonly used to achieve absolute anchorage during orthodontic treatment. However, when mini-screw is implanted in maxilla, there are many factors that can cause mini-screw unstable or damage surrounding structures. The purpose of this study is to develop the precision customization of orthodontic mini-screw surgical guide (under biomechanical consideration), and prove the performance by using the validated testing and clinical trial. First, the 3D digital geometry of the maxillary alveolar bone and tooth were reconstructed by using computed tomography images and reverse engineering, it could be applied to design surgical guide and implant mini-screw position. According to analysis result of the computer aided engineering (CAE), it can find not only the maximal Von-Mises strain, maximal principle strain and displacement of the interface between mini-screw and bone tissue, but also the displacement of the mini-screw head. Therefore, the ideal inserted path was performed according to the analysis results. After that, increasing guide hole and depth limiting device of the mini-screw and removable devices of the surgical guide by using computer aided design (CAD) on the surgical guide model. Final, surgical guide is made by 3D printing technology. In order to prove the indications of the surgical guide, it must be performed the functional test and clinical test. Results showed that, when the mini-screw inserted into palatal alveolar bone with 30 degree angle between the vertical (group A), the maximal Von-Mises strain around the bone tissue of the mini-screw was 1174μ. When the mini-screw inserted into palatal alveolar bone with horizontal direction (group B) the maximal Von-Mises strain around the bone tissue of the mini-screw was 694μ. Group B is greater than the A group but both were under critical strain level (4000μ). The ratio of group A to group B of the displacement between bone and mini-screw was found more than 3.2 times, and the mini-screw head displacement was found more than 100 times. Results showed that the group A is greater than group B. This study implied that the biomechanical response needs to be considered when using mini-screws as the skeletal anchorages.

Introduction: L’expansion palatine du maxillaire a beaucoup d’effets positifs sur la respiration et la qualité du sommeil, mais peu d'études ont examiné ces données sur des adultes ayant dépassé l’âge permettant de bénéficier d'une expansion palatine conventionnelle. Le but de cette recherche est d’évaluer la stabilité de l’EPRAC (expansion palatine rapide assistée chirurgicalement) et son effet sur les troubles respiratoires après l’ablation des appareils orthodontiques. Méthodes: Neuf patients (Âge moyen 21, entre 16-39 ans) nécessitant une EPRAC ont passé des nuits dans un laboratoire de sommeil, et ce avant l’EPRAC, après l’EPRAC, et après l’ablation des appareils fixes. Les radiographies céphalométriques postéroantérieures ainsi que les modèles d’étude ont été pris pendant ces trois périodes de temps. Résultats: L’analyse des modèles d’étude a démontré une récidive significative au niveau des distances inter-molaires et inter-canines au niveau du maxillaire seulement. Les analyses céphalométriques ont démontré une récidive au niveau de la largeur maxillaire. Aucun changement important n'a été observé dans les stades de sommeil, mais une réduction importante dans l’index de ronflement a été notée. De plus, il y avait moins de changements entre les stades de sommeil. Conclusions: La récidive squelettique est minime et cliniquement non significative. Par contre, les changements dans les distances intermolaires et intercanines sont cliniquement importants. Il semble également qu'une EPRAC ait un effet positif sur la qualité de sommeil par la réduction de l’indice de ronflement ainsi que sur la diminution des changements entre les stades de sommeil.
Introduction: Orthopedic expansion appears to have several positive effects on respiration as well as sleep quality, but a lack of studies examine these findings using SARPE on skeletally mature individuals. The aim of this study was to evaluate post-SARPE stability as well as its effect on sleep disordered breathing after completing full fixed orthodontics. Methods: 9 patients (average age 21, range 16-39) requiring SARPE underwent polysomnographic testing in sleep laboratory before SARPE (T0), after SARPE (T1), and after removal of full fixed appliances (T2). Study models and anteroposterior cephalometric radiographs were also taken at the 3 time points. Results: Study model analysis showed significant relapse for intermolar and intercanine widths. Anteroposterior cephalometric results were significant only for effective maxillary width. There were no significant changes in any sleep stages, however a dramatic reduction in snoring as well as fewer stage shifts were observed. Conclusions: Although statistically significant relapse was observed on study models and anteroposterior cephalometric radiographs, the dental relapse appears to be more clinically significant than the skeletal relapse. SARPE appears to have a positive effect on sleep quality by reducing the snoring index as well as reducing transitions between sleep stages.