Insertion angle of orthodontic mini-implants and their biomechanical performance: finite element analysis / Ângulo de inserção de mini-implantes ortodônticos e seu desempenho biomecânico: análise de elementos finitos

Objective: The aim of this study was to assess the stresses and strains generated after the application of two types of forces (traction of 200 gf and torsion of 20 N.cm) in two types of orthodontic mini-implants inserted at different (45° and 90° to the cortical bone) angles. Material and method: three-dimensional models of two brands of mini-implant (SIN - Sao Paulo, Brazil, and RMO - South Korea) were exported and analyzed by finite element analysis (FEA). Analyses were performed on simulations of cortical bone, cancellous bone and the screw. Result: FEA analysis showed that RMO mini-implants had greater elastic deformation when subjected to tensile and torsional forces when compared with SIN mini-implants. For both trademarks and insertion angles tested, there was greater cortical bone deformation, but with the greatest strain located on the mini-implant. Tension on the mini-implant was located in its transmucosal profile region. Conclusion: When comparing the two brands of mini-implants by FEA, it is fair to conclude that that the larger number of threads and their greater angle of inclination resulted in less resistance to deformation and induced a higher level of tension in the mini-implant and cortical bone when subjected to forces, especially when inserted at an angle of 45º to the cortical bone.

Objetivo: O objetivo deste estudo foi avaliar as tensões e deformações de duas marcas comerciais de mini-implantes ortodônticos geradas após a aplicação de dois tipos de forças (de tração de 200 gf e torção de 20 N.cm) inseridos em duas angulações (45° e 90° em relação ao osso cortical). Material e método: Modelos tridimensionais das duas marcas de mini-implantes (SIN - Sao Paulo, Brasil, e RMO - Coréia do Sul) foram construídos e analisados por análise de elementos finitos (FEA). As análises foram realizadas em simulações no osso cortical, osso esponjoso e no parafuso. Resultado: A análise FEA mostrou que os mini-implantes da marca RMO apresentaram maior deformação elástica quando submetidos à tração e as forças de torção quando comparado aos mini-implantes da marca SIN. Em ambas as marcas testadas, e para os diferentes ângulos de inserção, houve uma maior deformação do osso cortical, com maior tensão localizado no mini-implante. A tensão no mini-implante foi localizado na região do perfil transmucoso. Conclusão: Ao comparar as análises de elementos finitos das duas marcas comerciais de mini-implantes, concluiu-se que um maior número de roscas e maior inclinação resultam em menor resistência à deformação e induzem uma maior tensão no osso cortical quando submetidos à forças de torção e tração, especialmente quando inserido em um ângulo de 45º com o osso cortical.

In vitro evaluation of anti-adherence activity of the Ocimum basilicum l. ( basil) extract and of the Coriandrum sativum l. ( coriander) in acrylic surface of removable orthodontic appliances

AIM: The aim of this study is evaluate the antimicrobial activity of the Ocimum basilicum L. (basil) extract and of the Coriandrum sativum L. (coriander) extract in biofilm of Streptococcus mutans colonized in specimens confectioned in acrylic used to confection removable orthodontic appliances. MATERIAL AND METHODS: To perform this work, specimens were confectioned (spherical discs in sterile acrylic) which were immersed in extracts pure and in series dilutions (1:2 a 1:128) by 24, 48 and 72 hours. For each time of exposition, the disintegration of bacterial films was performed by sonication in saline solution. RESULTS: The results obtained were satisfactory for the extracts studied on the inhibition of biofilm formation. CONCLUSION: We conclude that polyphenols present in the extracts interfered on the glucan synthesis engine, possibly inhibiting the enzymes (glucosyl- and fructosyl transferase) which synthesize the extracellular polymers, also acting as antioxidant, and therewith they presented antimicrobial activity.

Calvarial autogenous bone graft for maxillary ridge and sinus reconstruction for rehabilitation with dental implants.

Autogenous bone grafting is the gold-standard technique for bone augmentation procedures prior to implant placement. If the amount of available intraoral donor bone is insufficient, it is necessary to harvest bone graft from extraoral sites, such as calvaria. Although this technique is well established, only a few case reports show the histological analysis of the grafted bone at the moment of implant placement. This article reports the case of a 48-year-old female patient with a critical atrophic maxillary ridge reconstructed using autogenous calvarial bone graft prior to implant placement, with clinical and histological evaluation. Bone was collected under general anesthesia from the parietal bone. The outer cortical originated the bone blocks, and the medullar bone layer between was collected to be used in the sinus augmentation procedure, together with 5 of the bone blocks triturated. Six months after bone augmentation, 8 implants were placed in the grafted area and 2 biopsies were retrieved (anterior and the posterior regions), allowing the visualization of the bone-remodeling process in the grafted areas. The patient had a stable recovery. Our results showed that although necrotic bone could still be seen in the outer layer of the grafted area, the interface between this necrotic bone and the already remodeled bone was consistent with biocompatibility. Two-year radiographic evaluation showed success of the grafts and the implants in supporting an esthetic and functionally stable prosthesis. Summarizing, calvarial bone grafts are a viable alternative for the attainment of adequate bone volume prior to implant placement.

Tratamento multidisciplinar: relato de casos clínicos / Multidisciplinary treatment: clinical cases report

Opaciente adulto apresenta maior predisposição para doença periodontal, decorrente, principalmente, do mal controle de placa. Nesses pacientes, a movimentação ortodôntica não é contraindicada, porém, é necessária uma avaliação da condição periodontal para que se possa estabelecer o plano de tratamento apropriado. / Objetivo / Descrever e discutir casos clínicos de indivíduos com necessidade de reabilitação bucal e com periodonto severamente comprometido. / Métodos / Os métodos consistiram no tratamento ortodôntico de dois casos com comprometimento periodontal. Após exames clínicos e radiográficos, os casos foram analisados de forma multidisciplinar, envolvendo as especialidades de Ortodontia, Periodontia e Prótese, com objetivo de proporcionar ao paciente os melhores resultados estético, funcional e estabilidade. O tratamento periodontal consistiu de raspagem supra- e subgengival, previamente ao tratamento ortodôntico, e programa de manutenção periódica trimestral durante toda movimentação ortodôntica. As ativações foram realizadas em intervalos de 45 a 50 dias, com a utilização de forças leves, sendo utilizadas contenções em ambas as arcadas, mesmo após a finalização da reabilitação. / Conclusão / O tratamento reabilitador bucal, quando feito de forma multidisciplinar, traz resultados bastante satisfatórios. A interação da Ortodontia e da Periodontia comprovou que pacientes com periodonto reduzido, porém saudável, podem receber tratamento ortodôntico, desde que as forças não excedam o limite biológico desse.

Effect of angled installation of orthodontic mini-implants on primary stability

AIM: The aim of this work was evaluate the insertion and removal torque for orthodontic mini-implants inserted in different inclination. Materials and methods: Ten self[drilling mini-implants from the brand SIN (Sistema de Implantes Nacional, São Paulo/SP, Brazil), and the surgical kit for their insertion were used. Two plaques of synthetic bone of 120mm x 170mm x 41,5mm were used (Sawbones, Pacific Research Laboratories Inc, Vashon, Wash), with 1,5mm height, simulating the cortical bone (density 40 pcf) and 40 mm simulating the medullary bone (density 15 pcf). In each block, five areas were demarcated for each mark, totalizing ten areas. The ten mini-implants were inserted by the same operator, previously calibrated; five of them at 900 and five at 600, using the manual key kit. After the insertion of all the mini-implants, the final threading and the reading of insertion torque value were carried out with a manual torque wrench digital Lutron TQ[8800 (Lutron Electronic Enterprise Co., Ltd, Taipei, Taiwan) until the trans-mucosal profile achieve the cortical bone. The maximum insertion torque value was registered in N/cm. After all the implants inserted, the measurement of removal torque was started, performed in the same way of insertion, but in the opposite anticlockwise. The results were submitted to the T test (parametric) and to a Mann-Whitney test (non-parametric). Results: The results demonstrated that the insertion torque was lower than the removal one in both insertion degrees, with statistically significance. Despite insertion torque at 90 degrees had been lightly higher than that inserted at 60 degrees, they were not statistically significant. Conclusion: In view of the results, it was possible conclude that insertion at 60º angulation does not offer advantages to the primary stability for orthodontic mini-implants.

Occurrence of skeletal malocclusions in Brazilian patients with dentofacial deformities.

In this study, a survey was conducted on the occurrence of skeletal malocclusions presented by patients of the Center for Research and Treatment of Buccofacial Deformities (CEDEFACE) in the city of Araraquara, SP, Brazil. The clinical charts of 381 patients with dentoskeletal deformities, who underwent combined orthodontic-surgical treatment in the period between 2000 and 2006, were reviewed. After sample selection (convenience method), based on the data of the pre- and post-surgical documentation, the number of patients was reduced to 171. For classification of the survey, the anteroposterior discrepancy (Class I, II and III), race, age, gender, absence or presence of asymmetry, vertical maxillary excess and maxillary biprotrusion were considered, in addition to determining in which bony base the surgical procedure was performed. Patients' documentations were analyzed by one examiner previously calibrated by repetition of the process until the method was considered adequate (intraclass correlation coefficient > 0.94). Patients' mean age was 23.59 (SD 6.93) years, the majority (102 patients) were women, and Caucasians (160 patients). Class III malocclusion was the most prevalent (81 patients). Asymmetry, vertical maxillary excess and biprotrusion were present in 54, 33, and 7 patients, respectively. The majority of surgeries for correction of dentoskeletal deformities were combined, involving the maxilla and mandible. In conclusion, Class III was the most prevalent skeletal deformity and Class I was the least prevalent; in general, the prevalence of skeletal deformities was higher in women; in the majority of patients with skeletal malocclusions there was a combination of maxillary and mandibular problems, which interferes directly in the decision regarding the most adequate treatment plan, and a higher incidence of asymmetry was observed in skeletal Class III; vertical excess occurred in a similar manner in Class II and III and there was a low incidence of biprotrusion among the malocclusions evaluated.

Occurrence of skeletal malocclusions in Brazilian patients with dentofacial deformities

In this study, a survey was conducted on the occurrence of skeletal malocclusions presented by patients of the Center for Research and Treatment of Buccofacial Deformities (CEDEFACE) in the city of Araraquara, SP, Brazil. The clinical charts of 381 patients with dentoskeletal deformities, who underwent combined orthodontic-surgical treatment in the period between 2000 and 2006, were reviewed. After sample selection (convenience method), based on the data of the pre- and post-surgical documentation, the number of patients was reduced to 171. For classification of the survey, the anteroposterior discrepancy (Class I, II and III), race, age, gender, absence or presence of asymmetry, vertical maxillary excess and maxillary biprotrusion were considered, in addition to determining in which bony base the surgical procedure was performed. Patients' documentations were analyzed by one examiner previously calibrated by repetition of the process until the method was considered adequate (intraclass correlation coefficient > 0.94). Patients' mean age was 23.59 (SD 6.93) years, the majority (102 patients) were women, and Caucasians (160 patients). Class III malocclusion was the most prevalent (81 patients). Asymmetry, vertical maxillary excess and biprotrusion were present in 54, 33, and 7 patients, respectively. The majority of surgeries for correction of dentoskeletal deformities were combined, involving the maxilla and mandible. In conclusion, Class III was the most prevalent skeletal deformity and Class I was the least prevalent; in general, the prevalence of skeletal deformities was higher in women; in the majority of patients with skeletal malocclusions there was a combination of maxillary and mandibular problems, which interferes directly in the decision regarding the most adequate treatment plan, and a higher incidence of asymmetry was observed in skeletal Class III; vertical excess occurred in a similar manner in Class II and III and there was a low incidence of biprotrusion among the malocclusions evaluated.

Este estudo avaliou a ocorrência de más oclusões esqueléticas apresentadas pelos pacientes do Centro de Pesquisa e Tratamento das Deformidades Bucofaciais (CEDEFACE), na cidade de Araraquara, SP, Brasil. Foram avaliados prontuários de 381 pacientes com deformidades dentoesqueléticas, que fizeram tratamento combinado ortodôntico-cirúrgico no período entre 2000 e 2006. Após a seleção da amostra (método de conveniência), baseado nos dados da documentação pré e pós-cirúrgica, o número de pacientes foi reduzido para 171. Para classificação do levantamento, considerou-se a discrepância ântero-posterior (Classe I, II e III), raça, idade, gênero, ausência ou presença de assimetria, excesso vertical maxilar e biprotrusão maxilar, além de determinar em qual base óssea o procedimento cirúrgico foi realizado. As documentações dos pacientes foram analisadas por um examinador previamente calibrado pelo processo de repetição até que o método fosse considerado adequado (correlação intraclasse >0,94). A idade média dos pacientes foi de 23,59 anos (DP 6,93), a maioria do gênero feminino (102 pacientes) e leucoderma (160 pacientes). A má oclusão mais prevalente foi a Classe III (81 pacientes). A assimetria, o excesso maxilar vertical e biprotrusão maxilar estavam presentes em 54, 33, e 7 pacientes, respectivamente. Na maioria dos casos, as cirurgias para correção de deformidades dentoesqueléticas foram combinadas, envolvendo os dois maxilares. Com base nos resultados, conclui-se que a Classe III foi a deformidade esquelética mais prevalente e a Classe I a menos prevalente. Em geral, a prevalência de deformidades esqueléticas foi maior entre as mulheres e a maioria dos pacientes apresentou uma combinação de problemas maxilares e mandibulares, o que interfere diretamente na decisão sobre o plano de tratamento mais adequado. Houve uma maior incidência de assimetria na Classe III esquelética; o excesso vertical ocorreu de forma semelhante na Classe II e III e a biprotrusão teve baixa incidência entre as más oclusões avaliadas.

Influência do formato do implante para reabilitação de casos com limitação de espaço mesiodistal / Influence of the format of the implant on rehabilitation in cases of mesio-distal space limitation

Apesar do grande desenvolvimento da implantodontia, seu sucesso depende de um planejamento rigoroso e em casos com limitação de espaço mesiodistal a seleção do formato do implante é muito importante. Objetivo e relato do caso clínico: Este artigo relata o caso clínico de um paciente com agenesia bilateral dos incisivos laterais superiores e ausência de espaço satisfatório no sentido mesiodistal, impedindo a utilização de implantes em proporções convencionais, apesar de ter realizado um tratamento ortodôntico prévio. Após a realização de exames radiográficos e estudo de modelos articulados em articulador semiajustável, optou-se pela realização de dois implantes de corpo único com carga imediata, da marca SIN®-Unident, de diâmetro reduzido para a solução do caso. Considerações finais: O correto planejamento, diagnóstico e execução da técnica apresentou resultado satisfatório imediato e a longo prazo.

Uso de um distrator ósseo dentoimplantossuportado, feito a partir de tornos expansores convencionais, na reabilitação oral / Use of a tooth-implant supported bone distractor, made from standard orthodontic expansion-screws, in oral rehabilitation. Case report

A osseodistração é uma realidade clínica disponível já há algumas décadas para a resolução de deficiências ósseas extensas, em casos em que existam dentes ou implantes osseointegrados, porém mal posicionados. O objetivo deste artigo é apresentar um caso clínico na qual uma nova possibilidade de distração óssea, baseada em um distrator dentoimplantossuportado (feito com tornos expansores ortodônticos convencionais), foi utilizada em uma área onde havia necessidade extensa de recuperação estética e de tecido ósseo, aliada ao mau posicionamento dentário e de um implante previamente instalado na região. A técnica utilizada apresentou bons resultados clínicos, associado à sua simplicidade e baixo custo, contribuindo como solução clínica viável para ganho tecidual e otimização estética. Como conclusão tem-se que a técnica sugerida alcançou os resultados esperados, melhorando a posição do implante e o perfil de tecidos duro e mole, permitindo a finalização de sua reabilitação oral.

Osteodistraction is a clinical reality, available in the last decades for the resolution of large bone deficiencies, in cases that there are pre-existing, but misplaced implants and teeth. The aims of thearticle is to present a case report in which a new possibility for bone distraction, based on tooth-implant bone distractors, made from standard orthodontic expansion-screws, was used in an area where there was an extensive need of alveolar bone and aesthetical recovery, allied to teeth and dental implant misplacement. This technique presented good clinical results, associated to effective simplicity and low cost, becoming viable clinical solution for bone tissue augmentation and aesthetical optimization. In resume, it is possible to say that the suggested technique achieved its objectives, improving the hard and soft tissue profile, whilst allowing completion of oral rehabilitation.

Histomorphometric evaluation of human sinus floor augmentation healing responses to placement of calcium phosphate or Ricinus communis polymer associated with autogenous bone.

BACKGROUND: Prosthetic rehabilitation of the posterior maxilla with dental implants is often difficult because of proximity to the maxillary sinus and insufficient bone height. Maxillary sinus floor augmentation procedures aim to obtain enough bone with an association between biomaterials and autogenous bone. PURPOSE: The purpose of this study was to evaluate histomorphometrically two grafting materials (calcium phosphate and Ricinus communis polymer) used in maxillary sinus floor augmentation associated with autogenous bone. MATERIALS AND METHODS: Biopsies were taken from 10 consecutive subjects (mean age 45 years) 10 months after maxillary sinus floor augmentation. The sinus lift was performed with a mixture of autogenous bone and R. communis polymer or calcium phosphate in a 1:2 proportion. Routine histologic processing and staining with hematoxylin and eosin were performed. RESULTS: The histomorphometric analysis indicated satisfactory regenerative results in both groups for a mean of bone tissue in the grafted area (44.24 +/- 13.79% for the calcium phosphate group and 38.77 +/- 12.85% for the polymer group). Histologic evaluation revealed the presence of an inflammatory infiltrate of mononuclear prevalence that, on average, was nonsignificant. The histologic sections depicted mature bone with compact and cancellous areas in both groups. CONCLUSION: The results indicated that both graft materials associated with the autogenous bone were biocompatible, although both were still present after 10 months.

Histomorphometrical analysis of bone formed after maxillary sinus floor augmentation by grafting with a combination of autogenous bone and demineralized freeze-dried bone allograft or hydroxyapatite.

BACKGROUND: Maxillary sinus floor augmentation procedures are currently the treatment of choice when the alveolar crest of the posterior maxilla is insufficient for dental implant anchorage. This procedure aims to obtain enough bone with biomaterial association with the autogenous bone graft to create volume and allow osteoconduction. The objective of this study was to histologically and histometrically evaluate the bone formed after maxillary sinus floor augmentation by grafting with a combination of autogenous bone, from the symphyseal area mixed with DFDBA or hydroxyapatite. METHODS: Ten biopsies were taken from 10 patients 10 months after sinus floor augmentation using a combination of 50% autogenous bone plus 50% demineralized freeze-dried bone allograft (DFDBA group) or 50% autogenous bone plus 50% hydroxyapatite (HA group). Routine histological processing and staining with hematoxylin and eosin and Masson's trichrome were performed. RESULTS: The histomorphometrical analysis indicated good regenerative results in both groups for the bone tissue mean in the grafted area (50.46+/-16.29% for the DFDBA group and 46.79+/-8.56% for the HA group). Histological evaluation revealed the presence of mature bone with compact and cancellous areas in both groups. The inflammatory infiltrate was on average nonsignificant and of mononuclear prevalence. Some biopsies showed blocks of the biomaterial in the medullary spaces close to the bone wall, with absence of osteogenic activity. CONCLUSIONS: The results indicated that both DFDBA and HA associated with an autogenous bone graft were biocompatible and promoted osteoconduction, acting as a matrix for bone formation. However, both materials were still present after 10 months.

Avaliação do comportamento de quatro biomateriais associados a enxertos ósseos autógenos nos procedimentos cirúrgicos de elevação de seio maxilar. Estudo histomorfométrico em humanos / Evaluation of the behavior of 4 different biomaterials associated with autogenous bone graft in the sinus procedures. A histomorphometric study in humans

O objetivo deste trabalho foi estuda, histológica e histométricamente, o comportamento de enxertos ósseos e biomateriais, utilizados para aumento de altura óssea em cavidade sinusal de humanos. Para tanto, foram selecionados 20 pacientes e divididos em quatro grupos que após obtenção do material de enxerto da região de sínfise mentoniana, receberam o seguinte tratamento: Grupo GI, após elevação do assoalho da cavidade sinusal receberam associação de osso autógeno e osso desmineralizado, seco e congelado (Dembone), Grupo GII, receberam após elevação do assoalho da cavidade sinusal associação de osso autógeno e hidroxiapatita (Osteogen), Grupo III, receberam associação do osso autógeno e polímero vegetal osteointegrável (Poliquil), após elevação da cavidade sinusal e Grupo GIV, após elevação do assoalho do seio maxilar receberam associação do osso autógeno cimento de fosfato de cálcio (Bone Source). Os pacientes de cada condição experimental permaneceram, durante o período de 10 meses, sem receber...

Manifestações bucais de doenças infecciosas na infância / Oral manifestations of infectious diseases in childhood

Durante a infância a ocorrência de doenças sistêmicas, tais como: escarlatina, roséola, rubéola, caxumba e sarampo, são comuns e não representam risco à saúde geral da criança, desde que seja feito um diagnóstico imediato e tratamento correto. Essas doenças têm importância para o cirurgião-dentista, pois sua ocorrência primária na cavidade bucal, pode auxiliar na sua detecção e conduzir à uma terapêutica adequada, evitando possíveis complicações

Implante de hidroxiapatita em alvéolos dentais: estudo histopatológico em ratos / Hydroxyapatite implants in dental sockets: histopatological study in rats

O objetivo deste trabalho foi estudar histopatologicamente o comportamento de uma hidroxiapatita implantada em alvéolos dentais de ratos. Para tanto, foram utilizados 40 ratos machos (Rattus norvegicus, albinus, Holtzman) divididos em dois grupos que, após exodontia do incisivo superior direito, receberam o seguinte tratamento: grupo G1, controle (näo tratado), e grupo G2, implante de hidroxiapatita particulada (64 µm). Os animais de cada condiçäo experimental foram sacrificados em grupos de quatro aos 4, 7, 15, 24 e 60 dias pós-operatórios, sendo os espécimes submetidos à tramitaçäo laboratorial de rotina para análise histopatológica. Os resultados mostraram que a hidroxiapatita testada produziu um atraso na cronologia do processo de reparo alveolar em comparaçäo aos animais controle, uma vez que menos tecido ósseo foi formado ao longo de todos os períodos. Além disso, o material utilizado apresentou compatibilidade biológica, pois foi integrado pelos tecidos ao longo do processo de reparo

Dentes supranumerários: revisão e relato de caso clínico / Supranumerary teeth: review and case report

Relato de caso clínico de extração de dente supranumerário localizado na região anterior da maxila em um paciente que apresentava diastema. De acordo com a discussão da técnica cirúrgica e oportunidade de tratamento foi concluído que é preferível a intervenção o mais precoce possível