Changes in skeletal and dental relationship in Class II Division I malocclusion after rapid maxillary expansion: a prospective study

OBJECTIVE: To assess skeletal and dental changes immediately after rapid maxillary expansion (RME) in Class II Division 1 malocclusion patients and after a retention period, using cone beam computed tomography (CBCT) imaging. METHODS: Seventeen children with Class II, Division 1 malocclusion and maxillary skeletal transverse deficiency underwent RME following the Haas protocol. CBCT were taken before treatment (T1), at the end of the active expansion phase (T2) and after a retention period of 6 months (T3). The scanned images were measured anteroposteriorly (SNA, SNB, ANB, overjet and MR) and vertically (N-ANS, ANS-Me, N-Me and overbite). RESULTS: Significant differences were identified immediately after RME as the maxilla moved forward, the mandible moved downward, overjet increased and overbite decreased. During the retention period, the maxilla relapsed backwards and the mandible was displaced forward, leaving patients with an overall increase in anterior facial height. CONCLUSION: RME treatment allowed more anterior than inferior positioning of the mandible during the retention period, thus significantly improving Class II dental relationship in 75% of the patients evaluated. .

OBJETIVO: avaliar, por meio de imagens de tomografia computadorizada de feixe cônico (TCFC), as mudanças esqueléticas e dentárias, imediatas e após 6 meses de contenção, causadas pela expansão rápida da maxila (ERM) em pacientes com má oclusão de Classe II, divisão 1. MÉTODOS: dezessete crianças com má oclusão de Classe II, divisão 1, e deficiência transversal da maxila, foram submetidas a ERM, de acordo com o protocolo proposto por Haas. TCFC foram realizadas antes da ERM (T1), imediatamente após a fase ativa (T2) e após 6 meses de contenção (T3). Alterações anteroposteriores (SNA, SNB, ANB, overjet e RM) e verticais (N-ANS, ANS-Me, N-Me e overbite) foram analisadas. RESULTADOS: imediatamente após a ERM, enquanto a maxila se deslocou para frente, a mandíbula se movimentou para frente e para baixo, aumentando o overjet e diminuindo o overbite. Durante o período de contenção, a maxila retornou para posterior e a mandíbula deslocou em direção anterior, aumentando a altura facial anterior. CONCLUSÃO: a realização da ERM permitiu que a mandíbula se posicionasse mais anteriormente do que inferior durante o período de contenção, melhorando a relação molar de Classe II em 75% dos pacientes avaliados. .

Tratamento conservador de uma má oclusão Classe I de Angle, com atresia maxilar e apinhamento anterior / The conservative treatment of Class I malocclusion with maxillary transverse deficiency and anterior teeth crowding

Este artigo relata o tratamento de uma paciente do sexo feminino, com 15 anos de idade, má oclusão Classe I de Angle, severo apinhamento anterossuperior, desvio da linha média superior para o lado esquerdo e atresia maxilar, associada à mordida cruzada posterior. Os procedimentos executados envolveram a expansão maxilar com disjuntor palatino do tipo Haas modificado e montagem de aparelho fixo com sistema Edgewise standard. Foram realizados desgastes proximais nos incisivos e caninos inferiores para o alinhamento anterior, bem como redução da discrepância de Bolton com excesso inferior. Esse caso foi apresentado à diretoria do Board Brasileiro de Ortodontia e Ortopedia Facial (BBO), representando a categoria livre escolha, como parte dos requisitos para a obtenção do título de Diplomado pelo BBO.

This report describes the treatment of a 15-year-old female patient with Angle Class I malocclusion, severe maxillary anterior crowding, maxillary midline shift to the left, and maxillary atresia associated with posterior crossbite. The treatment consisted of palatal expansion using a modified Haas expander and placement of a standard Edgewise fixed appliance. Interproximal reduction was performed on mandibular incisors and canines to align anterior teeth, as well as to reduce Bolton discrepancy due to wide mandibular teeth. This case was submitted to the Committee of the Brazilian Board of Orthodontics and Facial Orthopedics (BBO) in the Free Case category as part of the requisites to obtain the BBO Diploma.

Fatores etiológicos do apinhamento de incisivos inferiores permanentes / Etiologic factors in crowding of the mandibular incisors

O apinhamento dos incisivos inferiores permanentes é a má-oclusão mais prevalente. No entanto, essa condição gera dúvidas aos profissionais relacionadas às suas causas e ao estabelecimento de um prognóstico de estabilidade do segmento ânteroinferior. Esta pesquisa bibliográfica teve como objetivo investigar os fatores etiológicos do apinhamento dos incisivos inferiores permanentes. Os autores admitem haver uma etiologia multifatorial para o apinhamento dos incisivos inferiores, envolvendo a ausência de desgaste devido à dieta moderna, a morfologia dos incisivos, o estágio de desenvolvimento dentário, a erupção dos terceiros molares e o crescimento mandibular residual, e a combinação desses fatores.

The mandibular crowding is the most prevalent type of malocclusion. However, this condition creates doubts about to the professionals related to its causes and the establishment of a prognostic of stability of the mandibular incisors. This literature review aims to find the various causes of the crowding of the permanent incisors lower. Most authors admit a multifactorial etiology for the crowding of incisors, involving the due to lack of wear from modern diet, the dental morphology, dental development stage, the eruption the third molars and growth mandibular later and combination of these factors. All these seem to influence the crowding, and that in each case there is the combination of one or more factors.

Assessment of flexural strength of two self-curing acrylic resins containing pigment

Aim: To assess the flexural strength of orthodontic acrylic resins from two different manufacturers (VIPI, OrtoCril versus Clássico, OrtoClas) by comparing pigmented resins to colorless ones. Methods: Resins of blue, yellow and green colors were studied. A total of 120 specimens were made and then divided into groups of 15 elements each, all having the same dimensions. Next, they were kept in aqueous medium until being subjected to mechanical testing. The flexural strength was tested in a universal test machine (EMIC DL 10000) in which the specimens were subjected to a gradual load until fracture occurred. Results: Pigmented resins had flexural strength values compatible with clinical use, being similar to those from colorless ones, except for OrtoClas green-colored and yellow-colored resins, which showed greater flexural strength. The OrtoClas green-colored resin was the most resistant to fracture (482.2 N), whereas the OrtoCril colorless resin was the least resistant (368.4 N). All OrtoClas resins showed higher strength values compared to OrtoCril resins of same color, except for the OrtoCril’s blue-colored resin, which presented higher flexural strength than that of the other trademark. Conclusions: The use of pigments seems to have no effect on decreasing the flexural strength of self-curing acrylic resins. Therefore, pigmented resins are compatible with clinical use.