Treatment of a Class III growing patient with mandibular prognathism and severe anterior crossbite / Tratamento de paciente Classe III em crescimento com prognatismo mandibular e severa mordida cruzada anterior

The treatment of growing patients with Class III skeletal pattern represents one of the greatest clinical challenges for the orthodontist. Several treatment protocols have been proposed, almost all involving rapid maxillary expansion and maxillary protraction. However, there are cases where the maxilla is properly positioned in the anteroposterior direction and there is no transverse discrepancy, featuring only a mandibular prognathism. In such cases, when there is a set of favorable factors such as lack of laterognathism and lower mandibular plane angle, a viable option and which could prove quite interesting is the use of orthodontic chin cup during the night, aiming at trying to redirect the forward growth of the mandible. To have success, it is necessary that this procedure involves pubertal growth spurt and is extended to full skeletal maturation. This case was presented to the board of the Brazilian Board of Orthodontics and Dentofacial Orthopedics (BBO) as part of the requirements to become a BBO Diplomate.

O tratamento de pacientes em crescimento com padrão esquelético de Classe III representa um dos maiores desafios clínicos para o ortodontista. Vários protocolos de tratamento têm sido propostos, quase todos envolvendo expansão rápida da maxila e protração maxilar. Porém, existem casos onde a maxila está corretamente posicionada no sentido anteroposterior e não há discrepância transversa, caracterizando apenas um prognatismo mandibular. Nesses casos, quando há um conjunto de fatores favoráveis, tais como ausência de laterognatismo e menor ângulo do plano mandibular, uma opção viável e que pode se mostrar bastante interessante é o uso noturno da mentoneira, com o objetivo de tentar redirecionar o crescimento anterior da mandíbula. Para que haja sucesso, é necessário que esse procedimento envolva o surto de crescimento da puberdade e seja estendido até a completa maturação esquelética. O presente caso clínico foi apresentado à diretoria do Board Brasileiro de Ortodontia e Ortopedia Facial (BBO), como parte dos requisitos para a obtenção do titulo de Diplomado pelo BBO.

Comparison of longitudinal treatment effects with facemask and chincup therapy followed by fixed orthodontic treatment on Class III malocclusion / 대한치과교정학회지

OBJECTIVE: The purpose of this study was to compare the longitudinal treatment effects of facemask with rapid maxillary expansion (FM/RME) and chincup (CC) therapy followed by fixed orthodontic treatment (FOT) in Class III malocclusion (CIII) patients. METHODS: The samples consisted of twenty-one CIII patients who had similar skeletal and dental characteristics before FM/RME or CC therapy and good retention results (Class I molar/canine relationship and positive overbite/overjet) after FOT (Group 1, FM/RME, n = 11; Group 2, CC, n = 10). Lateral cephalograms were taken before (T0) and after FM/RME or CC therapy (T1), and after FOT and retention (T2). Skeletal and dental variables were measured. Mann-Whitney U-test and Wilcoxon signed-rank test were used for statistical analysis. RESULTS: During T0-T1, FM/RME therapy induced forward movement of point A, and labioversion of the upper incisors. Both groups showed posterior repositioning of the mandible. FM/RME resulted in increase of the vertical dimension; however, CC caused an increase in articular angle and decrease in gonial angle. During T1-T2, both groups exhibited forward growth of point A. Group 1 showed forward growth and counterclockwise rotation of the mandible and increase of IMPA; however, Group 2, showed increase of ANS-Me/N-Me and decrease of overbite. CONCLUSIONS: The key factor for successful FM/RME and CC therapy and good retention results might be a harmonized forward growth of the maxilla that could keep pace with the growth and rotation of the mandible.

Relación esquelética clase III con factor genético predominante reporte de un caso / Relation skeletal class III with predominant genetic factor report of a case

Hace casi un siglo se tenía como acertada la idea que los patrones faciales eran inmodificables porel ser humano, porque la genética lo impedía. En la actualidad este pensamiento ha cambiado porlas mismas necesidades evolutivas, ya que el ser humano tiene influencias ambientales que puedenactuar sobre su crecimiento y gracias a la innovación de nuevos instrumentos para investigar. Unabordaje temprano de una relación Clase III ofrece ventajas que permiten modificar positivamenteel crecimiento y desarrollo general de un niño, contribuyendo no solo en el aspecto craneofacialsino también en el psicosocial por lo tanto se hace primordial un adecuado diagnóstico, tratamientoy pronóstico basado en la evidencia científica para de esta manera obtener resultados valiosos. Eneste artículo se reporta el caso de un niño evaluado durante seis años con relación esquelética ClaseIII con antecedente genético de importancia, manejado en una fase inicial con aparato ortopédico ymentonera y fase intermedia con tornillo de expansión tipo hyrax y máscara facial...

Almost a century ago it was accepted that facial patterns were genetically predetermined and notmodifiable. This concept has changed and it is now agreed that environmental influences can alsoaffect and alter growth patterns and thus early intervention of class III malocclusion offers advantagesthat allow a favorable modification of craniofacial growth with a positive psychosocial impact.This article presents a case report a six year old patient with class III skeletal malocclusion who wastreated initially with a chin cup and a functional appliance and further on with a palatal expansion witha hyrax appliance and maxillary protraction with a face mask...