Avaliação Cefalométrica das Alterações Verticais em Indivíduos com Mordida Aberta Anterior com Padrão Basal de Classe II de Acordo com os Tipos Faciais

Abstract

Objecti ve: To compare diff erent verti cal measurements in Class II subjects with anterior open bite between the neutroverted and retroverted facial types and to identi fy which bone structure (maxilla and/or mandibula) is more related to open bite malocclusion based on the reference values of Rickett s and Schwarz analyses. Method: Based on the orthodonti c documentati on fi les of the Paulista University (UNIP) Specializati on Course (São Paulo, SP, Brazil), 300 lateral teleradiographs were selected from subjects of both genders aged 8 to 13 years, who presented decreased overbite (≤ 1mm), which was the initi al inclusion criterion. The teleradiographs were selected according to Schwarz's Class II patt ern and according to Rickett s's facial type, as follows (n=15): Group 1: neutroverted and Group 2: retroverted. The cephalograms were drawn from the teleradiographs. For each group, the following cephalometric variables were measured: denti ti on height, maxillary height, total facial height, palatal plane inclinati on (palatal plane/Frankfurt plane), mandibular plane angle, mandibular arch and cranial basal angle (BaNa)/ palatal plane. The data were stati sti cally analyzed by the Student's t-test (5%). Results: There were stati sti cally signifi cant diff erences between the groups (p<0.05) for the variables denti ti on height, total facial height, mandibular plane angle and mandibular arch between the groups. The groups had stati sti cally similar results (p>0.05) only for the variables relati ve to the palatal plane. Conclusion: Both the maxilla (represented by the palatal plane), due to its anti clockwise rotati on, and the mandible, due to its clockwise rotati on, are involved in the occurrence of malocclusion and the retroverted facial type presents more severe cephalometric characteristi cs of open bite. Objeti vo: Avaliar comparati vamente diferentes medidas verti cais em indivíduos Classe II basal com mordida aberta anterior entre os ti pos faciais neutro e retroverti dos, bem como identi fi car qual estrutura óssea (maxila e/ou mandíbula) está mais relacionada à má-oclusão de mordida aberta, baseado nos valores de referência das análises de Rickett s e Schwarz. Método: A parti r do acervo de documentação ortodônti ca do curso de Especialização da Universidade Paulista (UNIP), São Paulo/SP, foram selecionadas 300 telerradiografi as, em norma lateral, de indivíduos de ambos os sexos, com idade variando entre 8 e 13 anos, que apresentavam trespasse verti cal diminuído (≤ 1mm), sendo este o critério de inclusão inicial. As telerradiografi as foram selecionadas segundo o padrão basal de Classe II, segundo Schwarz e de acordo com o ti po facial, segundo Rickett s, sendo (n=15): Grupo 1-neutroverti do, Grupo 2-retroverti do. A parti r das telerradiografi as foram traçados os respecti vos cefalogramas. Para cada grupo foram mensuradas as seguintes grandezas cefalométricas: altura da denti ção, altura maxilar, altura facial total, inclinação do plano palati no (plano palati no/plano de Frankurt), ângulo do pl...