Craniofacial analysis of the Tweed Foundation in Angle Class II, division 1 malocclusion Análise craniofacial da Fundação Tweed na maloclusão Classe II, divisão 1 de Angle

This study has defined the cephalometric values of the Craniofacial Analysis of the Tweed Foundation for a sample of Brazilian subjects. The sample consisted of 211 cephalometric radiographs from subjects aged 12-15, which were divided into two groups: Class II group, with 168 lateral teleradiographs (cephalograms) of white Brazilian subjects, with Angle Class II, division 1 malocclusion, of both genders (82 males and 86 females); and the Control Group, with 43 lateral teleradiographs (cephalograms) of subjects whose occlusion was clinically excellent, and also of both genders (21 males and 22 females). The teleradiographs were selected from the files of the Department of Orthodontics, School of Dentistry of Piracicaba, State University of Campinas, previously to the orthodontic treatment. The results demonstrated no sexual dimorphism for each group, as attested by the Student's t-test. The exploratory analysis (± 0.5 standard deviation) enabled the tolerance limits to be determined and a Craniofacial Analysis Table to be constructed using the respective cephalometric intervals. In addition, the difference between the two groups was not statistically significant according to the maxilla position. The maxilla was in a good position in relation to the cranial base. On the other hand, the mandible was retruded in relation to the cranial base in the Class II cases. The skeletal pattern was not defined because only the Facial Height Index (FHI) showed a vertical pattern in Class II subjects, while the Y Axis, SN.PlO, SN.GoMe and FMA values did not show any statistically significant difference between the groups. The Class II division 1 subjects showed lower incisors more labially tipped and a convex facial profile.A pesquisa definiu os valores cefalométricos da Análise Craniofacial da Fundação Tweed em amostra de brasileiros. O estudo constava de 211 telerradiografias tomadas previamente ao tratamento ortodôntico de indivíduos na faixa etária de 12 a 15 anos, as quais foram divididas em dois grupos: o Grupo Classe II, com 168 telerradiografias registradas em norma lateral de indivíduos leucodermas, maloclusão Classe II, divisão 1 de Angle, de ambos os gêneros (82 do gênero masculino e 86 do feminino); e o Grupo Controle, com 43 telerradiografias registradas em norma lateral de indivíduos com oclusão clinicamente excelente, também de ambos os gêneros (21 do gênero masculino e 22 do feminino). As telerradiografias foram selecionadas no arquivo da Disciplina de Or