Comparative study of the chronology of eruption of permanent teeth and calcification of second molars in Angle Class I and Class II malocclusions. / Estudo comparativo da cronologia de erupção dos dentes permanentes e da calcificação dos segundos molares nas más oclusões de Classe I e Classe II de Angle

AUTOR(ES)
DATA DE PUBLICAÇÃO

2003

RESUMO

The objective of this study was to compare the chronology of eruption of permanent teeth and the stages of calcification of the second molars in Angle Class I and Class II malocclusions, as well as to investigate if there is any correlation between these stages of calcification and the cephalometric measurements SNA, SNB, ANB, Co-A, Co-Gn. For evaluation of the chronology of eruption of permanent teeth (except for the third molars), 527 pairs of dental casts of young subjects aged 5 to 13 years old were employed, which were divided in two groups. Group 1 comprised dental casts presenting Angle Class I molar relationship, whereas Group 2 included those displaying an Angle Class II molar relationship. The mean age of eruption of the permanent teeth was determined by means of the Karber’s method. Comparison between groups was evaluated by the independent t test. For evaluation of the stages of calcification of the second molars and presence of correlation with the cephalometric measurements SNA, SNB, ANB, Co-A, Co-Gn, 60 panoramic radiographs and 60 lateral cephalograms of the same subjects were used, which had been obtained at 8 years old. These radiographs were also divided in two groups. Group 1 comprised radiographs of young individuals presenting Class I molar relationship, and Group 2 involved subjects with Class II molar relationship. The stages of calcification of the second molars were determined as suggested by Nolla. Comparison between groups was accomplished through the nonparametric Mann-Whitney’s test. The results demonstrated that, in general, individuals presenting Class I molar relationship presented earlier mean ages of eruption of the permanent teeth when compared to those subjects with Class II molar relationship. This difference was statistically significant for all second molars, as well as for the teeth 15, 23, 34 and 45. No statistically significant differences could be found between the stages of calcification of the second molars in the evaluated groups; moreover, there was no correlation between the cephalometric measurements analyzed and the stages of calcification for either group.

ASSUNTO(S)

malocusão de angle classe i molar erupção dentária maloclusão de angle classe ii dente permanente calcificação de dente

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