Eruption times of permanent teeth and the relationship between the eruption of permanent teeth and the growth status of children and young adolescents in China Xi'an

Objective:To determine the age and sequence of eruption of permanent teeth, as well as, the relationship between the eruption of permanent teeth and the growth status of children and adolescents in Xi'an, China.Method:Cross-sectional data on permanent teeth eruption were collected by examining pre-school, primary and secondary school children of 2～17 years of age. The subjects were drawn by multistage random sampling from the school registers. There were 6755 subjects in the sample, 3637 boys and 3118 girls. The data were subjected to probit regression analysis. Result: The median age of eruption of each tooth was earlier in girls than in boys. Although the range of years during which the permanent teeth erupted was similar in both sexes, i.e. 6～12 years, the sequence of the tooth eruption differed. All mandibular teeth, with the exception of first and second premolars in both males and females, tended to erupt earlier than their maxillary counterparts.Conclusion:The findings seem to be different from earlier studies done in the other parts of China.