Eruption of permanent first molar and central incisor in Zhenghe,Fujian Province:a clinical investigation

AIM:To investigate the eruption of permanent teeth of children in Zhenghe County.METHODS:Three hundred and fifty-two children between 3 and 8 years old in Zhenghe County,Fujian Province were included in this study.Dental models were obtained and the eruption of permanent first molars and central incisors were analyzed.RESULTS:The maxillary and mandibular permanent first molars and the mandibular permanent central incisors mainly erupt in 7 year old children.The maxillary permanent central incisors mainly erupt in 8 year old children.No significant differences in the eruption rate between the male and the female or between the right side and the left side of teeth were observed,except that the rate of eruption of mandibular permanent central incisors in male was significantly higher than that in female.CONCLUSION:We should pay attention to the long time span of permanent first molars and mandibular permanent central incisor's eruption.The findings seem to be different from studies conducted in other parts of China and it suggests that there might be demographical differences in the eruption of teeth.