恒牙牙冠与牙根长度发育完成时间及性别差异探讨

Radiographic study of the age for crown and root length completion stages of permanent teeth in male and female children

目的:确定不同恒牙(除第三磨牙外)的牙冠与牙根长度的发育完成时间,探讨牙冠与牙根长度发育完成时间的性别差异。方法:选择3304例3~18岁儿童与青少年全口曲面体层片,应用Haavikko法分别记录每个恒牙的发育分期,采用SPSS 25.0软件包计算男女不同恒牙的牙冠与牙根长度发育完成时间的中位数,利用Mann-whitney U检验进行男女性别间差异比较。结果:中切牙和第一磨牙的牙冠发育完成时间无性别差异,P值分别为0.143(上颌中切牙)、0.122(上颌第一磨牙)、0.191(下颌中切牙)和0.558(下颌第一磨牙),其余牙女性均显著早于男性。上颌中、侧切牙、第二前磨牙和第二磨牙的牙根长度发育完成时间无性别差异,P值分别为0.057、0.130和0.294;下颌中,第二前磨牙和第二磨牙的牙根长度发育完成时间无性别差异,P值分别为0.428、0.057;上、下颌其余牙牙根长度发育完成时间女性均显著早于男性。结论:恒牙牙冠与牙根长度发育完成时间女性普遍早于男性,上、下颌恒牙牙冠与牙根长度发育完成时间的性别差异相似。

PURPOSE: To determine the age medians for crown and root length completion stages of permanent teeth(except for the third molars) and to study gender differences in crown and root length completion stages by radiographic examinations. METHODS: The development of permanent teeth(except for the third molars) was evaluated from 3304 panoramic radiographs of children aged between 3 and 18 years by Haavikko’s method. Statistical analysis was performed using SPSS 25.0 software package. Age medians for crown and root length completion stages of permanent teeth were calculated. Gender differences were analyzed by Mann-Whitney U test. RESULTS: There were no significant gender differences in crown completion stages of central incisor and first molar, of which P values were 0.143(for maxillary central incisor), 0.122(for maxillary first molar), 0.191(for mandibular central incisor) and 0.558(for mandibular first molar), while girls were found to be ahead of boys for crown completion stages of other teeth. In maxilla, girls were found to be ahead of boys for root length completion stages except for lateral incisor, second premolar and second molar, of which P values were 0.057, 0.130 and 0.294;in mandible, except for second premolar and second molar, girls were observed to be ahead of boys for root length completion stages, of which P values were 0.428 and 0.057.CONCLUSIONS: It is concluded that girls are advanced than boys for crown and root length completion stages in most teeth. There is a similarity in gender differences for crown and root length completion stages between maxilla and mandible.