正中埋伏多生牙对上颌中切牙根发育影响的CBCT测量分析

A CBCT study on the effect of impacted mesiodens on the root development of upper central incisors

目的:探讨正中埋伏多生牙对上颌中切牙根发育的影响。方法:统计4 576名患者中不同区域多生牙的发病率及上颌正中多生牙的临床特征,测量正中多生牙埋伏组(n=35例,70个牙)、萌出后拔除组(n=33例,66个牙)、埋伏早期拔除组(n=24例,48个牙)以及无正中多生牙组(对照组)(n=45例,90个牙)上颌中切牙发育完成后的牙根长度、牙冠长度、冠根比及弯根数目,并进行统计学分析。结果:(1)4 576名患者中,有176名(4.72%)发现上颌正中多生牙,其中男127例,女49例;71.02%的正中多生牙有阻生,83.5%的正中多生牙导致前牙区错牙合畸形;(2)中切牙牙根长度,埋伏组及拔除组均较对照组短(P<0.05),但埋伏组与拔除组相比差异不明显(P>0.05);埋伏组中切牙弯根例数较其他组多(P<0.05)。结论:正中埋伏多生牙使上颌中切牙的牙根长度变短,且弯根数目增多;早期手术拔除埋伏多生牙使上颌中切牙的牙根长度稍有变短;自行萌出的正中多生牙拔除后对上颌中切牙的牙根发育无明显影响。

AIM： To explore the influence of the mesiodens on the root development of the maxillary central incisors.METHODS： The incidence rate of supernumerary teeth and the clinical characteristics of the mesiodens in 4,576 patients were studied.The root length, crown length, crown/root ratio and the number of curved roots of the maxillary central incisors were measured in the group of impacted mesiodens（n=35 cases, 70 teeth）, the group after removal of the erupted mesiodens（n=33 cases, 66 teeth）, the group of the mensiodens removed by surgery（n=24 cases, 48 teeth） and the control group with no mesiodens（n=45 cases, 90 teeth）.Data were analyzed by SPSS 18.0 statistical software.RESULTS： ① The mesiodens was found in 176 out of the 4, 576 patients （4.72%）, 127 in the males and 49 in the females.71.02% of the mesiodens were impacted, and 83.5% of the mesiodens were followed by anterior teeth malocclusion.② The root length of the incisors in the group of impacted mesiodens and the group of mensiodens removed by surgery was shorter than that in the control group, however, no significant difference was found between former 2 groups.Significantly more curved roots of the incisors were found in the impacted group than in other groups（P〈0.05, among the other groups, P〉0.05）.CONCLUSION： The roots of maxillary central incisors are shortened and the curved roots are increased in the patients with impacted mesiodens.The removal of impacted mesiodens has a shorten effect on the root development of central incisors.Extraction of the impacted or erupted mesiodens does not affect the root development of maxillary central incisors.