基于锥形束CT的多生牙新分类方法临床意义研究

Clinical significance of new classification of supernumerary teeth by CBCT

目的应用锥形束CT(cone-beam CT,CBCT)对多生牙进行新的临床分类,并分析新分类方法的临床意义。方法收集2016—2019年首都医科大学附属北京友谊医院口腔科的CBCT影像资料5100例,其中多生牙患者209例,共计多生牙278颗。应用CBCT对多生牙进行新的临床分类,包括萌出型、骨埋伏高位型、骨埋伏低位型、骨埋伏复杂型和牙弓外型,并分析其临床意义。结果(1)临床资料分析:多生牙发生率为4.1%,其中有1颗多生牙的患者占76.6%,有2颗多生牙的患者占19.1%,有3颗及以上多生牙的患者占4.3%。多生牙好发部位依次为:上颌切牙区、上颌磨牙区、下颌尖牙及前磨牙区、上颌尖牙及前磨牙区、下颌磨牙区。34.9%的多生牙对邻近恒牙产生了继发影响,以萌出错位及阻生为主,主要发生在上颌切牙区。(2)新分类方法的临床意义分析:上颌切牙区多生牙以骨埋伏低位型及萌出型为主,尖牙、前磨牙及磨牙区多生牙以萌出型为主。不同类型多生牙对邻近恒牙产生继发影响的发生率不同或不全相同(χ2=26.057,P<0.001),提示对邻近恒牙易产生继发影响的多生牙类型依次为:萌出型、骨埋伏复杂型、骨埋伏高位型、牙弓外型、骨埋伏低位型。结论基于CBCT的多生牙新分类方法简单实用,其中萌出型、骨埋伏复杂型及骨埋伏高位型多生牙更易产生错畸形,建议尽早拔除多生牙、定期随访,必要时正畸治疗。

Objective The make new classification of supernumerary tooth based on cone-beam CT(CBCT)and to analyze its clinical significance.Methods Retrospectively analyze 5100 patients who were examined by CBCT in Department of Stomatology from 2016—2019,and 209 patients with 278 supernumerary teeth were found.The supernumerary teeth were newly classified as eruption type,higher impacted type,lower impacted type,complicated impacted type and outlying type.Its clinical significance was analyzed.Results(1)Clinical data analysis:the incidence of supernumerary tooth was 4.1%.About 76.6%of the patients had 1 supernumerary tooth,19.1%had 2,and 4.3%had 3 or more.The most common sites were as follows in turn:maxillary incisors,maxillary molars,mandibular canines and premolars,maxillary canines and premolars and mandibular molars.Secondary effect was found in 34.9%of the supernumerary teeth on the adjacent permanent teeth,mainly in the incisor area.The mainly effect was dislocation eruption and being impacted.(2)The clinical significance analysis of the new classification method:lower impacted type and eruption type were mainly in maxillary incisors,and eruption type were mainly in canine,premolars and molars area.The incidence of secondary effects of different types of supernumerary teeth on adjacent permanent teeth was different(χ~2=26.057,P<0.001).The order of the types of supernumerary teeth which had secondary effects on adjacent permanent teeth were:eruption type>complicated impacted type>higher impacted type>outlying type>lower impacted type.Conclusion The new classification of supernumerary teeth based on CBCT imaging is easy and practical.The eruption type,complicated impacted type and higher impacted type of supernumerary teeth are more prone to malocclusion,so they should be extracted as soon as possible and be followed up regularly,and orthodontic treatment should be performed if necessary.