云南地区人群下颌第一前磨牙、第二前磨牙和第一恒磨牙根管解剖形态的锥形束CT分析

Use of cone-beam computed tomography to evaluate root canal morphology of mandibular first premolar,second premolar and first permanent molar in Yunnan individual

目的利用锥形束CT(CBCT)分析云南地区人群下颌第一前磨牙、第二前磨牙和第一恒磨牙根管解剖形态,为临床根管治疗提供理论依据和参考。方法根据年龄(20~29岁、30~39岁、40~49岁、50~59岁)分层抽取2017年1月至2018年1月在昆明医科大学附属口腔医院放射科进行CBCT检查的患者的数据资料各100例。400例患者中有324例CBCT数据资料符合标准,其中男166例、女158例,年龄20~29岁82例、30~39岁82例、40~49岁82例、50~59岁78例。统计分析下颌第一前磨牙、第二前磨牙和第一恒磨牙的根管数目、根管长度和根管弯曲度,并对不同年龄段根管长度、下颌第一磨牙牙尖到根分叉距离及根尖孔到下颌神经管距离数据进行单因素方差分析,对不同性别下颌第一磨牙牙尖到根分叉距离及根尖孔到下颌神经管距离数据进行独立样本t检验。结果通过对324例患者CBCT影像资料的分析得出,下颌前磨牙基本为单根管(647/648颗),仅见1例右下第一前磨牙双根管。下颌前磨牙弯曲度以一级弯曲(5°~10°)和二级弯曲(10°~25°)为主,前磨牙根管长度大多处于正常范围(15~25 mm),下颌第一恒磨牙弯曲度近远中根均以二级弯曲(10°~25°)为主,下颌第一恒磨牙牙尖到根分叉的距离随年龄增长变短(F左侧=11.16,P左侧<0.001;F右侧=11.51,P右侧<0.001),男女性别差异无统计学意义(t左侧=1.31,P左侧=0.19;t右侧=0.51,P右侧=0.61);下颌第一恒磨牙根尖孔到下颌神经管的距离随年龄增长变长(F左侧=7.03,P左侧<0.001;F右侧=12.25,P右侧<0.001),男女性别差异无统计学意义(t左侧=-0.64,P左侧=0.52;t右侧=-0.11,P右侧=0.91)。结论本研究中云南地区人群下颌前磨牙根管解剖形态相对简单;下颌第一恒磨牙根管解剖形态复杂,云南地区人群下颌前磨牙、第一恒磨牙根管解剖系统与其他地区相比有所差异,但增龄性变化无区别,CBCT可为临床根管治疗提供依据。

Objective To observe and analyze the root canal anatomy of mandibular first premolar,second premolar and first permanent molar in Yunnan province by using cone-beam computed tomography(CBCT),and to provide theoretical basis and reference for clinical root canal therapy.Methods 400 patients were selected by stratified sampling based on the age(100 cases aged 20-29,100 cases aged 30-39,100 cases aged 40-49,and 100 cases aged 50-59)from January 2017 to January 2018 at theDepartment of radiology of Yunnan stomatological hospital.CBCT data of 324 patients met the standard,including 166 males and 158 females,from which 82 cases aged 20-29,82 cases aged 30-39,82 casesaged 40-49,and 78 cases aged 50-59.The number,length and curvature of root canals of mandibular firstpremolar,second premolar and first permanent molar was analyzed.The data of root canal length,thedistance from the dental cusp of mandibular first permanent molar to the root bifurcation and the distancefrom the apical foramen to the mandibular cannal of different age were analysed by single factor analysis ofvariance.The data of the distance from the dental cusp of mandibular first permanent molar to the rootbifurcation and the distance from the apical foramen to the mandibular cannal of different gender wereanalysed by independent samplet test.ResultsCBCT images of 324 patients showed that the mandibularpremolars were basically single root canal(647/648),and only one case of right mandibular first premolarwith 2 root canals.The curvature of mandibular premolars were mainly levelⅠ(5°,10°)and levelⅡ(10°,25°).The length of root canal of mandibular first permanent molars were mostly in the normal range(15~25 mm).The curvature of mandibular first permanent molars were mainly levelⅡ(10°,25°).Thedistance from the dental cusp of mandibular first molar to the root bifurcation became shorter and shorterwith age(Fleft=11.16,Pleft<0.001;Fright=11.51,Pright<0.001),there was no statistically significantdifference between male and female(tleft=1.31,Pleft=0.19;tright=0.51,Pright=0.61).The distance from theapical foramen of mandibular first molar to the mandibular canal increased with age(Fleft=7.03,Pleft<0.001;Fright=12.25,Pright<0.001).There was no statistically significant difference between male andfemale(tleft=-0.64,Pleft=0.52;tright=-0.11,Pright=0.91).Conclusions The root canal variation ofmandibular first premolar were less complex than others,the root canal anatomy of mandibular firstpermanent molar were complex.Compared with other regions,the root canal anatomical system of the firstpermanent molar and premolars of the mandibular in Yunnan is different,but there is no difference inaging.CBCT can provide an evidence for root canal therapy.