【摘要】 目的通过使用锥形束CT研究下颌第一恒磨牙远舌根根管口的位置。方法使用锥形束CT(Cone-Beam CT以下简称CBCT)观察随机选取符合标准的541名患者(男302名,女241名),年龄18-70岁,获得811颗下颌第一恒磨牙。其中获得具有远舌根的下颌第一恒磨牙222颗。根据年龄将其分为青年组(A组),中年组(B组),老年组(C组)。其中青年组77颗,中年组74颗,老年组71颗。使用CBCT在髓室底观察、测量下颌第一恒磨牙远舌根根管口(distal lingual root canal orifice以下简称DLO)的位置,各组DLO的钙化情况。结果下颌第一磨牙远舌根总发生率为27.37%,A组发生率为26.92%,B组为28.35%,C组发生率为26.89%。近舌根根管口(mesiallingualrootcanalorifice以下简称MLO)和DLO的连线平均距离为3.47±0.58 mm,远颊根根管口(distal buccal root canal orfice以下简称DBO)根管口与DLO连线平均距离为3.60±0.65 mm,近颊根管口(mesial buccal root canal orifice以下简称MBO)与DLO连线平均距离为4.66±0.71 mm。MLO到DLO的连线与DLO到DBO连线形成交角为∠MLO-DLO-DBO,∠MLO-DLO-DBO平均角度为86.22°+10.09°。有4颗下颌第一恒磨牙DL根管口在髓室底水平出现继发性牙本质。结论 CBCT是一个有效的观察下颌磨牙远中舌根形态的工具,可以进一步了解DL根管口的位置,为根管治疗提供了可靠的参考依据。更多还原

【Abstract】 Objective This study determined the prevalence of permanent threerooted mandibular first molars and their morphology among a anhui population by using cone-beam computed tomography(CBCT).Methods The use of CBCT was observed in 811 cases of mandibular ?rst molar root canal morphology of 541 patients.Select the three rooted mandibular ?rst molar distalingual root(222 cases).The patients ages ranged form18 to30 y(group A),31 to 50 y(group B),51 to 70 y(group C).Group A were collected 77 cases.Group B were collected74 cases.Group Cwere collected 71 cases.The number of root canals in distallingual root ot mandibular ?ret molar were investigated.The incidence and location of distal lingual root canal ori?ce(DLO) were investigated at the level of ? oor of pulp champer,the position of DLO,the number of DL cal?cation and thicknessof cal?cation denin were calculated at same level.Results The prevalence of permanent three-rooted mandibular ?rst molars was 27.37%.The incidence of group A was 26.92%.The incidence of group B was 28.35%.The incidence of group C was 26.89%.The mean distances from the MLO to the DLO,MBO to the DLO,and MBO to the DLO of the permanent threerooted mandibular molars were 3.47+0.58 mm,3.60+0.65 mm,and4.66+0.71 mm.The angle of cut MLO-DLO and DL O–DBOwas 86.22°±10.09°.It found 4 calci?ed dentin in DL cannal ori?ce at thelevel o ? oor of pulp champer.Conciusion CBCT is an effective tool for the detection of additional distolingual roots and it is a valuable aid for dentists providing root canal treatment.CBCT can observe the location of the DL root canal ori?ce,provides a reliable reference basis for root canal treatment.更多还原