［］1()0()-1182(201®02-0177-04人下颌恒切牙管间峡区解剖的显微CT研究刘成霞I李文2郑庆华I耿宁I孙拓祺I黄定明$(1•口腔疾病研究国家重点实验室，四川大学；2.四川大学华西口腔医院牙体牙髓病科，四川成都610041)［摘要］目的研究人离体下颌恒切牙管间峡区的解剖学特点。方法选择离体下颌恒切牙拍摄近远中向X线片,选出双根管牙33颗，对距根尖6mn】以内的牙根组织进行显微CT扫描。扫描层片2(川叫每颗牙齿获得扫描截面30()个。通过三维重建观察牙根管间峡区的解剖形态。记录距根尖1、2、3、4、5、6mm处各截面根管数目及管间峡区的出现情况，并测量根管壁的最小厚度。结果所有双根管下颌恒切牙都存在管间峽区，完全峡区占49.7%,部分峡区占4.5%。距根尖6mm内各截面管间峡区的岀现率为10・0%~85.5%,卡方检验显示距根尖I〜6mrn处管间峡区岀现率的差异有统计学意义(/—().()()1)。距根尖3~6nw处管间峡区出现率较高，以5mn.it最高，为85.5%。距根尖6mm以内的根管壁最小厚度均小于().5rnnio结论下颌恒切牙管间峡区的出现率较高，根管壁最小厚度位于峡部,在临床进行根管治疗和牙髓外科手术时应引起重视。［关键词］根管解剖；下颌切牙；管间峡区；根管壁厚度［］R781［文献标志码］A［doi］10.3969/j.issn.1000-1182.2010.02.016AnatomicstudyofcanalisthmusesofmandibularpermanentincisorsbyMicro-CTLIUCheng-xia\LIWen2,ZHENGQing-hua'、GENGSUNTuo-qi\HUANGDing-ining2.(1.StaleKeyLaboratoryofOralDis-eases,SichuanUniversity,Chengdu610041,China;2.Dept,ofConservativeDentistryandEndodontics^WestChinaCollegeofStomalolog)\SichuanUniversity,Chengdu610041,Chinci)[Abstract]ObjectiveToinvestigatetheanatomicfeatureofthecanalisthmusofmandibularpermanentincisorsbyMicro-CT.MethodsThirtv-thrccmandibularpcrinanentincisorswithtwocanalswereselectedthroughtheradiographinproximalview・TheseteethwerethenscannedusingMicro-CTandreconstructed.Thescanninglayerthicknesswas20pum.Weobsen'edtheapical6mmofthe33roots,and300sectionsweregainedeachtooth・givingatotalof9900sections・Thenumbersofcanalsateachlevelinlheapical6mmwererecorded.Thenum-l>ersofsectionsshowingisthmusesateachleveloftherootcanalswererecordedSo.DntawereanalyzedusingtheChi-squarestatistictotestthenullhypothesisthatlocationofthesectionsineachoftheapical6mmandpresenceoftheisthmuswereindependent.Theininiinumrootcanalwallthicknesswasmeasuredineachoftheapical6mmofllieroots・ResultsIsthmuseswerefoundtobe[)resentalalllevelswilhprevalencefrom10.0%to85.5%・TheChi-squaretestindicatedasignificantdifferenceinthedistributionofisthmuseswithsection(P=0.001).Theincidenceofisthmuseswashigherattheapical3-6mmlevel,andthehighestincidence(85.5%)wasat5mmlevel.Thereweremanymoresectionscontainingcompleteisllimuscs(49.7%)thanthoseconlainingpartialislhniuses(4.5%)・Thethicknessoftherniniinumrootcanalwaslessthan0.5mm.ConclusionTlieinandibularincisorshaveahighincidenceofisthmusandarenarrowinproximaldirection.Debridementoftheisthmusisamajorchallengeduringsurgicalandnonsurgicalrootcanaltreatment.[Keywords]canalanatomy;mandibularincisor；canalisthmus；rootcanalwallthickness管间峡区是位于同一牙根内的、两根管之间含有牙髓或牙攏生成组织的狭窄带状结构叫也可认为是存在于两根管间的交通支、侧向连接或横向吻［收稿日期］2009-07-25;［修回日期］2009-10-27［皋金项冃1国家“十五”科技攻关计划资助项冃(2004BA720A23)［作者简介］刘成霞(1981-),女，山东人，硕士［通讯作者］黄定明,Tel:028-85501439合R%任何含有双根管的牙根都可能存在管间峡区叫研究表明，下颌切牙双根管的发生率为11.5%〜44.1%。牙齿从外部解剖结构到根管系统均可因种族、个体等因素不同而存在差异。牙根内管间峡区的发生率可以随着牙齿的根管类型和不同...