Clinical evaluation of different angulation radiograph in diagnosing distolingual root of the mandibular first molar

目的 评价不同投照角度X线根尖片诊断下颌第一磨牙远中舌根的作用.方法 选择需行根管治疗的205颗下颌第一磨牙为研究对象.术前拍X线正位根尖片及近中20°～30°偏位根尖片,对比分析是否存在远中舌根.术中根据根管的弯曲情况把远中舌根分为3类.记录下颌第一磨牙牙根和根管的数量.结果 术前X线正位、近中偏位根尖片判断48颗(48/205)下颌第一磨牙存在远中舌根,临床治疗中均确定有远中舌根,其余157颗下颌第一磨牙术中均未见远中舌根.远中舌根发生率为23.41%.48颗下颌第一磨牙远中舌根中,Ⅰ类根管22颗(45.83%);Ⅱ类根管17颗(35.41%);Ⅲ类根管9颗(18.75%).205颗下颌第一磨牙106颗(51.70%)为3根管;98颗(47.80%)为4根管;1颗(0.48%)为5根管.结论 术前多角度根尖片能准确诊断下颌第一磨牙远中舌根.     

X线投照角度对诊断下颌第一恒磨牙远舌根变异的作用

目的:探讨X线投照角度对诊断下颌第一恒磨牙远舌根变异的作用。方法:从临床采集29个拔除的3根型下颌第一恒磨牙。X线数字化成像系统拍摄牙齿的颊舌向正位投照片、近远中向邻位片、近中20°及远中20°偏位投照片。以远舌根根尖是否被远颊根影像阻挡为标准,判断不同X线投照角度及投照组合对远舌根的显示效果。结果:远中20°偏位片显示远舌根的效果最佳,显示比例高达89.7%;近中20°偏位片显示比例为27.6%;正位投照片对远舌根显示比例最低,仅为17.2%。同时拍摄近中及远中20°偏位投照片,远舌根的显示比例可以达到100%。结论:临床上,远中20°偏位X线牙片对远舌根的诊断价值最高。     

X线投照角度对判断后牙颊舌向多根管的作用

目的探讨X线投照角度在判断多根管磨牙根管充填效果时的作用。方法选取存在近颊第二根管的上颌第一磨牙87颗、下颌第一磨牙105颗，拍摄术前X线片，完成根管治疗，术后分别拍摄X线正位投照片和远中偏位投照片，判断根充效果。结果X线正位投照片和远中偏位投照片能显示上颌第一磨牙MB与MB2的比例分别为23．0％和81．6％，显示下颌第一磨牙近中两根管的比例分别为38．1％和90．5％，X线远中偏位投照片显示颊、舌向根管的比例大于正位投照片（P〈0．005）。结论采用X线远中偏位投照法能更好地显示上、下颌第一磨牙颊舌向根管的充填效果。     

成都地区378颗中国人下颌第一恒磨牙远舌根的临床研究

目的:调查下颌第一恒磨牙远舌根的发现率及根管治疗情况。方法:收集下颌第一恒磨牙根管治疗的完整病例,包括病历记录和术前、术中、术后X线片,记录下颌第一磨牙远舌根发生的牙位、患者性别,统计下颌第一恒磨牙远舌根的发生率和治疗情况。结果:在378颗中国人下颌第一恒磨牙根管治疗病例中,下颌第一恒磨牙远舌根的发现率为26.98%(102/378),不同牙位和性别远舌根的发现率无统计学差异(P0.05)。在男性患者中,右侧远舌根发现率高于左侧(P0.05)。在下颌第一恒磨牙根管预备过程中,器械分离和根管侧穿发生率高于其它根管;在根管充填时,欠填率高于其它根管(P0.05)。结论:远舌根在下颌第一恒磨牙中有较高发现率,发生器械分离和根管侧穿以及欠填的比例高于其它根管。     

下颌第一恒磨牙远舌根的临床分析

目的调查下颌第一恒磨牙远舌根的发生率及根管治疗情况。方法临床收集378颗下颌第一恒磨牙根管治疗的完整病例,包括病历记录和术前、术中、术后X线片,记录下颌第一恒磨牙的牙根数目、根管数目及根管治疗情况。结果在378颗下颌第一恒磨牙中,远舌根的发生率为26.98％（102/378）,男、女患者和左、右侧远舌根的发生率均无统计学差异（P>0.05）。在根管治疗中,远舌根根管器械分离、侧穿和欠填的发生率高于其他根管（P<0.05）。结论远舌根在下颌第一恒磨牙中的发生率较高,发生器械分离、根管侧穿以及欠填的比例也高于其他根管。     

不同X线投照角度对下颌第一磨牙根管治疗的评价

目的探讨能清晰显示下颌第一磨牙全部根管的X线最佳投照角度,为根管治疗提供准确的信息。方法选取需行根管治疗且扩大针探查具有4个根管的下颌第一磨牙245例,完成根管治疗后,分别拍摄X线常规投照片、远中偏位投照片,判断所显示的根充效果。每颗牙拍摄角度分别为常规0°、远中偏30°、远中偏45°。由一个技师单独完成拍片,4位医师统一阅片,诊断牙根内的根管数目、形态及根管治疗情况。结果 X线常规投照片和远中偏30°位和45°位,显示下颌第一磨牙有四个根管的比例分别为36%、82%和95%。X线远中偏位投照片显示颊、舌向根管的比例大于常规投照片(P<0.001)。结论采用远中偏移30°～45°X线投照,能充分显示下颌第一磨牙的根管数目、形态,更好的评价根管治疗后根管显示情况。     

不同投照角度X线片诊断下颌第一前磨牙多根管的临床分析

目的探讨不同投照角度X线片在诊断下颌第一前磨牙多根管中的作用。方法选取需行根管治疗的88颗下颌第一前磨牙为研究对象。每颗患牙均拍摄术前X线正位、偏位投照片判断是否为多根管牙;K型锉探查和定位根管口,冠下法预备根管,冷侧压法充填根管,充填时记录根管形态及数量,并拍摄根管充填术后X线正位和偏位投照片,对根管进行分型。结果88颗下颌第一前磨牙中,术前X线片诊断多根管31颗,临床发现多根管30颗。术前X线诊断为多根管的31颗牙,临床治疗中3颗未定位到多根管;而术前诊断为单根管的2颗牙,在临床治疗中发现为多根管。术前正位X线片诊断多根管牙13颗,术前偏位X线片诊断多根管牙25颗,其中7颗牙的术前正位和偏位X线片均表现为多根管影像。下颌第一前磨牙多根管的临床发现率为34.09%（30/88）,其中Ⅳ、Ⅴ型根管为21颗,占多根管牙的70.00%。结论不同投照角度X线片有助于提高下颌第一前磨牙多根管的临床发现率。     

偏移投照技术与显微治疗诊治遗漏根管的疗效分析

目的分析根管治疗术后偏移投照技术与显微根管治疗的应用对遗漏根管的发现与治疗的临床疗效。方法选择需行初次牙髓治疗的下颌前牙、下颌前磨牙、下颌第一、二磨牙及上颌第一、二磨牙共360颗(分别为49、68、62、50、85、46颗)。常规拍摄术前正位根尖片,并于根治后拍摄正位及20°～30°偏位根尖片,通过对比分析,对可疑遗漏根管的患牙,在显微镜下寻找及治疗遗漏根管。结果经显微治疗,360颗患牙中25颗(6.9%)确诊为遗漏根管,各牙位依次为3、5、5、4、6、2颗,其中23颗患牙发现并成功充填遗漏根管,2颗根管可找到但不完全通畅;正位发现8颗(2.2%),偏位发现23颗(6.4%),术后偏移投照发现率明显高于正位(P<0.05)。结论根治术后偏移投照技术与显微根管治疗对遗漏根管的发现与治疗有较大的帮助。     

不同X线投照角度对下颌第一磨牙4根管分辨效果的临床分析

目的:探寻能使X线根尖片上清晰显示下颌第一磨牙全部根管的最佳投照角度,为临床治疗提供完全且准确的信息.方法:选取需行根管治疗且扩大针探查具有4个根管的下颌第一磨牙120例.每颗牙均拍摄诊断丝偏移投照片,拍摄角度分别为远中20°、远中10°、0°、近中10°、近中20°、近中30°.由3位观察者独立读片,诊断牙根内的根管数目及根尖清晰度.采用SPSS9.0软件包进行配对计数资料的X2检验.结果:近中30°对4根管的区分率为93.3%,近中20°对4根管的区分率为90.0%,均显著高于常规0°投照的40%(P<0.01).近中30°和近中20°所拍X线片的清晰度分别为71.5%和89.7%,后者与0°投照片的清晰度(95.0%)相比,无显著差异(P>0.05).结论:近中20°偏移投照能更好地显示下颌第一磨牙的4个根管.     

青少年下颌第一恒磨牙牙根及根管的锥形束 CT 研究

目的:应用锥形束CT(CBCT)分析青少年下颌第一恒磨牙牙根及根管形态。方法:收集2012-07~12拍摄CBCT的183例12~16岁青少年患者的366颗下颌第一恒磨牙的锥形束CT影像资料,记录患者年龄、性别、观察牙位及牙根数目、根管数目及根管形态,利用SPSS 19.0软件统计分析下颌第一恒磨牙牙根及根管数目的性别差异和左右侧差异。结果:纳入研究的366颗下颌第一恒磨牙中,近中单根者365颗,远中单根者282颗(77.05%),双根者83颗(22.68%),1颗牙为C形根。近中单根双根管者356颗(97.27%),单根一根管者9颗(2.46%);远中单根一根管者229颗(62.57%),单根双根管者53颗(14.48%),双根各一根管者83颗(22.68%);C形根3根管者1颗(0.27%)。牙根及根管数目在男女之间与左右侧之间差异均无统计学意义。结论:下颌第一恒磨牙以双根居多,牙根变异主要发生在远中根,远中舌根的发生率较高;性别间与左右侧牙之间无明显差异。     

Investigation of the root canal configuration of mandibular first molars in a Taiwan Chinese population

Aim  To investigate the root form and canal morphology of mandibular first molar teeth in a Taiwan Chinese population.
Methodology  A total of 183 mandibular first molars were collected and examined visually through a dissecting microscope after rendering the teeth transparent. The number of roots, number of canals and canal configuration were recorded. The root canal morphology was categorized and compared according to Vertucci (1984).
Results  Overall 46% of the mandibular first molars had four canals and 20% had extra-distal roots (distolingual root). In addition, 97% of the specimens had two mesial canals and 46% had two distal canals. In total, 68% of teeth with two mesial canals had two separated apical foramina, and 33% of teeth with two distal canals had two apical foramina. The most common canal configurations (Vertucci, 1984) of mesial roots were type 4 (46%) and type 2 (23%). Type 1 was encountered in 54% of the distal roots.
Conclusions  The frequency of the extra-distal root on the mandibular first molar was 20%, and the incidence of three canals (Vertucci's type 8 classification) with separate apical foramina at the apex of the mesial root was 6%. The three-rooted variation of the mandibular first molar appears to be a genetic characteristic of an Asiatic racial background.     

Root and canal morphology of permanent mandibular molars in a Sudanese population

AIM: To investigate variations in the root canal systems of first and second permanent mandibular molar teeth in a Sudanese population using a clearing technique. METHODOLOGY: Two hundred extracted first and second permanent mandibular molars from three cities in the state of Khartoum were studied. Access cavities were prepared and pulp tissue was removed by immersion in 5% sodium hypochlorite under ultrasonication; Indian ink was then injected into the root canal systems assisted by a vacuum applied apically. The teeth were rendered clear by demineralization and immersion in methyl salicylate before evaluation. The following observations were made (i) number of roots and their morphology; (ii) number of root canals per tooth; (iii) number of root canals per root and (iv) root canal configuration. RESULTS: Overall 59% of mandibular first molars had four canals with 3% having a third distolingual root. Seventy-eight per cent of second mandibular molars had two separate flat roots, whilst 10% were C-shaped. The most common canal system configurations were type IV (73%) and type II (14%). Inter-canal communications were more common in the mesial roots. The prevalence of inter-canal communications was 65% in first molars and 49% in second molars. CONCLUSIONS: In this sample of Sudanese teeth, 59% of the mandibular first permanent molars had four root canals whilst 10% of the mandibular second molars had C-shaped roots/canals.     

辽沈地区人群下颌第一磨牙牙根及根管解剖的CBCT观察

目的：利用锥形束CT（CBCT）观察辽沈地区人群下颌第一磨牙牙根及根管解剖形态,了解常见的变异型.方法：收集316名患者共548颗下颌第一恒磨牙CBCT影像,分别记录患者的姓名、性别、牙位、牙根数、根管数、变异型.启动Invivo Dental 5.0软件观察根管形态,分析辽沈地区人群下颌第一恒磨牙牙根及根管形态分布特点.结果：在548颗下颌第一磨牙中,2个牙根的下颌第一磨牙发生率为73.72％（404/548）;远舌根的发生率为26.28％（144/548）,男、女性别及左、右侧牙远舌根发生率比较差异无统计学意义;根管变异型以2根3根管为主,占51.64％（283/548）.结论：辽沈地区人群下颌第一磨牙远舌根的发生率较高;大部分有2个牙根;2个牙根3个根管是主要的根管分布类型;CBCT对于判断牙根和根管的解剖形态有诸多优势,可以为临床根管治疗提供参考.     

Evaluation of root canal morphology of human primary molars by using CBCT and comprehensive review of the literature

Objective Knowledge of primary tooth morphology is essential for clinical dentistry, especially for root canal treatment and dental traumatology. However, this has not been well documented to date with a large sample. This study was carried out to investigate the variation in number and morphology of the root canals of the primary molars, to study the applicability of cone beam computerized tomography (CBCT) in assessing the same and to provide a comprehensive review of the literature. Materials and methods A total of 343 primary molars, without any root resorption, were divided into four main groups including the maxillary first molars, maxillary second molars, mandibular first molars and mandibular second molars. All of them were analysed in CBCT images in the axial, sagittal and coronal planes. Various parameters such as the number of roots, number of canals, the root canal type, diameter of root and root canal and root canal curvature were studied. Results Primary molars in all four groups showed variability in the number of roots and root canals. As far as length of the roots was concerned, the palatal root of the maxillary molar was found to be longest, while the distobuccal root was shortest. In mandibular molars, the mesial root was longer than the distal root. The length of distobuccal root canal of the maxillary molars and the distolingual canal of the mandibular molars was found to be shortest. The number of roots and root canals varied from two to four and three to four, respectively. The maxillary molars exhibited more one-canal than two-canal roots. Conclusion The present study provides comprehensive information to the existing literature concerning the variation in root canal morphology of the maxillary and mandibular primary molar teeth. These data may help clinicians in the root canal treatment of these teeth.     

Root and canal morphology of mandibular first and second molar teeth in a Jordanian population

Aim  To examine the root and canal morphology of mandibular permanent first and second molar teeth in a Jordanian population.
Methodology  A total of 685 extracted mandibular first and second permanent molar teeth were collected from dental clinics within north Jordan. The teeth were examined visually and the root number and morphology were recorded. After that, access cavities were prepared, pulp tissue dissolved by sodium hypochlorite and the root canals injected with Indian ink. Stained teeth were decalcified with 10% nitric acid, dehydrated with ascending concentrations of alcohol and rendered clear by immersion in methyl salicylate. The following observations were evaluated: (i) number of canals per root; (ii) number of root canals per tooth; (iii) canal configuration in each root; (iv) number and location of lateral canals and (v) presence of intercanal communications.
Results  Of 330 mandibular first molars, the majority had three (48%) or four (46%) canals, whilst 4% had a third disto-lingual root. Of 355 mandibular second molars, 58% had three canals, 19% two and 17% had four canals, whilst 10% had C-shaped roots. The most prevalent canal configuration in the mesial root of both first (53%) and second (40%) molars was type IV, and in distal roots was type I (54% in first and 79% in second molars).
Conclusions  Jordanian mandibular first and second molar teeth exhibit features close to the average Caucasian root and canal morphology.     

Root and canal morphology of permanent mandibular molars in a Sri Lankan population

The main purpose of this study was to investigate the root and canal morphology of Sri Lankan mandibular molars and to determine the affinities of these morphological variations to those of people of European and Asian origin. Two hundred mandibular first and second molars were examined. The number of roots and the prevalence of C-shaped (gutter-shaped) roots in mandibular second molars were recorded. Root canal morphology was studied using a clearing technique. The examination of root canal systems of the teeth was based on Vertucci's classification. Among mandibular first molars, only 3% had three roots. Mesial roots of the first molar typically presented with two canals and two apical foramina with type IV, V, or VI canal configuration. Most distal roots of the first molar presented with a type I canal configuration. The remainder were distributed mainly between types III and V. Among mandibular second molars, 6% had single C-shaped roots, while C-shaped canals were found in only 2%. The majority of mesial roots of the second molar showed one or two canals, with one apical foramen with type I, II, or III canal morphology. In addition, the distal root commonly showed type I canal configuration. Intercanal communications and lateral canals were more frequently seen in the first molar than in the second. The root canal morphology in mandibular molars varies among population groups. Mandibular root and canal morphology of Sri Lankan people has closer affinities with that of people of European than of East Asian origin.     

Use of cone-beam computed tomography to evaluate root and canal morphology of mandibular first and second molars in Turkish individuals

Objective: The aim of this study was to investigate the root and canal morphology of mandibular first and second molars in a Turkish population by using cone beam computed tomography (CBCT). Study design: CBCT images of mandibular first (n = 823) and second molar (n = 925) teeth from 605 Turkish patients were analyzed. The root canal configurations were classified according to the method of Vertucci. Results: The majority of mandibular molars (95.8% of first molars, 85.4% of second molars) had two separate roots; however, three roots were identified in 2.06% of first molars and 3.45% of second molars. C-shaped canals occurred 0.85% of first molars and 4.1% of second molars. Three canals were found in 79.9% of first molars and 72.8% of second molars. Most distal roots had a simple type I configuration, whereas mesial roots had more complex canal systems, with more than one canal. The most common root morphology of first and second molars is the two rooted morphology with three canals. Both the mesial and distal roots showed wide variations in canal anatomy with type IV and type I canal configuration predominating in the mesial and distal roots, respectively. Conclusion: Vertucci type I and IV canal configurations were the most prevalent in the distal and mesial roots, respectively, of both the mandibular first and second permanent molar teeth. Key words:Cone-beam CT, Turkish, mandibular molars, root and canal morphology.     

Mandibular first molar with three distal root canals

CASE REPORT: A right mandibular first molar requiring root canal treatment was found to have one mesial and two distal roots and a total of five canals. The mesial and distobuccal root had two separate canals; the distolingual root had one. This case demonstrates a rare anatomical configuration and supplements previous reports of the existence of such configurations in mandibular first molars.     

Incidence of four canals in root-canal-treated mandibular first molars in a Saudi Arabian sub-population

AIM: The aim of this in-vivo study was to assess the incidence of three roots and four root canals in clinical cases of root-treated mandibular first molars in a Saudi Arabian population. METHODOLOGY: A clinical study of 251 root-canal treated permanent mandibular first molars was conducted. The teeth were examined clinically and radiographically. RESULTS: The results showed that 5.97% of the examined teeth had three roots, 57.76% had four root canals (two mesial and two distal) and 42.3% had three root canals (two mesial and one distal). CONCLUSIONS: The occurrence of four root canals in the mandibular first molar of a Saudi Arabian subpopulation was high.