下颌前牙根根管系统解剖及临床意义

目的了解下颌前牙牙根数目,根管类型,及侧副根管出现率,为提高下颌前牙根管治疗提供解剖学依据。方法采用开髓真空负压吸入美兰染色的透明牙标本,用XXT-3A连续变倍体视显微镜检侧下颌前牙根管系统。结果945颗下颌前牙947支牙根的主根管类型分为六型,I型占74.97%,Ⅱ~Ⅵ型占25.03%;侧副根管分四种,根管侧支检出率11.51%,管间吻合检出率1.69%,根尖分歧检出率4.22%,根尖分叉6.02%。结论下颌前牙根管系统具有规律性、多变性。     

恒牙根管系统形态学研究

目的 研究恒牙根管系统的形态，为临床提供解剖学资料。方法 采用真空负压吸入美兰染色的透明牙标本，用XTT-3A连续变倍体视显微镜检测恒牙根管系统。结果 5414颗牙8125支牙根的主根管类型分为Ⅷ型；根管侧支检出率29．70％，管间吻合检出率8．38％，副根管检出率0．52％，根尖分歧检出率4．80％，根尖分叉检出率7．73％。根管侧支出现的部位，根颈1／3占3．48％，根中1／3占12．39，根尖1／3占84．13％。结论 恒牙根管系统主根管类型可分为Ⅷ型，侧副根管检出率与国内同类资料相比有显性差异。     

805颗上下颌第三磨牙牙根及根管形态的观测

目的检测上下颌第三磨牙牙根及根管形态，为人类学提供资料。方法采用离体牙经透明牙标本制备，用XXT-3A连续变倍体视显微镜检测上下颌第三磨牙根管形态。结果805颗第三磨牙牙根形态可分为六型，上颌第三磨牙牙根形态Ⅲ型占57．5％。下颌第三磨牙牙根形态Ⅳ占52．88％。其主根管形态可分六型，Ⅰ型占62．12％。结论上下颌第三磨牙牙根形态，根管类型具有复杂性。     

下颌第一前磨牙根管系统和根尖孔解剖及临床意义

采用牙髓透明法对 347颗下颌第一前磨牙根管系统的数目和形态进行观察。下颌第一前磨牙根管可分为Ⅰ、Ⅱ、Ⅲ、Ⅳ型。其中Ⅰ型 (单根单管型 )占 83 86 % ,Ⅱ型 (单根双管型 )占 4 6 1% ,Ⅲ型 (单双管混合型 )占 11 2 4 % ,Ⅳ型 (双根双管型 )占 0 2 9%。应用XTT— 3A连续变倍体视显微镜对 347颗下颌第一前磨牙的根管系统形态进行观察 ,根尖分歧出现率 15 6 3% ,根尖分叉出现率 2 4 3% ,根管侧支出现率 1 0 8%。并对 347颗下颌第一前磨牙的根尖孔与根尖顶的位置关系进行观察 ,根尖孔位于根尖顶者占 88 14 % ,位于旁侧者占 11 86 %。并就上述内容的临床意义进行了讨论。     

300个下颌第一恒磨牙根管类型的透明牙观测

目的 了解下颌第一恒磨牙根管的类型，为提高根管预备的效果提供解剖学依据。方法 采用透明牙技术用连续变倍体视显微镜对该牙根管类型进行观测。结果 300个离体牙中，共检出八种根管类型。其中1—1—1型、2—2—1型、2—2—2型最多，占91．4％。远中舌根的发生率为24．7％；双根管口率：近中根为78．3％，远中根(不含远中舌根，下同)为19．3％；双根管率：近中根为88．3％，远中根为23．3％；双根尖孔率：近中根为56．7％，远中根8．3％，单根管口而有双根尖孔，近中为6．7％，远中为3．3％。结论 下颌第一恒磨牙根管的类型复杂，充分了解其根管解剖对提高根管预备效果、减少根臂遗漏有重要意义。     

应用锥形束CT对华南地区924颗下颌第1磨牙的根管形态学研究

目的　应用锥形束 CT(cone beam computed tomography,CBCT)观察下颌第1磨牙的根管解剖形态,为临床根管治疗提供参考依据。 方法　由两名牙体牙髓专业医生筛选我院口腔科自2014年12月至2015年12月进行 CBCT 检查的500名患者,共计924颗下颌第1磨牙的影像资料,分别记录患者的基本信息、牙位、根管构型及钙化情况,并进行统计学分析。 结果　424名存在双侧下颌第1磨牙的患者中,76.2%(323)根管构型完全对称。924颗下颌第1磨牙中,双根率为76.7%(709),3根率即远舌根发生率为23.3%(215);近中根最常见根管类型为Vertucci IV型,占 71.97%(665),其次为II型,占23.70%(219);远中根最常见根管类型为I型,占 49.35%(458),其次为IV型占31.82%(292)。存在远舌根时,远舌根管口与远颊根管口距离为(2.94±0.27) mm。下颌第1磨牙根管钙化率与年龄有关,老年人钙化率高,中年人次之。 结论　华南地区人群下颌第1磨牙根管形态多样,变异性较大;CBCT 是观察根管形态的有效工具,可以为根管治疗提供辅助诊断。     

下颌管的应用解剖及临床意义

目的:为下颌牙种植术等临床口腔外科提供解剖学基础.方法:选取下颌骨标本10例、新鲜下颌骨标本10例和成人全牙下颌骨标本20例,分别暴露出下颌管截面、下牙槽神经血管束和下颌管与下颌后牙牙根.观察下颌管的形态、走行和下牙槽神经、血管的排列关系,用游标卡尺测量下颌后牙牙根尖至下颌管上壁的距离.结果:下颌管呈椭圆形,自磨牙牙根尖舌侧和前磨牙牙根尖颊侧的下方走行;下颌管内的下牙槽血管位于下牙槽神经上方.下颌后牙牙根至下颌管的距离以第2磨牙最近,由近及远依次为第2磨牙、第1磨牙、第3磨牙、第2前磨牙和第1前磨牙;下颌磨牙的远中根至下颌管的距离均较近中根近.第1前磨牙、第2前磨牙、第1磨牙、第2磨牙、第3磨牙牙根至下颌管上壁的最短距离分别为(8.19±0.87) mm(左)和(8.29±0.88) mm(右)、(7.38±0.85) mm、(3.30±0.66) mm、(2.98±0.77) mm(左)和(2.92±0.75) mm(右)、(3.82±0.63) mm(左)和(3.86±0.64) mm(右).结论:下颌管的应用解剖对选择适宜长度的牙种植体,避免牙种植体损伤下牙槽神经等具有重要意义.     

下颌管的三维重建及临床意义

目的　为下颌牙种植术等临床口腔外科提供解剖学基础。 方法　选取全牙志愿者20名,在螺旋CT机以眶耳线(OML)为基线连续扫描,采用ADW 4.2重建软件的曲面重组技术(CPR)重建下颌管,观察下颌管的位置、构造和测量下颌后牙牙根至下颌管上壁的距离;在Amira三维重建软件下重建下颌骨及下颌管的可视化模型,观察透明下颌骨内下颌管的走行及其与下颌后牙的关系。 结果　下颌管壁由一薄层骨密质构成,自磨牙牙根尖舌侧和前磨牙牙根尖颊侧的下方走行;透明下颌骨内的下颌管可清晰显示其位置、形态及走行,下颌管与下颌体下缘、牙槽嵴及内、外侧骨板的距离。下颌后牙牙根至下颌管的距离以第2磨牙最近,由近及远依次为第2磨牙、第1磨牙、第3磨牙、第2前磨牙和第1前磨牙;下颌磨牙的远中根至下颌管的距离均较近中根近。第1前磨牙、第2前磨牙、第1磨牙、第2磨牙、第3磨牙牙根至下颌管上壁的最短距离分别为(8.38±1.04) mm(左)和(8.44±1.05) mm(右)、(7.51±0.85) mm、(3.40±　0.65) mm、(2.93±0.61) mm、(3.92±0.63) mm(左)和(3.97±0.63) mm(右)。 结论　下颌管的三维重建对选择适宜长度的牙种植体,避免牙种植体损伤下牙槽神经等具有重要意义。     

下颌第三磨牙根尖与下颌管的位置关系

本文对50侧96例成人下颌骨第三磨牙根尖与下颌管的位置关系等进行了观测,下颌管在根尖下方者占86.5%,在根尖外侧者占8.3%,在根尖内侧者占5.2%。第三磨牙根尖至下颌管间的距离在2mm以内占35.4%.根尖与下颌管之间的位置关系及距离可供临床应用参考。     

间接数字化成像技术分析208颗山东地区汉族人恒前牙根管的弯曲情况

背景:熟悉根管解剖形态,了解其弯曲程度,可以在一定程度上预防根管预备时的并发症,提高根管治疗的成功率.目的:了解山东地区汉族人恒前牙根管弯曲的情况.方法:采用间接数字化X射线成像技术,对收集的离体208颗前牙进行颊舌向和近远中向拍摄,采用改良的Schneider测量方法,分析根管弯曲情况.结果与结论:山东地区汉族人前牙...     

Anatomical evaluation of the root canal diameter and root thickness on the apical third of mesial roots of molars

The purpose was to determine the diameter of the main root canal and wall thickness in the apical dentin in mesial roots of maxillary and mandibular molars. Forty mesiobuccal and mesial root specimens were sectioned horizontally at 1, 2 and 3 mm from the apex, and measured at each top surface by using optical microscopy to an accuracy of ×20 magnification. The anatomical parameters were established as the following points of reference: AB, two points connected by a line from the outer edge of the mesial wall to the outer edge of the distal one through the center of the root canal to measure the thickness of the root and mesiodistal diameter of the root canal (CD). A second line (EF) was designed to evaluate the diameter of the root canal in the buccolingual direction. All data were summarized, and values were assessed statistically by ANOVA and Bonferroni multiple comparisons. The buccolingual (BL) root canal diameters at 1, 2 and 3 mm in the mandibular and maxillary molars were greater than in the mesiodistal (MD), showing statistically significant differences (p < 0.05). The MD root thicknesses at 1, 2 and 3 mm in mandibular and maxillary molars were statistically significant (p < 0.05). The lowest value to 1 mm from the apex in the mandibular molars was 1.219 mm and the highest at 3 mm from the root apex in maxillary molars was 1.741 mm. The BL diameters in maxillary and mandibular molars were higher than the MD diameter. The thickness (MD) of maxillary and mandibular molars decreased as a function of apical proximity.     

Anatomic characteristics of the furcation and root surfaces of molar teeth and their significance in the clinical management of marginal periodontitis

Treatment of periodontitis which involves the furcation area of molar teeth has always been a challenge. Sixty extracted human molar teeth were used for an anatomic study to clarify the possible morphologic factors which may affect the diagnosis, prognosis, and clinical management of periodontally involved teeth. Teeth were embedded in methylmethacrylate and cut in 70 μm cross sections from the cementoenamel junction to the apex. Cervical enamel projection, root and root trunk lengths, root proximities as well as depths of root concavities coronally, apically, and at the furcation roof were measured. Cervical enamel projections were observed in 30% of the teeth examined. The shortest root trunk was found at the buccal aspect of mandibular first molars, permitting furcation involvement at early stages of periodontal disease. The most apically located furcation was found at the distal site of maxillary first molars. Furcation roofs showed severe concavities and complex cementum morphology. Teeth exhibiting cervical enamel projection were found to have deeper root concavities compared to teeth without cervical enamel projection and mesial roots of mandibular molars possessed greater furcal concavities than distal roots. The presence of root concavities complicates the diagnosis of furcation involvement and restricts access of periodontal instruments, resulting in incomplete treatment. Furcation anatomy may also influence the long-term prognosis of the teeth by favoring the retention of bacterial deposits and making oral hygiene procedures almost impossible. The present study shows that knowledge of a tooth's unique anatomic characteristics is a prerequisite for effective periodontal therapy. Clin. Anat. 11:177–186, 1998. © 1998 Wiley-Liss, Inc.     

层递探查法探查下颌第一恒磨牙近中中央根管成功率的体外评价

目的探讨体外三阶段层递探查法探查离体下颌第一恒磨牙近中中央根管(MMC)的成功率,并研究下颌第一恒磨牙MMC的解剖形态学特征。方法收集近期拔除的下颌第一恒磨牙60颗,采用肉眼直视下探针探查、显微镜辅助探查、显微镜辅助超声预备三阶段层递探查法探查下颌第一恒磨牙MMC,最终对未发现MMC的离体牙采用透明牙染色法,以此为对照评价上述三阶段探查MMC的成功率;分析MMC的形态分类以及在各年龄段中的分布情况。结果层递探查法各阶段探查离体牙MMC的发现率分别为5.3%(3颗)、8.8%(5颗)、21.1%(12颗);经透明牙染色法确认后,有1颗离体牙的MMC被遗漏;体外三阶段各自的探查成功率分别为23.1%、38.5%、92.3%;第一、二阶段MMC发现率比较差异无统计学意义(P>0.05),第三阶段与第一、二阶段比较,差异均有统计学意义(P<0.05);MMC的根管解剖学分型多为融合型(3-2型、3-1型);MMC在21~40岁组中的发现率最高(33.3%)。结论体外三阶段层递探查法能有效提高下颌第一恒磨牙中MMC的发现率,在显微镜辅助超声预备下探查MMC的成功率明显较高;MMC的解剖形态相对复杂,与近中主根管间的联系紧密,且随着年龄的增长,MMC的发现率逐渐降低。     

Rare courses of the mandibular canal in the molar regions of the human mandible: a cadaveric study

The inferior alveolar artery, vein and nerve send some branches to the molar teeth via the mandibular canal to the mental foramen. The present study attempted to define the presence and course of the mandibular canal in the mandible with the alveolar process by macroscopic cadaveric dissection and computerized tomography (CT) in order to provide information that might prevent injuries to vessels and nerves at risk during root canal treatment. We identified the position of the mandibular canal within a 30% ratio of the distance from inferior border of mandible to the apices of the root for 39 out of 131 sides (mesial root of first molar, 20%; distal root of first molar, 22.6%; mesial root of second molar, 27.8% and distal root of second molar, 47%) on panoramic X-ray observation. In one cadaver (male, 64 years old), the root apex of the second molar was in close proximity to the upper bony mandibular canal. Macroscopic dissection and computerized tomography showed that the main trunks of the inferior alveolar artery, vein, and nerve were in tight contact with the apex of the second molar. These observations of the anatomic course of the mandibular canal will be important to consider during root canal treatment of mandibular teeth.     

Root Canal Morphology of Chalcolithic and Early Bronze Age Human Populations of El Mirador Cave (Sierra de Atapuerca,Spain)

This study provides a morphological characterization of the inner anatomy of the root canals of permanent first and second molars in Chalcolithic and early Bronze Age human fossils using cone‐beam computed tomography. The general evolutionary trend in present‐day human dentition is related to morphological simplification. As little is known about when this trend appeared in Homo sapiens populations, the aim of this work is to test the presence of modern radicular morphology 4,400 years ago. Fifty‐four permanent first and second maxillary and mandibular molars of 17 individuals were included in the study. All maxillary first and second molars showed three separate roots. Almost all the lower molars analyzed (100% of first molars and 75% of second molars) had two separate roots. More differences in the canal system configuration were documented in the maxillary mesiobuccal roots than in the palatal or distobuccal roots. The most variable tooth in root and canal configuration is the maxillary second molar. It should be pointed out that 12.5% of the teeth analyzed showed a C‐shaped root configuration. Anat Rec, 297:2342–2348, 2014. © 2014 Wiley Periodicals, Inc.     

上、下颌骨的CT影像与断层标本对照研究及临床意义

目的:为牙种植术等临床口腔外科提供解剖学基础.方法:选取成人全牙上、下颌骨标本和志愿者全牙CT重建影像各20例,观察上颌窦下壁的凸起结构和下颌管的走行,测量上颌窦下壁、下颌管上壁至牙根的距离.结果:上颌窦系呈三边形或四边形的锥形腔隙,其下壁常有凸起的骨隔.在标本及影像上的上颌窦下壁至第1前磨牙、第2前磨牙、第1磨牙、第2磨牙、第3磨牙牙根的距离左、右分别为(9.30±2.64)mm和(9.50±2.72)mm、(4.50±1.98)mm和(4.60±1.95)mm、(2.02±0.91) mm和(2.18±0.96)mm、(2.06±1.04) mm和(2.26±1.20)mm、(3.74±1.73)mm和(3.82±1.84)mm.下颌管自牙槽窝下方走行,其舌侧骨板较厚.在标本及影像上的下颌管上壁至第1前磨牙、第2前磨牙、第1磨牙、第2磨牙、第3磨牙牙根的距离左、右分别为(8.36 +2.34) mm和(8.42±2.42)mm、(7.36±2.21)mm和(7.52±2.18)mm、(3.22±1.40)mm和(3.36±1.85)mm、(2.96±1.54)mm和(2.84±1.55)mm、(3.64±1.72) mm和(3.88±1.76)mm.结论:上颌窦、下颌管至牙根的距离测量,对选择适宜长度的牙种植体,避免牙种植体误入上颌窦和损伤下牙槽神经等具有重要意义.     

Root canal system of the maxillary canine

To better assess the efficacy of mechanical preparation of root canals, transparent specimens of 250 extracted maxillary canines were investigated for canal configuration, thickness and curvature of the root canal, condition of any accessory canals, and location of the apical foramen. Fewer than 40% of the specimens showed accessory canals that were mechanically impossible to clean. The majority of the lateral branches were small, greater than a #15 file, and none of the branches were larger than a #20 file. Although apical foramina located away from the apex were observed in 30% of the maxillary teeth, 96% of all apical foramina were within 0.5 mm of the apex. Data on the thickness of the root and main canal in the apical portion and curvature of the root canal suggest that, for adequate apical preparation, a #60 file must be able to reach the apical constriction.