上颌第一磨牙根管口形态、位置的应用解剖

目的 研究上颌第一磨牙根管口形态和位置关系，为根管治疗时寻找根管口提供解剖学依据。方法 采用目镜配置测微尺的XTL－2型体视摄影显微镜，观测42个上颌第一磨牙的根管口形态及其与髓室底截面形态和髓室底沟的位置关系。结果 ①上颌第一磨牙根管口可呈长条形、卵圆形、圆形、哑铃形和肾形；80．95％含3个根管口，其远颊根管口孔径最小。②近颊根舌侧根管口的出现率为14．29％。③骶室底截面呈长方形和圆三角形的占76．19％。结论 ①寻找根管口可综合髓室壁夹角、根管口间距及髓室底沟的走各进行；②上颌第一磨牙的第四根管口的出现率约为15％。     

乳磨牙早失间隙变化的临床观察

在乳牙列和混合牙列期如果由于各种原因导致乳磨牙早失 ,将引起间隙丧失 ,导致错牙合畸形的发生。　　　 1.临床资料 :选择门诊患者 2 5例 ,乳磨牙缺失后间隙31个 ,年龄 6 .5岁～ 10岁 ,上颌间隙 13个 ,下颌间隙 18个 ;6 .5岁～ 7.5岁 9例间隙 12个 ,7.5岁～ 9岁 10例间隙 12个 ,9岁～ 10岁 6例间隙 7个。2 .观察方法 :2 5例患者由于各种原因致使确实不能保留的乳磨牙予以拔除 ,从拔牙之日起观察 1年的间隙变化 ,分别于初诊、1.5个月、3个月、6个月、9个月、12个月用两脚规、游标尺测量缺失牙间隙邻牙近远中面最突点的直线距离作为间隙的量…     

乳磨牙早失前后缺隙变化的观察

乳磨牙早失前后缺隙变化的观察海军４２２医院口腔科李文荟，陈志勇乳磨牙由于各种原因过早丧失，可导致恒牙牙弓长度的减少，影响继承恒牙萌出后的位置，而造成牙列拥挤，牙齿错位及牙弓不对称等。我们对１８例乳磨牙早失患儿，共２０个缺牙间隙的变化情况进行观察，报告...     

不同方法探查上颌第一恒磨牙根管口的研究

目的 :比较临床上不同探查方法探查根管口的效率。方法 :采用肉眼观察 (上颌位 )、肉眼观察 (直视位 )、放大镜观察、# 15K型锉探查、牙科手术显微镜观察研究 80个离体上颌第一恒磨牙的髓腔系统。结果 :上颌第一恒磨牙近颊根有较高的多根管口率 ,五种方法多根管口的发现率分别为 :30 %、30 %、30 %、5 1.2 % ,6 6 .2 % ,K型锉和牙科手术显微镜多根管发现率与前三种方法比较差异有统计学意义 (P <0 .0 5 ) ,K型锉与牙科手术显微镜多根管发现率差异无统计学意义 (P >0 .0 5 )。手术显微镜还发现远颊根双根管口率为3.75 %。结论 :上颌第一恒磨牙根管系统复杂。临床使用小号K型锉能发现绝大部分根管口 ,而使用牙科手术显微镜对于完善的根管治疗术是有益的。     

离体上颌第二磨牙髓室底形态特点及根管口的定位研究

目的观察上颌第二磨牙的髓底形态特点及根管定位。方法51颗离体的上颌第二磨牙，其中5颗牙齿拍常规的烦舌向x线片，牙齿均用金刚钻在喷水下依釉牙骨质界横断牙冠（cememo—enamel junction，简称CEJ），取根侧部分为实验样品，用放大镜观察髓室底的解剖形态和根管口的位置。髓室底沟分5型。结果根管口总是位于髓室壁和髓室的交汇处，或位于牙根发育融合线的顶点。髓室底沟呈“Y”型的牙齿28颗（占55％．28／51），呈“7”形的牙齿11颗（22％），上述根管口均与牙根发育融合线相接，远中烦舌沟的牙齿5颗（10％），近中烦舌沟的牙齿1颗（2％），2个根管口的牙齿6颗（12％）。结论由于x线片上有时很难准确显示上颌第二磨牙牙根的形态，修复性牙本质或矿化常闭塞根管口，应该仔细地进行x线片阅读和临床探查，防止根管遗漏。     

上颌第一恒磨牙近中颊根第二根管口的定位研究

目的通过上颌恒磨牙近颊根与髓底参数的测量研究寻找近颊根(MB2)根管定位的方法,为上颌磨牙四边形髓腔入口的制备提供依据.方法选取新鲜拔除的上颌第一恒磨牙36颗,沿髓底平面截除牙冠,测量髓底参数,记录近中颊根根面外形,于MB1与MB2根管中插针示折摄X-线片,记录根管分型,将所得资料进行统计学分析.结果上颌第一恒磨牙近颊根根管分型与根形相适应2-1型根管的近颊根多为扁斜根(85.71%),2-2型根管的近颊根多为宽扁根(80%).MB1-MB2根管口距离在1～3 mm之间,平均距离为1.93 mm.2-1型与2-2型根管其MB1与MB2根管口的平均距离无显著性差异(P>0.05).MB1与MB2根管口至近颊根近中根面颈缘的垂直距离无显著性差异(P>0.05).结论临床医生可采用改进的四边形髓腔入口,在MB1根管口的腭侧、近中方向距MB1根管口1～3 mm 处,沿经过MB1根管口的与近中颈缘平行的直线上寻找MB2根管口.     

121例乳磨牙早失间隙变化的分析研究

乳牙早失在临床上较为多见,若不重视乳磨牙龋病的早期防治及乳磨牙早失后间隙的处理,继而引起恒牙列发育的紊乱、从而导致错(牙合)及机能不全,需要复杂的正畸治疗。故熟知和掌握乳牙早失后间隙变化的规律,有利于对     

乳磨牙空管治疗临床观察

乳磨牙从 1.5～ 2 .5岁萌出到 10～ 12岁被恒牙替换 ,在儿童口腔内存在 10年左右 ,是儿童进行咀嚼的主要器官。乳磨牙的保存治疗对儿童颌骨的发育、恒牙的正常萌出及正常建牙合都具有重要意义。笔者在临床工作中 ,根据患儿的合作程度 ,对部分患儿采用了乳磨牙空管治疗 ,收到了理想的临床效果。现报道如下。1　临床资料和方法1.1　临床资料随机选择门诊患者 2 4例 ,患牙 32个。上颌乳磨牙 15个 ,下颌乳磨牙 17个。年龄 4～ 9岁。根据临床症状及检查诊断为牙髓坏死、坏疽、急慢性根尖周炎及晚期牙髓炎 ,且均能得到随访者。1.2　治疗方法对患牙…     

金属成品冠修复乳磨牙和年轻恒磨牙大面积缺损的疗效观察

目的 观察金属成品冠修复乳磨牙和年轻恒磨牙大面积缺损的疗效。方法 对乳磨牙及年轻恒磨牙面积缺损的病例随机分成实验组和对照组，龋齿、髓病、根尖周病治疗后作金属成品冠或充填修复。结果 用金属成品冠修复的病例，其成功率为85％；而采用充填修复在成工率为59.7%。结论 对大面积缺损的乳磨牙及年轻恒磨牙，应在充填修复的基础上，进一步采用金属成品冠修复，从而提高修复成功率。     

中山市3060名幼儿园学生乳磨牙龋病调查

目的 调查中山市3～6岁儿童乳磨牙龋病发生的情况,为开展儿童口腔保健工作提供理论根据。方法 对3060名3～6岁幼儿园学生进行口腔检查,调查乳牙的患龋情况,重点对乳磨牙患龋资料进行分析。结果中山市3～6岁儿童乳磨牙患龋率为61.41％,随年龄增长发病率几乎呈直线上升,最高患龋率达89.53％;女童患龋率稍高于男童;龋齿的好发牙面以邻(牙合)面龋最高,占51.78％。结论 中山市3～6岁儿童乳磨牙患龋率高,邻(牙合)面龋为最好发部位,应重视儿童口腔预防保健工作。     

上颌第二乳磨牙根管数目的临床研究

目的 观察临床治疗中上颌第二乳磨牙根管数目.方法 选取需行上颌第二乳磨牙根管治疗的3~8岁患儿204例,共216颗患牙.常规方法开髓、制备开髓洞型,使髓室底完全暴露,用小号锉结合17%乙二胺四乙酸(ethylene diamine tetraacetic acid,EDTA)溶液探查各根管口的位置,确定并记录根管数目,根管预备完成后采用碘仿氧化锌糊剂进行根管充填.结果 216颗上颌第二乳磨牙中,122颗为3根管(占56.5%);94颗为4根管(占43.5%),根管数目变异以近中颊根第二根管(second mesiobuccal canal,MB2)出现频率较高,占比41.2%.上颌第二乳磨牙MB2的发现率在性别(X2=1.004,P=0.316)及牙位方面的差异(X2=0.072,P=0.788)没有统计学意义.结论 上颌第二乳磨牙根管数目存在较多变异,MB2发现率较高.     

上颌第一恒磨牙近中颊根根管宽度和锥度测量分析

目的: 测量分析上颌第一恒磨牙近中颊根根管宽度和锥度,为临床提供参考。方法: 收集50颗上颌第一恒磨牙制作透明牙,然后自近中颊根根尖孔处每隔0.4 mm与根管走行方向垂直连续横切,立体显微镜下放大30倍测量各个切片宽度,计算根尖1/3、中1/3、颈1/3各区段的锥度值。结果: 近中颊根第一根管宽度：根尖最大径（0.38±0.12）mm、最小径（0.34±0.16）mm,根中最大径（0.55±0.26）mm、最小径（0.57±0.12）mm,根颈最大径（1.13±0.34）mm、最小径（0.59±0.18）mm。第二根管宽度：根尖最大径（0.25±0.13）mm、最小径（0.28±0.10）mm,根中最大径（0.36±0.09）mm,最小径（0.17±0.06）mm,根颈最大径（0.79±0.23）mm、最小径（0.23±0.17）mm。近中颊根第一根管锥度：根尖1/3最大径0.03 mm、最小径0.01 mm,中1/3最大径0.06 mm、最小径0.03 mm,冠1/3最大径0.10 mm、最小径0.09 mm。第二根管锥度：根尖1/3最大径0.02、最小径-0.01,中1/3最大径0.06,最小径0.00,冠1/3最大径-0.02、最小径-0.02。结论: MB1具有较大的宽度和锥度,且根尖1/3、中1/3、冠1/3锥度不同,而MB2的宽度和锥度都很小,还会出现倒锥度。     

新疆地区人群上颌第二磨牙牙根和根管形态的CBCT研究

目的 采用锥形束CT研究新疆地区人群上颌第二磨牙的牙根和根管形态，为本地区口腔临床诊疗提供参考依据。方法 对纳入研究的539例新疆地区人群的上颌第二磨牙，利用CBCT对其牙根形态、数目，根管形态、数目和弯曲度，牙冠颊舌径和近远中径以及对称性进行观察、分析和统计。结果 在1017颗上颌第二磨牙中，三根牙的检出率最高为85.2%，四根牙检出率最低为3.2%，不同牙位和性别在牙根形态上的分布存在统计学差异；MB2的检出率与年龄无统计学差异；56岁及以上年龄组的四根牙检出率最高。颊舌径、近远中径的平均测量值越大，其对应的根管数目越多。上颌第二磨牙的牙根数目和形态对称、根管形态及四种特征均对称方面较高，上颌第二磨牙近颊根管和远颊根管68%为重度弯曲，弯曲位于根中1/3较多。结论 新疆地区人群上颌第二磨牙以三根牙为主，对称率较高，弯曲程度大，但存在一些牙根和根管的变异，临床上可以运用CBCT来指导诊疗。     

The mid-mesial canal prevalence in mandibular molars of a Saudi population: A cone-beam computed tomography study

IntroductionThe aim was to assess the prevalence of Mid Mesial Canal (MMC) in the first and second mandibular molars in a Saudi subpopulation sample and assess its relation to side, gender, and age using Cone beam computed tomography (CBCT).MethodsThe CBCT scans at King Saud University Dental Hospital between 2016 and 2019 were reviewed and filtered. The MMC of the mandibular molars were assessed according to Pomeranz et al. classification which was: (1) independent; (2) fin; (3) confluent with the mesiobuccal canal; and (4) confluent with the mesiolingual canal. Three calibrated observers examined the MMC on all planes at both sides. Age and gender factors were used to analyze that prevalence. A chi-squared test was used and (P ≤ 0.05) was considered to be statistically significant.Results395 patients, and 1377 teeth met the inclusion criteria. The total number of mid-mesial canals was 12 (0.9%): nine at the mandibular first molar (1.3%) and three in the mandibular second molar (0.4%). The most common type of mid-mesial canal was confluent (n = 10), of which 6 fused with the mesiobuccal canal and 4 fused with the mesiolingual canal. Two canals were of the fin type, and there was no instance of independent mid-mesial canal. There was no significant difference between all variables: tooth type, tooth side, patient gender, and patient age group (p > 0.05).ConclusionIn this study, the most common MMC configuration was the confluent type followed by the fin type and no independent type were found. The patient side, gender and age did not influence the prevalence of the MMC.     

下颌第二磨牙根管系统的临床诊断和治疗

目的:探讨下颌第二磨牙根管系统的特征及临床诊断和治疗方法。方法:选取患牙髓炎或根尖周炎的下颌第二磨牙 127个,拍摄术前X线片,探查根管,确定根管形态和类型;采用机用镍钛器械Hero642预备根管,热牙胶垂直加压技术充填根管。根据治疗前后的X线片评价根管预备和充填效果。结果:下颌第二磨牙独立 3个根管的发生率为 54. 3%, 独立 2个根管和单一根管的发生率为 11. 0%和 3. 1%,C形根管的发生率为 31. 5%,以Ⅰ、Ⅱ型居多。所有患牙均无根管内并发症发生,治疗效果佳。结论:下颌第二磨牙根管系统以独立的 3个根管为主,其次为C形根管,根管探查结合X线片可诊断C形根管;机用镍钛器械预备根管热牙胶垂直加压技术充填根管可获得良好的治疗效果。     

显微CT法研究上颌第一磨牙根管系统解剖形态

目的 使用显微CT研究上颌第一磨牙根管系统解剖形态.方法 随机收集33颗上颌第一磨牙,使用显微CT扫描后重建根管系统.观察并记录各牙根根管形态和分支根管的发生数目、位置.记录各根管口位置并测量根管口间的距离和所成角度.在距离根尖1、2和3mm处进行虚拟切割,记录断面上分支根管暴露情况.结果 上颌第一磨牙近颊根第二根管发生率为75.76%.近颊根发生分支根管为71.64%;近颊根分支根管发生率为72.73%.91.04%的分支根管发生于根尖1/3段,近颊根距根尖3mm处截面分支根管暴露率为12.12%.近颊根第一、第二根管口间的距离为(1.60±0.41)mm.结论 上颌第一磨牙根管系统解剖形态复杂,近颊根根管形态存在较大解剖变异.     

Root and canal morphology of Thai mandibular molars

AIM: To investigate the root and canal morphology of 351 mandibular permanent molars collected from an indigenous Thai population. METHODOLOGY: The cleaned teeth were accessed, the pulp dissolved by sodium hypochlorite under ultrasonication and the pulp system injected with Indian ink. The teeth were rendered clear by demineralization and immersion in methyl salicylate. 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; (iv) root canal configuration in each root using Vertucci's classification, with additional modifications; and (v) presence and location of lateral canals and intercanal communications. RESULTS: Of 118 mandibular first molars, 13% had a third disto-lingual root. In three-rooted teeth, 80% of the main distal roots and 100% of the disto-lingual roots had type 1 canal systems. Of 60 mandibular second molars, 10% had C-shaped roots, the majority of which had type 1 (33%) or type IV (33%) canal systems. Of 173 third molars, 68% had two separate roots, 20% had fused roots and 11% had a single C-shaped root; the majority had two canals (61%). CONCLUSIONS: This study suggests that Thai molars exhibit features of both Caucasian and Chinese teeth.     

Localization of root canal orifices in mandibular second molars in relation to occlusal dimension

Aim  To evaluate the localization and distribution of canal orifices of mandibular second molar teeth in relation to the mesio-distal and bucco-lingual dimensions of coronal tissue.
Methodology  Fifty extracted mandibular second molar teeth were embedded into plaster blocks with their vertical axes aligned perpendicular to the horizontal plane. The teeth were photographed digitally from the occlusal aspect under 12 × magnification. Thereafter, the occlusal halves of crowns were sectioned off to expose the root canal orifices. The teeth were than photographed under the same magnification, after which the pre- and post-sectioning images of each specimen were stacked into a single file. To plot the coordinate of each canal orifice, a 0.5-mm grid analytical plane was mounted digitally on the stack so that the x - and y -axes of the plane were superimposed on the mesiodistal and buccolingual axes (bisectors) of the tooth crowns. Localization and distribution of the coordinates of the canal orifices were evaluated using the chi-square test ( P  = 0.05).
Results  Only one tooth displayed a single root canal orifice, located in the mesiobuccal-distolingual 'centre' of the occlusal surface. The majority of mandibular second molars had three orifices (72%), followed by those with two (16%) and four (10%). The distal canal was located lingual to the centre of the occlusal plane.
Conclusion  The distal canal was located lingual to the centre of the occlusal plane of mandibular second molars. The possibility of observing more divergent localizations and orifice numbers should not be overlooked in clinical practice.     

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.     

壳聚糖用于乳牙根管充填的实验研究

目的观察壳聚糖糊剂用于乳牙根管充填后的效果和反应,为研制生物型乳牙根管充填材料提供实验依据。方法①取正常单根离体牙60颗,随机分为4组,每组15颗。行常规根管充填术,实验组分别用壳聚糖糊剂、壳聚糖硫酸钡糊剂、氧化锌丁香油糊剂根管充填,第4组为空白对照。用染料法评价4种根充材料的根端封闭性能。②取5月龄小型猪8头,选双侧上、下颌乳前磨牙共32颗;随机选择一侧乳前磨牙16颗为实验组,壳聚糖硫酸钡糊剂根管充填,对侧同名牙为对照组,用氧化锌丁香油糊剂根管充填。分别于术后1、2、4、8周各处死2只动物,做组织病理学观察。结果①壳聚糖糊剂组、壳聚糖硫酸钡糊剂组与氧化锌丁香油糊剂组染料微渗漏深度无显著性差异,与空白对照组相比均有极显著性差异。②动物实验显示用壳聚糖糊剂充填乳牙根管引起的根尖周炎症反应轻,超充物对周围组织的刺激小、吸收快;ZOE糊剂根充后引起的根尖周炎症反应重,超充物对周围组织刺激大,氧化锌颗粒被机体当作异物包裹,吸收缓慢。结论用壳聚糖作乳牙根管充填糊剂,根端封闭性能与传统的氧化锌丁香油糊剂相当,且具有良好的生物相容性和促进组织修复的作用。