下颌第二恒磨牙牙根及根管形态的锥形束CT研究

目的 使用锥形束CT扫描评估下颌第二恒磨牙牙根和根管解剖形态.方法 收集354例患者双侧下颌第二恒磨牙的锥形束CT图像,统计下颌第二恒磨牙牙根数目、根管数目和构型,以及C形根管的发生率.结果 下颌第二恒磨牙以双根最多,发生率为57.34%,C形根的发生率为38.28%;双根者近中根多为2-2型(80.54%),远中根多为1-1型(96.06%);C形根管的发生率为25.99%,左、右下颌的发生率没有统计学差异(P>0.05).结论 下颌第二恒磨牙牙根和根管解剖形态复杂多样,锥形束CT能为根管治疗提供参考.     

辽宁地区汉族人下颌第二恒磨牙牙根和根管数目的锥形束CT研究

目的：利用锥形束CT（CBCT）扫描评估辽宁地区汉族人下颌第二恒磨牙牙根和根管数目的情况。方法：调取于我院口腔科行CBCT扫描患者的图像资料,统计分析下颌第二恒磨牙牙根和根管数目的情况。结果：在900例下颌第二恒磨牙中,双根的发生率为51．22％,其中82％的近中根内为双根管,100％的远中根内为单根管;三根的发生率为2．18％;融合根的发生率为46．6％,其中完全融合的锥形根占5．71％,不完全融合的C形根（C型根管）占40．89％,C型根管发生率在男女性别间差异无统计学意义（p〉0．05）,以双侧对称性分布较多,单侧发生率以右侧为多。结论：在辽宁地区汉族人中,下颌第二恒磨牙以双根或融合根居多,c形根（C型根管）的发生率较高。     

西北地区中国人下颌第一恒磨牙牙根根管数目的锥束CT研究

目的:利用锥形束CT(CBCT)观察分析西北地区中国人下颌第一恒磨牙牙根和根管数目及其变异情况,以期为临床治疗提供参考。方法:随机调取来我院放射科行CBCT检查的病人图像资料,统计分析下颌第一恒磨牙牙根和根管数目及其分布情况。结果:共获取800例病人1 600个下颌第一恒磨牙CBCT图像数据。下颌第一恒磨牙2个牙根的发生率为72.69%(1163/1600),其中2根2管的发生率3.27%,2根3管的发生率73.00%,2根4管的发生率23.73%;3个牙根的发生率为27.31%(437/1 600),其中3根3管的发生率4.12%,3根4管的发生率95.88%。下颌第一恒磨牙远中舌根的个体发生率为33.75%(270/800)。男女性别间发生率无统计学差异(P>0.05)。下颌第一恒磨牙远舌根双侧对称性的发生率61.85%(167/270),且右侧高于左侧,差异有统计学意义(P<0.05)。结论:下颌第一恒磨牙牙根和根管数目以及解剖形态存在多样性,CBCT影像可为临床根管治疗术提供可靠的依据。     

应用锥形束CT研究下颌第二磨牙根管数目和构型

目的采用锥形束CT（cone-beam computed tomography,CBCT）观察下颌第二磨牙根管数目及构型,为根管治疗提供影像学参考。方法随机调取700颗下颌第二磨牙的CBCT资料,统计下颌第二磨牙牙根数目、根管数目和构型,以及C型根管的发生率。结果下颌第二磨牙c形牙根的发生率为36．O％;2根牙的根管构型：61．1％近中根管为Ⅳ型,96．1％远中根管为I型;C形根管在根管口及根尖1／3处类型变化多。结论下颌第二磨牙牙根和根管解剖形态多样,CBCT清晰的三维影像能为根管治疗提供参考。     

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。     

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.     

下颌第二恒磨牙C形根管系统的锥体束CT研究

目的：采用三维锥体束CT成像系统探讨下颌第二恒磨牙C形根管的发生率。方法：选择238名门诊患者/476颗下颌第二恒磨牙的CBCT扫描数据,进行三维重建下颌第二恒磨牙,观察C形根管的发生率。结果：存在C形根管的下颌第二恒磨牙共191颗,发生率40.12%;左右两侧同时发生C形根管的概率为31.9%;左右侧发生比率无统计学差异;男女发生比率无统计学差异。结论：C形根管在下颌第二恒磨牙中具有较高的发生率,CBCT影像技术能在诊疗过程中为临床医师提供更直观,更准确的影像学依据。     

下颌第二磨牙根管的解剖形态研究

目的 了解下颌第二磨牙根管的解剖形态，为根管治疗提供依据。方法 用透明标本法将152个下颌第二磨牙依次作髓腔染色，5％盐酸脱矿，酒精系列脱水，最后置冬青油制成透明牙观察根管形态。结果 下颌第二磨牙双根85例（55．9％），其近中根1－1型根管40例（47．1％），2－1型23例（27．1％），1－2型13例（15．3％），2－2型9例（10．6％）；远中根根管1－1型79例（92．9％）。C形根56例（36．8％），其中仅有24例C形根管（15．8％），完全性C形根管及部分性C形根管各12例。结论 根管形态的多变性及C形根管的存在给下颌第二磨牙的根管治疗带来困难，彻底的根管清理，严密的根管充填是治疗成功的关键。     

下颌第二恒磨牙C型根管发生率的临床研究

目的:研究下颌第二恒磨牙C型根管发生率及分布特点。方法:收集524例需作根管治疗的下颌第二恒磨牙,术前拍根尖X线片,揭髓室顶,观察根管口分布形式,常规根管治疗,拍根管充填后X线片,记录,存档。结果:总样本中下颌第二恒磨牙C型根管发生率为46. 37%。其中男性、女性C型根管发生率分别为38. 25%和52. 65% (P<0. 01)。左、右侧C型根管发生率分别为46. 53%和46. 24% (P>0. 05)。35岁以下和35岁以上者C型根管发生率分别为47. 25%和46. 62% (P>0. 05)。在所有双侧均作根管治疗的33个病例中,双侧根管分布形式不一致的病例6例,占18. 18%。结论:①C型根管是下颌第二恒磨牙一种常见的根管分布形式,发生率为46. 37%。②女性C型根管发生率高于男性。③左侧和右侧及不同年龄段C型根管发生率无差异。④同一患者双侧根管分布形式不一定相同。     

锥形束CT在下颌第二磨牙C形根管治疗前中后的应用

下颌第二磨牙C形根管存在根管变异和不规则峡区,容易造成根管清理不彻底和充填不足。锥形束CT(CBCT)可清晰地显示C形根管在矢状面、冠状面和横断面的解剖形态。CBCT空间分辨率高,图像清晰;可选择合适的视野,小视野图像更清晰;可以光盘形式最大限度的保存图像信息,方便临床医生在计算机上多层面、多方位的仔细观察;金属伪影少,辐射剂量低,扫描时间短;所显示下颌第二磨牙C形根管图像的矢状面、冠状面和横断面无前后重叠、无变形和无放大等情况,可为了解下颌第二磨牙C形根管形态提供清晰的三维影像。下颌第二磨牙C形根管预备的难度主要有相对独立的根管间有大量的副根管、交通支和根管弯曲,传统器械难以进入峡区;将显微镜和CBCT共同使用,可提高下颌第二磨牙C形根管的治疗效果。在根管预备前行CBCT检查,可提醒术者避免过度切削并防止侧穿。本文就CBCT在下颌第二磨牙C形根管治疗前中后的应用等研究进展作一综述。     

锥形束CT在下颌第二磨牙C形根管系统应用的研究

目的　采用锥形束CT（简称CBCT）研究下颌第二磨牙C形根管的解剖形态,为根管治疗提供更加直观的影像学依据。方法　使用CBCT观察441例患者双侧下颌第二磨牙,统计C形根管的发生率以及根管形态。结果　C形根管的发生率为41.72%,C形根管类型变化多样,C形根管的发生率在性别、年龄间无统计学差异。结论　C形根管在下颌第二磨牙有很高的发生率,并且解剖形态有较大差异,CBCT在诊断C形根管方面具有重要作用。     

Root and root canal morphology of permanent mandibular first and second molars in a Kuwaiti population: A retrospective cone-beam computed tomography study

AimEndodontic diseases typically affect the mandibular molars. Understanding the complex morphology of the root canal system and its variations is necessary for successful endodontic treatment. The aim of this study was to evaluate the morphology of roots and root canals of mandibular first and second permanent molar teeth in a Kuwaiti population using cone-beam computed tomography (CBCT).Materials and methodsCBCT images of 651 mandibular first and second molar teeth were obtained from specialist government dental centers. The age, sex, root canal configuration, and number and type of roots were recorded. The data were statistically analyzed.ResultsThe most common canal configuration in the mandibular first and second molars was type II (65.6% and 54.4%, respectively), with no significant difference seen between the sexes (p = 0.234). The canal configuration was significantly different between the mandibular first and second molars (p < 0.001). Most teeth had two roots (94.5%); split roots were common (92.6%) and the number thereof varied significantly. Radicular grooves were most common on the lingual side (4.9%). C-shaped canals were present in 43 (6.60%) teeth. Additionally, one tooth had a confluent middle mesial canal and nine (1.4%) had radix entomolaris.ConclusionMandibular molars in our Kuwaiti population typically had two split roots with type II and IV canal configurations. The prevalence rates of C-shaped canals, middle mesial canals, and radix entomolaris were remarkably low.     

双侧下颌第一恒磨牙融合根伴C形根管1例

下颌第一恒磨牙的牙根通常为2~3根伴2~4个根管,融合根伴C形根管较罕见。本文报道1例双侧均为融合根伴C型根管的下颌第一恒磨牙患者。     

C-shaped root canals in mandibular second molars in a Chinese population

Abstract The purpose of this investigation was to study the prevalence of C-shaped roots, root canal orifices, and root canals in the mandibular second molars of a Chinese population. A total of 581 second mandibular molars were collected in Hong Kong and Taiwan. The teeth were demineralized and placed in methyl salicylate to induce transparency. The pulp chamber floor was examined to ascertain the number of root canal orifices. Chinese ink was then injected into the root canal system to demonstrate the root canal anatomy. The mandibular second molars had separate roots in 66.4%, cone-shaped roots in 2.1% and C-shaped roots in 31.5%. The C-shaped roots had C-shaped canal orifices in 68.3% (21.5% of whole material). True C-shaped root canals were observed in 65.8% of the teeth with C-shaped orifices and in 13.9% of the whole material. Separate root canals were seen in 34.2% of the teeth with C-shaped orifices. Separate canal orifices were found in 31.7% of the C-shaped roots and 7.4% of these roots had true C-shaped canals. In the whole material 0.9% of the roots with individual canal orifices had C-shaped canals. In conclusion, C-shaped root canals were common in mandibular second molars in the Chinese subjects studied. The C-shaped root canals were often, but not always recognized because of a C-shaped canal orifice.     

Association between impacted third molars and position of the mandibular canal: a morphological analysis using cone-beam computed tomography

Our aim was to assess the association between the angle of impaction of the third molar and the position of the mandibular canal on cone-beam computed tomography (CT). We designed a retrospective study of 100 cone-beam CT images of 173 mandibular third molars that were obtained between January 2012 and December 2015, and recorded the angle of impaction of the third molar, the position of the mandibular canal in relation to the impacted tooth, and the potential contact between the roots of the tooth and the mandibular canal. Most third molars tilted mesially (n = 33), while the mandibular canal was positioned below the roots of the third molar in most cases (n = 73). Contact between the two was most likely when the mandibular canal was between (RR = 1.49; 95% CI 1.27 to 1.75, p < 0.001), or to the lingual side (RR = 1.49; 95% CI 1.27 to 1.75, p < 0.001) of the roots of the tooth. These outcomes indicate a greater likelihood of contact between the canal and the roots when the canal is between, and to the lingual side, of the roots. We found no association between the angle of impaction and the position of the canal. These findings illustrate the importance of surgical planning using complementary imaging tests such as cone-beam CT.