Yadav Rakesh-Kumar, Tandon Jyoti, Jasrasaria Neha
Professor. Conservative Dentistry and Endodontics KGMU, Lucknow.
Senior Resident. Conservative Dentistry and Endodontics KGMU, Lucknow.
J Clin Exp Dent. 2023 Feb 1;15(2):e135-e141. doi: 10.4317/jced.60063. eCollection 2023 Feb.
To evaluate bilateral symmetry and anatomical variations of root morphology of permanent mandibular second molar using systematic evaluation of CBCT scans.
This cross-sectional study involved the mandible which were imaged using serial axial cone-beam computed tomography (CBCT) from 680 North Indian patients who visited dental hospital for various reasons unrelated to the study. CBCT Records with presence of bilateral fully erupted permanent mandibular second molars with fully formed apexes were selected.
Bilaterally present two root and three canal configurations were most consistently seen (75.88 % and 59.11 %, respectively). The occurrence of two roots with two canals and four canals was 15.14% and 1.61% respectively. Mandibular second molar present with one extra root, radix entomolaris with three canals and four canals was 0.44% and 3.53% while radix paramolaris present with three canals and four canals 1.32% and 1.03% respectively. The occurrence of C-shaped root bilaterally with C shaped canal was 15.88% whereas the presence of one fused root bilaterally was 0.44%. The presence of four roots bilaterally with four canals was identified in only one CBCT scanned image (0.14%). The frequency distribution of root morphology on bilateral symmetrical analysis revealed 98.58 % bilateral symmetry.
In 402 CBCT scans, bilateral presence of two roots with three canals was the most typical root structure seen in mandibular second molars (59.11%). A rare variation found was the presence of four roots occurring bilaterally, seen in only 1 CBCT scan. Bilateral symmetrical analysis of root morphology revealed 98.58 % bilateral symmetry. Anatomic root variations, mandibular second molar, Cone Beam Computed Tomography scans, bilateral symmetry.
通过对锥形束计算机断层扫描（CBCT）图像进行系统评估，以评价恒牙下颌第二磨牙牙根形态的双侧对称性及解剖变异情况。
本横断面研究纳入了680名因与本研究无关的各种原因前往牙科医院就诊的北印度患者的下颌骨，对其进行了系列轴向锥形束计算机断层扫描（CBCT）成像。选择存在双侧完全萌出且根尖完全形成的恒牙下颌第二磨牙的CBCT记录。
双侧出现两根和三根管形态的情况最为常见（分别为75.88%和59.11%）。出现两根且有两个根管和四个根管的情况分别为15.14%和1.61%。下颌第二磨牙出现一根额外牙根、远中根且有三个根管和四个根管的情况分别为0.44%和3.53%，而出现副根管且有三个根管和四个根管的情况分别为1.32%和1.03%。双侧出现C形牙根及C形根管的情况为15.88%，而双侧出现一根融合根的情况为0.44%。仅在一张CBCT扫描图像中发现双侧出现四根且有四个根管的情况（0.14%）。双侧对称分析显示牙根形态的频率分布有98.58%呈双侧对称。
在402例CBCT扫描中，双侧出现两根且有三根管是下颌第二磨牙最典型的牙根结构（59.11%）。发现的一种罕见变异是双侧出现四根，仅在1例CBCT扫描中可见。牙根形态的双侧对称分析显示98.58%呈双侧对称。解剖性牙根变异、下颌第二磨牙、锥形束计算机断层扫描、双侧对称
