Lavanya A, Tewari Rajendra Kumar, Ali Sajid, Mahajan Puneet, Yusufi Faiz Noor Khan
Department of Conservative Dentistry and Endodontics, Dr. ZADC, AMU, Aligarh, Uttar Pradesh, India.
Indian Institute of Technology (IIT), New Delhi, India.
J Conserv Dent Endod. 2023 Sep-Oct;26(5):584-589. doi: 10.4103/JCDE.JCDE_52_23. Epub 2023 Sep 16.
This study evaluated the prevalence, configurations, and correlation of isthmuses at coronal, middle, and apical root 3 in mandibular molars of the Indian population using micro-computed tomography μCT).
One hundred and five permanent mandibular molar teeth were scanned under μCT. The axial sections were analyzed at the coronal, middle, and apical thirds of the root for isthmus types and classified according to Hsu and Kim's classification. Descriptive statistics for each isthmus type were calculated. The correlations between the apical, middle, and coronal thirds of the root were determined using Pearson's correlation coefficient.
Type IV isthmus was the most common in the coronal third of the mesial root of mandibular 1 molar (42.9%), while Type V was prevalent in the coronal third of the mesial root of 2 molar (42.9%). Type I isthmus was found to be highly prevalent in the middle 3 (71.4%) and apical 3 (61.9%) of mesial roots of 1 molars, and in the middle 3 (71.4%) and apical 3 (42.9%) of mesial roots of 2 molars. Type V isthmus was the most prevalent in all the thirds of the distal roots of both 1 and 2 molars, ranging from 40% to 50%. Furthermore, a strong correlation of 0.965 ( < 0.01) was found between the isthmuses in the apical and middle thirds of roots.
There are variations in the prevalence and type of isthmuses across different sections of the root, including the presence of atypical isthmuses. Micro-CT with high-resolution imaging and three-dimensional reconstruction is crucial for investigating root canal morphology. Clinicians could benefit from considering demographic characteristics to better predict the presence of isthmus variations.
The isthmus configurations and frequency differ at each section of mandibular teeth.
本研究使用微计算机断层扫描（μCT）评估印度人群下颌磨牙在冠部、中部和根尖三分之一处峡部的患病率、形态及相关性。
对105颗恒牙下颌磨牙进行μCT扫描。在牙根的冠部、中部和根尖三分之一处的轴向切片分析峡部类型，并根据许和金的分类法进行分类。计算每种峡部类型的描述性统计数据。使用Pearson相关系数确定牙根根尖、中部和冠部三分之一之间的相关性。
IV型峡部在下颌第一磨牙近中根冠部三分之一处最为常见（42.9%），而V型峡部在下颌第二磨牙近中根冠部三分之一处最为常见（42.9%）。I型峡部在下颌第一磨牙近中根中部三分之一（71.4%）和根尖三分之一（61.9%）以及下颌第二磨牙近中根中部三分之一（71.4%）和根尖三分之一（42.9%）中高度常见。V型峡部在下颌第一和第二磨牙远中根的所有三分之一处最为常见，范围在40%至50%之间。此外，在牙根根尖和中部三分之一处的峡部之间发现了0.965的强相关性（<0.01）。
牙根不同部位峡部的患病率和类型存在差异，包括非典型峡部的存在。具有高分辨率成像和三维重建功能的微CT对于研究根管形态至关重要。临床医生可通过考虑人口统计学特征更好地预测峡部变异的存在而受益。
下颌牙齿各部位的峡部形态和频率不同。
