100 颗成人下颌第一磨牙拔除原因,牙根外形、根管数目及形状研究

下颌第一恒磨牙因萌出早,处在左右侧颌骨的中份,所承担的咀嚼功能最大,发生疾病和失牙的概率高.为分析成人下颌第一磨牙拔除原因,进一步了解牙齿外形和根管解剖形态,提高下颌第一磨牙牙周病、牙髓病和根尖周病治疗的成功率,收集成人离体下颌第一磨牙100 颗,分析拔除原因;体视显微镜下观察、测量根长及不同部位根管数目和形状,为临床治疗下颌第一磨牙积累资料.

A study on the reason of extraction, length, number and transverse morphology of the root and root canals of 100 extracted first permanent mandibular molars

To investigate the reason of extraction, length, number and transverse morphology of the root and root canals of first permanent mandibular molars. 100 extracted first permanent mandibular molars were collected. The length of mesial and distal root of the first permanent mandibular molars was 13.00 mm and 13.51 mm separately. 75% double roots and 25% three roots were observed under the stereomicroscope. Difference of root number and shape of transverse morphology in mesial root were more obvious than those in distal roots of the same first mandibular molars in this study.