Libfeld H, Rotstein I
J Endod. 1989 Mar;15(3):129-31. doi: 10.1016/S0099-2399(89)80134-7.
A study of 1,200 teeth was carried out in order to determine the occurrence of four-rooted maxillary second molars. One-thousand untreated teeth were examined radiographically. Two-hundred teeth were evaluated radiographically following endodontic treatment. The results indicated that only 0.4% of the teeth presented with four separate roots. Endodontic therapy in such a tooth is described.
为了确定上颌第二磨牙四根的发生率，对1200颗牙齿进行了一项研究。对1000颗未经治疗的牙齿进行了影像学检查。对200颗牙齿在根管治疗后进行了影像学评估。结果表明，只有0.4%的牙齿有四个独立的牙根。本文描述了对这类牙齿的根管治疗。
