截冠留根法拔除下颌第三磨牙时对下牙槽神经损伤的影响

［摘要］目的观察截冠留根法拔除下颌第三磨牙时对下牙槽神经损伤的影响。方法选取62例要求拔除下颌第三磨牙患者（智齿牙根尖与下颌管连结），按照拔除方式不同分为截冠留根组与传统拔牙组，比较2组术后1周下牙槽神经损伤发生率、出血率、术后疼痛时间及患者满意度，观察2组术后18个月感染发生率，观察截冠留根组患者不同时间点（术后6个月、12个月及18个月）断根移位情况。结果2组术后1周出血率比较差异无统计学意义（P＞0.05），截冠留根组下牙槽神经损伤发生率低于传统拔牙组（P＜0.05）；截冠留根组术后疼痛时间短于传统拔牙组（P＜0.01）；截冠留根组患者满意度优于传统拔牙组（P＜0.05）；2组术后18个月之内感染发生率比较差异无统计学意义（P＞0.05）；术后3个月断根移位（0.51±0.06） mm，术后6个月移位（1.14±0.13） mm，术后12个月移位（1.48±0.17） mm，术后18个月移位（1.50±0.18）mm，趋于稳定，21例经二次手术拔除断根。结论截冠留根法拔除下颌第三磨牙可减轻对下牙槽神经损伤，改善患者术后疼痛情况，获得其满意，具有临床可行性。

Effect of extraction of the mandibular third molar by coronectomy on inferior alveolar nerve inj ury

［Abstract］ Objective〖HTSS〗To observe the effects of extraction of the mandibular third molar by coronectomy on inferior alveolar nerve injury. 〖WTHZ〗Methods〖HTSS〗Sixty-two patients who requested for extraction of the mandibular third molar(root apex of the wisdom tooth connecting with mandibular canal) were selected and divided into the coronectomy group and the traditional extraction group according to the extraction method. The incidence of inferior alveolar nerve injury, bleeding rate, duration of postoperative pain and patient's satisfaction were compared between the two groups at 1 week after surgery. The incidence of infection in both groups at 18 months after surgery, the situation of root fracture displacement at different time points(6 months, 12 months and 18 months after surgery) were observed. 〖WTHZ〗Results〖HTSS〗There was no significant difference in the bleeding rate between the two groups at 1 week after surgery(P＞0.05). The incidence of inferior alveolar nerve injury in the coronectomy group was significantly lower than that in the traditional extraction group(0.00% vs 18.52%)(P＜0.05). The duration of postoperative pain in the coronectomy group was significantly shorter than that in the traditional extraction group(P＜0.01). The satisfaction of the coronectomy group was significantly better than that of the traditional extraction group(P＜0.05). There was no significant difference in the incidence rate of infection between two groups at 18 months after surgery(P＞0.05). The root fracture displaced(0.51±0.06) mm, (1.14±0.13) mm, (1.48±0.17) mm and (1.50±0.18) mm at 3 months, 6 months, 12 months and 18 months respectively after surgery, tending to be stable. 21 patients had their roots removed by secondary extraction. 〖WTHZ〗Conclusion〖HTSS〗Extraction of the mandibular third molar by coronectomy can alleviate the injury to the inferior alveolar nerve and relieve postoperative pain. It is satisfactory and with clinical feasibility.