锥形束CT在下颌阻生第三磨牙微创拔牙术中的应用

Application of cone beam computed tomography in minimally invasive dental extraction for impacted mandibular third molar

目的探讨锥形束CT(cone beam computed tomography,CBCT)在下颌阻生第三磨牙(impacted mandibular third molar,IMTM)微创拔牙术中的应用价值。方法筛选2014年朝阳医院口腔科需要进行IMTM拔除、全景曲面体层片(panoramic radiography,PAN)显示IMTM根尖部与下颌管相邻、部分重叠或显影不清的患者,分为试验组和对照组,试验组术前进一步CBCT检查,而对照组仅拍摄PAN。每组男、女患者各30例。采用微创拔牙术拔除IMTM。术后立即记录拔牙时间、术中断根情况,术后3d电话回访患者疼痛、出血、肿胀及下唇麻木情况。结果试验组的拔牙时间、断根率、术后疼痛发生率、术后出血发生率、术后肿胀发生率以及术后下唇麻木发生率(分别为11.7min、5、8.3、5、16.7和0)低于对照组(分别为13.1min、16.7、20、11.7、28.3和6.7),其中拔牙时间、断根率及术后下唇麻木发生率具有统计学显著性差异。结论根据本研究结果,CBCT应用于IMTM微创拔牙术可进一步提高手术的安全性,达到更好的微创效果。

Objective To investigate the application of cone beam computed tomography（CBCT）in minimally invasive dental extraction for impacted mandibular third molar（IMTM）. Methods Patients that require IMTM extraction with neighboring or partially overlapped or obscure images of IMTM tip and mandibular canal upon panoramic radiography（PAN） were selected. The patients were divided into a treatment group and a control group. A further CBCT test was performed for each of the patients in the treatment group and only PAN was performed for each of the patients in the control group. And 30 males and 30 females were included in each group. Minimally invasive dental extraction was performed for the IMTM. The extraction time and cases with broken tooth roots were recorded immediately after the operation. The patients were followed up 3 days after the operation through phone calls for such symptoms as pains,bleeding, swelling, and lower lip numbness. Results The extraction time, the rate of broken tooth, the rate of post operation pains, the rate of post operation bleeding, the rate of post operation swelling, and the rate of post operation lower limb numbness（11.7min, 5%, 8.3%, 5%, 16.7and 0respectively） were lower than those of the control group（13.1min, 16.7%, 20%, 11.7%, 28.3and 6.7%）. And the differences in the extraction time, the rate of broken tooth and the rate of post operation numbness are statistically significant differences. Conclusion According to the results of this study, the use of CBCT in minimally invasive dental extraction of IMTM can further improve the safety of this operation to ensure better minimally invasive effects.