术中CBCT降低下颌第三磨牙拔除术下齿槽神经损伤风险的价值

目的研究术中CBCT降低阻生下颌第三磨牙(mandibular third molar,MTM)拔除术下齿槽神经(interior alveolar nerve,IAN)损伤风险的应用价值。方法纳入2016年1月-2018年12月诊治的181例患者(244侧阻生MTM)为研究对象,所有患者术前接受影像学检查并拟定MTM拔除术,其中研究组115侧阻生MTM拔除时术中应用CBCT实时评估下颌神经管情况并引导手术,对照组129侧阻生MTM拔除时未行术中CBCT。术后1周随访评估拔牙侧IAN损伤及统计学分析。结果研究组均未出现IAN损伤,下颌神经管位于牙根颊侧、根下、舌侧、根间的例数为10:87:12:6;对照组出现IAN损伤6例,下颌神经管位于牙根颊侧、根下、舌侧、根间的例数为11:94:16:8。研究组和对照组患者IAN损伤的情况差异存在统计学意义(P=0.0309)。舌侧型下颌神经管两组患者出现IAN损伤的差异存在统计学意义(P=0.0237),而颊侧、根下、根间型下颌神经管中差异无统计学意义。结论阻生MTM拔除术中CBCT可实时评估下颌神经管并引导手术,降低IAN损伤的风险。

Value of Intraoperative CBCT in Reducing the Risk of Interior Alveolar Nerve Injury During Extraction of Mandibular Third Molar

Objective To explore the value of intraoperative cone-beam computed tomography(CBCT) in extraction of mandibular third molar(MTM) for reducing the risk of interior alveolar nerve(IAN) injury. Methods From January 2016 to December 2018, 181 patients(presenting with 244 impacted MTM) were enrolled. All patients were diagnosed impacted MTM by CBCT and the extractions of MTM were performed. Of 115 cases of the study group, intraoperative CBCT was used to evaluate the spatial relationship of MTM and mandibular canal(MC) and guide the operation. The rest 129 cases of impacted MTM extraction were performed without intraoperative CBCT, defined as the control group. The IAN injury assessment and statistical analysis were performed one week after surgery. Results Six cases of IAN injury were confirmed in the control group while no IAN injury was found in the study group. The number of cases in which MC located in buccal, under the roots, lingual and between the roots of MTM was 10:8:12:6 in the study group and 11:94:16:8 in the control group. There was statistically significant difference in IAN injury between the study and control group(P=0.0309). Subgroups analysis showed a significant difference of IAN injury in lingual type of MC(P=0.0237), but no differences in other types of MC. Conclusion The intraoperative CBCT in extraction of impacted MTM can monitors the mandibular canal and guides operation, thus reducing the risk of IAN injury.