目的:探讨上颌第一磨牙变异根管的诊断及治疗对策。方法:1例右上颌第一磨牙根管治疗病例,通过根尖片和清理髓腔及根管系统,探测出腭侧双根管,即刻对其进行冠向下法根管预备,超声荡洗后氢氧化钙封药,冷牙胶侧方加压充填根管。结果:术后6个月复查,患者无主观症状,咀嚼功能良好,X线片示根尖无病变,达到临床治疗成功标准。结论:临床上要减少遗漏根管,需要注意上颌第一磨牙根管治疗前的根管数目、位置的判断,以及治疗过程中髓腔入口的改良、根管定位及扩通,提高根管治疗的成功率。 Objective: To investigate the diagnosis and treatment of maxillary first molar modified root canal. Methods: One case of root canal of right maxillary first molars was treated by root canal and the canal and the root canal system. The palatal double root canal was detected and immediately followed by coronal root canal preparation and sonication Calcium hydroxide sealant, cold toothpaste lateral pressure filling root canal. Results: Six months after the operation, the patients had no subjective symptoms and good chewing function. X-ray showed no apical lesions and reached the standard of clinical treatment success. Conclusion: To reduce the missed root canal clinically, attention should be paid to the number of root canal before root canal root canal treatment, the location of the root canal, the improvement of the canal entrance, the root canal positioning and expansion, and the improvement of root canal therapy The success rate.