Abstract: With the continuous development of techniques such as cone beam CT and root canal microscopy，more and more studies have found the diversity and variability of the root and root canal morphology of maxillary second molars. Proper understanding of the root and root canal morphology of maxillary second molars is helpful to increase the success rate of clinical treatment. This article reviews the research progress in the classification methods and morphology of the root and root canal of maxillary second molars，aiming to provide reference for related clinical work.

Key words: maxillary second molars, root morphology, root canal morphology, root canal variation, root canal treatment

摘要： 随着锥形束CT和根管显微镜等技术的不断发展，越来越多的研究发现上颌第二磨牙牙根及根管形态的多样性和变异性。正确认识上颌第二磨牙牙根及根管形态，有助于提高临床治疗成功率。文章就上颌第二磨牙牙根及根管的分类方法及形态的研究进展做一综述，以期为相关临床工作提供参考。

关键词: 上颌第二磨牙, 牙根形态, 根管形态, 根管变异, 根管治疗