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

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