融合牙和多生牙是临床常见的牙齿发育异常。融合牙常由两个正常牙胚融合而成,可以是完全融合的,也可以是不完全融合的,多出现在下前牙区;多生牙则是正常牙数之外多生的牙,多见于上颌两中切牙之间;然而两者同时出现的概率较小[1]。现报告1例下颌第二磨牙与多生牙融合并伴有牙周疾病和牙体龋损的复杂病例及其治疗体会。 Fusion teeth and multiple births are clinically common dental development. Fusion often consists of two normal tooth germ fusion, can be completely integrated, can also be incomplete fusion, mostly in the lower anterior teeth area; polygamy is more than the normal number of teeth more teeth, more Seen in the maxillary incisors between the two; however, the probability of both simultaneously smaller [1]. Now report a case of mandibular second molar and multiple teeth combined with periodontal disease and dental caries complicated cases and treatment experience.