对1例青少年不明原因的牙齿萌出障碍的患者进行临床和影像学检查，原发性萌出障碍、不明确萌出障碍和机械性牙齿萌出障碍进行鉴别诊断。通过实验性拔牙、临床检查及锥形束CT（CBCT）观察，确诊为原发性萌出障碍。原发性萌出障碍是一种口腔罕见疾病，在没有遗传病史的情况下很难与其他类型的萌出障碍鉴别，实验性拔牙可以是很好的辅助手段。

Primary failure of eruption was diagnosed by oral general examination and CBCT. The features of primary failure of eruption, mechanical failure of eruption and indeterminate failure of eruption, especially differentiate points among them were discussed. The case of failure of eruption from right maxillary and mandible was diagnosed definitely by the combined application of oral general examination, experimental tooth extraction and CBCT. Primary failure of eruption is a rare phenomenon, which is difficult to be differentiated from other failure of eruption in the absence of a genetic history. Experimental tooth extraction can improve accuracy of diagnosis.