根端囊肿是口腔科常见疾病，一般不难诊治。囊肿急性感染、化脓、向外债破，易误诊为颌面部脓肿，造成治疗上的错误，形成瘘管，久治不愈。笔者曾遇1例，误诊误治达4年之久。1误诊病例介绍患者马某，女，20岁，1991年3月，因颏部正中肿物伴疼痛1周，在本院外科门诊就诊，经穿刺 Root cyst is a common disease in dentistry, the general is not difficult to diagnosis and treatment. Cyst acute infection, purulent, broken to foreign debt, misdiagnosed as maxillofacial abscess, resulting in treatment errors, the formation of fistulas, long treatment. I have encountered in 1 case, misdiagnosis and mistreatment for up to 4 years. 1 misdiagnosed cases of patients Ma Mou, female, 20 years old, in March 1991, due to the middle of the chin with pain for 1 week, in our hospital surgical clinic, puncture