一般资料　患者 5 6例 ,其中男性 2 6例 ,女性 30例 ,年龄 31～78岁 ,平均年龄 5 1岁。既往都有半年以上慢性根尖周病病史 ,发病均在进藏后 4个月内。所有患者均穿刺抽出脓液 ,涂片查出不同类型厌氧菌及专性厌氧菌 ,其优势菌为产黑色素类杆菌、真菌、放线菌和消化链球菌等 ; General information 56 cases of patients, including 26 males and 30 females, aged 31 to 78 years old, with an average age of 51 years. Past history of chronic apical week more than six months, the incidence is within 4 months after entering Tibet. All patients were puncture pus extraction, smear detection of different types of anaerobic bacteria and obligate anaerobic bacteria, the dominant bacteria for the production of melanobacteria, fungi, Actinomyces and Peptostreptococcus;