[Using fenestration and decompression technique to treat enormous odontogenic keratocyst]

3 cases of enormous odontogenic keratocyst were treated with the technique of fenestration and decompression other than removal of jaws. After a follow-up period of two years, radiographic assessment showed that the image of keratocyst disappeared basically, neogenetic bone had been found and the defect of jaws had been restored. The teeth had no dysfunction, the lower lip had no numbness and the keratocyst epithelium was modulated histologically to mucosa after decompression. Fenestration and decompression are satisfied conservative approaches to treat enormous keratocyst which usually is treated by removal of jaws and extraction of teeth.