抄録
The present study is based on clinical and roentgenological observations of 12 cases of simple bone cyst that were encountered in past 3 years at Okayama University Dental School affiliated Hospital. The occurrence rate of simple bone cyst was 0.21% by roentgenographical evaluation of 5700 patients. The youngest patient was 11 years old and average age of cases was 23.9 years old. In one instanse cementomas were associated with cyst and the patient was relatively advanced age of 63 years. Cysts were present in the lower part of alveolar area of the mandible. In 8 cases the border of the lesions was weak and the nature of the inside radiolucency showed uniform radiopacity. In 4 cases small round more radiolucent area or soap bubble appearance were visible inside and showed scalloped resorption of both buccal and lingual sides of cortex at the same time. In case or cortical bone expansion, expansion was mild and the transition from the normal to the expanded site was gradual and smooth. The periodontal space and the lamina dura of adjacent dental roots were remained without any resorption but became thin. In a case with cementoma hypercementosis attached to a root apex projected into the radiolucent cavity. Of the 9 cases involving the mandibular canal 5 cases showed only a slight dislocation of the canal.
