歯原性角化嚢胞の臨床病理組織学的検討

Abstract

The name odontogenic keratocyst was given to cysts which may undergo keratinization. By Philipsen in 1956 many studies have since shown that this cyst should be recognized as a separate entity. Furthermore, it may be associated with the basal cell nevus syndrome (BCNS).In this paper, a detailed analysis was made of the clinicopathologic findings of 16 cysts from 13 patients experienced over a period of 12 years, and certain clinicopathologic features were discussed. The following results were obtained.1. Odontogenic keratocysts comprised 10. 6 per cent of the total jaw cysts in this study.2. The most common site was the mandibular molar region. The mean age of the patients was 26. 4 years, the frequency was relatively high below the age of 20 years, and there was a male predominance. The cyst fluids were often like yellow ‘tofu’ or yellow ‘mud’ in their appearance.3. Some cysts were found accidentally by X-ray. The radiographic appearance could be commonly described as a unilocular cystic radiolucency with a well-defined smooth periphery. About one third of the cysts were bordered by a sclerotic border of surrounding bone, and about one half of them were found in association with an impacted tooth. Root absorption was observed in 2 cysts.4. Three cysts (21.4 per cent) appeared to have recurred after a mean of 7 years 3 months, as indicated by the radiographically unilocular appearance, and they were closed primarily after extirpation. The following factors seem tenable as the mechanism of recurrence: remnants of dental lamina epithelium within the jaws, incomplete removal of the original cyst lining, and epithelial islands within the cyst capsules. Therefore, such patients should have periodic follow-up including radiographic examination for the first time 5 years or more postoperatively.5. We believe that the treatment of odontogenic keratocysts should be total enucleation en bloc. When adhesion to the surrounding tissue and/or a bone defect exists, bone curratage and excision of the surrounding soft tissue must be done. Marsupialization may be still a good procedure in young patients with large odontogenic keratocysts.6. With regard to pathologic features, epithelial islands and daughter cysts were the most common findings, although, in general, there were various other findings togethet with them. Odontogenic keratocyst epithelium is believed to originate in the dental lamina or its remnants, in the enamel organ before tooth formation, in reduced enamel epithelium, and in epithelial cells of the primitive oral cavity. Therefore, we propose that jaw cysts with keratinizing epithelium should be called ‘Keratocysts’.7. Three BCNS patients (23.1 per cent) were included in this study and the importance of a wide and detailed family pedigree was reconfirmed.