2014 年 5 巻 1 号 p. 40-44
Metaplasia is a reversible change in which one adult cell type is replaced by another adult cell type, and this phenomenon is usually associated with inflammation and neoplasms. Although metaplasia is also observed in the dental pulp consisting of cementum-like and/or osteoid tissues, it is rarely observed in human dental pulp tissues. We evaluated the histopathological characteristics of cemental metaplasia in the non-treated human dental pulp tissues of surgical specimens to treat squamous cell carcinoma or ameloblastoma. The histopathological study revealed cementum-like tissues with embedded cells, a lamellar structure, and Sharpey’s fiber-like features adjacent to the dentin in the dental pulp, showing cemental hyperplasia of the root and/or root resorption by progression of ameloblastoma. The metaplastic cementum-like tissue was mixed with dystrophic calcification in some areas. These findings suggest that the presence of cemental metaplasia and dystrophic calcification in the dental pulp should be considered in endodontic clinics. In addition, these structures might be associated with chronic stimuli and/or aging.
