Search

Dermoid cysts of the jaw are exceedingly rare, and only six such cases have been documented. The present paper reports a case with multiple microcysts showing histological characteristics of dermoid cyst in the surgically resected mandibular bone. These cysts were located near the inferior border of the mandibular bone, and histologically composed of an inner thin layer of squamous epithelium with marked hyperorthokeratinization and an outer layer of fibrous tissue containing numerous mature sebaceous glands. In addition, a hair follicle-like epithelial sphere was seen in part. The present microcysts suggest that it arises de novo, and one possible cause of jaw cysts could be sequestration of the stomadeal ectoderm that may have been trapped deep in the surface and embedded in the developing mandibular bone during embryogenesis. It may not be possible that such cysts developed from the odontogenic epithelial remnant undergoing dermoid metaplasia.

An unusual case of sialolith with bone formation, occurring in the submandibular gland of a 33-year-old woman, is reported. In addition to the irregularly laminated structure of sialolith, sparsely scattered foci of bone tissue were found. Some of them were mature, lamellar bone with lacunae containing osteocytes, endosteum and a bone marrow-like element. Others were immature bone associated with or without multinucleated giant cells. Foci of bone tissue were in contact with caliculi or fibrous tissue, and no epithelial component was seen around them. These observations suggest that bone formation in the present case may be in the nature of pathological ossification, and that in the earlier stage, the bone that is deposited is woven and is replaced through successive remodeling cycles by lamellar bone. This is the first case of sialolith with bone formation, although sialolithiasis is a common disease of the salivary glands.