The secretion of amelogenins is associated with the induction of enamel and dentinoid in an ameloblastic fibro‐odontoma

Abstract

Ameloblastic fibro-odontoma is the unique entity of epithelial-ectomesenchymal odontogenic tumors, which is characterized by enamel formation in addition to dentine. We examined immunohistochemically a case of this tumor in which enamel having prism structures was developed in the absence of odontoblast differentiation but was in contact with mesenchymal matrices. Histological examination showed diverse morphological features of epithelial tumor cells, e.g., cuboidal cells comprising tooth bud-like projections, ameloblast- and stellate reticulum-like cells, and residual cells in forms of extended cords or islands of odontogenic epithelium. Immunostaining with anti-amelogenin sera proved that the intracellular production of amelogenins was initiated at the tooth bud-like stage. The secreted amelogenins were detected almost exclusively in the induced enamel and dentinoid areas, as well as in the core region of cementicle-like spheres deposited in the encapsulating stroma. The results obtained indicate that the odontogenic tumor epithelia and its products, i.e., amelogenins, participate in multifaceted aspects of dental hard tissue formation that takes place during oncogenesis.

Ameloblastic fibro-odontoma: Report of a case presenting an unusual clinical course

“…The case reported in the present study supports the hypothesis of a distinction between ameloblastic odontoma and complex odontoma, since the patient presented a lesion of highly aggressive behavior and was affected at a young age, thus indicating a neoplastic behavior for AFO, a fact reported by Yagishita et al (2001).…”

“…Calcified structures consisting of dentin-or osteodentin-like material, as well as an enamel matrix can be identified [6,7].…”

Clinical and Radiological Profile of Ameloblastic Fibro-Odontoma: an Update on an Uncommon Odontogenic Tumor Based on a Critical Analysis of 114 Cases

“…The unerupted teeth were usually displaced inferiorly in the mandible and superiorly in the maxilla. In a very few cases, the AFOs had developed between roots of erupted teeth, in the periapical area of erupted teeth, or in place of a tooth [10,56,61,63,65,84], Cases 2, 7, and 8 of the present study]. Root resorption caused by AFO was rare, having been reported in only three cases [33,56,74].…”

“…In a very few cases, the AFOs had developed between roots of erupted teeth, in the periapical area of erupted teeth, or in place of a tooth [10,56,61,63,65,84], Cases 2, 7, and 8 of the present study]. Root resorption caused by AFO was rare, having been reported in only three cases [33,56,74]. Perforation of the cortical plates is also uncommon, having been reported in only six cases [23,30,43,45,71,75].…”

The Receptor Activator of Nuclear Factor-κB Ligand-mediated Osteoclastogenic Pathway Is Elevated in Amelogenin-null Mice

“…In addition to the cementum resorption, the tooth roots of amelogenin-null mice exhibited increased numbers of cementicles adhering to the surface of the cementum. Recent reports showed calcified bodies known as psammoma-like ossicles and cementicles in the osteoblastoma and juvenile ossifying fibroma of the craniofacial skeleton (44,45). In rare pathological conditions, a large number of cementicles may fuse together to give rise to an odontogenic tumor (45,46).…”