Observations on the enamel of odontomas.
The morphological study of odontomas provides an alternative model for observing the formation of dental tissues, since different maturing stages are present simultaneously. Investigations were performed on decalcified samples (using light microscopy and transmission electron microscopy) and on undecalcified samples of complex odontoma enamel (using transmission electron microscopy). Simultaneous presence of prismatic enamel at various maturing stages with different structural characteristics was observed. Such enamel was sometimes associated with layers of ameloblastic cells with characteristics of cells in functional activity. In other sites, the enamel did not present a prismatic structure but it appeared as unstructured material clusters with abundant organic component. It was concluded that the theory according to which an ecto-mesenchymal inductive failure occurs in odontomas is not confirmed. The defect seen at the beginning of the differentiated and anomalous tissue maturation may be related to latest events in the development of the enamel organ. In this regard, it was concluded that such events involve the efficiency of the ameloblasts and the possible alterations in the organic matrix.
Marchetti
C
C
Istituto di Istologia ed Embriologia Generale, Università di Pavia, Italy.
Piacentini
C
C
Menghini
P
P
Reguzzoni
M
M
D000293:Adolescent; D000328:Adult; D000565:Ameloblasts / Q000648:ultrastructure; D003743:Dental Enamel / Q000648:ultrastructure*; D006801:Humans; D008339:Mandibular Neoplasms / Q000648:ultrastructure*; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D009810:Odontoma / Q000648:ultrastructure*