title: Soft-tissue calcifications of the dental follicle in regional odontodysplasia: a structural and ultrastructural study.
abstract: Soft-tissue calcifications of the dental follicle in regional odontodysplasia were studied via the correlated techniques of light microscopy, scanning electron microscopy (SEM), calcium x-ray cartography, and high-resolution transmission electron microscopy (TEM). The study revealed several types of calcification, mostly located within an area normally occupied by enamel formation. Some of them are produced without collagen being involved; others result from the mineralization of collagen fibers. Sometimes they were surrounded by a structureless homogeneous zone and resulted from the fusion of several smaller globules. High-resolution TEM revealed two different types of calcifications: a few composed of platelike crystallites, presenting a "sheath" characteristic of apatite formation, most of them poorly crystallized. The calcifications were in close contact with the cytoplasm of the neighboring connective tissue cells in which an abundance of microfilaments was found. It is suggested that these filaments might be involved in the formation of dystrophic soft-tissue calcifications.
mesh_terms: D000293:Adolescent; D002114:Calcinosis / Q000473:pathology*; D003795:Dental Sac / Q000473:pathology* / Q000648:ultrastructure; D005260:Female; D006801:Humans; D008855:Microscopy, Electron, Scanning; D018126:Odontodysplasia / Q000473:pathology*; D014076:Tooth Diseases / Q000473:pathology; D014083:Tooth Germ / Q000473:pathology*