MICROANATOMY OF THE DENTAL ENAMEL IN AUTOIMMUNE POLYENDOCRINOPATHY-CANDIDIASIS-ECTODERMAL DYSTROPHY (APECED) - REPORT OF 3 CASES

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED ) is an autosomal recessive disease composed of failure of various end ocrine glands, chronic mucocutaneous candidiasis, and an ectodermal dy strophy complex including hypoplasia of the dental enamel. To characte rize the enamel defect further, we studied enamel microanatomy by ligh t microscopy and scanning electron microscopy in clinically affected p ermanent teeth from three APECED patients. In all three cases, the ena mel was partially hypoplastic and morphologically aberrant. Hypoplasia was evident as a horizontal band or as rows of pits. The incremental pattern in the abnormal enamel was obscure, and the prisms were either barely detectable or accentuated and disoriented. In scanning electro n microscopy, imprints of the Tomes' processes were seen on the enamel surface, but the perikymata were poorly contoured. The distribution p attern of the defective enamel corresponded to the sequence of tooth d evelopment and was suggestive of a transient insult. In the enamel aff ected with a hypoplastic pitted form of amelogenesis imperfecta, studi ed for comparison, only local hypoplastic defects were seen. Together with normal parathyroid function in one patient and normal calcificati on of dentin in one of the two patients with hypoparathyroidism, morph ology of the enamel in APECED appears to preclude calcium deficiency a s the primary cause of the enamel dystrophy.