The syndrome of enamel dysplasia with hamartomatous atypical follicular
hyperplasia (EDHFH) is an unusual syndrome and is unique to black South Africans. Major criteria for the syndrome are enamel dysplasia with generalized
amelogenesis imperfecta-like features and atypical hyperplastic dental follicles with microscopic features of central odontogenic
fibroma WHO-type (follicle analogue) attached to the
crowns of multiple
impacted teeth. Minor features of some cases are anterior
open-bite malocclusion,
supernumerary teeth, pulpal calcification, aberrant roots with
hypercementosis, and
hypodontia. The pathogenic mechanisms that lead to the development of EDHFH are unknown. We speculate that faulty synthesis of
enamel matrix proteins may interfere with enamel formation and play a role in the generalized
enamel hypoplasia described in this syndrome. Alterations in inductive signalling by the odontogenic epithelium mediated by
enamel matrix proteins may explain the development of the follicle analogues, the root
hypercementosis and the presence of dysplastic cementum deposition juxtaposed to odontogenic epithelium in the
gingival overgrowth. Thus, alterations in the function of enamel matrix
protein function, may be the common denominator responsible for the development of the EDHFH phenotype.