STRUCTURAL AND COMPOSITIONAL ALTERATION OF TOOTH ENAMEL IN HEREDITARYEPIDERMOLYSIS-BULLOSA

Epidermolysis bullosa (EB) is a group of conditions characterized by b asement membrane and cellular defects that result in skin fragility an d variable extra-cutaneous involvement. The teeth can be severely affe cted with marked enamel malformations, The purpose of this study was t o characterize the structure and composition of teeth from individuals representing the major EB groups (EE simplex, dystrophic EB and junct ional EB), Teeth were examined from 28 individuals with EB and 10 heal thy people unaffected by EB, Teeth from individuals with junctional EB had marked enamel hypoplasia with varying abnormalities in the enamel structure, Minor structural defects of enamel, including areas of sur face pitting, were seen in the other EB types, Although there was a sl ight reduction (approximate to 10%) in the enamel mineral content in s everal dystrophic EB and junctional EB teeth, the mean mineral content was similar for all EB enamel types and normal enamel, This study sho ws that while individuals with junctional EB have marked alteration of the enamel structure, the composition may be normal to only mildly al tered, Laminin-5, the molecular defect in junctional EB, is associated primarily with alteration in the amount and/or structure of enamel wh ile the mineralization process appears relatively intact, The marked e namel hypoplasia in this EB type suggests that laminin-5 plays an impo rtant role in the secretory phase of enamel development.