Abstract

Genetic alterations of enamel and dentin include different sub-groups recognized on the basis of their clinical appearance.Ameloblasts secrete three major enamel ECM proteins: AMEL (amelogenin associated with Amelogenesis Imperfecta phenotypes, ranging from hypoplastic to hypomineralized enamel), AMBN (ameloblastin) and ENAM (enamelin) They are localized within a cluster of genes critical to biomineralization mapped on chromosome 4q21. Hypoplastic enamel displays secretory defects (pitted, rough or local). Hypomineralized (with eruption pathology), hypocalcified types with mineralization defects, and hypomature enamel result to altered protein processing and crystallite maturation defects. They display a chalky appearance, orange, brown or white colour. Enamel is pigmented, snow capped. Dentin defects are classified into three types of Dentinogenesis Imperfecta (DGI, types I-III) and two types Dentin Dysplasia (DDs, types I and II).DGI type II was originally called hereditary opalescent dentin or Capdepont’s teeth. Clinically, DGI-II is characterized by soft blue-brown, translucent teeth (opalescent teeth).Abnormal dentin obliterate the pulp chamber of DD type I.Genetically altered enamel and dentin structures allow significant insigths on dental tissue genetic alterations, and consequently increase our understanding of the formation of normal dental tissues. The affected dental tissues involve gene mutations, translated into structural proteins and/or implicated in the composition of dental tissues. This shed light on the cleavage of the constituent molecules of the ECM.

Keywords

proteins, molecules, phenotypes, dental tissues, gene mutations, heterogeneity, clinical appearance, autosomal recessive, basement membrane, maturation stage, enamel crystallites, gene