Enamel Formation and Amelogenesis Imperfecta

Dental enamel is the epithelial-derived hard tissue covering the crowns of teeth. It is the most highly mineralized and hardest tissue in the body. Dental enamel is acellular and has no physiological means of repair outside of the protective and remineralization potential provided by saliva. Enamel is comprised of highly organized hydroxyapatite crystals that form in a defined extracellular space, the contents of which are supplied and regulated by ameloblasts. The entire process is under genetic instruction. The genetic control of amelogenesis is poorly understood, but requires the activities of multiple components that are uniquely important for dental enamel formation. Amelogenesis imperfecta (AI) is a collective designation for the variety of inherited conditions displaying isolated enamel malformations, but the designation is also used to indicate the presence of an enamel phenotype in syndromes. Recently, genetic studies have demonstrated the importance of genes encoding enamel matrix proteins in the etiology of isolated AI. Here we review the essential elements of dental enamel formation and the results of genetic analyses that have identified disease-causing mutations in genes encoding enamel matrix proteins. In addition, we provide a fresh perspective on the roles matrix proteins play in catalyzing the biomineralization of dental enamel.

[1]  H. Sekiguchi,et al.  A Novel Missense Mutation (p.P52R) in Amelogenin Gene Causing X-linked Amelogenesis Imperfecta , 2007, Journal of dental research.

[2]  A. Nanci,et al.  Cloning of rat amelotin and localization of the protein to the basal lamina of maturation stage ameloblasts and junctional epithelium. , 2006, The Biochemical journal.

[3]  K. Weiss,et al.  Evolutionary genetics of vertebrate tissue mineralization: the origin and evolution of the secretory calcium-binding phosphoprotein family. , 2006, Journal of experimental zoology. Part B, Molecular and developmental evolution.

[4]  Jung‐Wook Kim,et al.  Mutational analysis of candidate genes in 24 amelogenesis imperfecta families. , 2006, European journal of oral sciences.

[5]  P. Krebsbach,et al.  Proteomics and Genetics of Dental Enamel , 2006, Cells Tissues Organs.

[6]  M. Wendel,et al.  Amelotin—a Novel Secreted, Ameloblast-specific Protein , 2005, Journal of dental research.

[7]  K. Lyroudia,et al.  Genes and Related Proteins Involved in Amelogenesis Imperfecta , 2005, Journal of dental research.

[8]  O. BlancaUrzúa,et al.  [Genetic, clinical and molecular analysis of a family affected by amelogenesis imperfecta]. , 2005 .

[9]  M. Ozdemir-Karatas,et al.  MMP20 Active-site Mutation in Hypomaturation Amelogenesis Imperfecta , 2005, Journal of dental research.

[10]  E. Fıratlı,et al.  Phenotype of ENAM Mutations is Dosage-dependent , 2005, Journal of dental research.

[11]  P. T. Sharpe,et al.  Cell lineage of primary and secondary enamel knots , 2005, Developmental dynamics : an official publication of the American Association of Anatomists.

[12]  J. T. Wright,et al.  The psychosocial impact of developmental dental defects in people with hereditary amelogenesis imperfecta. , 2005, Journal of the American Dental Association.

[13]  M. Escamilla,et al.  DLX3 mutation associated with autosomal dominant amelogenesis imperfecta with taurodontism , 2005, American journal of medical genetics. Part A.

[14]  F. Seymen,et al.  ENAM Mutations in Autosomal-dominant Amelogenesis Imperfecta , 2005, Journal of dental research.

[15]  T. Hart,et al.  MMP-20 mutation in autosomal recessive pigmented hypomaturation amelogenesis imperfecta , 2005, Journal of Medical Genetics.

[16]  Blanca Urzúa O,et al.  [Genetic, clinical and molecular analysis of a family affected by amelogenesis imperfecta]. , 2005, Revista medica de Chile.

[17]  A. Kulkarni,et al.  Ameloblastin is a cell adhesion molecule required for maintaining the differentiation state of ameloblasts , 2004, The Journal of cell biology.

[18]  J. T. Wright,et al.  Increased bone density associated with DLX3 mutation in the tricho-dento-osseous syndrome. , 2004, Bone.

[19]  A. Klausegger,et al.  Analysis of the LAMB3 gene in a junctional epidermolysis bullosa patient reveals exonic splicing and allele-specific nonsense-mediated mRNA decay , 2004, Laboratory Investigation.

[20]  J. T. Wright,et al.  Mutation in kallikrein 4 causes autosomal recessive hypomaturation amelogenesis imperfecta , 2004, Journal of Medical Genetics.

[21]  P. Sharpe,et al.  The cutting-edge of mammalian development; how the embryo makes teeth , 2004, Nature Reviews Genetics.

[22]  J-W Kim,et al.  Amelogenin p.M1T and p.W4S Mutations Underlying Hypoplastic X-linked Amelogenesis Imperfecta , 2004, Journal of dental research.

[23]  N. Thomas,et al.  Identification of a nonsense mutation in the amelogenin gene (AMELX) in a family with X-linked amelogenesis imperfecta (AIH1) , 1992, Human Genetics.

[24]  M. Gorry,et al.  Novel ENAM mutation responsible for autosomal recessive amelogenesis imperfecta and localised enamel defects , 2003, Journal of medical genetics.

[25]  Y. Yamakoshi,et al.  Enamelin and autosomal-dominant amelogenesis imperfecta. , 2003, Critical reviews in oral biology and medicine : an official publication of the American Association of Oral Biologists.

[26]  M. Gorry,et al.  Exclusion of candidate genes in two families with autosomal dominant hypocalcified amelogenesis imperfecta. , 2003, European journal of oral sciences.

[27]  T. Hart,et al.  Identification of the enamelin (g.8344delG) mutation in a new kindred and presentation of a standardized ENAM nomenclature. , 2003, Archives of oral biology.

[28]  Antonio Nanci,et al.  Ten Cate's Oral Histology: Development, Structure, and Function , 2003 .

[29]  P. Sharpe,et al.  Tooth and jaw: molecular mechanisms of patterning in the first branchial arch. , 2003, Archives of oral biology.

[30]  H. Birkedal‐Hansen,et al.  Enamelysin (Matrix Metalloproteinase 20)-deficient Mice Display an Amelogenesis Imperfecta Phenotype* , 2002, The Journal of Biological Chemistry.

[31]  J. Simmer,et al.  Enamelysin and kallikrein-4 mRNA expression in developing mouse molars. , 2002, European journal of oral sciences.

[32]  G. Holmgren,et al.  A nonsense mutation in the enamelin gene causes local hypoplastic autosomal dominant amelogenesis imperfecta (AIH2). , 2002, Human molecular genetics.

[33]  T. Hart,et al.  A nomenclature for X-linked amelogenesis imperfecta. , 2002, Archives of oral biology.

[34]  C. Gibson,et al.  A new frameshift mutation encoding a truncated amelogenin leads to X-linked amelogenesis imperfecta. , 2002, Archives of oral biology.

[35]  S. Oida,et al.  Calcium binding of enamel proteins and their derivatives with emphasis on the calcium-binding domain of porcine sheathlin. , 2001, Archives of oral biology.

[36]  R. Davies,et al.  Mutation of the gene encoding the enamel-specific protein, enamelin, causes autosomal-dominant amelogenesis imperfecta. , 2001, Human molecular genetics.

[37]  S. Keranen,et al.  Enamel Knots as Signaling Centers Linking Tooth Morphogenesis and Odontoblast Differentiation , 2001, Advances in dental research.

[38]  H. Sekiguchi.  DNA Diagnosis of X-linked Amelogenesis Imperfecta Using PCR Detection Method of the Human Amelogenin Gene , 2001 .

[39]  G. Foster,et al.  Detection of a Novel Mutation in X-linked Amelogenesis Imperfecta , 2000, Journal of dental research.

[40]  M. Dean,et al.  Brief communication: the timing of linear hypoplasias on human anterior teeth. , 2000, American journal of physical anthropology.

[41]  M. Yamauchi,et al.  Unique Enamel Phenotype Associated with Amelogenin Gene (AMELX) Codon 41 Point Mutation , 2000, Journal of dental research.

[42]  C.H. Zhang,et al.  Cloning Human Enamelin cDNA, Chromosomal Localization, and Analysis of Expression during Tooth Development , 2000, Journal of dental research.

[43]  C. Gibson,et al.  Mutational analysis of X-linked amelogenesis imperfecta in multiple families. , 2000, Archives of oral biology.

[44]  T. Hart,et al.  Tricho‐dento‐osseous syndrome and amelogenesis imperfecta with taurodontism are genetically distinct conditions , 1999, Clinical genetics.

[45]  J. Moradian-Oldak,et al.  The structural biology of the developing dental enamel matrix. , 1999, Journal of structural biology.

[46]  D. Bowden,et al.  A common DLX3 gene mutation is responsible for tricho-dento-osseous syndrome in Virginia and North Carolina families. , 1998, Journal of medical genetics.

[47]  D. Bowden,et al.  Identification of a mutation in DLX3 associated with tricho-dento-osseous (TDO) syndrome. , 1998, Human molecular genetics.

[48]  H. Slavkin,et al.  Ameloblastin: Gene Structure, Expression of Isoforms, and Role in Enamel Formation , 1998 .

[49]  A. Nanci,et al.  Protein Synthesis by Ameloblasts and Selective Accumulation of Some Nonamelogenins at Enamel Growth Sites , 1998 .

[50]  C. Smith,et al.  Cellular and chemical events during enamel maturation. , 1998, Critical reviews in oral biology and medicine : an official publication of the American Association of Oral Biologists.

[51]  L. Sorokin,et al.  Differential expression of laminin α chains during murine tooth development , 1997 .

[52]  M. Fukae,et al.  Cloning and Characterization of Porcine Enamelin mRNAs , 1997, Journal of dental research.

[53]  I. Thesleff,et al.  Signalling networks regulating dental development , 1997, Mechanisms of Development.

[54]  S. Hillson,et al.  Relationship of enamel hypoplasia to the pattern of tooth crown growth: a discussion. , 1997, American journal of physical anthropology.

[55]  C. Gibson,et al.  An amelogenin gene defect associated with human X-linked amelogenesis imperfecta. , 1997, Archives of oral biology.

[56]  A. Fincham,et al.  Amelogenin proteins of developing dental enamel. , 1997, Ciba Foundation symposium.

[57]  I. Thesleff,et al.  The enamel knot: a putative signaling center regulating tooth development. , 1997, Cold Spring Harbor symposia on quantitative biology.

[58]  L. Sorokin,et al.  Differential expression of laminin alpha chains during murine tooth development. , 1997, Developmental dynamics : an official publication of the American Association of Anatomists.

[59]  T. Satoda,et al.  IMMUNOCHEMICAL AND IMMUNOCYTOCHEMICAL STUDY OF A 15 kDa NON-AMELOGENIN AND RELATED PROTEINS IN THE PORCINE IMMATURE ENAMEL: PROPOSAL OF A NEW GROUP OF ENAMEL PROTEINS ‘SHEATH PROTEINS’ , 1995 .

[60]  E. Salido,et al.  Amelogenin signal peptide mutation: correlation between mutations in the amelogenin gene (AMGX) and manifestations of X-linked amelogenesis imperfecta. , 1995, Genomics.

[61]  N. Lench,et al.  Characterisation of molecular defects in X‐linked amelogenesis imperfecta (AIH1) , 1995, Human mutation.

[62]  A. Fincham,et al.  Molecular mechanisms of dental enamel formation. , 1995, Critical reviews in oral biology and medicine : an official publication of the American Association of Oral Biologists.

[63]  N. Lench,et al.  SSCP detection of a nonsense mutation in exon 5 of the amelogenin gene (AMGX) causing X-linked amelogenesis imperfecta (AIH1). , 1994, Human molecular genetics.

[64]  T. Diekwisch,et al.  Self-assembly of a recombinant amelogenin protein generates supramolecular structures. , 1994, Journal of structural biology.

[65]  E. Salido,et al.  The human enamel protein gene amelogenin is expressed from both the X and the Y chromosomes. , 1992, American journal of human genetics.

[66]  M. Fukae,et al.  Immunocytochemical and immunochemical detection of a 32 kDa nonamelogenin and related proteins in porcine tooth germs. , 1991, Archives of histology and cytology.

[67]  U. Landegren,et al.  A deletion in the amelogenin gene (AMG) causes X-linked amelogenesis imperfecta (AIH1). , 1991, Genomics.

[68]  O. Takenaka,et al.  A human X-Y homologous region encodes "amelogenin". , 1991, Genomics.

[69]  T. Mohandas,et al.  Human and mouse amelogenin gene loci are on the sex chromosomes. , 1989, Genomics.

[70]  C. Witkop,et al.  Amelogenesis imperfecta, dentinogenesis imperfecta and dentin dysplasia revisited: problems in classification. , 1988, Journal of oral pathology.

[71]  S. Risnes,et al.  Enamel apposition rate and the prism periodicity in human teeth. , 1986, Scandinavian journal of dental research.

[72]  I. Mjör,et al.  Human Oral Embryology and Histology , 1986 .

[73]  U. Skalerič,et al.  The caries resistance of human teeth is determined by the spatial arrangement of hydroxyapatite microcrystals in the enamel , 1980, Nature.

[74]  M. Berkman,et al.  Demonstration of the lyon hypothesis in X-linked dominant hypoplastic amelogenesis imperfecta. , 1971, Birth defects original article series.

[75]  R. Neal,et al.  Structure of mature human dental enamel as observed by electron microscopy. , 1965, Archives of oral biology.