Tuesday 25 November 2003
tooth Adj; dental
Teeth develop from epithelial cells from the mucosal lining of the oral cavity and cranial neural crest-derived ectomesenchymal cells. The epithelial part forms the cap-shaped enamel organ consisting of an inner side of high cylindrical inner enamel epithelium that differentiates into enamel-forming ameloblasts, an external surface consisting of cuboidal outer enamel epithelium and an intervening loose epithelial structure known as stellate reticulum.
The ectomesenchymal part that is enclosed by the enamel organ is known as the dental papilla: dental papilla cells at the border with the inner enamel epithelium develop into dentin-forming odontoblasts. Both enamel organ and dental papilla together are surrounded by a fibrous capsule, the dental sac or dental follicle.
As the enamel organ elongates through downward proliferation, it creates a tube that maps out the form and size of the roots of the teeth.
Therefore, remnants of odontogenic epithelium can be found in the jaw bone at a level as deep as the root tips of the teeth.
Those that lie in the connective tissue that connects the tooth with the jaw, the so-called periodontal ligament, are known as rests of Malassez. Corresponding epithelial remnants in the gingiva are named rests of Serres.
Tooth developement (by Washington Deceit)
Tooth eruption (by Washington Deceit)
Peters H, Balling R. Teeth. Where and how to make them. Trends Genet. 1999 Feb;15(2):59-65. PMID: 10098408