File:Tooth molecular development.jpg

Diagram showing stages of teeth development, a few genetic factors affecting phenotypes, and some signalling molecules and growth factors expressed in the epithelial and mesenchymal components of developing teeth.

While most teeth-related genes exhibit, in general, similar expression patterns in the developing teeth in both humans and mice, several genes, including MSX1, FGF8, PAX9, and SHOX2, show some slightly different expression profiles].

[Arrows = activation; (T) = inhibition at the indicated stages; italic fond = genes; regular, bold fond = growth factors.

Link: http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2651620&rendertype=figure&id=F5 Original File Name: Ijbsv05p0226g05.jpg

A Curriculum Vitae of Teeth: Evolution, Generation, Regeneration Despina S. Koussoulakou, Lukas H. Margaritis, and Stauros L. Koussoulakos Int J Biol Sci. 2009; 5(3): 226–243. Published online 2009 February 24. PMCID: PMC2651620

"The ancestor of recent vertebrate teeth was a tooth-like structure on the outer body surface of jawless fishes. Over the course of 500,000,000 years of evolution, many of those structures migrated into the mouth cavity. In addition, the total number of teeth per dentition generally decreased and teeth morphological complexity increased. Teeth form mainly on the jaws within the mouth cavity through mutual, delicate interactions between dental epithelium and oral ectomesenchyme. These interactions involve spatially restricted expression of several, teeth-related genes and the secretion of various transcription and signaling factors."

Int J Biol Sci. 2009; 5(3): 226–243. Published online 2009 February 24.

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