Rudiment incisors survive and erupt as supernumerary teeth as a result of USAG-1 abrogation

Biochem Biophys Res Commun. 2007 Aug 3;359(3):549-55. doi: 10.1016/j.bbrc.2007.05.148. Epub 2007 May 30.


The term "supernumerary teeth" describes production of more than the normal number of teeth in the primary or permanent dentitions. Their aetiology is not understood. Uterine sensitization associated gene-1 (USAG-1) is a BMP antagonist that plays important roles in the local regulation of BMP signaling by binding and neutralizing BMP activities, and also serves as a modulator of Wnt signaling. We report here that USAG-1 deficient mice have supernumerary teeth. The supernumerary maxillary incisor appears to form as a result of the successive development of the rudimentary upper incisor tooth. We confirmed that the USAG-1 expression is localized to the epithelium and mesenchyme of the rudimentary maxillary incisor tooth organ formation. USAG-1 abrogation rescued apoptotic elimination of odontogenic mesenchymal cells. Based upon these results, we conclude that USAG-1 controls the number of teeth in the maxillary incisor region by regulating apoptosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis
  • Body Patterning
  • Bone Morphogenetic Proteins / deficiency*
  • Bone Morphogenetic Proteins / genetics
  • Bone Morphogenetic Proteins / metabolism*
  • Gene Expression Regulation
  • Incisor / abnormalities
  • Incisor / embryology
  • Incisor / metabolism
  • Incisor / pathology
  • Mesenchymal Stem Cells / cytology
  • Mesenchymal Stem Cells / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Odontogenesis
  • Phenotype
  • Tooth Germ / metabolism
  • Tooth, Supernumerary / embryology
  • Tooth, Supernumerary / genetics
  • Tooth, Supernumerary / metabolism*
  • Tooth, Supernumerary / pathology*


  • Bone Morphogenetic Proteins
  • Sostdc1 protein, mouse