Scientists Create Mouse Model for Human Dental Disorder

A team led by scientists at the National Institute of Dental and Craniofacial Research (NIDCR) has successfully created a murine model of the hereditary disorder dentinogenesis imperfecta III. This model is described in the July 4 issue of the Journal of Biological Chemistry.
The knockout mouse model lacked the dentin sialophosphoprotein (DSPP) gene, thought to be responsible for coordinating the mineralization of a tooth’s dentin. The animals’ teeth showed discoloration, large pulp cavities, and pulp exposure. Detailed studies of the teeth revealed abnormalities in the dentin.

Classified into three subtypes, dentinogenesis imperfecta occurs in about 1 in 8,000 newborns in the US. The teeth can be bluish or brownish with a somewhat translucent appearance. On x-ray, the teeth of patients with dentinogenesis imperfecta III (DGI-III) appear as ‘shell teeth,’ with a layer of enamel, a thin layer of dentin, and very large pulp chambers. Because of the unstable dentin, the enamel can shear off and expose the dentin, which could then wear down to the pulp. Most of those severely affected with DGI-III are candidates for dentures or implants by age 30 despite dental intervention.

Source: NIH News, July 3, 2003