Molecular Analysis of Tooth Eruption Disorders

Objectives: Dental ankylosis is a histological definition for a condition that is often clinically indistinguishable from other eruption disorders. Confusion between ankylosis and Primary Failure of Eruption (PFE) can result in an inaccurate diagnosis, inappropriate orthodontic management and frustration for the clinician and patient. In this study we test the hypothesis that eruption disorders are clinically distinguishable with a distinct molecular and genetic expression profile. We posit that a specific genetic and molecular profile exists in PFE as compared to those with an unspecified eruption disorder.
Methods: To test our hypothesis, we used previously diagnosed patients with completed mutational analysis of PTH1R on and/or suspected ankylosis to performed gene expression studies of PDL tissue from affected extracted teeth. PDL tissue collected from extracted teeth was subject to RNA extraction followed by RT-PCR. Gene expression studies of PTH1R, RANKL, BMP2, BMP-4, and BMP6 for ankylosed, control, and PFE teeth were completed.
Results: RT-PCR revealed differences in the expression of BMP4, BMP6, and PTH1R between control, PFE and ankylosed cell cultures; BMP4 expression levels were absent in the RNA extracted from PFE-affected teeth.
Conclusions: Our data suggest that BMP4 may be a downstream effector in a pathway affected by PTH1R mutations. Ongoing studies will interrogate the association between PFE and ankylosis in our sample.