Experimental odontomas in osteopetrotic op/op rats.

Osteopetrosis is an autosomal recessive disease in several mammalian species. Osteopetrotic op/op rats suffer from complete failure of tooth eruption related to reduced bone resorption. In our earlier studies, op/op rats grafted with bone marrow cells 3 days after birth were cured of the disease and their molar eruption was restored. However, the incisors failed to erupt and their proliferating ends were distorted, forming odontomas. The purpose of the present investigation was to study the odontogenic tissues in the odontomas, using the correlated techniques of radiography and microradiography of undecalcified material, together with histology of decalcified material and scanning electron microscopy.