[Arrest of dental development in the osteopetrotic rat and the healing effect of normal bone marrow].

The development of the osteopetrotic "op" rat's mandible was examined from birth to 4 months of age. Before birth the growth of incisors is disturbed and after birth the molar growth stops. Bone resorption is severely reduced and enamel formation ceases soon on the inferior aspect of the incisor, due to degeneration of ameloblasts and lack of vascularisation. A single injection or normal bone marrow cured the disorder at the long bone level within 2-3 months and had a beneficial effect in re-establishing the growth of dental tissue, yet without leading to tooth eruption.