Effects of isoproterenol on postnatal tooth development in mice with special reference to neural crest derivatives.

In the lower incisors of mice injected with isoproterenol during postnatal development, cell groups or cell masses formed in the pulp showed spiral or concentric figures composed of atypical cells. Among these cells were spindle-shaped non-staining neural crest cells and spaces caused by the death of the spindle-shaped neural crest cells. In the pulp and future periodontal ligament, compact intertwining patterns of elongated spindle-shaped cells, representing non-staining neural crest cells were seen. In the periodontal ligament, the elongated spindle-shaped cells grew parallel to the ligament's long dimension. In both pulp and periodontal ligament, the cells lost 'contact inhibition', and further the histological figures resembled melanoma.