Embryogenesis of the gingival cyst.

The embryogenesis of gingival cysts derived from the dental lamina was studied histologically in paraffin prepared sections of 10 pairs of human fetal jaws and in individual celloidin sections of human fetal skulls. Cystic degeneration in the dental lamina was noted as early as 10 weeks in utero prior to the separation of the developing tooth bud. Rapid proliferation and growth of such cysts was seen in 15-20 week old embryos during the morphodifferentiation stage of tooth development after fragmentation of the lamina had occurred. Islands, strands and nests of dental lamina epithelium were dispersed into extraosseous locations and demonstrated histomorphologic characteristics similar to odontogenically related epithelium seen in adult gingiva. Dental lamina epithelium appears to have a particular predisposition for cystic degeneration and is probably the source of other neoplasms and hamartomas seen in the gingiva.