Changes in ultrastructural distribution of dental basement membrane heparan sulfate during early mouse tooth development.

With the invagination of the deep surface of the tooth buds of mouse embryos (15 days of gestation), heparan sulfate in the region of the lamina lucida of the dental basement membrane began to disappear. Subsequently, as the outline of the future dentino-enamel junction, which elaborates the molar cusp pattern, was formed (16-17 days of gestation), heparan sulfate disappeared not only in the lamina lucida but also at the external side of the lamina densa. However, prior to or during predentin matrix deposition (18 days of gestation), heparan sulfate reappeared in the dental basement membrane.