Transient red discoloration: report of case.

The different evolutions of a red discoloration of the primary maxillary central incisors in the same patient are charted. In the right central incisor the red discoloration disappeared; in the left it faded but was sustained until exfoliation. This case supports the theoretical existence of a transient type of discoloration following trauma. The resorption of posttraumatic intrapulpal bleeding in a primary tooth is discussed as a possible pathogenesis.