Enamel changes in permanent teeth after trauma to their primary predecessors.

The frequency of developmental disturbances in the permanent dentition due to traumatic injuries to primary teeth was examined in a Danish population sample consisting of 487 schoolchildren 9-17 years old. Of these children, 147 (30 %) had a history of traumatic injuries to the primary dentition. Frequencies of 57.8 % and 45.3 % of developmental disturbances were found in the trauma and in the non-trauma group, respectively. The following types of developmental disturbances were more frequent in the trauma group than in the non-trauma group: (1) internal white enamel hypoplasia with a diameter of 0.5 mm or more, (2) internal and external white and yellow-brown enamel hypoplasia, (3) white and yellow-brown enamel hypoplasia and horizontal enamel hypopiasia. Internal white enamel hypoplasia with a diameter of less than 0.5 mm, and generalized internal and external white enamel hypoplasias were found with the same frequency in the two groups. About 10 % of enamel hypoplasias in anterior teeth are due to trauma. [ABSTRACT FROM AUTHOR]