Histomorphologic changes in the gingiva and pulp of overretained primary teeth.

This study examined the influence of overretention on the tissues of human primary teeth. The range of overretention was two to thirty-two years. Light microscopy and computerized morphometry were utilized for histologic assessment of twenty-five sites of twenty-one teeth. Dentinoclasts were found on the resorbing root surface of nine teeth; polymorphonuclear leucocytes were found in the pulp of fourteen teeth; and monocytes were present in all pulps. The apical and coronal ends of the junctional epithelium were apical to the cemento-enamel junction in eighteen and fourteen teeth, respectively. Significant correlations were found between the extent of overretention and gingival height, the length of the junctional epithelium and the extent of apical migration of the junctional epithelium. Present and previous findings indicate that odontoclastic activity in the pulp is reduced with overretention; and while at the beginning of overretention there is a lower percentage of pulps with polymorphonuclear leucocytes in the pulp, with an extended period of overretention an increase in this percentage takes place.