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. Ligh t microscopy and computerized morphometry were utilized for histologic asse ssment of twenty-five sites of twenty-one teeth. Dentinoclasts were found o n the resorbing root surface of nine teeth; polymorphonuclear leucocytes we re found in the pulp of fourteen teeth; and monocytes were present in all p ulps. The epical 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 a nd gingival height, the length of the junctional epithelium and the extent of apical migration of the junctional epithelium. Present and previous find ings indicate that odontoclastic activity in the pulp is reduced with overr etention; and while at the beginning of overretention there is a lower perc entage of pulps with polymorphonuclear leucocytes in the pulp, with an exte nded period of overretention an increase in this percentage takes place.