CASE REPORT Spectrum of dentin dysplasia in a family: case report and literature review

The dentin dysplasias (DD), which may be classified as type I (DD1) or type 2 (DD2), form a group of rare, inherited abnormalities that are clinically distinct from dentinogenesis imperfecta. Studies of affected families may help to distinguish different types of DD and provide further insight into their etiology and clinical management. This report describes a family that showed characteristic dental features of D D1, including clinically normal crowns in both primary and permanent dentitions, and mobile teeth that may be associated with premature xfoliation. Radiographic features included calcification of the pulp with crescent-shaped, radiolucent pulp remnants, short, tapering, taurodontic roots, and many periapical pathoses that may be q¢sts or granulomas. A spectrum of dentin dysplasia was noted within the family. Strategies to prevent pulp and periapical infections and early exfoliation of the teeth include meticulous oral hygiene and effective caries-preventive measures. ( P ed iatr Dent 16:437-42,1994) Introduction and literature review Dentin dysplasias (DD) form a group of rare dentin abnormalities that are clinically distinct from dentinogenesis imperfecta. 1-3 Since its recognition in 19203 as "rootless teeth" and as "dentin dysplasia" by Rushton in 1933,4 the clinical features of DD have been well described. However, to date, relatively little is known about the pathogenesis of the dentin defects, or their pathological and clinical implications. As overlapping pathological features may be present in the various types of DD, studies of affected families may help to delineate different types and provide further insight into the etiology and clinical management of these conditions. Classification of dentin dysplasias Generally, two main classes of DD are recognized based on clinical and radiographic appearance. Shields et al. 2 proposed the classifications -type I, or "dentin dysplasia," and type II or "anomalous dysplasia of dentin." Witkop1 later described type I as "radicular dentin dysplasia" and type II as "coronal dentin dysplasia" to indicate the parts of the teeth that are primarily involved. A third type of dentin dysplasia, DD3 or focal odontoblastic dysplasia, also has been proposed.S Dentin dysplasia, type I (DD1) The classical features in DD1, which have been well documented by several case reports, 3-9 are: 1) normalappearing clinical crowns in both dentitions; 2) short, conical, or absent roots that may lead to mobility and early exfoliation of the teeth; 3) total obliteration of the pulps except for thin, crescent-shaped pulpal remnants parallel to the cementoenamel junctions; and 4) periapical radiolucent areas, which may be granulomas or cysts associated with noncarious teeth. Histologically, in DD1, most of the coronal and mantle dentin of the root is usually reported to be normal, and the dentin defect is confined mainly to the root2, s, 10 The dysplastic dentin has been reported to consist of numerous denticles, containing whorls of osteodentin that block the normal course of the dentinal tubules, s, 10,11 A recent suggestion 12 to subclassify DD1 into four subdivisions based on the radiographic appearance of the pulp chambers is not likely to be clinically feasible due to the simultaneous presence of all varieties of the pulp chambers in any particular patient. Simpler subclassifications 13 into either mild or severe may be more clinically relevant. Dentin dysplasia, type II (DD2) The clinical features of DD2 contrast sharply with those of DD1, and consist classically of: primary teeth that have a bluish or amber discoloration, and permanent teeth that appear normal;14-17 and primary teeth that show total pulp obliteration, and permanent teeth that show thistle-tube pulp configuration and pulp stones in pulp chambers. 14-17 Histologically, the affected teeth in DD2 typically show a thin layer of normal coronal dentin and a sudden transition to dysplastic dentin, which is sclerotic and amorphous with few tubules. 2,3, 17