The dentin dysplasias (DD), which may be classified as type 1 (DD1) or type 2 (DD2), form a group of rare, inherited dentin 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 DD1, including clinically normal crowns in both primary and permanent dentitions, and mobile teeth that may be associated with premature exfoliation. Radiographic features included calcification of the pulp with crescent-shaped, radiolucent pulp remnants, short, tapering, taurodontic roots, and many periapical pathoses that may be cysts 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.