Oral and dental manifestations of vitamin D-dependent rickets type I: report of a pediatric case.

Vitamin D-dependent rickets type I (VDDRI) represents an autosomal recessive hereditary defect in vitamin D metabolism. Patients with VDDRI have mutations of chromosome 12 that affect the gene for the enzyme 1-alpha-hydroxylase, resulting in decreased levels of 1,25(OH)(2) vitamin D. Clinical features include growth failure, hypotonia, weakness, rachitic rosary, convulsions, tetany, open fontanels, and pathologic fractures. The oral and dental manifestations of VDDRI have not been described. Here we present the case of a 10-year-old girl affected by VDDRI, as established by the combination of clinical and radiographic findings, family history, and laboratory values. Dental examination revealed markedly hypoplastic, yellowish-to-brownish enamel in all permanent teeth, malocclusion, and chronic periodontal disease. Large quadrangular pulp chambers and short roots were evident in dental radiographs. Light microscopic and ultrastructural examination showed abnormalities of dental hard tissues, affecting both enamel and dentin. The differential diagnosis and treatment of VDDRI are discussed.