Effects of Enzyme Replacement Therapy for Primary Teeth in a Patient with Infantile Hypophosphatasia

Hypophosphatasia (HPP) is a skeletal disorder characterized by hypomineralization of bone, with early exfoliation of primary teeth. Alkaline phosphatase enzyme replacement therapy (ERT) has been shown to improve bone hypomineralization for patients with HPP, although its dental effects are unknown. A 20-month-old Japanese boy diagnosed with infantile HPP was referred to our clinic because of early exfoliation of primary teeth. The patient had been followed by a pediatrician since the age of 3 months, due to slow weight gain. At the age of 12 months, primary incisors showed sudden exfoliation; at the age of 19 months, a diagnosis of HPP was made based on bone and dental manifestations. ERT was initiated at the age of 21 months. The patient demonstrated stable periodontal conditions of primary molars that erupted after initiation of ERT, due to improved alveolar bone and tooth mineralization. Thus, ERT may improve both dental and systemic conditions.