Oral findings in patient with lethal hypophosphatasia treated with enzyme replacement therapy

Hypophosphatasia (HPP) is a skeletal disorder, with hypocalcification of bone and early exfoliation of primary teeth displayed in affected individuals. We report here a 3-year-old female diagnosed with perinatal HPP who had received enzyme replacement therapy starting from 1 day after birth. Oral and radiographic examinations revealed deep periodontal pockets, severe mobility, and dentinogenesis imperfecta with root formation defects, especially in the mandibular primary second molars, while the tooth germs of permanent teeth except for the first molars were unclear. Dental manifestations of lethal HPP following treatment with enzyme replacement therapy were markedly different from those of mild HPP.