Adult-onset hypophosphatasia diagnosed after consecutive tooth loss during orthodontic treatment: a case report

Background: Adult hypophosphatasia is an uncommon inherited disorder of mineral homeostasis affecting bone. It arises from mutations within the Alkaline Phosphatase, Biomineralization Associated (ALPL) gene, which encodes tissue-nonspecific alkaline phosphatase. Because of its low prevalence and non-specific clinical manifestations, underdiagnosis and misdiagnosis are frequent, particularly in Asian populations.

Case presentation: We present a case of a 38-year-old Japanese male diagnosed with adult hypophosphatasia following consecutive tooth loss during orthodontic treatment. Genetic analysis revealed a compound heterozygous mutation within the ALPL gene. The patient remained asymptomatic until orthodontic treatment, suggesting that increased mechanical stress overwhelmed residual enzyme activity, triggering the hypophosphatasia symptoms. Asfotase Alfa enzyme replacement therapy improved healing following tooth extraction.

Conclusion: This case highlights the significance of including adult hypophosphatasia in the differential diagnosis for obscure dental complications arising during orthodontic procedures, particularly in Asian patients where certain ALPL variants may be more prevalent. Effective diagnosis and management of adult hypophosphatasia necessitate collaboration between orthodontic practitioners and medical specialists. Improved awareness and a multidisciplinary approach are crucial for timely diagnosis and successful intervention.