Early non-traumatic exfoliation of primary teeth as the first sign of hypophosphatasia: a 6-year pediatric case report

Background: Premature exfoliation of primary teeth without trauma is an unusual finding that raises suspicion of an underlying systemic disorder. Among the possible causes, hypophosphatasia (HPP) is a rare inherited metabolic disease characterized by deficient alkaline phosphatase (ALP) activity, leading to impaired skeletal and dental mineralization. Pediatric dentists are frequently the first professionals to identify the initial signs of this condition. Case: This report describes the 6-year follow-up of a male patient who first presented at 22 months of age with premature loss of four anterior primary teeth, short stature, and balance issues. No traumatic events were reported by the parents. Clinical examination revealed further mobility of the primary incisors and confirmed short stature and unstable gait. Laboratory tests revealed persistently low ALP levels, hypercalciuria, and high urinary phosphoethanolamine (PEA) levels. Radiography revealed subtle metaphyseal radiolucency. Genetic analysis confirmed a heterozygous mutation in the liver/bone/kidney alkaline phosphatase (ALPL) gene, establishing the diagnosis of HPP. Management was performed by a multidisciplinary team, including pediatric endocrinologists, geneticists, orthopedists, orthodontists, and pediatric dentists. Dental care focused on prevention, professional hygiene sessions, topical fluoride applications, and monitoring occlusal development. Orthodontic assessments were performed when the permanent teeth erupted. Over the years, the child lost additional primary teeth with intact roots but maintained masticatory efficiency, vertical dimension, and good oral function. Growth parameters and skeletal phenotype remained stable, and enzyme replacement therapy (ERT) was not considered necessary. Conclusions: This case illustrates the key role of early dental signs in timely HPP diagnosis, the potential significance of a rare haplotype, and the effectiveness of interceptive orthodontic management over six years.

Case report; Hypophosphatasia; Pediatric dentistry; Premature tooth loss; Primary dentition

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