Early Dental Manifestations and Multidisciplinary Management of X-Linked Hypophosphatemic Rickets in a Pediatric Patient: A Case Report

<b>Background:</b> X-linked hypophosphatemic rickets (XLH) is a rare hereditary disorder characterized by renal phosphate wasting and impaired bone mineralization. Oral manifestations such as spontaneous periapical lesions and dental abscesses in the absence of caries or trauma may precede systemic features in XLH due to underlying dentin hypomineralization and enamel-dentin junction defects, and could serve as early diagnostic indicators. <b>Case Report:</b> We report on the case of a 4-year-old boy referred to our pediatric dental unit with recurrent intraoral fistulas persisting over the past year. Clinical examinations and an orthopantomogram revealed extensive root resorption and periapical pathology affecting multiple primary molars without evident caries or trauma. Laboratory investigations showed hypophosphatemia, elevated renal phosphate loss, and raised inflammatory markers (CRP (C-reactive protein) and granulocytes). Genetic testing of the child and his mother confirmed a diagnosis of X-linked hypophosphatemic rickets. <b>Management:</b> Due to behavioral challenges, treatment proceeded with difficulty over multiple visits. Endodontic treatment was initiated using a formalin-resorcinol technique; however, several primary molars developed progressive necrosis and required extraction. Orthodontic space maintainers were placed to preserve arch integrity and support future eruption. The patient remains under follow-up and is currently awaiting Burosumab therapy. Despite systemic management, spontaneous necroses of the primary molars persist, highlighting the refractory nature of dental involvement in XLH. <b>Conclusions:</b> This case underscores the pivotal role of pediatric dentists in recognizing systemic diseases through oral findings and demonstrates the challenges of managing XLH-related dental pathology, even under targeted systemic therapy. Early interdisciplinary collaboration is essential to optimize both dental and systemic outcomes in affected children.