Oral Health Status and Parental Awareness in Children with X-Linked Hypophosphatemic Rickets: A Case-Control Study

X-linked hypophosphatemic rickets (XLH) is a rare genetic disorder with a frequency of 1:20,000, caused by mutations in the PHEX gene, resulting in impaired phosphate metabolism and bone mineralization. There is an association between hypophosphatemia and dental issues, though this link is not definitively established. This study aims to evaluate the dental status, including oral hygiene, caries prevalence, and malocclusions, as well as parental awareness of dental complications, in children with XLH in Bulgaria, particularly those receiving or about to begin burosumab treatment, and to compare their oral health status with that of healthy children. Eleven children with XLH (seven girls, four boys, aged 2.5-17 years), nine receiving burosumab, were assessed and compared with eleven age- and gender-matched healthy children (seven girls, four boys, aged 2.5-17 years) without XLH or systemic conditions affecting dental health. Parental awareness of dental implications was assessed via a questionnaire, revealing no awareness of potential complications. Oral hygiene, measured using the Oral Hygiene Index-Simplified (OHI-s), was poor in 66.67% of children, with an average of 6.45 ± 5.80 carious lesions per child, and was highest in the 11-16 age group. Malocclusions were observed in 63.64% of children, and spontaneous endodontic infections occurred in 18.18%. Compared with healthy children, patients with XLH had significantly worse oral hygiene (p = 0.013) and a higher caries prevalence (p = 0.001). Children with XLH exhibit poor oral hygiene, a high caries burden, and frequent malocclusions, compounded by a lack of parental awareness of dental risks. These findings underscore the need for targeted dental interventions and education in XLH management, including the integration of routine dental assessments and structured parental education programs into existing clinical protocols to improve oral health outcomes.