Burosumab and Dental Abscesses in Children With X-Linked Hypophosphatemia.

X-linked hypophosphatemia (XLH) is a rare genetic disorder that disrupts skeletal and dental mineralization. In addition to rickets in children, XLH patients also have frequent spontaneous dental abscesses that increase the risk of tooth loss and may lead to facial cellulitis. Hypomineralized and hypoplastic dentin is the main driver of these infections. Conventional treatment (CT) of XLH improves this tissue defect and reduces the occurrence of dental abscesses. Burosumab is a recent treatment for XLH that targets excess circulating fibroblast growth factor 23 (FGF23), and its benefits on rickets have been demonstrated. It is not yet known whether burosumab improves dental manifestations of XLH. The main objective of our study was to compare the incidence of dental abscesses with XLH treated with either CT or burosumab. In this monocentric retrospective study, we measured and compared the incidence of dental abscess in children with XLH treated with either CT or burosumab, followed at our dental center for at least 1 year. The primary endpoint was the number of dental abscesses per month of dental follow-up. A total of 71 children were included in the study, with a mean ± standard deviation (SD) age at the start of dental follow-up of 7.86 ± 3.76. Thirty-eight children were treated with CT (53.5%) and 33 with burosumab (46.5%). All children treated with burosumab had previously been treated with CT. The mean number of dental abscesses per month of dental follow-up was significantly reduced in the burosumab group compared with the CT group (0.01 versus 0.04; p  = 0.04). Burosumab treatment appears to be associated with a reduction in the number of dental abscesses in XLH children, compared with CT. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.