Multiple External Root Resorption in a Pediatric Patient with Familial Expansile Osteolysis

External root resorption (ERR) of permanent teeth is a pathological process that can lead to their loss. There are several systemic and/or genetic abnormalities that have been associated with ERR. Among them, familial expansile osteolysis (FEO) is an autosomal dominant disease characterized by skeletal defects, middle ear deafness, and abnormal root resorption. The purpose of this paper was to describe the case of a 10-year-old female with familial expansile osteolysis born with missing ossicles and, therefore, deafness. The patient was not diagnosed with FEO until the age of 10 years, when she presented to the dental clinic with advanced ERR in several permanent teeth. The series of tests she underwent for diagnosis and the treatments rendered are presented and discussed. It is recommended that when ERR cannot be explained by local etiologic factors, systemic abnormalities and genetic testing should be considered.