Fibrous dysplasia has been identified for more than a century, however the scientific and clinical interest for this pathology has been relatively low, probably because of its reduced incidence. The recent genetic investigations permitted to recognize the etiology of this malady, seen as uncertain and controversial for a long time. The study analyzes the cases of 2 patients with fibrous dysplasia at the level of the viscero‑cranium bone, subjected to surgical interventions of modelling resections of the pathological bone tissue, the pieces being examined histopathologically. Analysis of the 2 cases attempted at elucidating the etiological character of this genetically‑determined malady, with no traumatic, reactive or amartomatous origin.