Stability of Rigid Fixation in Craniofacial Fibrous Dysplasia and Cherubism: Report of Two Cases and Review of the Literature

Abstract

Fibrous dysplasia (FD) is a rare non-malignant condition that involves the replacement of normal bone and marrow with fibrous tissue and woven bone. Both monostotic and polyostotic FD frequently involve the craniofacial region. Cherubism, previously described as familial FD, is genetically distinct from FD but is a related disorder with large fibro-osseous lesions. Though the majority of individuals with cherubism eventually go into remission and lesions involute, changes may persist in some individuals. Consequences of craniofacial involvement in FD and persistent cherubism include severe skeletofacial deformity, asymmetry, and malocclusion, and thus, these individuals will often benefit from orthognathic surgery. When an individual with FD involving the craniofacial region presents for an orthognathic surgery work-up, the question of fixation type arises. Poor bone quality can make rigid fixation with miniplates and screws challenging intraoperatively. Although there has been some investigation into the histology of the bone/screw interface in FD, little attention is given to clinical stability from a rigid fixation standpoint. Here we evaluate the stability of rigid fixation in dysplastic bone after orthognathic surgery in conjunction with a review of the literature.