[Facial skin fistula as a postoperative complication of a mandibular guided bone regeneration].

Bone resorption is a consequence of the loss of a tooth. Alveolar ridge resorption can restrict the volume of bone available for the positioning of a dental implant. Bone graft is a routinely performed procedure in order to increase this volume and provide an adequate situation for the replacement of the tooth. However, autogenous bone is the gold standard for this procedure, xenogenous bone is a good alternative. It presents reliable results and a low complication rate. In this article, we describe the case of an infection resulting in a facial skin fistula following a guided bone regeneration. A 52-year-old woman visited a maxillofacial unit with complaints of persistent swelling of the right cheek, associated to a facial skin fistula. She had a history of xenograft with OsteoBiol Gen-os©, performed at a dental office nine months earlier. Clinical examination and computed tomography suggested that there was a migration process of the bone substitute inside the cheek, which had led to the infection with a facial skin fistula. Loss of stability of the bone graft and particular anatomy of the posterior region of the mandible could explain the migration of the particles and the formation of the fistula.