Unilateral condylar hyperplasia (UCH) is characterized by an overgrowth of the mandibular condyle responsible for a facial and dental asymmetry associated with temporomandibular joint function and maxillary growth consequences. The diagnosis is based on a body of clinical, radiological and histological arguments. A 38 years old woman with a reactivation of UCH after a latency period of 16 years following an orthognathic surgery performed for facial asymmetry normalization is presented. She was addressed to our department for a facial progressive asymmetry relapse and dental prosthetic consequences.The radiological images and the planar scintigraphy combined with single-photon emission computed tomography scans showed an active left unilateral condylar hyperplasia. A left proportional condylectomy was performed.The case presented highlights the possibility for the UCH to be reactivated after a long period of latency, leading to a relapse of the occlusal and facial disorders and so advocates the need for first condylectomy or at least a long-term follow-up if condylectomy is not performed as a first-line treatment.