Costochondral grafts are used to replace the mandibular condyle in cases of TMJ ankylosis, and are generally viewed as a gold standard for autogenous reconstruction of the mandibular condyle (Güven, 2000; Posnick and Goldstein, 1993 [1,2]). We report a case where overgrowth of costochondral grafts is seen, resulting in asymmetric mandibular growth and dentofacial asymmetry (Posnick and Goldstein, 1993 [2]). A 17 year old male patient presented with an existing costochondral graft performed due to TMJ ankylosis during childhood. He fell from a height at the age of 4, and was lost to follow up through non-attendance until the age of 9, when he presented with a progressive reduction in maximal incisal opening (MIO). At this stage his maximal incisal opening was noted to be 11mm, and the CT showed a grossly deformed ankylosed left TMJ. This post traumatic ankyloses was managed with gap arthroplasty and costochondral graft reconstruction. This immediately improved his MIO to 22mm and at 1 year follow up was noted to be 30mm. At age 12 he was noted to have a clinically obvious overgrowth of the left ramus of the mandible, and deviation of the chin point to the right. MIO remained at 38mm. He declined orthognathic surgery and represented 2 years later requesting treatment without orthodontic intervention for his facial asymmetry. He subsequently underwent a Le Fort 1 impaction osteotomy, right BSSO and left condylar ostectomy, coronoidectomy and left lower border mandibulectomy. Regrowth of the CCG occurred during the 6 months of follow up. This case illustrates the problems that can occur after condylar trauma. It also highlights issues with costochondral grafts which can continue to grow.