BACKGROUND: Mandibular distraction osteogenesis (MDO) is an effective treatment for severe micrognathia, as it helps to avoid tracheostomy but has some adverse effects on the temporomandibular joint (TMJ). TMJ ankylosis is a serious condition leading to feeding difficulties and growth impairment, and could result in worse consequences in cases with micrognathia who already have limited growth potential. Here, we aimed to report on cases with TMJ ankylosis-a rare but devastating complication of MDO. In total, we described 3 syndromic cases with TMJ ankylosis that developed after MDO and reviewed the associated literature. METHODS: We retrospectively enrolled 3 patients who presented with TMJ ankylosis following MDO at the Oral and Maxillofacial Surgery Department of the University Hospital of Lille, France. RESULTS: All 3 patients had craniofacial syndrome with micrognathia. MDO was performed at least twice in each case, and the 3 patients developed subsequent TMJ ankylosis. They all presented with TMJ ankylosis and micrognathia in our Department. CONCLUSIONS: MDO leads to a certain amount of stress on the TMJ, and in cases with congenital TMJ deformation, such stress could lead to TMJ ankylosis. To our knowledge, 12 cases of TMJ ankylosis after MDO have been described in studies involving 309 patients while it is not reported in other publications. They were all syndromic patients. Thus, TMJ health should be carefully monitored during and after MDO to avoid TMJ ankylosis, and alternative treatments such as costochondral grafts should be considered.