Prospective data will be collected in approximately 200 patients treated with an TMJ replacement. Patients will be followed up according to the standard (routine) for up to 5 years after the treatment. Data collection will include underlying disease, treatment details, functional and patient reported outcomes (PRO)s and anticipated or procedure-related adverse events (i.e. complications). This registry is designed to be able to assess the number of patients who refuse alloplastic total TMJ replacement. Therefore, the participating sites are asked to register all cases of refused TMJ replacements too.