A rare case of synovial chondromatosis of the temporomandibular joint with unspecific symptoms is presented. This causes difficulties in classifying the different clinically and technically acquired features at differential diagnosis. The concept of chondrometaplasia as being triphasic and self-limiting is strongly supported and extreme care should be taken during therapy in order to avoid any unnecessary destruction and mutilation. This case seems to indicate that chronic parafunctional overload was the initiating stimulus for this reactive metaplastic process. Nonphysiologic overstrain of any cause should be diagnosed and corrected.