Purpose: A comparative study was performed to evaluate the function of the temporomandibular system after open and closed treatment of condylar fractures. Materials and Methods: A total of 37 temporomandibular joints were examined that had undergone either open treatment (n = 24) or closed treatment with maxillomandibular fixation (n = 13) for condylar fracture. The joints were investigated clinically and on the basis of radiographs, in addition, the movements of the condyles of the temporomandibular system were recorded in 3 dimensions with a computed electronic jaw tracking system (stereognathograph). Results: The clinical investigation revealed no severe functional abnormality in either of the 2 groups. The mean of the recorded condyle paths was, however, consistently lower ill file temporomandibular joints with closed treatment than in those with open treatment, although the difference was only significant for movements without tooth contact (Mann-Whitney, U test, P < .05), Conclusions: in summary, open as well as closed treatment gave clinically, acceptable functional results. However, condylar mobility was markedly greater after open treatment than after closed treatment. (c) 2005 American Association of Oral and Maxillofacial Surgeons.