The purpose of this study was to aid in the evaluation of prognosis of temporomandibular joint after open reduction of fractured mandible. The author studied the bony changes (remodelling) of 116 temporomandibular joints and facial asymmetry in 58 patients. Subjects were divided into 4 Groups according to the follow up periods after open reduction of fractured mandible. The bony changes and facial asymmetry were observed on lateral tomograms and cephalometric posteroanterior skull radiograms. The results were as follows: 1. The bony changes of condyles were observed in 56 cases (38 flattening, 14 osteophyte, 3 erosion, 1 sclerosis). Flattening was observed in 32.8% (Group Ⅰ 27.8%, Group Ⅱ 37.5%, Group Ⅲ 35.7%, Group Ⅳ 32.1%). Osteophyte was observed in 12.1% (Group Ⅰ 11.1%, Group Ⅱ 8.3%, Group Ⅲ 7.1%, Group Ⅳ 21.4%). Erosion and sclerosis were observed in 2.6%, 0.9%, respectively. 2. The bony changes of articular fossa were observed in 18 cases (15.5%). Flattening was observed in 12.1% (Group Ⅰ 2.8%, Group Ⅱ 4.2%, Group Ⅲ 10.7%, Group Ⅳ 17.9%). Sclerosis was observed in 3.4% (Group Ⅰ 5.6%, Group Ⅲ 3.6%, Group Ⅳ 3.6%). 3. The amount of facial asymmetry was 2.81±2.20㎜ (Group Ⅰ 3.06±1.93㎜, Group Ⅱ 2.38±2.44㎜, Group Ⅲ 2.74±1.19㎜, Group Ⅳ 2.93±2.93㎜). There was no significant difference between all groups according to bony changes of temporomandibular joints after open reduction of fractured mandibles (x²-Test, P>0.05).