Abstract
Bilateral temporomandibular joints of 33 patients with temporomandibular joint dysfunction syndrome (TMJDS) and 12 normal people were examined using fuji computed radiography (FCR) and magnetic resonance imaging (MRI). Then, the author evaluated the relationship between the signs of TMJDS and the state of the internal temporomandibular joint.
Temporomandibular joints of the TMJDS patients were separated into four groups based on MRI findings. Group I: No anterior disc displacement (ADD)Group II: ADD with reduction Group IIIa: ADD without reduction and maximum opening width is over 32 mm Group IIIb: ADD without reduction and maximum opening width is under 24 mm.
The following results were obtained:
1. The frequency of occurrence of limitation was significantly high in the group IIIa and IIIb patients. The locus area of condyle and disc in the group IIIa and IIIb was found to be smaller than that in the normal group based on the MRI findings.
2. The frequency of occurrence of TMJ pain was significantly high in the group IIIa and IIIb. Physiological compression of disc with opening was recognized in the group IIIa and IIIb as observed from the MRI findings.
3. The frequency of occurrence of TMJ sounds was highest in the group II.
4. The period from the initial attack of limitation and visiting our hospital for the group IIIa patients was significantly long compared with the group IIIb patients. The condyle position in fossa was much lower vertically in the group IIIa as compared with the group IIIb based on the FCR findings. The frequency of the mesio-lateral disc location was significantly low and the area of disc forward movement increased in the group IIIa compared with the group IIIb as observed from the MRI findings.
5. The condyle position in fossa of the normal group was in the center area horizontally. It was significantly backward in the group I, II, IIIa and IIIb as compared with the normal group. The condyle position in fossa of the normal group was in the lower area vertically. It was much higher in the group II and IIIb compared with the normal group.
6. Based on the quantitative evaluation in the normal group, the locus area of condyle and disc on mandibular opening was found to be small from the intercuspal position to the 24 mm opening position and it increased forward in the bigger opening position.
