Abstract:

Objective　To investigate the MR imagine features of TMJ coronal structures.Methods　28 TMJs from 15 cadav- ers dipped in formalin over1 yearwere included. Theirmandibleswere fixed at intercuspal positionwhenTMJs oblique coronalMR scan was taken. Baseline was draw on the oblique coronal imagining along the ramus of mandible through its center. The corre- sponding dimensions and areas were measured with electronic ruler.Results　The dimensions were in accordance from large to small as: lateral-medial dimension of fossa, lateral-medial dimension of condyle, medial dimension of fossa, medial dimension of condyle, lateral dimension of condyle and lateral dimension of fossa. Three significant co-relative relationshipwere found: the lat- eral dimension of condyle with lateral dimension of fossa, the medial dimension of condyle withmedial dimension of fossa, and the lateral-medial dimension of condyle with lateral-medial dimension of fossa. CVof lateral dimension of fossa was higher than that of lateral and medial dimension of condyle, and then all the three were higher than other dimensions. The size of the area of joint space shown on oblique coronal imaginings was positively related to that of the area of coronal disc imaginings.Conclusion　Sig- nificant co-ordinate relationship of condyle and fossa ofTMJ coronallywas existed, and the condyle position to fossa lateral-medial- ly varied in great.

Key words: tempor mandibular joint, magnetic resonance imaging, anatomy, temporo mandibular joint disorders