As part of the article, Dynamic Magnetic Resonance Imaging Technique for the Study of the Temporomandibular Joint by Drs Yunn-Jy Chen, Luigi M. Gallo, Dieter Meier, and Sandro Palla (J Orofac Pain 2000;14:65-73), website visitors can now view a series of dynamic MRI of temporomandibular joint movements.
Drs Chen, Gallo, Meier, and Palla investigated different pulse sequences, echo time, fields of view, slice thicknesses, scanning matrices, and other factors to obtain high-quality images that clearly showed joint components as patients opened and closed their mouths. The images were then combined and converted into animations. Click here to view complete opening and closing sequences of patients with joint clicking, disc displacement, and normal anatomy.
The journal article, published in the Winter 2000 issue of the Journal of Orofacial Pain, provides complete information on the parameters chosen to obtain these animations and a full discussion of the issues involved in trying to capture images of joint movement. Copies of this issue of JOP can be obtained from the Quintessence office.
Static images taken at maximum intercuspation
Dynamic MRI sequence of a TMJ of a 25-year old patient with an anterior disc displacement with reduction. The clicking occurred in the late stage of mouth opening. Notice how the disc is pushed past the eminence, where it bends into a U shape. Then the disc-condyle relationship is reduced while the bent disc returns to its normal shape.
Dynamic MRI sequence of a TMJ of a 22-year-old female patient with an anterior disc displacement without reduction. During opening the mobile disc is pushed ventrally by the condyle.
Dynamic MRI sequence of an opening/closing movement of a normal TMJ of a 38-year-old male subject. The harmonious movements between condyle and disc are clearly visible. Notice also some bending of the disc at the end of the opening.
Dynamic MRI sequence of the TMJ of a 50-year-old male patient with a chief complaint of crepitation. The static images of this patient show clearly the irregular bony surfaces of both the condyle and the eminence. An area of low signal cranially and dorsally to the condyle is visible. During condylar movement this structure moves ventrally together with the condyle. Notice also the area of high signal (joint fluid) ventrally and cranially to the condyle.
| Case 5
Dynamic MRI sequence of a TMJ of a 20-year-old male patient with an anterior disc displacement without reduction. During opening the ventral part of the disc hardly moves, while the dorsal part tends to bend by moving ventrally. The sequence suggests that the disc is stuck.
Dynamic MRI sequence of a 19-year-old female patient with an anterior disc displacement with reduction. The disc is located under the eminence. Notice how during the initial opening the disc bends caudally to a U shape. Suddenly, the disc springs dorsally to a reduced position. At the end of closing the disc is again in its initial position under the eminence.
Dynamic MRI sequence of a TMJ of a 24-year-old female patient with an anterior disc displacement with reduction. Notice that the patient needs 3 movement phases to fully open the mouth. In the first phase there is some translation, followed by a rotary movement and dorsal translation. The disc is not reduced. In the second phase the disc is reduced. The sequence stops with the condyle under the eminence. Finally, the condyle translates and rotates ventrally to the eminence.
Dynamic MRI sequence of a 19-year old female patient with an anterior disc displacement with and without reduction, ie, with occasional locking. The sequence demonstrates the full opening path with disc reduction (first cycle) and without reduction (second cycle). In the sequence without reduction, the disc is pushed ventrally and caudally without bending.