Radiological changes of R.A. Reduced mobility Reduction of joint space Erosion Flattening Osteophyte formation Osteosclerosis Osteoporosis Deformation,total loss of condyle
Clinical features of R.A. Pain,swelling,limitation of jaw movement,crepitation. Changes in the occlusion of the teeth (advanced case )progressive opening of the bite. Total ankylosis(rare)
MRI image of TMJ with jaw in closed position,sagittal plane,A- Normal MRI of TMJ,coronal plane of image,jaw closed,arc-shaped disk- A B- Normal MRI image,jaw open position,sagittal plane, relatively high signal noted in post.band of disk, is attached to neck of condyle via firm capsular attachment(arrowheads) T- tubercle C -condyle Arrowheads-attachment of sup.belly of lat.pterygoid m.to the ant.band of disk
Normal MRI of TMJ,coronal plane of image,jaw closed,arc-shaped disk
Internal derangement anterior displacement of the disk
Internal TMJ derangement The early click
Severe disk derangement closed lock
Normal TMJ arthrogram
Change in relationship of disk to osseous structures with mouth opening when the condyle articulates with the intermediate zone of the disk 1post.band C condyle 2 smaller ant.band e eminence
Normal relationship of the disk to the condyle and fosssa(mouth closed) post.band(1) directly above the condyle(c)smaller ant.band(2)immmediattely below the eminence,ant.band of normally positioned disk can cause a small concave defect on the ant.recess(arrow)
Bifid condyle (duplication of condyle)
Panoramic radiogram, chondrosarcoma
Indications for radiography of TMJ １） Pain ２） Systemic disease ３） Noise,clicking sounds during movement ４） Masticatory muscle pain 5)trismus, limitation of mouth opening 6) trauma 7)asymmetrical face 8)morphological abnormalities
Diagnostic values between several techniques TLOP ＞ TMP>TPP TLOP ： ostephyte on anterior aspect of condyle,flattening of post.slope and crest of articular eminence. TMP: erosion on condyle.flattening of later.parts of articular eminence or most laterally situated osteophyte. TLOP and TMP complement each other, if they are used in conjunction,more structural changes are demonstrated. (Pertersson)
Principles of radiographic examination of TMJ Ideal examination should result in three- dimensional topography of the shape,size,and the structure of joint components. 1)Avoiding the superimposition of cranial structures. 2)Direct the X-Ray beam perpendicular to the cassette. 3)Put the film as close as possible to the joint under examination. 4)Reproducibility of the radiographic procedure.
Radiographic technique of TMJ three dimensional topography of the joint components A.Conventional methods 1)Lateral views TLOP( transcranial lateral oblique projection,Schuller’s modification) TPP(transpharyngealprojection,Parma,Toller,Lewis ） 2)Anteroposterior views Ante ｒ oposterior projection(Towne’s proj.) ORP(orbitao-ramus projection,Grant-Lanting proj.) TMP(transmaxillary projection ） 3)Axial view Base projection,Submento-vertical Projection) 4)Panoramic radiography
Arthrography of TMJ Arthrography of the tmj Double Contrast Arthrography Digital Subtraction Arthrography
TMJ arthrography An accurate and effective means of diagnosing Internal derangements and other abnormalities. Shows perforated disk which no other diagnostic method can demonstrate with reliability. Allows evaluation of the dynamics of the joint with mouth opening and closing. Helpful in patients with clicking from other than a displaced disk (i.e. a prominent articular eminence). Cost-efficeint
Arthrography Double contrast An alternative arthrographic tehnique Injections of contrast medium and air into both upper and lower joint spaces followed by tomography. Can demonstrate the soft tissues of the joint with greater detail than single contrast technique.
Nuclear Medicine Imaging Radionuclide bone scintigraphy offers a sensitive method for detecting the presence of tmj pathology and serving as an economical screening technique. For determination of the presence of significant organic tmj disease. Small remodeling changes in bony structures,or Inflammation in the surrounding tissues can be detected long before than other conventional radiographs.