1. TMJ radiographic techniques

2. Techniques
1- plain radiography
2- panoramic radiography
3- Tomography
4- Arthrography
5- Computed tomography (CT)
6- Magnetic resonance imaging (MRI)

3. *Plain radiography :
Plain films of TMJ are made with a stationary
x-ray source and film. In order to avoid
superimposition of adjacent anatomic bony
structures making visualization of all parts of
TMJ, different projections of transcranial films
have been applied, which include
-lateral transcranial view
- transmaxillary view
- submental-vertex view
- transpharyngeal view

4. -lateral transcranial

8. -Transmaxillary

9. -Submental vertex

11. -Transpharyngeal view

14. *Panoramic radiography
It’s a good imaging method for evaluating TMJ
since information about the teeth and other
parts of the jaws were also shown on the image

15. However, the relationship between the condyle
and glenoid fossa cannot be evaluated in the
panoramic film because the fossa cannot be seen
with superimposition of the base of the skull and
zygomatic arch.
The morphology of the condyle becomes wider
than the anatomic structure of the condyle

17. *Tomography
Tomography of TMJ is generated through the
synchronous movement of the x-ray tube and
film cassette through an imaginary fulcrum
located in the center of the desired imaging
plane. Linear tomography and complex
tomography are involved

18. tomography is a good method for depicting the
osseous changes with arthrosis in TMJ
For evaluation of condyle position in glenoid fossa
of TMJ, tomography has been reported to be
more reliable than plain film and panoramic
radiography
On the other hand, the relationship between the
condyle position and disc displacement is
uncertain. The condyle position is not reliable in
estimating the disc displacement of TMJ and
related symptoms

19. The major disadvantage of tomography is the lack
of visualization of the soft tissue of TMJ, a
problem shared with plain film radiography.

20. * Arthrography :
A 25 or 23 gauge needle is placed into the inferior
joint space immediately posterior to the condyle.
Small amounts of iodinated contrast are injected
under fluoroscopy. The contrast tracks along the
posterior, superior and anterior portions of the
condyle. The anterior collection of contrast,
called the anterior recess, normally has a
smooth, tear-drop shape.

21. If the meniscus is perforated, contrast flows into
both the superior and inferior joint recesses.
However, the arthrographic needle can
inadvertently puncture the meniscus and cause
iatrogenic filling of both joint spaces.

22. *computed tomography (CT):
Computed tomography (CT) can be used to
diagnose internal derangement and other
disorders of the TMJ.
The patient is scanned in either the transverse or
direct sagittal plane using thin sections (1-2 mm)
and a soft tissue technique.

23. If transverse sections are obtained, sagittal
reconstructions are made through the condyle.
The meniscus can be visualized on CT since it is
slightly higher in density than the surrounding
muscle and soft
tissue.

24. Normally, there is only a small amount of
increased soft tissue density anterior to the
condyle on CT. In internal derangement, the
anteriorly displaced meniscus results in
abnormally increased soft tissue density anterior
to the condyle.

25. *Magnetic resonance imaging (MRI)
Magnetic resonance (MR) can also be used to
diagnose internal derangement and other disorders
of the TMJ.
The patient is scanned in the sagittal plane using a
surface coil and a high resolution technique
The low intensity cortex of the condyle surrounds the
high signal fat in the marrow. The meniscus is a low
intensity structure which is attached posteriorly by
the intermediate intensity bilaminar zone.

26. Normally, the anterior band lies immediately in
front of the condyle. The junction of the
bilaminar zone and the meniscus normally lies
at the superior aspect of the condyle.

27. In internal derangement, the meniscus is
abnormally positioned anterior to the condyle.