Temporomandibular joint (axiolateral view)

The axiolateral temporomandibular joint (TMJ) view allows for visualization of the articular tubercle, mandibular condyle and fossa of the temporomandibular joint (TMJ).

Indications

This projection is useful in identifying structural changes and displaced fractures, assessing excursion and joint spaces in the trauma setting, and evaluating the presence of joint noises, trismus and occlusal alterations.

Patient position

  • the patient is seated upright with the side of interest closest to the detector.
  • the head is placed in a true lateral position
    • interpupillary line (IPL) perpendicular and midsagittal plane (MSP) parallel to the detector
  • oblique the body to assist in patient positioning and reduce the object to image receptor distance
  • depending on the projection (open or closed mouth) instruct the patient to open their mouth side and keep it there or keep it shut

Technical factors

  • left and right lateral and open and closed mouth
  • centering point
    • central ray 25º-30º caudad, centered 5 cm superior and 1 cm anterior to the external auditory meatus
  • collimation
    • no more than 10 x 10 cm with temporomandibular joint of interest in the middle of the image
  • orientation
    • portrait
  • detector size
    • 18 cm x 24 cm
  • exposure
    • 70-75 kVp
    • 16-25 mAs
  • SID
    •  100 cm
  • grid
    • yes

Image technical evaluation

  • the temporomandibular joint closest to the image receptor should be clearly demonstrated without the superimposition of the opposite temporomandibular joint.
  • the joint is central on the radiograph

Practical points

  • a radiolucent support such as a sponge can be used to help maintain the head position
  • in patients that cannot stand unsupported, this projection can be performed prone to increase patient stability