What are scan protocol considerations for TMJ imaging?

CBCT Imaging

  • TMJ Cases: Depending on the clinical circumstances, there are two scan protocols for imaging the TMJ)
    • Option 1: A single scan in closed position
      • FOV: Large (~ 10 cm in height). FOV should extend from ~1 inch above the mandibular/glenoid fossae (TMJ) to the inferior border of the mandible and include both upper and lower arches; the patient’s occlusion/biting position should be visualized.
      • Voxel: ~0.2-0.3 mm
      • Time: 15-20 sec.
      • Positioning: Teeth lightly touching in MIP, occlusal plane parallel to floor.
      • Stabilization: Ideally use a headband or occipital brace. The chin cup can alter the condylar position.
    • Option 2: One scan in closed position and one scan in open position *
      • See option 1 above for closed position protocol.
      • NOTE: The open position scan is being used solely to determine special relationships of the TMJ and therefore the FOV can be much smaller, and the resolution can be much lower than the closed scan (aka much lower radiation dose to the patient).
      • FOV: Large (~ 4 cm in height). FOV should extend from ~1 inch above the mandibular/glenoid fossae (TMJ) to just blow the sigmoid notch/neck of the condyle.
      • Voxel: ~0.3 mm
      • Time: 5 sec.
      • Positioning: Patient in maximum opening, occlusal plane parallel to floor
      • Stabilization: Ideally use a headband or occipital bar.

   *For this option you will need to use the Complex case adder when adding services to the case

MRI Imaging

The MRI should be done without contrast. Additional requirements for MRI imaging of the TMJs can be found here.

Please provide clinical observations when submitting all TMD cases. Examples of information needed include: The presence or absence of popping, clicking, pain, limited opening, and any relevant patient history.