TMJ Axiolateral is a radiography positioning projection of the Skull. Axiolateral TMJ. Joint space, condyle. CR 25-30° caudad. The centering point is located tmj articulation. can be closed-mouth or open-mouth position.. The central ray is cr angled 25-30° caudad, entering above the upside eam and exiting through the downside tmj, which is the joint of interest against the ir.. Image-quality criteria include joint space clearly visualized., condyle centered in articular fossa.. Standard exposure ranges from 70 to 80 kVp, 12 to 20 mAs, at an SID of 40 inches (102 cm).
Anatomy demonstrated
- Temporomandibular joint space.
- Mandibular condyle, condylar neck and process.
- Articular fossa of temporal bone.
- Articular eminence.
- Relationship of condyle to fossa in closed-mouth position.
- Condylar movement in open-mouth position.
Patient preparation
- Verify patient identity.
- Remove glasses, earrings, dentures, hairpins.
- Position patient upright or prone in true lateral position.
- Affected side toward IR; mid-sagittal plane parallel to IR.
- IOML (infraorbitomeatal line) parallel to long axis of IR.
- Closed-mouth position: teeth gently clenched together.
- Open-mouth position: open approximately 1 inch; suspend respiration.
Position & centering point
TMJ articulation. Can be closed-mouth or open-mouth position.
Central ray
CR angled 25-30° caudad, entering above the upside EAM and exiting through the downside TMJ, which is the joint of interest against the IR.
Exposure / technique
- kVp
- 70–80
- mAs
- 12–20
- SID
- 40" (102 cm)
- Notes
- CR angle 25-30 degrees. Perform both closed and open mouth for function.
Image-quality criteria
- Joint space clearly visualized.
- Condyle centered in articular fossa.
- Mandibular condyle and temporal articular surface outlined.
- No superimposition of TMJ by mandibular ramus.
- Detail of condylar process and articular surfaces.
- Minimal surrounding anatomic structures.
Common errors / ARRT traps
- 1 Insufficient caudad angle superimposes the opposite TMJ on the one of interest.
- 2 Rotation: joint space not clearly visualized.
- 3 Tilt: condyle appears elongated or shortened.
- 4 Mouth not closed or properly opened: inconsistent positioning.
- 5 CR left horizontal instead of angled 25-30° caudad distorts the joint.
Clinical indications
- Temporomandibular joint dysfunction assessment.
- TMJ arthritis evaluation.
- Condylar fracture or dislocation assessment.
- TMJ functional evaluation: closed vs. open mouth.
- Pre- or post-operative TMJ follow-up.
Aligned to the current ARRT Radiography Content Specifications.