TMJ Axiolateral is a radiography positioning projection of the Skull. Axiolateral TMJ (Schuller method). Joint space, condyle. CR 25-30° caudad. The centering point is located enter ~1/2 inch anterior and 2 inches superior to the up-side EAM; the CR passes through the down-side TMJ. Closed- 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. The SID is 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
- Possible fracture or recent injury: do not open the mouth, because fragments can displace. Trauma patients are examined without stress movement of the mandible.
- Verify patient identity.
- Remove glasses, earrings, dentures, hairpins.
- Position patient erect or semiprone in true lateral position.
- Affected side toward IR; mid-sagittal plane parallel to IR.
- IOML (infraorbitomeatal line) perpendicular to the front edge of the IR.
- Closed-mouth position: posterior teeth in contact, not the incisors (Merrill's).
- Open-mouth position, unless contraindicated: open widely without jutting the jaw forward (Merrill's; Bontrager prints no distance). Suspend respiration.
Position & centering point
Enter ~1/2 inch anterior and 2 inches superior to the up-side EAM; the CR passes through the down-side TMJ. Closed- 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
- N/A
- mAs
- N/A
- SID
- 40" (102 cm)
- Notes
- CR angle 25-30 degrees. Closed and open mouth are often taken to show range of motion; never open the mouth with possible fracture or recent injury. On the 2022 ARRT outline as axiolateral (modified Schuller), through February 28, 2027. Off the 2027 outline from March 1, 2027. Bontrager prints digital 80 to 90 kV and no mAs; Merrill's chart has no row for this method, so no mAs is printed.
Image-quality criteria
- Joint space clearly visualized.
- Condyle centered in articular fossa.
- Mandibular condyle and temporal articular surface outlined.
- No rotation: lateral margins superimposed.
- Detail of condylar process and articular surfaces.
- Collimation to the area of interest.
Common errors
- 1 Rotation: lateral margins not superimposed.
- 2 Rotation: joint space not clearly visualized.
- 3 Mouth not closed or properly opened: inconsistent positioning.
- 4 Closing on the incisors protrudes the mandible and carries the condyles out of the fossae (Merrill's).
Clinical indications
- Abnormal relationship or range of motion between the condyle and TMJ fossa.
- TMJ functional evaluation: closed vs. open mouth.