Mandible Axiolateral and Oblique Axiolateral is a radiography positioning projection of the Skull. Axiolateral & oblique axiolateral mandible. Face turned toward the IR by region, CR 25° cephalad. The centering point is located region of interest on the IR-side mandible. Face turned toward the IR by region: ramus true lateral, body ~30°, symphysis ~45°, general survey 10-15°. The central ray is CR angled 25° cephalad, directed to exit the mandibular region of interest on the IR side. (Bontrager also allows head tilt plus CR angle totalling 25°, or 25° of head tilt with a perpendicular CR. Horizontal beam trauma position: add 5° to 10° posteriorly.). Image-quality criteria include ramus or body of interest free of superimposition from the opposite side, ramus not superimposed on the cervical spine (neck extended enough). A sample technique is 80 kVp with DR 6.3 or CR 12.5 mAs, at an SID of 40 inches (102 cm).
Anatomy demonstrated
- Region parallel to the IR: ramus, body, or mentum.
- Mandibular angle and ascending ramus.
- TMJ region and condyle in projected area.
- Lateral aspect of mandible without foreshortening.
- Condyloid and coronoid processes.
- Body of mandible and alveolar process.
Patient preparation
- Trauma patient: use the horizontal beam trauma position with the IR parallel to the mandible, and rule out cervical spine injury before moving the head or neck.
- Verify patient identity.
- Remove glasses, earrings, dentures, hairpins.
- Position patient erect or semiprone in a lateral position, side of interest against the IR, chin extended.
- Turn the face toward the IR by region: ramus true lateral, body about 30 degrees, symphysis about 45 degrees, general survey 10-15 degrees.
- Start with the mid-sagittal plane parallel to the IR, then turn the face.
- Suspend respiration during exposure.
Position & centering point
Region of interest on the IR-side mandible. Face turned toward the IR by region: ramus true lateral, body ~30°, symphysis ~45°, general survey 10-15°.
Central ray
CR angled 25° cephalad, directed to exit the mandibular region of interest on the IR side. (Bontrager also allows head tilt plus CR angle totalling 25°, or 25° of head tilt with a perpendicular CR. Horizontal beam trauma position: add 5° to 10° posteriorly.)
Exposure / technique
- kVp
- 80
- mAs
- DR 6.3 / CR 12.5
- SID
- 40" (102 cm)
- Notes
- CR angle 25 degrees cephalad. Face turned toward the IR by region: ramus true lateral, body ~30, symphysis ~45, general survey 10-15 degrees. Sample technique: DR 6.3 / CR 12.5 mAs at 80 kVp, 40 in SID, for a 13 cm part. Adjust for your equipment.
kVp and mAs are sample values. Use caution when applying them in your department.
Image-quality criteria
- Ramus or body of interest free of superimposition from the opposite side.
- Ramus not superimposed on the cervical spine (neck extended enough).
- Ramus, condyloid and coronoid processes, body, and mentum nearest the IR shown.
- Ramus and body without foreshortening (correct head rotation).
- Minimal overlap of mandible and surrounding facial bones.
- Detail of mandibular structure at region of interest.
Common errors
- 1 Wrong CR angle superimposes the opposite side of the mandible; foreshortening comes from head rotation.
- 2 Too little neck extension superimposes the ramus on the cervical spine.
- 3 CR left horizontal instead of angled 25° cephalad superimposes the opposite side of the mandible.
Clinical indications
- Fractures of the mandible; examine both sides for comparison.
- Specific mandibular region trauma.
- Neoplastic or inflammatory processes of the mandible.