Test 2 - Mandible Rami Projections

What should you check before selecting which projections to do for mandible

First determine if injury is on ramus or body, since they are almost right angles from each other, routines will vary

How many possibilities are there for rami

2 Projections

• PA and PA axial

PA Axial Projection

• Usually done upright

• Rest patient’s forehead and nose on IR,
  (OML perpendicular)

• MSP centered

• CR is 20 to 25 degrees cephalic to exit acanthion

• it will elongate the rami and “open” them up (PA Axial)

Evaluation Criteria:

• Shows body and rami, but body of mandible not well seen because of spine.

• Still see medial vs. lateral displacement

• Include entire mandible with no rotation

What are some other possibilities for rami and body

• Axiolateral projections

• SMV projection

• AP axial projection (Towne)

PA Projection

• Usually done upright

• Rest patient’s forehead and nose on IR,
  (OML perpendicular)

• MSP centered

• CR perpendicular to exit acanthion

Evaluation Criteria:

• Shows mandibular rami and body, but the central part of the body is not well seen because of superimposed spine.

• Demonstrates any medial or lateral displacements of fracture fragments in the rami

Lateral

• Put head in a true lateral and extend neck so the mandibular body is parallel with the IR

• head stays true lateral

• Angle CR 25 degrees cephalad

• CR passes through mandibular region of interest

• (Merrill’s says to oblique the patient to avoid shoulders)

Evaluation Criteria:

• body of mandible from symphysis to TMJ with no overlap of opposite side or by c-spine