The Facial Bones

Facial Bones Projections

Occipito-mental View

  • The PA occipito-mental view provides excellent demonstration of the upper and middle thirds of the face including the orbital margins, frontal sinuses, zygomatic arches and maxillary antra:

Normal facial bones

Occipito-mental 30 View

  • With 30 degrees of caudal angulation, the orbits are demonstrated less well. However, the zygomatic arches and the walls of the maxillary antra are seen clearly:

Normal facial bones
Three lines for inspecting the OM views
Normal lines   Normal lines
Line 1:
  • Look for widening of the zygomatico-frontal sutures
  • Fractures of the superior rim of the orbits
  • "Black-Eyebrow" sign due to orbital emphysema
  • Opacification / air-fluid level in the frontal sinuses

Line 2:
  • Look for fractures of the superior aspect of the zygomatic arch
  • Fractures of the inferior rim of the orbits
  • Soft tissue shadow in the superior maxillary antrum
  • Fractures of the nasoethmoid bones and medial orbits

Line 3:
  • Look for fractures of the inferior aspect of the zygomatic arch
  • Fractures of the lateral maxillary antrum
  • Opacification / air-fluid level in the maxillary sinuses
  • Fractures of the alveolar ridge
Compare the injured side with the uninjured side.

Fractures of the Facial Skeleton
Fractures of the Orbits
Blow out fracture - left
Orbital emphysema - right   Orbital emphysema - right
Fractures of the Zygoma
Tripod fracture - left   Tripod fracture - left
Zygomatic arch fracture - left
Fractures of the Maxilla
Mandibular Projections
Orthopantomogram (OPG)
  • This is an excellent method of demonstrating virtually all mandibular fractures, including the coronoid and condylar processes. Be aware however; occasionally symphysis menti fractures may not be seen.
Normal OPG

Posteroanterior (PA) Mandible
  • The OPG must be supplemented with a PA mandible to establish displacement of fractures. This will demonstrate the body and symphysis menti, and also provide tangential views of the rami and the necks of the condyles:
Normal PA mandible
Lateral obliques
  • In the absence of an OPG, the lateral obliques will demonstrate the body and ramus on each side. The articulation at the temporomandibular joint may also be assessed:
Normal lateral oblique - paediatric   Normal lateral oblique - paediatric
Anatomy of the mandible
Mandibular anatomy   Mandibular anatomy
Fractures of the mandible
Condyle
15-20%
Coronoid process
1-2%
Ramus
3-9%
Angle
20-31%
Body
21-40%
Symphysis menti
10-15%
Alveolar ridge
3-4%

Fracture right angle and left body
Bilateral condyle fractures
Fracture right body, left coronoid and ramus   Fracture right body, left coronoid and ramus


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