L19 Radiology- trauma and facial fractures Flashcards
What is the separation sign?
Radiolucent line between 2 seperated pieces of bone
What does widening of the PDL space indicate?
Widening is an indication of fracture involving the teeth
What does widening of the sutures indicate?
Widening of sutures occurs if the fracture involves the mid third of the face e.g. fronto-nasal, fronto-zygomatic, naso-maxillary sutures
What is the overlap sign?
A radiopaque line due to 2 fragments of bone overlapping eachother, often subtle
What is meant by the term abnormal linear density?
Where the fragmetn is displaced/rotated so is seen in an ‘end on’ position.
What is the disappearing fragment sign?
When the thin bone plates are rotated out of the tangent, the fragment diappears.
Name 3 other direct signs of a fracture.
- Abnormal curvature
- Step deformity
- Displaced bone
Name the indirect signs of a fracture.
- Soft tissue swelling
- Paranasal sinus opacification (could be due to bleeding or CSF leaking into maxillary antrum)
- Ait in soft tissues (could be due to traumatic emphysema)
- Changes in occlusal plane
- Dental injury
Name the 5 radiographic views that may be used for a mandibular fracture.
- Panoramic radiograph
- PA mandible
- Oblique lateral view
- Lower 45 degree occlusal
- Lower 90 degree occlusal
What view does this image show?
Lower 45 degree occlusal
What view does this image show?
Lower 90 degree occlusal
Where are the fractures on this OPT?
- Right buccal and lingual cortex (appears as 2 lines but joins to make 1 so is only a single fracture)
- Symphyseal region on the left
What types of radiographs are being taken in these images?
- OPT
- Posterior anterior (PA) mandible
What view is this? Describe what the radiograph shows.
- Oblique lateral view
- Step deformity of lower border of the mandible
What does the image on the right represent?
Illustrating that fracture displacement can occur due to original trauma, and from the musucular pull on the fragments by the muscles.
Muscles can actually help depending on the direction of the fracture (a- horizontally stable fracture) or make them worse (b).
What does the image on the right show?
Vertically stable and unstable fractures.
a) Medial pterygoid has pulled the displaced fragments together making the fracture stable
b) Medial pterygoid has opened up the fragments making it unstable
Describe what this radiograph shows.
- Lower right fracture, 2 lines join together = single fracture
- Widening of PDL space mesialto LR6
- Fracture of the left angle of the mandible and a step deformity
What does this PA mandible show?
- Fracture of the left angle of the mandible
What muscles have caused displacement of the bone pieces in this fracture?
Muscular pull from the digastric and mylohyoid muscles = displacement
What does this image illustrate?
Patient had jaw fracture wired (historic technique), woke up and tried to speak, the muscular pull caused the mandible to fall out of place again.
What is the effect of muscular pull on a condylar head fracture?
Lateral pterygoid is attached to the condylar head, during a fracture the muscle pulls the head medially and anteriorly.
What is a Guardsman fracture?
Fracture caused by falling forwards onto your chin.
Bilateral condyle fractures + symphysis fracture.
Name the various fractures of the middle third of the skeleton.
- Dentoalveolar
- Zygomatic complex
- Le Fort I, II, III
- Naso-ethmoidal complex
- Fractures of the orbit
What radiographic views are used for fractures of the middle third of the skeleton?
- 0-degree occipitomental
- 30-degree occipitomental
- Submentovertex view (less common)
- Lateral skull (historically)
What are the 4s to look for in radiographs?
- Symmetry
- Sharpness
- Sinus
- Soft tissues
What view is this?
Standard OM view (0-degree occipitomental)
What view is this?
30 degree occipitomental (good for viewing the zygomatic arches)
What view is this?
Submentovertex view, not commonly used, challenging to take, good patient compliance needed, cannot have a neck injury.
What search patterns are used to identify fractures?
Campbell’s lines
1: zygomaticofrontal sutures, supraorbital margin, frontal sinus
2: zygomatic arch, lower border of orbital rim, nasal cavity
3: condylar head, coronoid processes, lateral margin of antrum
4: angle of mandible, occlusal plane
Secondary lines:
- Trapnell’s line to assess mandible
- Dolan’s line (orbital, zygomatic and maxillary line)
Where is the fracture?
Left zygomatic arch fracture (radiopaque antrum)
