SA Musculoskeletal Conditions of the Skull

Question 1

Musculoskeletal conditions of the skull.

Answer 1

Growth = prognathic and brachygnathic - dental issues.
Inflammatory = craniomandibular osteopathy.
Fractures = mandible, mandibular symphysis, maxilla.
Tumours = common in older dogs and cats, SCC, epulis, osteosarcoma etc.

Dislocation = of temporomandibular joints.
I = OA of temporomandibular joint.
Muscular = masticatory myositis.

Question 2

1. Synonyms for craniomandibular osteopathy?
2. Aetiology of craniomandibular osteopathy?
3. Signalment for craniomandibular osteopathy?

Answer 2

1. Lion’s jaw, temporomandibular periostitis.
2. Unknown, genetic, infectious.
3. WHWT, Scotties, Cairns 4-10mnths.

Question 3

1. Clinical signs of craniomandibular osteopathy?
2. Dx of craniomandibular osteopathy?
3. Tx of craniomandibular osteopathy?
4. Px?

Answer 3

1. Enlarged mandible, dull, drooling.
   Pain on attempting to open mouth.
2. Imaging - proliferative new bone on mandible / temporomandibular joint.
3. NSAIDs, steroids, liquefied food.
4. Good as self-limiting, bone may regress.
   Can interfere w/ prehension / respiration in more extreme cases.

Question 4

1. Mandibular fracture aetiology?
2. Signalment for mandibular fracture?
3. Clinical signs of mandibular fracture?
4. Dx of mandibular fractures?

Answer 4

1. Trauma, RTA, dog fight, fall, dental disease.
2. More commonly cats than dogs.
3. Malocclusion, swelling, oral haemorrhage.
4. CT is best but can use x ray.
   - difficult due to superimposition of the 2 hemi mandibles (x ray).
   Careful oral examination.

Question 5

Tx options for mandibular fractures?

Answer 5

ESF.
Transarticular ESF
- pins in maxilla and mandible.
BEARD suture.
Bone plates and screws.
- important to contour everything accurately to reduce fracture accurately to allow teeth the aligns and open and closure of the mouth.
Other:
- interfragmentary wire.
- interdental wire.
- interdental acrylic.
- partial mandibulectomy.

Question 6

Tx principles for mandibular fractures?

Answer 6

Aim = perfect occlusion.
Place ET tube via pharyngostomy incision.
Preserve dentition - inform owners may need dental work at later date.
Provide route for nutrition.
If use plate - accurate contouring needed.
Avoid placing IM pin in mandible.
Avoid damaging neurovascular structures w/ implants.
Suture repair gum - aids stability.

Question 7

1. Mandibular fracture ESF indications?
2. Advantages of ESF in mandibular fracture?

Answer 7

1. Open fractures.
   Rostral fractures.
2. Allows oral feeding.
   Can use transarticular frames for complicated fractures.
   Acrylic bars / epoxy putty useful to go around jaw.
   - istead of straight pins and bars used in diaphyseal fractures.

Question 8

The MAMA BEARD for mandibular fractures.
Indications and technique.

Answer 8

Mandibular And Maxillary Bignathic Encircling And Reduction Device.
Indicated for - caudal mandibular fractures / immature animals.
Place a piece of monofilament nylon (40lb) between skin and bone over maxilla and under chin.
Close mouth - interdigitate teeth.
Place suture tightly or risk loss of reduction esp. if canine teeth fractures.
Care during recovery that cat does not regurgitate as risk of aspiration.
- have scissors handy to cut suture if necessary for first 24hrs.
Maintains bone alignment during early healing.
Secure w/ metal tube crimp.
Leave in place for 2-3wks.

Question 9

1. Advantages of MAMA BEARD suture technique?
2. Disadvantages of MAMA BEARD suture technique?

Answer 9

1. Non-invasive.
   Not damaging tooth roots in younger animals.
   Not damaging any NV structures.
2. Keeps mouth closed.
   But can orally feed if suture loosens.

Question 10

1. Post operative care of mandibular fracture repair?
2. Complications of mandibular fracture repair?
3. Px of mandibular fractures?

Answer 10

1. Soft/liquid food.
   Oral hygiene.
   Radiographs/CT 3-4wks and palpable assessment of stability.
2. Infection (if open or dental disease present), malunion, non union.
3. Generally good.
   Guarded for open fractures / older animals w/ dental disease.

Question 11

Symphyseal separations.

Answer 11

Common mandibular fracture / luxation esp. in cats.
Repair methods:
- encircling piece of malleable orthopaedic wire – cerclage wire.
- use large gauge wire and apply tightly.
- good success rate, rarely complications, and most commonly performed repair.
- (lag screw or pin)

Question 12

Symphyseal separation cerclage wiring technique.

Answer 12

Make stab incision on ventral aspect of the chin.
Hypodermic needle placed between skin and bone.
Wire placed and then goes back up through hypodermic needle.
Wire twisted around itself.
Cut off excess wire to leave 3 twists of wire under chin.
Cut wire after 4wks.