S2 - Maxillofacial Injuries Flashcards
Name 3 common causes of maxillofacial injuries
- interpersonal violence
- RTA (road traffic accident)
- falls
also sport
Which pt group is most susceptible to maxillofacial injuries
males, age 13-35
Most common maxillofacial fracture
- nasal fractures (most common)
- mandibular fractures (next most)
Components of treating a pt who has maxillofacial injury
- initial assessment
- applied anatomy (what is broken, fractured, lacerated etc)
- diagnosis
- treatment planning
- principles of treatment
- definitive treatment
- complications of fractures
What should be done in initial assessment? (6)
- rapid survey of vital functions & prioritize management options
- ABCDE (airway, breathing, circulation)
- head injury
- prevent infection
- pain management
- temporary immobilisation/fixation of fractures (helps stop pain and haemorrhage)
*During head injury, the face might be very injured/broken by absorbing the force from the injury but this may have prevented PRIMARY brain injury. E.g. a patient with severe face injury is conscious and alert, but what is now important to prevent?
prevent secondary brain injury from inadequate cerebral circulation:
- airway - 100% oxygen
- breathing - chest injury
- circulation:
- control haemmorhage
- treat hypovolaemia
- isotonic fluid therapy (to raise blood pressure in pt w hypovolaemia)
For context: haemorrhage vs hypovolaemia
haemorrhage - loss of blood from ruptured/injured blood vessels
hypovolaemia - fall in circulatory volume
can have hypovolaemia due to haemmorhage
What to know about head injury?
- frequently associated with facial injury
- may be milder when associated with severe facial injury
- often associated with alcohol/drug use
Applied anatomy of the face which may be affected by maxillofacial injuries
- dento-alveolar
- mandible
- middle 1/3 of face
- zygoma
- orbit
- nasal bones & naso-ethmoidal complex
- cranio-facial (shared)
How to diagnose the injury?
- history (to understand what happened)
- examination
- recognition of diagnostic features**
- imaging
- study models (e.g. to show how broken maxilla or md fit tgt)
What are some soft tissue structures often damaged?
- parotid gland
- parotid duct (Stensen’s duct)
- branches of facial nerve
- muscles of facial expression
- sensory nerves (supraorbital, infraorbital)
- nasolacrimal duct
Branches of the facial nerve
TZBMC
Temporal
Zygomatic
Buccal
Marginal mandibular
Cervical
**4 principles of managing a fracture
- Reduction: reduce fracture by putting broken ends tgt in anatomical position
- Fixation (ORIF): open reduction internal fixation - open wound and fix bones in correct position
- Immobilisation (IMF): intermaxillary fixation - wiring teeth together to stabilise face/jaws
- Rehabilitation
Best way to treat a nasal fracture and why?
push nasal bones back into place straightaway, if you wait too long oedema wont allow pushing it back
can put splint on after to protect broken bones
How does mandibular fracture commonly occur?
- direct injury to parasymphyseal/mental region
- can lead to indirect injury to the condyle and angle (areas of weakness in md) - on opposite side
(angle = where horizontal body meets vertical ramus, can have impacted 3rd molars in this area too, neck of condyle is thin and narrow - postulated that it has evolved so injury to chin doesnt cause md to go into temporal area and cause cranial damage and instead the condyle neck fractures)
Types of mandibular fractures (by region) and how
parasymphyseal/mental and body - direct injury
angle and condyle - indirect
ramus and condyle - very rare, may be associated with severe, communited fractures in multiple fragments(??)
What injury is shown
left parasymphysis (direct) and right condyle (indirect) #
classic presentation
What injury is shown?
right parasymphsis (direct) and left angular fracture (indirect) - weak spot at 3rd molar
**Diagnostic features of unilateral condyle fracture. (5,2) What is usually an accompanying problem?
Afffected side:
- pain in joint, worse on moving
- tenderness & swelling
- absent/abnormal movements of condylar head
- deviation of mandible on opening
- premature contact on molars
Opposite side:
- open bite
- limited lateral excursion (cant move)
i.e. when pt opens mouth, jaw deviates to side of #
Rarely by itself, usually parasymphyseal fracture on other side
Which is more common, unilateral or bilateral condyle fracture
bilateral
Diagnostic features of bilateral condyle fracture. (4)
- pain, tenderness, swelling over both joints
- premature contact on posterior teeth and AOB
- restricted lateral movements (isnt going anywhere laterally)
- absence of movement of condylar heads
may be caused by falling right onto chin - midline symphyseal fracture + bilateral condyle
Diagnostic features of body of mandible fractures. (7) Specify the pathognomonic feature.
- pain on moving jaw
- trismus
- movement/crepitus (scraping) at fracture site
- step deformity of lower border
- derangement of occlusion
- mental nerve anaesthesia
- haematoma of FOM/buccal sulcus (pathognomic!)
Treatment for mandibular fracture
ORIF (open reduction internal fixation) - titanium plates used to hold in place after fracture is reduced, occlusion of teeth can be a guide to position
IMF (temporary inter-maxillary fixation) - can be used to stabilise occlusion just intraoperatively or sometimes left on for weeks so that occlusion is correct as bone heals
Diagnostic features of zygoma fractures (9)
- depression of cheek prominence
- step deformity of infra-orbital ridge
- subconjuctival haemorrhage* (pathognomonic)
- diplopia (double vision)
- infra-orbital nerve anaesthesia
- trismus (zygoma impacts into coronoid process)
- blood in antrum
- circumorbital ecchymosis (black eye)
- retrobulbar haemorrhage
*bruise under conjuctiva stays red as oxygen can pass across conjunctiva
cheekbone designed to break when hit in order to protect eye
sometimes present to dentist due to trismus and numb upper anterior teeth and lip
What is shown? (15-30 deg occipo-mental radiographs)
yellow - fracture lines, very close to condyle
green - fluid line (blood in mx sinus)
Name types of zygoma fracture treatment
Gillies temporal
Intra-oral (same as ^ but infraoral - advantage is can expose zygoma and put chains etc to fix)
Hook (to lift bone)
What is the Gillies temporal method for zygoma fracture treatment?
incision in temporal scalp, large blunt instrument introduced down to zygoma then lifts it and cracks bone into place
What may need to be done to ensure repositioned zygoma fracture stays in place?
stabilise with plates
What is retrobulbar haemorrhage and how does it happen?
complication of zygoma fracture/orbital injuries
because the muscle cone of the eye is tight, bleed will create pressure and will push the eye forward - pressure spasm in posterior ciliary arteries can cause blindness
How are middle third fractures categorised?
Le Fort I, II, III
3 principle fracture lines affecting bones in middle ⅓ of the face. Useful to classify and tx plan but its not completely distinct may have mixed
What are Le Fort I, II and III?
I: least injury, horizontal/transverse fracture causing a floating palate
II: more severe, pyramidal fracture, takes face away from cheekbones in infraorbital region
III: high transverse, seperates whole face from cranium
Appearance of patients with middle ⅓ fractures
face balloons up with swelling and bleeding, major risk to airway and hypovolaemia
Diagnostic features of Le Fort I fracture (4)
- floating palate
- blood in antrum
- bilateral haematoma in buccal sulcus
- deranged occlusion with anterior ope n bite
What orthognathic surgery procedure does Le Fort I fracture form the basis of? (extra)
repositioning jaw in facial assymetry
Diagnostic features of Le Fort II fracture (5)
- gross swelling then dish-faced deformity
- subconjunctival haemorrhage and dipoplia
- bilateral infra-orbital nerve anaesthesia
- bilateral haematoma intra-orally over zygomatic/malar buttress
- retroposed upper dental arch* with anterior open bite
*middle face pushed back)
Diagnostic features of Le Fort III fracture
- gross swelling then dish-faced deformity
- subconjuctival haemorrhage and sometimes diplopia
- retroposed upper dental arch with AOB
- CSF (cerebrospinal fluid) leak from nose
- head injury
very serious, life threatening
What can cause isolated orbital floor fracture?
when an object bigger/wider than the orbit hits it (e.g. tennis ball, fist)
orbital floor is very thin therefore fractures
What happens to eye function in isolated orbital floor fracture/why it is called a ‘trap door’ fracture
contents of orbital fat and sometimes inferior rectus muscle drop down to mx sinus → can cause bleeding into the antrum and trapping of eye, cant move it → diplopia (happens when eyes cant move together)
What may be done during orbital floor repair (extra)
Incision to get to orbital floor
Titanium mesh, plastic or bone graft used to replace missing floor and free up muscle and fat
Complications of maxillofacial injuries
- psychological trauma
- scarring
- soft tissue/bone loss
- infection
- malunion/non-union (bone heals in abnormal position)
- trismus
