Oral Surgery Flashcards
What are the two treatment goals of zygomatic fracture management?
- Restore facial projection/symmetry
- Restoration of orbital volume/globe position/shape palpebral fissure
What is meant by comminution?
Where bone fractures into multiple fragments
What suture is the most reliable indicator of proper reduction & orientation in 3D with restoration of function and symmetry?
Zygomaticosphendoidal suture
What treatment does a non-displaced zygomatic fracture require?
Very little, can be conservative. However, needs monitoring and potential reduction and internal fixation.
What treatment does a displaced, minimally comminuted zygomatic fracture require?
Straightforward open reduction and internal fixation at minimally 2, or maybe 3 points.
What treatment does a complex and comminuted, or isolated zygomatic fracture require?
Major reconstruction with larger flaps for exposure and reconstruction of facial buttresses to fix fracture.
What are the 4 advantages of open reduction and internal fixation of a zygomatic fracture?
- Improved alignment
- Fixation of zygomaticomaxillary buttress provides vertical support
- Orbital rim exposure allows inspection of orbital floor
- Inspection of fracture sites prior to closure
In what three scenarios is two-point fixation indicated?
- Minimally displaced fractures
- When zygomaticomaxillary complex fracture remains stable after initial reduction with no palpable step deformity at the infraorbital rim
- There are minimal changes on orbital volume and globe displacement is not evident on CT scan.
In what two situations is three point fixation indicated?
Where there is instability of fragments and/or exploration of the orbital floor is required.
Name 5 methods of fixation (includes historical techniques and present).
- Kirscher wires
- Lag screw fixation
- Wire osteosynthesis
- Titanium plates and screws
- Resorbable plates and screws
What fixation method is most commonly used in current day?
Titanium plates and screws
What are the 4 most likely sites for fixation?
- Fronto-zygomatic area
- Infra-orbital margin region
- Zygomaticalmaxillary buttress
- Zygomatic arch
What is the aim of reduction?
Provides force in the direction opposite to that which caused the fracture and to re-approximate the bone to the original position.
What are the two main treatment goals of open fixation and internal reduction?
- Restore facial asymmetry
- Restore globe volume position and function
What is a common approach to reduction of a zygomatic arch farcture?
Gillies temporal approach
Describe the gillies temporal approach in 4 steps.
- Identify incision site
- Skin incision and dissect/incise the temporalis fascia
- Introduce the instrument and navigate beneath the zygomatic arch
- Introduce elevator to reduce
What instruments are used for the gillies temporal approach for reduction of zygomatic farctures?
Bristow elevator
Rowe elevator
What are the two points of fixation of a zygomatic farcture for a two point fixation approach?
- Fronto-zygomatic buttress
- Zygomatico-maxillary buttress
What are the three points of fixation of a zygomatic farcture for a three point fixation approach?
- Fronto-zygomatic buttress
- Zygomatico-maxillary buttress
- Infra-orbital margin
What type of flap is required to access the zygomatic arch area in a comminuted high energy fracture to allow for four point fixation?
Bi-coronal flap
What are the 7 general complications of orbital fracture?
- Decreased visual activity
- Ectropion/entropion/lid malposition
- Corneal exposure/abrasion
- Ptosis
- Epiphora
- Enophthalmos/orbital dystopia
- Diplopia
What does “ectropion” mean?
eyelid turns upward/ becomes averted. eyelid exposed, watery eyes occur with excessive tearing, dryness and irritation.
What does “entropion” mean?
eyelid turns inwards, eyelashes rub against inner surface of eye. Left with redness, irritation and sensitivity.
What is meant by “ptosis”?
Eyelid droops
What is meant by “enopthalmos”?
Eyes sunken in
What is meant by “orbital dystopia”?
Eyes are not at same level
What are the three main/major complications of orbital fracture?
- Blindness
- Superior orbital fissure syndrome (SOFS)
- Retrobulbar haemorrhage with compartment syndrome (RBH+OCS)
What is superior orbital fissure syndrome?
Complex impaired function of cranial nerves (III, IV, V and VI) that enter the orbit through superior orbital fissure. Trauma is a major precipitating factor.
What are symptoms of RBH +OCS?
Globe pain and diplopia (double vision)
What is retrobulbar haemorrhage with orbital compartment syndrome?
Bleeding from infra-orbital artery, blood accumulation in the retrobulbar space , an increase in intra-orbital pressure which may result in OCS presenting as proptosis of the eye.
What is the managment of SOFS?
Conservative with observation
What is the aim of non-surgical management of RBH +OCS?
Used as immediate management to reduce pressure in the eye until surgical management can be implicated.
What is the surgical management of RBH+OCS?
Lateral canthotomy- surgical decompression.
What are the 4 main causes of mandibular fracture?
- Assault
- Sporting injury
- Road traffic accidents
- Pathological
Give an example of pathological fracture.
If you have a cyst, tumour or some other osteolytic lesion affecting the mandible it will undermine the strength of the mandible a predispose it to fracture. The fracture can happen spontaneously or with a weak force (such as biting into toast.)
Define the type of fracture:
Undisplaced fracture, where overlying periosteum is intact. If you look at radiograph you can see a small crack running through cortical layer of bone, but the two parts haven’t moved apart.
Simple fracture
Define the type of fracture:
one that has perforated through the overlying periosteum.often it can perforate through the overlying skin and present externally. (Bone protruding through skin).
Compound fracture
What type of fracture is a fracture involving a tooth socket? What is the significance of this type of fracture?
Compound fracture,
the fracture line runs through the PDL into the oral cavity, exposing the fractured mandible to the oral microbiota which predisposes it to becoming infected
Which type of fracture has a higher potential for wound infection, simple or compound fracture?
Compound fracture
What type of fracture is described:
where the fracture pattern has multiple fracture lines, so it tends to be more high impact fractures. You often see these types of fractures with high velocity road traffic accidents or even bullet wounds, where the bone is broken into multiple small fragments. This is far more challenging to manage than a clean break.
Comminuted fracture
What type of fracture is described:
uncommon in mandible, associated with fractures in children. Where you get flexing of bone such that one of the outer cortex’s will fracture but the inner cortex will flex so there is no displacement.
Greenstick fracture
What type of fracture is described:
If you a cyst, tumour or some other osteolytic lesion affecting the mandible it will undermine the strength of the mandible a predispose it to fracture.
Pathological fracture
What are the three most common sites for fracture in the mandible?
- Condyle
- Angle of mandible
- Parasymphysis
How do muscles attached to mandible cause displacement of fractures?
By either pulling the fracture together or pulling it apart
What 4 factors determine the amount of displacement of a fracture?
- The pattern of fracture
- The degree of comminution
- Teeth in the fracture line
- Muscle pull
What is meant by a ‘bucket handle’ fracture?
This is a bilateral parasymphyseal fracture, where muscles pull the anterior segment of mandible downwards and backwards.
In what patients do you most commonly see ‘bucket handle’ fractures?
Edentulous patients
What sign in the way teeth meet together might suggest a displaced fracture of the mandible?
Malocclusion
What are the extra-oral clinical feature suggestive of a mandibular fracture?
- Pain
- Swelling
- Bruising
- Trismus
- Concurrent soft tissue injury
- Otorrhoea (ear discharge)
- Anaesthesia/paraesthesia of lip
What might otorrhoea (ear discharge) be a specific sign of? explain why.
Condylar fracture.
External auditory meatus can tear when condyle fractures, condylar neck driven backwards can breach bony wall of external auditory meatus and that can cause condylar head to be driven into muddle cranial fossa. So blood mixed with CSF can leak out of external auditory meatus.
If a patient suspects fracture and complains of numbness in lower lip, what does this suggest about the location of the fracture upon extra-oral examination?
The fracture is some point between the mental foramen and the lingula on the medial portion of the mandible.
(So anywhere between the last standing molar and the premolar region there is a fracture as this is exactly where IAN canal is situated)
What are the intra-oral clinical features of a fracture of the mandible?
- Haematoma in FOM & buccal mucosa
- Malocclusion
- Tongue swelling
- Step deformity in occlusion
- Gingival laceration
- Mobility or loss of teeth/ fractured teeth
What intra-oral sign is considered pathognomonic of a mandibular fracture?
Haematoma in the FOM (Coleman’s sign)
If a step deformity in occlusion is present what this suggest about a fracture?
There is quite a degree of displacement
What are the two ideal radiographic views to investigate a suspected mandibular fracture? Why are these views ideal to take?
DPT and PA mandible, ideal because they are 90 degrees to each other so allow fracture to be seen from different angles. Also, PA view allows you to determine if there is displacement in all three dimensions.
What is the time/window of treatment that would ideal for a patient to be treated within for a fracture?
Within a 72 hour window
Delay to presentation/ treatment of a fracture can cause increased risk of complications. Name these 4 complications.
- Wound dehiscence 2. Infection 3. Exposure of hardware 4. Non-union or fibrous union
Delay to presentation/ treatment of a fracture can cause increased risk of complications. Name these 4 complications.
- Wound dehiscence (breakdown)
- Infection
- Exposure of hardware
- Non-union or fibrous union
Who should a patient be referred to if they have a fracture of the head?
Maxillofacial surgery
What treatment technique is used nowadays to fix fracture of the head?
Open techniques.
Specifically, Open Reduction and Internal Fixation.
Describe an open technique for treated a fracture of the head.
Fracture margins are directly visualised through an incision, and aligned with mini-plates to reduce the fracture.
Why are open techniques generally preferred over closed techniques for treating fractures of the head?
Because open techniques involve immobilisation of the fracture to allow for a period of healing. Whereas, closed techniques often leave the fracture site mobile which can have detrimental effects on healing.
What are the two aims of ‘reduction’ as part of open reduction and internal fixation treatment for a fracture?
- Aligns the bone ends anatomically
- Recreates the normal bone anatomy
What are the three aims of ‘fixation’ as part of open reduction and internal fixation treatment for a fracture?
- Prevents movement of bone margins whilst healing occurs
- Can be load-bearing so that 100% of the functional load is supported by the fixation e.g. two large plates.
- Can be load sharing such that the load is distributed between the hardware and and the bone margins e.g. one upper boarder plate and arch bars.
What is more ideal, fixation being load bearing or load sharing?
Load-bearing fixation
What is the difference between mini-plates and reconstruction plates?
Mini-plates made of titanium placed to fix fracture. These are placed and not removed/there for life.
Reconstruction plates tend to be used within edentulous patients, they are thicker and longer which hold mandible very rigidly.
Why might you opt to use a closed technique of intermaxillary fixation if you have a bilateral condylar fracture?
To ensure you don’t loose condylar height in the process
What are the 5 advantages of open reduction and internal fixation?
- Improved alignment and occlusion
- Fracture immobilised
- Avoid IMF
- Low rate of non-union
- Lower rate of infection
What are the three disadvantages of open reduction and internal fixation?
- Morbidity of surgical procedure
- Expensive hardware
- Need for GA
According to champy’s principles, what line should plates be placed in within the mandibular angle region, and mental foramina region?
In the mandibular region, plates should be placed either along or just below the oblique line of the mandible.
Between the mental foramina, 2 plates are recommended below the apices of teeth.
Why are edentulous fractures more difficult to manage?
- Atrophic
- Poorly vascularised so poor healing capacity
- Lack of anatomical landmarks
Name 8 complications of surgery for mandibular fractures.
- Non-union, fibrous union, mal-union
- Altered occlusion
- Distracted TMJ
- Scars
- Infection
- Necrosis
- Numb lip
- Exposed plate
What are the two types of condylar fracture?
- Extra-capsular
- Intra-capsular
How are condylar fractures often managed?
Conservatively with soft diet and NSAIDs
What is a main concern with intra capsular fracture of condyle?
You can get ankylosis of the joint if it is completely immobilised which can lead to problems with trismus and inability to move joint in the long term.
How are greenstick fractures in children usually managed?
With simple blow-down splint