Oral Surgery Flashcards
What names can a zygomatic fracture be called?
Zygoma
Zygomatic complex
Zygomatico-maxillary complex: best term to encompass everything
Zygomatic arch fracture
What is the main cause for facial fractures?
RTA then IPV
More prevalent in males than females
What is the aetiology of Zygomatic fractures?
2nd most common facial fracture in males
Most common 2/3rd & 7th decades
Unilateral
How many parts is the zygomatic bone and what are they named?
Zygomatic bone
4 major parts
Frontal: here it connects to the frontal bone at the frontal zygomatic suture
Medial
Maxillary: here you can palpate in the buccal sulcus
Temporal
The zygomatic bone is closely related to:
The maxillary sinus
the mandible: the coronoid process it can affect mouth opening this might have notable consequences. this might indicate a coronoid process fracture which would be hard to diagnose due to the limited mouth opening
the orbit of the eye: as it makes up the lateral wall and the floor of the orbit and in a high impact injury that would directly affect these structures
what do we do on radiographs to identify if the is a zygomatic fracture?
you look at the coronoid process and compare the asymmetry on both sides and the distance between
Wat soft tissue structures would be affected in a zygomatic fracture?
Temporalis
Fascia -is inserted in the superior zygomatic bone
Muscle –is inserted with a tendon into the tip/anteromedial coronoid
What is the presentation of a fracture
Rapidly cause
Swelling: closing the eye due to fluids
intraorbital Bruising: ecchymoses
Depression over malar prominence: راس الخد you check with a birds eye view and place finger over malar prominence
Subcutaneous emphysema: air trapped underneath skin layer
Subconjunctival haemorrhage : no posterior border may also be an indication of cranial fractures
What happens if the fracture is involved with the infraorbital margin
this will give altered sensation affecting the maxillary division of the trigeminal nerve: numb lip, cheek and teeth, change in dental alveolar segment and occlusal discrepancy
What happens if the maxilla buttress is involved in the fracture?
1-Intra-oral palpable step Maxillary buttress
2-Maxillary sinus disruption: it might be full with blood
3-Maxillary buccal sulcus Ecchymosis: you can see blood evident in the mouth
4-Epistaxis: nose bleeds
5-Subcutaneous emphysema: the patient will try and blow their nose and that area would fill up with air and when you press on it the air will come out and then they would hear a egg crackling sound
What is the impact on the orbit in a zygomatic fracture?
1-Subconjunctival haemorrhage: bleeding within the eye socket
2-Opthalmoplegia: entrapment of one of the eye muscles so problems with moving the eye in certain directions
3-Orbital dystopia: one orbit is at a different level, severe injury
4-Enopthalmos: increased bony volume in the orbit, the globe is sunken in
5-Exopthalomos: decreased orbit volume the globe is protruded
6- Orbital blowout: swelling
7- Retrobulbar haemorrhage: a bleed behind the eye, increase in volume, this causes pressure on the optic nerve
8- Superior Orbital Fissure Syndome: rare, high impact trauma, cranial nerve damage, 3+5 CN
9- Diplopia: double vision
What investigation are done in case of a zygomatic fracture?
1-Plain radiographs
2-Occipitomental views
10 30 degree
30 degree (Water’s view)
3-CT - suspected orbital floor, severely displaced
4-Opthalmology :Hess chart
What are the goals that we try to achieve with TX of Zygomatic fractures?
1- Restoration facial projection/symmetry
2-Restoration of orbital volume/globe position/shape palpebral fissure.
what effect has timing have on TX?
1- Immediate: there is a tendency to avoid it as there should be time to allow reduction of facial oedema and swelling and any conjunctival ecchymoses(fluid leakage)
2- Early : an interval of a few day to week, allows better understanding of anatomy and asymmetry and to allow better surgical access
3- Delayed: this could cause problems if there is un union, this could cause osteology cuts and reposition of the bone
how can we classify fractures by type?
1- Early non-comminuted, minimal displacement: little reduction
2-Older minimal-comminuted, minimal displaced: open reduction and fixation
3- Signif comminution, fragmentation of supporting buttresses with instability: reconstruction in the buttress orbits and zygomatic arches
what is the most reliable indicator of proper reduction & orientation in 3D with restoration of function, symmetry?
1- Proper alignment of zygomaticosphenoid suture (sphenozygomatic)
2- Anatomic reduction of zygomatic arch
This is in some cases difficult as it is hard to visualise the zygomaticosphenoid suture
Pattern and degree of reduction and fixation is dependent on:
1- Orbital content/volume derangement
2-Facial asymmetry
3-Inf Orb Nerve issues
4- Functional issues
jaw opening
masticatory
5- Associated fractures: so other fractures might require other techniques
How do we treat a non displaced Zygomatic fracture?
Non-displaced ZMC
1- Confirmed by CT
2- Non-surgical MX
3- Serial observation : you can prescribe antibiotics and a decongestion if maxillary sinus involved
4- Soft diet
You continue to monitor and if you see any asymmetry or issues you would go to open reduction and internal fixation
How would you treat a minimal displaced communited fracture?
you can attempt Reduction alone with no fixation or with
Fixation;
one-point
two-point
three-point + orbital floor
Depending on severity of injury
Where are fixation plates placed?
Reduction by direct visualisation at least at one point but if not stable we would continue, start at the;
first
1- Frontozygomatic suture
then
2- Zygomaticomaxillary buttress
then
3-Inferior orbital areas
What are the advantages of oral reduction and internal fixation?
1- Improved alignment: as it allows superior reduction and 3D visualisation
2-Fixation of zygomaticomaxillary buttress provides vertical support to the zygoma against forces
3-Orbital rim exposure allows inspection orbital floor to allow restoration of the orbital volume
4- Inspection of fractures sites prior to closure
What are the indications for Orbital floor exploration?
- Defects larger than 5 mm on CT scan
- Severe displacement
- Comminution
- Soft tissue entrapment with limited upward gaze
- Orbital contents herniation into maxillary sinus
what are the indications for orbital reconstruction?
1-Enophthalmos: the globe is sunken in due to loss of supporting structures
2-Larger defects (5-10mm)
3- Defects posterior to the axis of the globe
What are the indications for two point fixation?
- Minimally displaced fractures
- The 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.
what are the indications for a three point fixation?
1- Instability with two point fixation
2- Exploration of orbital floor required
What are the fixation methods available?
1- Kirschner wires: these fixate the broken fragment to the intact bone by piercing through with wires, not commonly used in the face
2-Lag screw fixation: you drill one hole into the solid bone with another hole in the fractured fragment with is slightly larger بيوصلهن سوا ببرغي واحد
3- Wire Osteosynthesis: drilling holes distant from the fracture site and wire is threaded through and across perpendicularly and wound together بيتخيطو سوا
4- titanium screws and plates: fix the plates with screws they have sizes and thicknesses depending on the load needed
Reduction aim:
Aim of reduction is to provide force in the direction opposite to that which caused the fracture and to re-approximate the bone to the original position.
reduction methods:
1-Stab incision and introduction of an instrument (percutaneous bone hook) to hook under the bone to provide traction.
2-Intra-oral approach vestibular incision and introduction of similar instrument ( bone hook) to hook under the bone to provide traction.
3- Screw insertion to provide traction
4-Screw insertion to provide traction: same as 3 but a different instrument
5-Approach Oral: this is in isolated arch fractures, in an intra oral vestibular incision to introduce an instrument under the arch and pushing it into place
6-Gillies temporal approach
what is the Gillies temporal approach?
you would make a 2mm incision in the hair line superiorly and anteriorly to the helix of the ear and avoid the superficial temporal artery keep on making the incision deeper past all the fascia till the temporal muscle then Introduce instrument and navigate beneath zygomatic arch and Introduce elevator to reduce
What are the instruments used in the mobilisation of the zygomaxillary complex #?
Bristow: it is an elevator straight
Rowe: it is a modification the lower half is identical to the Bristow but has a hinge, the handle is lifted it acts to lift the fracture
what flap do we need for Access to zygomatic arch area in comminuted high energy injuries to allow for Four point fixation ?
Bi coronal flap
what are the post operative orbital complications?
1- Decreased visual acuity
2- Ectropion/entropion/lid malposition: the inner eye lid is exposed or the eyelid is inwards and eyelashes touch the eye
3- Corneal exposure/abrasion: from trauma and intra operatively
4- Ptosis: droopy eye
5- Epiphora: excessive watering
6- Enophthalmos/orbital dystopia : sinking in eye and not in the same level as other eye
7- Diplopia: double vision
8- Blindness due to:
9- Superior Orbital Fissure Syndrome (SOFS)
10- Retrobulbar Haemorrhage with Compartment Syndrome (RBH+OCS)
what is Superior Orbital Fissure Syndrome (SOFS)?
Very rare complication (0.3-0.8%)
Superior Orbital Fissure
pathway for Motor nerves to eye, ophthalmic nerve to the eye
Split into Superior & inferior: inferior has the oculomotor nerve, trochlear and abducens nerve which makes it Subject to trauma – shear forces
(more so inferior)
how is SOFS seen clinically ?
this would be seen clinically as 1-Opthalmoplegia problems moving the eye.
2-Ptosis : dropping of the eyelid
3-Proptosis: decreases tension of the globe retractors
4- Mydriasis - Fixed dilated pupil
5- Loss of accommodation
6- Anaesthesia forehead/upper eyelid
7-Lacrimal (hyposecretion)
8-Anaesthesia cornea /bridge of nose
