7. Maxillofacial Trauma Flashcards
Glasgow Coma Scale
Objective measure of patient’s neurological status and used serially to track clinical progress.
Patients >5yo
Score 8 or less, early airway protection is encouraged
Minimum score is 3
Eye Opening
1 no response
2 to pain only
3 to verbal stimuli, command, speech
4 spontaneous opening with blinking
Verbal Response
1 no response
2 incomprehensible
3 inappropriate words
4 confused conversation but able to answer
5 oriented
Motor Response
1 no response
2 extension in response (decerebrate posturing)
3 flexion in response (decorticate posturing)
4 withdraws in response to pain
5 purposeful movement to pain
6 obeys commands for movement
What are the classes of hemorrhagic shock and how much blood loss can be expected with each?
1 <750
2 750-1500
3 1500-2000
4 >2000
Severity of head injury based on GCS
Severe head injury/coma GCS 8 or less
Moderate head injury GCS 9-12
Mild head injury GCS 13-15
Denotation of “T” after the score is applied to intubated patient
Describe the zones of the neck for penetrating trauma
Zone 1: thoracic inlet to cricoid cartilage
Zone 2: cricoid cartilage to angle of the mandible
Zone 3: angle of the mandible to base of skull
Define load bearing vs. load sharing
Load bearing is hardware of sufficient strength to bear the entire load
-Plates and screws immobilize fractured segments. Thicker, rigid plates with bicortical screws or lag screws. 3 screws on each segment.
Load sharing is unable to bear all functional load across fracture
- Miniplates and monocortical screws along lines of osteosynthesis as described by Champy
What is the ideal line of osteosynthesis of the mandible?
Described by Maxime Champy 1976: a line around the mandible where plating the tension and compression forces are balanced, thus offering the best biomechanical advantage for positioning of plates and screws
Non-locking plates/screws
Plates must be adapted intimately to the bone. Compression of the plate onto the bone may cause bone resorption under the plate.
Locking plates/screws
Screws lock into the plate while it is being tightened. Does not require a perfect adaptation of the plate to the bone. Plate bears the load of mechanical forces.
General approach to facial trauma patient
Mechanism of injury, LOC
Confirm ATLS/PALS has been performed w/ appropriate consultations
C spine evaluation and clearance
Physical exam: GCS
Facial asymmetry, lacerations
Cranial nerve exam II-XII
Paresthesias V1, V2, V3
Ocular movements, pupillary reaction, diplopia, intraocular pressure, proptosis, dystopia, enophthalmos, periorbital ecchymosis, telecanthus
Ecchymosis behind ears (Battle’s sign), otorrhea, eval tympanic membrane
Midface loss of projection, edema, step deformities
Nose for asymmetry, septal hematoma, bleeding
Jaws for range deviations on opening, step deformities, hematoma, intraoral lacerations
Muscle action classification for mandible fractures
Vertically favorable = resistance to medial pull
Horizontally favorable = resistance to upward movement
Contraindications for closed reduction of the mandible
Alcoholics, seizure disorders, mental retardation, nutritional concerns, respiratory diseases (COPD), unfavorable fractures
Considerations for edentulous mandible fractures
Decreased bone height, decreased buttressing effect
Significant effect of muscular pull (digastrics)
Biological differences = dependent on periosteal (centripetal) blood flow. Delayed healing, decreased ability to heal with age
Tx: circummandibular wires fixated to piriform rims and circum zygomatic wires with patient’s denture or Gunning style splints. Requires IMF with longer periods due to age.
Open reduction >20mm mandible treated as dentate mandible. Load bearing plates. Bone grafts commonly incorporated.
Indications for open reduction of condylar fractures
Zide’s absolute indications:
1. middle cranial fossa involvement with disability
2. inability to achieve occlusion with closed reduction
3. invasion of joint space by foreign body
4. lateral capsule violation and displacement
Zide’s relative indications:
1. bilateral condylar fractures where vertical facial height needs to be restored
2. associated injuries that dictate early or immediate function
3. medical conditions that indicate open procedures
4. delayed treatment with misalignment of segments
When to remove teeth in the line of fracture
- Gross mobility
- Periapical pathology
- Preventing reduction
- Roots with a fracture
- Exposed root
- Delay in repair from time of fracture
- Recurrent infection at fracture site despite antibiotic therapy
LeFort classifications
LeFort I: horizontal fracture above apices of maxillary dentition across nasal septum and maxillary sinuses. Posteriorly extends through pyramidal process of palatine bone and pterygoid processes of sphenoid bone. May also involve fracture of the palate.
LeFort II: pyramidal fracture extends from nasofrontal region down through medial orbital wall, drossing infraorbital rim and zygomatic buttresses. Posteriorly similar to LF1.
LeFort III: complete craniofacial disjunction with fracture lines through nasofrontal junction, zygomaticofrontal articulations, zygomaticomaxillary suture, temporozygomatic suture, pterygomaxillary junction, medial and lateral orbital walls, and superior articulation of nasal septum.
Usually mixed combination.
Four key areas to evaluate for LeFort fractures on CT
- Pterygoid plates (strong indication of LeFort fracture)
- Lateral margin of nasal fossa (LeFort I)
- Inferior orbital rim (LeFort II)
- Zygomatic arch (LeFort III)
Principles of LeFort fracture management
-Non-displaced fractures without clinical compromise = soft diet with observation & soft diet or 4-6 weeks IMF
- Edentulous patients open treatment or observation
Treat as soon as possible. Longer open or compound fractures are untreated, greater incidence of infection and malunion.
- Fixate fractures to allow immobilization and optimal healing
- Use buttresses for fixation
- Restore preoperative occlusion
- Ensure to treat nasal complex and orbital fractures as indicated
Four articulations of the zygoma
Where is the weakest portion of the zygomatic arch?
- frontozygomatic
- zygomaticomaxillary
- zygomaticosphenoid
- zygomaticotemporal
Weakest portion of the zygomatic arch is not the zygomaticotemporal suture, but a point 1.5cm posterior to this.
Recommended sequence of fixation for ZMC fractures
- Fixate frontozygomatic region first to restore facial height of the complex
- Fixate zygomaticomaxillary buttress region to restore facial projection and ensure that the medially rotated body is back in its normal anatomical position
- Fixate the orbital rim to define orbital volume and facial volume
- Orbital floor should be managed last as it is critical that the aforementioned sites are placed back into alignment to prevent enophthalmos and facial widening
Alignment of the sphenozygomatic suture is a good indicator of the three-dimensional position of the zygoma.
Bones of the orbit
- Orbital roof (2 bones)
- Lateral wall (2 bones)
- Orbital floor (3 bones)
- Medial wall (4 bones)
Orbital roof: frontal and lesser wings of sphenoid
Lateral wall: greater wing of sphenoid and zygomatic bone
Orbital floor: maxillary bone, zygomatic bone, and palatine bone
Medial wall: frontal process of maxillary, ethmoid (lamina papyracea), lacrimal, and sphenoid bones
Contents of the superior orbital fissure
CN III, IV, VI
Sensory nerve V1
Sympathetic fibers
Superior ophthalmic vein
Recurrent and middle meningeal artery
Separates greater and lesser wings of sphenoid
Delineates between orbital roof and lateral orbital wall
Contents of the inferior orbital fissure
Sensory nerve V2, parasympathetic branch of the pterygopalatine ganglion, and inferior ophthalmic vein
Contents of the optic canal
Optic nerve, ophthalmic artery, sympathetic fibers
Whitnall’s tubercle
10mm below FZ suture and 3-4mm inside the lateral orbital rim.
Attachments: (1) lateral horn of levator aponeurosis, (2) lateral canthal tendon of the eyelids, (3) Lockwood’s ligament, (4) check ligaments
All four of these comprise the lateral retinaculum
Annulus of Zinn
Tendinous ring of fibrous tissue at apex of the orbit surrounding the optic nerve that is the origin of the rectus muscles of the eye.
Describe the measurements for safe dissection in the orbit
All measurements from intact anterior lacrimal crest. Anterior ethmoidal foramen 24mm, posterior ethmoidal foramen 36mm, optic foramen 42mm
Layers of the lid
Skin, subcutaneous tissue, orbicularis oculi, septum, tarsal plate, conjunctiva
Normal ocular pressures with tonometry pen
10-20mmHg
Indications for orbital fracture repair
-Large orbital fractures >50% of orbital floor; enophthalmos >2mm, diplopia in primary gaze
-Asymptomatic patients without the aforementioned signs and symptoms-observation
-Muscle incarceration is a true emergency as entrapped tissue will become ischemic
-Signs of oculocardiac reflex require emergent surgical intervention
-Most fractures can be observed for 2 weeks for resolution of motility disturbance resulting from edema, hemorrhage, or rectus muscle contusion
Antibiotics (sinus coverage), sinus precautions, nasal decongestants, ice packs, HOB elevation
Describe your technique for a transconjunctival approach
- Corneal shield with ophthalmic-grade bacitracin/ocular lubricant placed on globe
- Local w/ vasoconstrictor under conjunctiva as well as around lateral canthus if lateral canthotomy is planned
- 15 blade sharp incision through lateral canthus. Tip of iris scissor inside palpebral fissure, extending laterally to depth of underlying lateral orbital rim (do not exceed 7mm laterally to ensure safe distance from temporal branch of facial nerve). Scissors used to cut horizontally through lateral palpebral fissure (skin, orbicularis muscle, orbital septum, lateral canthal tendon, and conjunctiva)
- Using lateral orbital rim as a stop, inferior cantholysis is performed by turning the orientation of the scissors vertically to incise the inferior canthal ligament.
- Conjunctiva is approached using blunt tipped pointed scissors to dissect through the small incision through the conjunctiva made during lateral canthotomy. Bluntly undermine conjunctiva over the orbital septum and extend as far medially (3mm away from caruncle).
- Incise conjunctiva below curvature of tarsal plate
- Palpate inferior orbital rim. Retract orbital contents and lower lid and dissect to rim.
- Strip periosteum over orbital rim, anterior surface of maxilla, zygoma, and orbital floor
- Place broad malleable retractor
- Explore orbit, release entrapped tissue, identify bony landings
- Forced duction test
- 4-0 Vicryl to reattach lower limb of lateral canthal tendon
- Subcutaneous sutures and 6-0 skin suture placed along horizontal lateral canthotomy
- Some surgeons reapproximate bulbar conjunctiva with 6-0 fast gut
Test for nasolacrimal duct injury
Jones I test: few drops of fluorescence dye or propofol in the lower conjunctival sac, observe for fluorescein/propofol in the nose. If not identified, proceed to Jones II test
Jones II test: irrigate punctum and inject fluorescein into the (SAC) puncta/canaliculi. If fluorescein is seen, then the blockage is above the lacrimal sac; if not, then blockage is near the punctum or canaliculus
Dacryocystorhinostomy
Secondary repair of nasolacrimal duct injury - goal to create a bony window between lacrimal sac and nose
What is hyphema?
Bleeding from torn vessels at root of iris in anterior chamber.
Positional blurred vision, photophobia.
Graded based on percent of anterior chamber filled/involved
Grade 1: 1/4 of anterior chamber
Grade 2: 1/2
Grade 3: 3/4
Grade 4: complete coverage (blackball or 8-ball hyphema)
Managed with
- atropine 1% ophthalmic drops to dilate pupil, immobilize iris to prevent future bleeding;
- timolol ophthalmic drops (beta-blocker to decrease intraocular pressure)
- acetazolamide PO (carbonic anhydrase inhibitor)
- steroids
- bed rest, HOB elevated
Complications: rebleeding, glaucoma, corneal staining
What is a Marcus Gunn pupil?
afferent pupillary defect - swinging flashlight test
What is Horner’s syndrome?
Injury to sympathetic nerves supplying the globe
TRIAD
(1) miosis (unopposed parasympathetic)
(2) eyelid ptosis (decreased Muller’s muscle tone)
(3) anhidrosis (sweat glands)
Dx: 4% cocaine drops to affected eye fails to dilate compared to unaffectted pupil.
What is superior orbital fissure syndrome?
Ophthalmoplegia (CN III, IV, VI)
Lid ptosis (CN III)
Mydriasis and loss of direct pupillary light reflex (CN III parasympathetic fibers)
What is orbital apex syndrome?
Superior orbital fissure syndrome + injury to CN II (loss of vision and direct and consensual pupillary light reflex).
Superior orbital fissure syndrome
-Ophthalmoplegia (CN III, IV, VI)
-Lid ptosis (CN III)
-Mydriasis (CN III parasympathetic fibers)
NOE complex
Nasal bones, frontal process of the maxilla, nasal process of the frontal bone, and medial orbital wall (composed of lacrimal bone and ethmoid bones)
Manson and Markowitz Classification
Classification of NOE fracture based on condition of central fragment (frontal process of the maxilla) and medial canthal tendon.
- Type I: no comminution of the central fragment and tendon is intact
- Type II: comminution of the central fragment and the tendon is intact
- Type III: severe comminution of the central fragment and the tendon is avulsed
How do you test for CSF leak
- Beta-2 transferrin
- May also send sample for glucose and chloride level
Chloride is usually greater and glucose is less than serum - Halo test involves placing drop of the bloody rhinorrhea on filter paper and seeing a center of blood and straw-colored halo
How are type III NOE fractures treated?
Canthopexy with posterior-superior vector
Transnasal wiring technique: the vector of fixation is posterior and superior to the lacrimal fossa
Suturing the tendon to a miniplate in the NOE region (non-resorbable suture with posterior-superior vector)
Mitek anchoring procedure (use of suture anchoring device for management of medial canthal tendon)
Complications of NOE fracture
Dacryocystitis: infection of lacrimal sac due to obstruction. Antibiotics (PCN-based).
Epiphora: attempt lower lid massage. If no improvement, dacryocystorhinostomy
How is a dacryocystorhinostomy performed?
Incision 6mm from medial canthal angle, dissect to lacrimal sac. H incision made in nasal soft tissue and lacrimal sac. Posterior flaps sutured together. Puncta intubated with Crawford tube and passed through the openings of the nose. Ends of the Crawford tube are tied and the anterior flaps of the nasal mucosa and lacrimal sac are sutured together. Orbicularis muscle and skin are closed. Stent left in place for 3-6 months.
What is Kiesslebach’s plexus?
Located along anterior aspect of the septum, the confluence of anterior ethmoidal artery, posterior ethmoidal artery, nasopalatine artery, and septal branch of the superior labial artery.
Most common site of epistaxis
Drainage of the frontal sinus
15% have true nasofrontal duct facilitating sinus drainage into middle meatus of the nose.
The remaining population drains via hiatus semilunaris to nasal frontal tract.
Gonty’s classification of frontal sinus fractures
- Isolated anterior table
- Anterior and posterior table
- Posterior table
- Comminuted fracture
