Facial Trauma Flashcards
What is the craniofacial ratio in adulthood
0.0840277777777778
What is the craniofacial ratio at birth
0.334027777777778
How many deciduous teeth are there
20
In an adult, what # is the right 3rd molar of the mandible
32
What is the appropriate tetanus prophylaxis for a patient with a tetanus-prone wound, who has not been previously immunized
0.5 ml absorbed toxoid and 250 units of human tetanus immune globulin.
What is the proper tetanus prophylaxis for a patient with a tetanus-prone wound, who last received a booster 7 years ago’
0.5 ml absorbed toxoid.
What do “microplates” refer to
1.0 mm screw applications.
In what % of the population is the nasofrontal duct a true duct
15% (in 85% it exists as a foramen draining directly into the nasal cavity).
How long should immobilization typically be maintained in children
2 - 3 weeks.
Where is this located in relation to the lateral canthus
2 em inferior.
What do “miniplates” refer to
2.0 mm, 1.5 mm, or 1.3 mm screw applications.
What % of mandible fractures are associated with cervical spine injury
2.6%.
What post-orbital fracture visual acuity scores are associated with a return to normal acuity after treatment
20/400 or better.
Where are the anterior and posterior ethmoid arteries and optic canal in relation to the anterior lacrimal crest
24 - 12 - 6 rule: anterior ethmoid artery is approximately 24 mm posterior to the lacrimal crest; the posterior ethmoid artery is 12 mm posterior to the anterior ethmoid artery; the optic canal is 6 mm posterior to the posterior ethmoid artery.
What is the typical long-term interincisal opening after surgical correction of TMJ ankylosis
25 - 28 mm.
What % of patients with ZMC fractures have other associated facial injuries
25%.
What % of thoracic perforations will be missed with water-soluble contrast agents
25%.
What is the incidence of permanent scleral show with the subciliary approach
28%.
What is the normal intercanthal width
30 - 35 mm in Caucasians or roughly the width of the alar base.
How far posterior should dissection proceed when placing a Medpor implant for defects of the posterior convex orbital floor
4 em.
What % of mandible fractures are associated with other injuries
40 - 60%.
What is the average depth of the orbit
40 -50 mm.
What is normal interincisal opening
40 -50 mm.
What % of cervical perforations will be missed with water-soluble contrast agents
50%.
What are the indications for endoscopic optic nerve decompression after facial trauma
66% reduction in amplitude of the visual-evoked response, loss of red color vision, bony impingement on the optic canal, afferent papillary defect.
What is the incidence of persistent diplopia after orbital reconstruction
7%.
What is the incidence of infection after mandible fracture
7%.
Cerebral perfusion-directed therapy attempts to maintain CPP at or above what
70 mm Hg.
What is the sensitivity of barium in detecting perforations
80- 90%.
How much force is required to fracture the frontal sinus
800 - 2200 lbs.
How are they numbered
A to T.
What is the best way to treat mandible fractures in infants
Acrylic splints x 2 - 3 weeks.
What is the “bowstring sign”
An obvious give that occurs with lateral tension on the lower lid, indicating disruption of the medial canthal tendon.
What is the most likely mechanism of injury for bilateral condylar fractures
Anterior blow to the chin.
What are the 3 limbs of the medial canthal tendon
Anterior, superior and posterior limbs.
What are the contraindications to primary closure of bites
Any human bite; animal bites seen after 5 hours of injury; all avulsion injuries from any animal bite.
What are the weakest areas of the mandible
Area around the 3rd molar, socket of the canine tooth, and the condyle.
What is the strongest predictor of negative outcome in trauma patients
Arterial hypotension
Where are inferiorly positioned plates placed
At the inferior border of the mandible to avoid the neurovascular bundle.
What is the treatment for a nondisplaced posterior table fracture with a CSF leak
Bed rest with head elevation +/lumbar drain; cranialization considered if not resolved after 5 - 7 days.
What is the general approach for repair of panfacial fractures
Begin laterally, work medially, and correct NOE and nasal septal fractures last; frontal fractures should be repaired before midface fractures.
What is the general approach to repair of LeFort III fractures
Begin stabilization at the cranium then work caudally.
What are the relative indications for open reduction of a condylar fracture
Bilateral condylar fractures in an edentulous patient when M MF is impossible, condylar fractures when MMF is not recommended for medical reasons, bilateral condylar fractures associated with midface fractures.
Anterior open bite suggests which type of fracture
Bilateral condylar fractures.
What is the most serious complication after orbital reconstruction
Blindness.
What can be done for trismus that does not respond to brisement force
C oronoidectomies.
Which tooth has the longest root
Canine.
What is a type I I NOE fracture as described by Markovitz et al
Comminuted, but identifiable, central fragment.
What is a type C ZMC fracture
Complex fracture with comminution of the zygomatic bone.
Which mandible fractures require ORI F with bicortical screws
Complex open fractures that are displaced, comminuted, or infected.
Rigid fixation is based on what two means of stabilization
Compression and splinting.
Why should compression plates be over-contoured by 3° - 5°
Compression at the buccal surface tends to produce spreading on the lingual side; over-contouring will overcome this.
Which parts of the mandible are most commonly fractured
Condyle (36°/o), body (21°/o), and angle (20%).
Which part of the mandible is most commonly fractured in children
Condyle.
What are the typical physical findings of a unilateral condylar neck fracture
Contralateral open bite and ipsilateral chin deviation.
What is the “workhorse” for exposure of the nasoethmoidal region
Coronal approach.
What is the indication for surgical treatment of isolated anterior table fractures
Cosmetic deformity.
What is the definition of cerebral perfusion pressure (CPP)
CPP = mean arterial pressure (MAP) - intracranial pressure (ICP).
What are the potential complications of endoscopic optic nerve decompression
CSF leak, carotid artery injury, transection of the ophthalmic artery, orbital fat herniation.
What is a potential complication of this approach
Damage to the temporal fat pad, resulting in temporal wasting.
Which teeth can be used in children between the ages of 5 and 8 for immobilization
Deciduous molars.
What are the most common injuries associated with facial trauma in children
Dental injuries.
What are the 3 approaches to zygomatic arch fractures
Direct percutaneous, temporal (Gillies), and hemicoronal approaches.
What is the treatment of choice for an edentulous 40-year-old epileptic man who sustains a LeFort I fracture during a seizure
Direct wiring of the zygomaticomaxillary buttresses.
When is cranialization required for treatment of frontal sinus fractures
Displaced posterior table fractures with a CSF leak or significantly comminuted posterior table fractures.
What are the indications for frontal sinus obliteration in the presence of a fracture
Displaced posterior table fractures with involvement of the nasofrontal duct.
What are the absolute indications for open reduction of a condylar fracture
Displacement of the fractured fragments into the middle cranial fossa, inadequate reduction with MMF, lateral extracapsular displacement of the condyle, foreign body (ie, bullet) embedded in the joint.
What is the most likely cause of cyclovertical diplopia following repair of a NOE fracture
Disruption of the trochlea.
When approaching the frontozygomatic buttress through the hemicoronal incision, how is the temporal branch of the facial nerve avoided
Dissection begins just superficial to the superficial layer of the deep temporal fascia; 2 em above the zygomatic arch, the dissection is carried deep to the superficial layer of the deep temporal fascia.
What is the plane of dissection with the Gillies approach
Dissection is carried out between the temporalis muscle and its overlying fascia.
What are the only plates that can bear the stress of mastication during healing
Eccentric dynamic compression plates.
What is the most common complication after orbital reconstruction
Enophthalmos.
What is the most helpful test for evaluation of aerodigestive injuries caused by transcervical gunshot wounds
Esophagram with water-soluble contrast agent followed by barium.
T/F: Patients with titanium implants cannot undergo MRI
False.
What materials can be used to obliterate the frontal sinus
Fat, muscle, fascia, or cancellous bone; can also allow spontaneous osteogenesis after burring the inner cortices.
Your patient has a fracture of the mandibular body and a comminuted midface fracture. How do you approach reconstruction
First MMF, then ORlF the mandible, then ORlF the midface.
Your patient has a fracture of the condylar head and mandibular body and a comminuted midface fracture. How do you approach reconstruction
First ORIF the midface, then place the patient into MMF, then ORIF the mandibular body fracture.
When should lag screws be used to reduce a fracture
For an oblique fracture with an intact inner fragment where the length of the fracture is at least twice the thickness of the bone.
When are serial explorations indicated after penetrating injuries to the face
For high-energy gunshot or rifle (> 1200 ft/s) injuries, shotgun injuries, and high-energy avulsion injuries.
What test is performed to evaluate for entrapment of the extraocular muscles
Forced duction test.
What is brisement force
Forced jaw opening under anesthesia; usually successful for treatment of trismus that does not respond to physiotherapy.
What is a class I mandible fracture
Fracture between two teeth.
What is a class Ill mandible fracture
Fracture in an edentulous area.