Cummings Chap 23 Maxillofacial
Trauma
10/31/12
Anatomy/Physiology
Upper 1/3
• Frontal bones- “relates” to FS, brain, orbits,
cribiform, supratrochlear/supraorbital n
Middle 1/3
• Zygoma- facial projection, masseter insertion,
inferolateral orbital rims/walls
• Orbits- 7 bones (frontal, zygomatic, max, lacrimal,
ethmoid, sphenoid, palatine).
• maxilla- V2, infraorbital rims/floors, NLD, teeth,
MCL
• nose- breathing/olfaction, cosmesis
– Most freq fx bone in human body
Anatomy/Physiology
Lower 1/3
• Mandible
– Dentition/occlusion
– Horseshoe shape + TMJ absorbs force from transmitting to
MCF
– 32 teeth, 8/quadrant
– Angel Classification of occlusion
• Class I mesiobuccal cusp of max 1st molar sits in buccal groove of
the mandib 1st molar.
• Class II max molar more anterior/chin retruded- overbite
• Class III max molar more posterior/chin prognathic- underbite
Eval/Diagnosis
PE
• ABCD, gen appearance, CNs, Blood/CSF, FB
Upper 1/3
• Test motor, sensation, step offs
Mid 1/3
• Eval globe/orbits, visual acuity, EOMs,
proptosis/enopthalmos, ophthal consult
• Nasal bone- fx, septal hematoma, NOE
• NOE fx- Intercanthal distance- normal 30mm, ½
interpupillary distace, >45mm=telecanthus, loss of nasal
dorsal height, epicanthal folds, MCL traction test
Lower 1/3
• Open mucosal teas, V3 sensation, occlusion, mouth
opening/trismus.
Radiographic Eval
Axial cuts- good to eval FS, zygomatic arch,
vertical orbital walls, vertical structures
Coronal cuts- good to eval orbital roof/floor,
pterygoid plates, horizontal structures
CT face w/ fine cuts 1.5mm
Schemas
Upper 1/3
• FS fx –
– Ant table- cosmesis, sinus function
– post table- sinus fxn, neurosurg
• Supraorbital rim comminuted fx  FS recess injury
• Centrally located + severe fx  CSF leak
Mid 1/3
Orbits
– Orbital apex syndrome- II, III, IV, V, VI
– Superior orbital fissure syndrome- III, IV, V, VI
– Blowout fx- rims intact w/ 1 or more walls fx, usu floor/medial
wall
Le Forte
NOE
Schemas
Le Forte ?- complete
craniofacial separationzygoma, through orbit,
nasaofrontal jxn
Le Forte ?- horizontal max
fx above dentition
Le Forte ?- pyramidal fxorbital rims/floor, nasal
root
Schemas
Le Forte I- horizontal max
fx above dentition
Le Forte lI- pyramidal fxorbital rims/floor, nasal
root
Le Forte III- complete
craniofacial separationzygoma, through orbit,
nasaofrontal jxn
Schemas
• Type ? bone fragment
containing MCL freed from
surrounding bone
• Type ? MCL tendon detached
or attached to a fragment
that is irreparable ie bilat
orbital wall fx
• Type ? comminuted fx,
repairable via transnasal
fixation
Schemas
• Type I bone fragment
containing MCL freed from
surrounding bone
• Type II comminuted fx,
repairable via transnasal
fixation
• Type III MCL tendon
detached or attached to a
fragment that is irreparable
ie bilat orbital wall fx
Management- access
• Start ppx abx immed
Surgical access- existing lac?
Upper 1/3
• Coronal incision, access to pericranial flap, beware frontal br and
supraorbital n
Mid 1/3
• Zygoma- gilles, gingivobuccal
• Lateral orbital rim- upper bleph, lateral brow, lower lid
transconjunctival +/- lateral canthotomy
• Orbital floor- transconj pre v post septal, transcutaneous subciliary v
lower lid crease (frost stitch)
• Medial orbit- transcaruncular, lynch
Lower 1/3
• Mandible- intraoral, beware mental n, transcervicalsubmand/submental incision, retromandib inci, beware mental n,
facial n.
Biomechanics
Facial skeleton has areas of strength and
weakness
Strength- buttresses/pillars
Weakness- crumple zones eg. LP/ethmoid
bones- direct blunt trauma to central face 
telescoping NOE fx, dissipates force protecting
globes. Same concept for purpose of sinuses.
Biomechanics
Upper 1/3
• frontal ant table- weak
• supraorbital rim- strong, protects orbits and ant
cranial fossa
Mid 1/3
• vertical buttress x4: nasofrontal/nasomax,
frontozygomatic/zygomaticomax, pterygoid
• horizontal bars x4: frontal bar, zygoma, infraorbital
rim, palate
Low 1/3
• Mandible upper beam- tension forces
• Lower beam- compressive forces
Fracture Repair- principles
Purpose of fx repair- regain aesthetic form and occlusal fxn
Rigid fix- elim movement across fx, allows primary bone
healing, minimizes callus formation
Occlusion>>fracture reduction
MMF, ivy loops, IMF- to re-est occlusion
Work from stable to unstable, known to unknown, periphery
to center
Re-est facial height 1st -repair mandible 1st, make sure midface
not impacted/rotated before rigid fixation
Then stabilize buttresses- L/J plates
Then central face
Then orbits- floor has irregular convexity, not a complete
sphere, failure to recognize will cause enopthalmos
Repair CSF leaks immediately, longer leak  incr r/o
meningits
Mandible fx repair
2 schools
1) Champy- miniplates + monocortical screws
2) Speisl- MMF + compressive plate w/ bicortical screws
Body- single miniplate +/- bicortical compression plate
Symphysis- 2 miniplates
Angle- very complex/changing forces, recon plate v single 1.3mm miniplate v
2 2mm miniplates, highest rate complications
Ramus- 2 2mm miniplates
Subchondylar- MMF v open- risk to FN
indications for open–
–
–
–
chondylar displacement into MCF
inability to obtain reduction
lateral extracapsular displacement of chondyle
FB
Relative indications– B chondylar fx + edentulous, + comminuted midface fx, +gnathologic problems
– when splinting not recommended
Mandible fx repair
Load sharing- depends on integrity of bone, eg miniplate,
compression plate, lag screw
Load bearing- atrophic/thin/comminuted fx- repair needs to
bear load across the affect bone eg recon plate w/ 4
bicortical screws on each side. Fall-back technique for all
repairs
Locking (v nonlocking) screws allows for less than perfect
plate bending.
Other options:
• ex fix, MMF 4-6 wks
Tooth in fx lineleave alone if: healthy, 3rd molar in angle fx
remove if: infected, interferes w/ reduction
Frontal Sinus Fx
Anterior wall nondisplaced- obs
Anterior wall displaced- repair
Anterior wall + FSR injury- oblit v obs
Posterior wall nondispl +/- FSR- obs
Posterior wall displ- trephine + transcut endoscopy
(r/o herniated brain)
Obliteration- pack w/ fat, seal recess w/ cement or
pericranial flap
Cranilization- removal of posterior table
NOE repair
Type I- stabilize the
floating bone to
surrounding bone w/
plate
Type II/III- stabilize MCL
to the contralat frontal
bone or MCL w/
permanent suture or
wire
Complications
Malocclusion
Continued movement across a fx leads to:
• nonunion- persistent gap/fx
• fibrous union/pseudoarthrosis- persistent callus
w/o bone formation
• malunion- bone heals in wrong position
Scar
Entropion/extropion
Nerve injury