This document discusses the anatomy and fractures of the zygomatic bone. It notes that the zygoma forms the cheekbone and articulates with several other facial bones. Zygomatic fractures most commonly occur in the arch or body due to blunt trauma. Diagnosis involves checking for diplopia, ecchymosis, and other signs of orbital or facial bone involvement. Treatment may involve closed or open reduction based on the severity of displacement. Closed reduction techniques try to elevate the bone back into position without surgery, while open reduction requires surgical exposure and fixation of the fracture site.
4. 12/28/2020
Dr.SimonRock The Zygoma
Paired
Form the “cheekbones”
Articulate with the temporal, frontal, and maxillary bones
Their prominent position and shape renders them susceptible to injury
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Importance of zygoma
Esthetics :
Provides normal check contour.
Orbit :
Provide support
Separates it from the temporal fossa and the maxillary sinus.
Binocular vision :
The ZMC provides the necessary lateral globe support.
Lockwood’s suspensory ligament
Whitnall’s tubercle
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Mastication :
The zygomatic arch is the insertion for
masseter muscle.
Protects the temporalis muscle and the
coronoid process.
Innervation:
Zygomaticofacial, zygomaticotemporal
and infraorbital nerves are attached to
zygoma
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Articulations of Zygoma :
A. Superficial Articulations
1. With frontal bone through :
zygomaticofrontal suture.
2. With maxilla at
the lateral antral wall
(zygomaticomaxillary buttresses).
3. With With temporal bone through
the zygomaticotemporal suture.
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2
3
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B. Deep Articulations
1. With orbital
process of
sphenoid bone.
1. With orbital
process of
maxilla.
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2
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Dr.SimonRock Zygoma Fractures
The zygoma has 2 major components:
Zygomatic arch
Zygomatic body
Blunt trauma most common cause.
Two types of fractures can occur:
Arch fracture (most common)
Body fracture (most serious)
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CLASSIFICATION
Fractures of the body, the zygomatic complex
involving the orbit.
1)Minimal or no displacement
2)Inward and downward displacement
3)Inward and posterior displacement
4)Outward displacement
5)Comminution of the complex as a whole
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CLASSIFICATION
Fractures of the body the
zygomatic arch alone not
involving the orbit.
1) Minimal or no
displacement
2) V- type in-fracture.
3) Comminuted
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Diagnosis of ZMC Fractures
Orbital Area Involvement:
1. Binocular diplopia
Binocular diplopia is double vision when both eyes are open
and disappear with closure of one eye.
Noted in as many as 30% of zygomatic
fractures, this can occur secondary to
a. muscle entrapment,
b. neuromuscular injury or
c. intramuscular hematoma.
d. Enophthalmous
Mononuclear diplopia is double vision when one eye is open and the other is
closed, it arises as a defect in the retina, cornea or any orbital structure.
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2. Subconjunctival hemorrhage
The conjunctiva is permeable to oxygen so the blood is
oxygenated blood with characteristic bright red color.
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Nose:
Ipsilateral epistaxis:
Result of lacerated maxillary sinus mucosa.
Cheek:
Flattening of the check due to depression of the molar eminence
Tenderness in 70% of patients.
Nerve Affection
Parasthesia in the distribution of the infraorbital, zygomaticotemporal or zygomaticofacial
nerves can occur
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Mandibular Movements:
• Trismus can occur because of
masseter spasm or
bony impingement of the coronoid process.
Crepitation from subcutaneous emphysema:
Subcutaneous emphysema → entrance of air from the maxillary sinus into tissue
spaces in the infraorbital area, the air may enter the orbit exerting pressure on the
eye leading to blindness.
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Zygomatic Arch Fractures
Can fracture 2 to 3 places along the arch
Lateral to each end of the arch
Fracture in the middle of the arch
Patients usually present with pain on opening their mouth.
23. z Imaging studies :
1. Postero-anterior view
2. CT scan
3. Submentovertex view (soft)
Soft → decreased amount of X-ray, used for soft tissue and soft bone as zygomatic
arch.
Hard → increased amount of X-ray, used for hard bone.
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Treatment of ZMC Fracture
Absolute indications:
Diplopia
Restricted mouth opening
Relative indications:
Parasthesia of cheek
Flattening of cheek
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Treatment of ZMC Fracture
• Closed Reduction:
• Gillies approach :
Intraoral approach
• Hook method :
• Carroll Girard method
B. Open reduction
1. Surgical approach to zygomaticomaxillary buttress
2. Surgical approach to the zygomaticofrontal buttress
a. Supratarsal fold incision
b. Lateral eye brow incision
3. Surgical approach to the infraorbital rim or orbit
a. Orbital rim incision
b. Subciliary incision
c. Subtarsal approach
d. Transconjunctival approach
C. Surgical approach to the zygomatic arch :
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A. Closed Reduction:
1. Gillies approach :
A 2 cm in length temporal
incision is made in the
skin with in the hair line
away from the superficial
temporal vessels is done.
The superficial fascia and
subcutaneous tissue are incised and retracted.
The incision extends to the deep temporalis fascia overlying muscle.
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• Heavy elevator (Rowe zygoma elevator) is lipped
between the
temporal fascia and the
temporalis muscle.
• The zygoma is elevated with
care not to fracture the temporal
bone.
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2. Intraoral approach
Keeo suggests an incision in the buccal sulcus
An elevator is introduced under the arch and by proper leverage the arch is elevated.
Rowe elevator can be used.
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3. Hook method :
Zygomatic hook pierce the
skin under the arch and pull
out movement make elevation.
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4.Carrol Girard method
The screw is fixed
to the body of the
zygoma and then
pull out the T-
shaped handle to
reduce the zygoma.
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Complications of Closed
Reduction:
• The common serious complication with
closed reduction is post reduction
stability
• Trials have been done to overcome
this problem
More dressing on the face to stabilize reduced bone
Supporting the maxillary sinus using balloon but this may
cause injury to other vital structures.
Placing of packs into the sinus to elevate the zygoma for
10-14 days, but this may lead to secondary infection and
serious complications.
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B. Open Reduction:
1. Surgical approach to zygomaticomaxillary
buttress
An intraoral incision is made in the maxillary vestibule 3-5 mm above the
mucogingival junction.
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2. Surgical approach to the zygomaticofrontal
buttress
A. Supratarsal fold incision
An incision is made 10-14 mm above the
margin of the eye lid.
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B. Lateral eye brow
incision
This incision is
performed by
palpating the
frontozygomatic
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3. Surgical approach to the
infraorbital rim or orbit
A. Orbital rim incision
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B. Subciliary incision
• 1-2 mm below and parallel to the lower
eyelash margin.
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