History
Vision can be threatened as a result of direct ocular injury or intraorbital hemorrhage.
Binocular diplopia is noted in as many as 30% of zygomatic fractures. This can be secondary to muscle entrapment, neuromuscular injury, or intramuscular hematoma.
Difficulty with mastication, otherwise known as trismus, can occur because of masseter spasm or bony impingement of the coronoid process.
In some patients, ipsilateral epistaxis also is noted as a result of lacerated maxillary sinus mucosa.
Physical Examination
Since most of these patients are involved in multisystem trauma, involvement by a trauma team for airway, breathing, and circulatory status is essential.
Ophthalmic evaluation, including globe integrity, should be performed promptly. Inferior displacement of the lateral canthal tendon is common. Proptosis may be present due to orbital edema or hemorrhage. Acute orbital hematoma may cause vision compromise and should be managed appropriately. [6]
Periorbital and/or subconjunctival ecchymosis are seen in as many as 50% of patients.
Significant malar depression can be seen with step defects at the infraorbital rim, frontozygomatic suture, and zygomatic buttress of the maxilla intraorally.
Fractures of the zygomatic bone evoke pain on palpation in 70% of patients.
Paresthesias in the distribution of the infraorbital, zygomaticofacial, or zygomaticotemporal nerves can occur.
Posterior displacement of the fracture fragment may impinge on movement of the mandible causing difficulty with mastication. Inferior displacement of the lateral canthal angle may indicate inferior migration of the fractured zygomatic bone. Although these are not true orbital blowout fractures, entrapment of orbital contents, enophthalmos, and diplopia with restriction of motility may occur because of the contributions of the zygomatic bone to the orbital floor. Use of the Hertel exophthalmometer in the assessment of relative enophthalmos or exophthalmos may be complicated because the lateral orbital rim, which is displaced in most zygomatic complex fractures, serves as a reference point for this instrument. Consideration should be given to the use of the Naugle exophthalmometer in these cases, which uses the frontal bone as a reference. [12]
Crepitus from subcutaneous emphysema or proptosis and visual loss from orbital emphysema may occur with forceful nose blowing. Patients should be cautioned against this.
Zygomatic fractures may be associated with skull base fractures, which may present with rhinorrhea or otorrhea. [13]
Complications
In patients with a zygomatic complex fracture, the injury itself can be complicated by associated ophthalmic or intracranial trauma. The necessary components of a thorough physical examination to assess for associated injuries are listed in Physical Examination.
Rare postoperative complications include hemorrhage, which can lead to permanent blindness in the affected eye; [11] ; plate exposure; and wound infections, potentially requiring removal of implanted material. [10] However, routine administration of a postoperative course of oral antibiotics has not been found to decrease the incidence of wound infections. [14]
The complications of an inadequately or unreduced zygomatic fracture are very difficult to correct secondarily. Malunion is the most common complication of zygomatic fractures and is the result of improper reduction and fixation, resulting in malocclusion, facial asymmetry, and enophthalmos.
Extraocular muscle entrapment, although usually attributable to the initial fractures, also can occur secondary to fracture repair. The rare complication of sudden onset blindness resulting from retrobulbar hemorrhage following reduction of even simple zygomatic fractures means that, in some instances, this procedure may be unsuitable for outpatient surgery. This serious complication, although rare (0.3% in the largest case series of surgically treated zygomatic fractures [15] ), is potentially reversible upon early recognition of the symptoms and signs of retrobulbar hemorrhage (eg, pain, proptosis, loss of vision, decreased motility). If the surgeon suspects a retrobulbar hemorrhage, a lateral canthotomy and cantholysis should be performed without delay. This should be completed at the bedside if the patient has visual compromise and is not near the operating suite.
Late complications usually result from scar formation, which can lead to lid retraction, ectropion, and epiphora. [9]
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The zygoma forms a firm buttress for the orbit and typically fractures at its sutures.
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Waters view demonstrating a zygomatic complex fracture involving the zygomaticofrontal suture, inferior orbital rim, and opacification of the maxillary sinus.
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CT scan of the orbit demonstrating disruption of the zygomatic arch.
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CT scan demonstrating disruption of the lateral wall of the orbit and medial inferior orbital rim.
