Ocular Implications of Zygomaticomaxillary Fractures: Beyond the Surface

Introduction

These eye injuries could be anywhere from a simple conjunctival hemorrhage to globe rupture, thus leading to impairment of the eye. This kind of trauma, which involves the maxillofacial region, leads to varying degrees of disrupted soft and hard tissue, thus injuring even the neighboring structures like the brain, eye, nasal apparatus, and paranasal sinuses. These types of injuries undoubtedly compromise the ocular function and result in vision loss. When the injuries get severe, an ophthalmologist or a maxillofacial surgeon must be appointed as they can detect any injury more easily than a non-ophthalmologist.. The second most common fracture of the face is “zygoma” and could be a leading cause of significant cosmetic and functional deformity.

What Is Zygomaticomaxillary Fracture, and What Are Its Main Causes?

This type of fracture is also known as tripod, tetrapod, quadripod, malar, and trimalar fracture. These types of fractures are seen in the setting of traumatic injury of the face. It mainly comprises fracture of the zygomatic arch, the inferior rim of the orbit, anterior and posterior walls of the maxillary sinus, and the lateral rim of the orbit. They can have an accountability of about 40 percent of the midface fractures; thus, following the nasal bone fracture, they account for the second most common ones. The face is more vulnerable to injuries as it occupies a very prominent position within the human body. The prominence of the zygomatic region makes it predisposed to bearing the brunt of facial injuries.

The cause of its occurrence could be related to the following:

• Assaults.

• Falls.

• Road traffic accidents (RTAs).

• Injuries relating to sports.

• Civilian warfare.

What Are the Signs and Symptoms Seen in Zygomaticomaxillary Fracture?

For those presenting with ZMC reports with:

• Tenderness: Tenderness over the area.

• Ecchymosis: It is the discoloration that results due to bleeding underneath

• Edema Over the Malar Region: Indicates that there is a swelling in the area of cheekbones.

• Edema of the Lateral Orbit: It refers to swelling in the outer part of the eye socket

• Edema Of Eyelids: Edema of the upper and lower eyelid.

• Loss of Malar Projection: There is a reduction in the contour or the prominence of the cheekbone of the face

• Blunting of the Lateral Canthus: A less defined and rounded appearance of the outer corner of the eye.

Those ZMC fractures that get displaced medially impinge on the temporalis tendon, the coronoid process, thus leading to trismus. Paresthesia is also noted in the region of the infraorbital nerve of the eye. When there is significant involvement of the eye muscles, it leads to their dysfunction, entrapment, diplopia, and enophthalmos.

How Can Zygomaticomaxillary Fractures Be Classified?

As per the description by Marcus Zingg et al., three injuries lead to ZMC fractures.

• Type A: Isolated fracture of one component of the tetrapod structure.

• Type B: Involving all four components of the tetrapod structure.

• Type C: Complex fracture with comminution of the zygomatic bone.

Another classification scheme was suggested by Lefort in 1991. As per that, the following classification is suggested:

• Le Forte I: Low transverse maxillary fracture.

• Le Forte II: Pyramidal fracture.

• Le Forte III: Craniofacial disjunction fracture.

How Do Zygomaticomaxillary Fractures Impact Vision?

It must be understood that “vision,” a prime important sense, relies on the eye, an organ occupying about 0.3 percent of the body surface. Even though the eye has built-in protection anatomy, ocular injuries cause significant aesthetic and functional defects associated with six to 94 percent of maxillofacial injuries. These ocular injuries often accompany midface injuries. Thus, all those injuries above the mouth level require a meticulous ophthalmic examination.

How Can the Severity of Ocular Injury Be Determined?

In such cases, the severity varies for the eye and the adjacent structures involved. These injuries can range from the contused lacerated wound of the eyelid and abrasion of the cornea to rupturing of the sclera, dislocation of the lens, infraorbital hemorrhage, and retinal detachments. The retrobulbar hemorrhage and perineural edema would lead to globe rupture, optic nerve damage, and derangement of the visual pathways. The subsequent compression of the nerve causes ischemic optic neuropathy, which remains the most commonly occurring ocular injury.

What Are the Ocular Complications Caused by ZMC?

The ocular complications seen are:

• Diplopia: This is known as double vision.

• Enophthalmos: The sunken eye.

• Vitreous Hemorrhage: Any blood in the vitreous cavity is known as VH.

• Retinal Hemorrhage: This happens when something damages or breaks the retina's blood vessels.

• Choroidal Rupture: A break in the choroid bruch membrane.

• Traumatic Mydriasis: This results in the tear of the eye sphincter muscle.

Blindness remains an uncommon complication of facial trauma and has an incidence rate of about two to five percent.

How to Get Clinically Diagnosed for Such Fractures?

The diagnosis mainly relies on the history of ocular trauma through confirmation made through radiographic examination, most commonly by non-contrast maxillofacial CT scans. The step-offs around the zygomatic arch remain one of the most vital indicators of ZMC fractures. The CT scans remain vital in evaluating ZMC fracture, EOM entrapment, and retrobulbar hemorrhage. Additionally, head CT can help further determine the fracture size and surgical planning and evaluate any intracranial bleeding. The submental views offer a very detailed view of the zygomatic arches. Radiographically, the CT images are obtained in multiplanar reformats, and generally, three components are verified:

• Zygomatic arch fracture.

• Fracture of infraorbital rim.

• Anterior or posterior maxillary sinus wall.

• Lateral orbital rim fracture and diastasis of frontozygomatic sutures.

What Are the Differential Diagnosis and Prognosis for ZMC Fractures?

As the zygoma forms a significant portion of the inferior and lateral orbital walls, if any portion of the zygoma gets fractured, an investigation must be made to look for any fracture or injury to the orbit. The cervical spine injury must also be ruled out along with facial fractures, frontal sinus, nasal, midface, and mandibular fractures. The septal hematoma must be ruled out to avoid septal necrosis and resultant saddle nose deformity. Lastly, the malocclusion must also be checked.

If the fracture is comminuted, the outcome is worse, but the operation rate becomes higher if it is non-comminuted. It is estimated that about five percent of the patients would require reoperation within four weeks as a result of inadequate reduction of the fracture. About 20 to 40 percent of the patients' facial asymmetry is seen, with a significant asymmetry in three to four percent of patients. Permanent paresthesia results in about 22 to 65 percent of patients.

What Are the Orbital Complications of Zygomaticomaxillary Fractures?

The orbital complication includes:

• Blindness.

• Decreased visual acuity.

• Ectropian or entropion lid malposition.

• Exposure or abrasion of the cornea.

• Epiphora.

• Diplopia.

• Enophthalmos.

• Superior orbital fissure syndrome.

What Is the Management for Orbital Injury Caused by ZMC Fractures?

As ocular complications are prevalent in ZMC fractures, the examination is a must and must be very carefully done, including estimating the visual acuity of each type. Patients must be managed accordingly to avoid blinding complications. The general public must be educated about the impact of maxillofacial trauma and how such accidents can be prevented. If needed, open and closed reductions can be adopted, keeping the goal of treatment to preserve the facial structures, sensory function, globe position, and functionality of mastication.

Conclusion

The orbital complications are equally devastating for the patients, even though severe complications leading to blindness are rare. Exploring the implications of this type of fracture reveals the intricate interplay between facial trauma and visual health, thus highlighting the importance of early diagnosis and multidisciplinary management to reduce the potential damage to the eye.