A zygomaticomaxillary complex fracture (ZMC) is a facial injury involving the bones of the mid-face. This fracture is significant due to the intricate network of bones that support the face and protect delicate structures, impacting both appearance and function. ZMC fractures are second only to nasal fractures in frequency among facial bone injuries.
What is a Zygomaticomaxillary Complex Fracture
The zygomaticomaxillary complex (ZMC) involves several bones, primarily the zygoma (cheekbone) and the maxilla (upper jawbone). The zygoma is a prominent bone that forms the cheek’s projection and contributes to the lateral wall and floor of the eye socket, or orbit. It connects with the frontal bone, temporal bone, and sphenoid bone, creating a complex network of articulations.
The maxilla forms a large part of the upper jaw, holding the upper teeth, and also contributes to the floor of the orbit. These connections are often referred to as buttresses, which provide structural support to the mid-face. The ZMC also plays a role in supporting the eye and providing attachment for muscles involved in chewing.
Recognizing the Injury
Zygomaticomaxillary complex fractures result from blunt trauma to the mid-face. Common causes include motor vehicle accidents, assaults, falls, and sports injuries. These injuries are more common in young adult males.
Signs and symptoms often appear around the cheek and eye. Facial swelling and bruising, particularly around the periorbital area, are common indicators. Patients may experience pain in the cheek or jaw, along with numbness or tingling in the cheek, upper lip, or teeth due to potential damage to the infraorbital nerve.
Changes in vision, such as double vision (diplopia) or a sunken eye (enophthalmos), can occur due to orbital involvement. Difficulty opening the mouth widely (trismus) or pain when chewing may also be present due to impingement on jaw muscles. Other signs include nosebleeds, changes in bite alignment, or a noticeable flattening of the cheekbone.
Diagnosis and Treatment
Diagnosis begins with a physical examination, where a healthcare provider will visually inspect the face, palpate the bones for irregularities, and assess eye movement and sensation. Imaging studies are then used to confirm the diagnosis and determine the extent of the injury. While X-rays can show some fractures, a Computed Tomography (CT) scan is considered the gold standard for detailed visualization of these fractures and associated injuries. CT scans provide multiplanar and 3D reconstructions, which are invaluable for assessing displacement and planning treatment.
The goals of treatment are to restore facial symmetry, eye function, and proper bite, while also preventing long-term complications. Treatment decisions consider the fracture’s severity, displacement, involvement of the eye orbit, and the patient’s overall health. Non-surgical management is rare and typically reserved for very minor, non-displaced fractures, focusing on pain management, observation, and a soft diet.
Surgical management, often involving Open Reduction Internal Fixation (ORIF), is the most common approach for displaced fractures. This procedure involves making incisions to access the fracture sites, realigning the bone fragments, and then securing them with small plates and screws.
Common surgical approaches include incisions through existing lacerations, or small incisions near the eyebrow, eyelid, or inside the mouth (sublabial incision). For more complex fractures, a coronal scalp incision may be needed to achieve adequate exposure. Oral and maxillofacial surgeons, plastic surgeons, and ophthalmologists often collaborate in managing these injuries.
Recovery and Outlook
The recovery process after a zygomaticomaxillary complex fracture, especially following surgery, involves several stages. Patients may have a hospital stay depending on the severity of the injury and extent of the surgery. Pain management is provided during the initial recovery period. Swelling and bruising around the face and eyes gradually resolve over several weeks.
Patients are typically advised to adhere to dietary restrictions, often requiring a soft diet for a period of time to allow for proper healing. Activity restrictions are also common, with patients needing to avoid strenuous activities and contact sports. Follow-up appointments are scheduled to monitor healing and address any concerns.
Most patients experience good functional and aesthetic outcomes after proper treatment. However, some individuals may experience residual numbness in the cheek, upper lip, or teeth due to nerve involvement, which can improve over time but may persist. Rare complications include persistent double vision, infection, or malunion (improper healing), which might necessitate revision surgery. Adherence to post-operative instructions is important for optimal healing and recovery.