The zygomatic arch, often referred to as the cheekbone, is the prominent bony structure that defines the width of the face. This arch forms a bridge composed of the temporal process of the zygomatic bone and the zygomatic process of the temporal bone, which meet at an oblique suture. A fracture of this bony bridge significantly affects both facial aesthetics and function. The arch serves as an attachment point for the masseter muscle, a major muscle involved in chewing, and creates a space through which the temporalis muscle passes.
Recognizing the Signs and Symptoms
The immediate aftermath of a zygomatic arch fracture involves signs resulting from the impact and subsequent bone displacement. Localized pain and swelling are the most consistent early complaints, often accompanied by ecchymosis (bruising) around the eye and beneath the conjunctiva. A noticeable physical manifestation is the flattening or depression of the cheek contour when the fractured arch segment is driven inward.
Functional symptoms indicate interference with adjacent structures. Trismus, the difficulty or inability to fully open the mouth, results from the depressed bone fragment impinging on the coronoid process of the mandible. If the fracture extends to the orbital floor, the patient may experience diplopia (double vision), caused by muscle entrapment or swelling affecting eye movement. Numbness or a tingling sensation (paresthesia) may also be felt in the cheek, upper lip, or upper teeth due to trauma to the nearby infraorbital nerve.
Diagnostic Imaging and Injury Assessment
A medical assessment begins with a thorough physical examination to palpate for a “step defect”—a noticeable irregularity along the bone’s surface—and to check for restricted jaw and eye movement. Traditional X-rays, such as the submental-vertex view, provide initial evidence of a break but are limited by overlapping bony structures. Computed Tomography (CT) scanning has become the standard for accurately diagnosing and assessing zygomatic arch fractures.
The CT scan provides detailed cross-sectional images, reconstructed into axial, coronal, and sagittal views, allowing for precise three-dimensional visualization of the injury. This is essential for determining the degree of bone displacement and whether the fracture is isolated or part of a more extensive Zygomaticomaxillary Complex (ZMC) injury, sometimes called a tripod fracture. The imaging also reveals associated injuries, such as orbital wall fractures or blood within the maxillary sinus, which guides the treatment strategy. The assessment determines if the fracture is non-displaced and stable or if it is displaced enough to warrant physical reduction.
Surgical and Non-Surgical Treatment Options
Treatment depends on the fracture’s extent and whether it causes functional impairment or significant cosmetic deformity. Non-surgical management is typically reserved for non-displaced or minimally depressed fractures that cause no limitation in jaw movement or visual disturbances. Treatment involves observation, pain control, and a soft diet recommendation to minimize stress on the healing bone.
If the fracture is displaced, causing a visible contour defect or functional issues like trismus, surgical reduction is necessary to restore form and function. A common technique for isolated arch fractures is the Gillies approach, a closed reduction method. This procedure uses a small incision hidden within the temporal hairline. A specialized instrument is inserted beneath the temporalis fascia and guided under the depressed arch, where the surgeon uses it as a lever to elevate the bone fragments back into their correct anatomical position.
For more complex or unstable fractures, such as ZMC fractures involving multiple breaks, open reduction and internal fixation (ORIF) may be required. This involves surgically exposing the fracture site, manipulating the fragments back into alignment, and securing them with small, biocompatible titanium plates and screws. Alternative closed reduction methods, like the Keen approach, use an incision inside the mouth to access and elevate the bone, restoring the arch’s projection without visible external scarring. The goal of any surgical intervention is to achieve a stable reduction that resolves functional problems and restores the aesthetic facial contour.
Post-Treatment Care and Healing Timeline
Following treatment, a structured recovery protocol is put in place to ensure the bone heals correctly and minimize the risk of complications. Pain management is addressed with prescribed medication. Patients are advised to maintain a modified soft food diet for one to two weeks to avoid strenuous chewing that could disrupt the healing site. It is recommended to avoid strenuous activity for at least ten days and contact sports for several weeks until the bone achieves initial stability.
Patients must attend follow-up appointments to monitor healing progress, check for infection, and assess for late complications. An important instruction is to avoid blowing the nose, as this can force air into the soft tissues and potentially displace fragments or cause swelling. While initial swelling and bruising diminish within the first two weeks, complete bone healing (consolidation) typically occurs around six weeks after the intervention. Monitoring for persistent numbness or difficulty with jaw movement remains a consideration during the extended recovery period.