Zygomatic-maxillary complex fractures


The zygomatic-maxillary complex should be considered as a quadripod. The zygoma articulates with 4 bones: frontal, temporal, maxilla, and sphenoid. It is also important in establishing the borders of the orbits and protecting the contents. The lateral orbital wall is a pivotal part of the zygomatic complex and should be considered the base with 4 legs:
• Lateral orbital rim
• Inferior orbital rim
• Zygomatico-maxillary buttress
• Zygomatic arch
It’s important to note the greater wing of the sphenoid forms the posterior wall of the orbit with the zygoma making up the lateral orbital wall. Therefore, the zygomatic-sphenoid suture is a good indicator of the degree and direction of displacement in a fracture.

Figure 1. Anatomy of the zygomatic-maxillary complex [1]


Commonly, patients with fractures of the ZMC will present to you in an emergency setting, often having received a blow to the cheek and complain of pain, numbness in the infra-orbital region, swelling and an inability to open their mouths due to the zygomatic arch impinging on the coronoid process.
We only perform surgical interventions if there is an issue with either function or aesthetics. See common clinical findings below:

• Subconjunctival haemorrhage
• Inferior orbital nerve anaesthesia
• Displacement of the globe
• Diplopia
• Bony steps at ZF suture, inferior orbital rim
• Malar flattening
• Periorbital ecchymosis
• Displacement of the zygoma, depression of the arch
• Trismus, reduction in lateral excursion
• Intra-oral signs: bruising over buccal mucosa,

Figure 2. Examining malar flattening [2]


Standard imaging for midface fractures are OM views looking for disruption in the bony contours. Fluid within the maxillary sinus can also indicate a fracture. Patients with complex facial fractures or those involving the orbits should have a CT scan to evaluate damage to hard and soft tissues. Once again, ensure all 3 views are available: coronal, axial, sagittal and it is also advised when making the request, specify for the CT to extend inferiorly to include the mandible.

Figure 3. Displaced fractures of the anterior and posterior
maxillary sinus and a subtle fracture of the zygomatic arch [3]
Figure 4. Fracture of the lateral wall of the orbit [3]

Surgical Management

The patient is usually evaluated 1 week after initial presentation. If it is determined surgical intervention is required, the patient is then prepared.
Common indications for surgical management include trismus, significant restriction in lateral excursions, cosmetic concerns e.g. depression and flattening. Common procedures for isolated zygomatic arch fractures or simple ZMC fractures include a Keen’s lift (intra-oral approach) or a Gillies lift,performed through a temporal approach to lift the arch.
For more complex ZMC fractures, alignment of the zygomatic-sphenoid suture at the lateral orbital wall is likely to ensure appropriate reduction of ZMC injuries. Exposure of the different fractures may be required for adequate fixation.

Figure 5. 4 point fixation of a ZMC fracture [4]

General Management

As mentioned previously, most fractures you will encounter are not life threatening and often we will wait for the swelling to reduce post-injury to determine the true extent of any functional deficiencies or aesthetic issues.
Your initial management of these patients should include:
• If you have any concerns regarding the patient’s vision/eyes get an ophthalmology consultation
• Advise on a soft diet and nose blowing for 4-6 weeks to prevent surgical emphysema
• Prescribe analgesia. Note antibiotic prescriptions may not always be required and can be controversial therefore check with your senior

Prior to the operation ensure:
• CT scan available – axial, coronal and sagittal views
• Patient has been fasted
• FBC, U&Es, Clotting screen
• Cannula

Due to the anatomy of the zygomatic-maxillary complex and the process of reduction, there is a risk of blindness (due to retrobulblar haemorrhage) from these operations as well as other eye signs such as enophthalmos, diplopia, traumatic optic neuropathy, superior orbital fissure syndrome. Therefore, the patient should follow strict eye observation protocols in line with your trust protocol. For example:
• Every 15 minutes for 2 hours
• Every 30 minutes for 2 hours
• 1 hourly for 16 hours
In terms of what these eye observations comprise:
• Visual acuity
• Reaction to light
• Retrobulbar pain
• Proptosis
• Diplopia
If there are any concerns arising from the eye observations, this should be raised with the registrar.


[1] Meslemani, Danny and Robert M. Kellman. “Zygomaticomaxillary complex fractures.” Archives of facial plastic surgery 14 1 (2012): 62-6 .
[2] Themes U. 16: Fractures of the Zygomatic Complex and Arch [Internet]. Pocket Dentistry. Available from: https://pocketdentistry.com/16-fractures-of-the-zygomatic-complex-and-arch/
[3] Zygomaticomaxillary Complex (ZMC) Fracture [Internet]. Radiologyinthai.blogspot.com. 2020 .Available from: http://radiologyinthai.blogspot.com/2009/12/zygomaticomaxillary-complex-zmc.html
[4] Cornelius C, Gellrich N, Hillerup S, Kusumoto K, Schubert W, III E et al. ORIF, 4-point fixation (with orbital reconstruction) for Zygoma, zygomatic complex fracture [Internet]. Surgeryreference.aofoundation.org. 2020. Available from: https://surgeryreference.aofoundation.org/cmf/trauma/midface/zygomatic-complex-fracture/orif-4-point-fixation-with-orbital-reconstruction#principles