The zygomaticomaxillary complex fracture, also known as a quadripod fracture, quadramalar fracture, and formerly referred to as a tripod fracture or trimalar fracture, has four components, three of which are directly related to connections between the zygoma and the face, and the fourth being the orbital floor. Its specific locations are the lateral orbital wall (at its superior junction with the

zygomaticofrontal suture The zygomaticofrontal suture (or frontozygomatic suture) is the cranial suture between the zygomatic bone and the frontal bone. The suture can be palpated just lateral to the eye. Additional images File:Gray164.png, Left zygomatic bone in situ. F ...

or its inferior junction with the zygomaticosphenoid suture at the sphenoid greater wing, separation of the maxilla and zygoma at the anterior maxilla (near the zygomaticomaxillary suture), the zygomatic arch, and the orbital floor near the infraorbital canal.

Signs and symptoms

On physical exam, the fracture appears as a loss of cheek projection with increased width of the face. In most cases, there is loss of sensation in the cheek and upper lip due to infraorbital nerve injury. Facial bruising, periorbital ecchymosis, soft tissue gas, swelling, trismus, altered

mastication Chewing or mastication is the process by which food is crushed and ground by teeth. It is the first step of digestion, and it increases the surface area of foods to allow a more efficient break down by enzymes. During the mastication process, th ...

, diplopia, and ophthalmoplegia are other indirect features of the injury. The zygomatic arch usually fractures at its weakest point, 1.5 cm behind the zygomaticotemporal suture.

Cause

The cause is usually a direct blow to the

malar eminence In the human skull, the zygomatic bone (from grc, ζῠγόν, zugón, yoke), also called cheekbone or malar bone, is a paired irregular bone which articulates with the maxilla, the temporal bone, the sphenoid bone and the frontal bone. It is si ...

of the cheek during assault. The paired zygomas each have two attachments to the cranium, and two attachments to the maxilla, making up the orbital floors and lateral walls. These complexes are referred to as the zygomaticomaxillary complex. The upper and transverse maxillary bone has the zygomaticomaxillary and zygomaticotemporal sutures, while the lateral and vertical maxillary bone has the zygomaticomaxillary and frontozygomatic sutures. The formerly used 'tripod fracture' refers to these buttresses, but did not also incorporate the posterior relationship of the zygoma to the sphenoid bone at the zygomaticosphenoid suture. There is an association of ZMC fractures with naso-orbito-ethmoidal fractures (NOE) on the same side as the injury. Concomitant NOE fractures predict a higher incidence of post operative deformity.

Treatment

Non-displaced or minimally displaced fractures may be treated conservatively. Open reduction and internal fixation is reserved for cases that are severely angulated or

comminuted Comminuted may refer to: *Comminution, the process in which solid materials are reduced in size, by crushing, grinding and other processes *Bone fracture, as in a crushed or splintered bone *Comminuted skull fracture A skull fracture is a break ...

. The purpose of fixation is to restore the normal appearance of the face. Specific attention is given to the position of the

and reduction of

orbital Orbital may refer to: Sciences Chemistry and physics * Atomic orbital * Molecular orbital * Hybrid orbital Astronomy and space flight * Orbit ** Earth orbit Medicine and physiology * Orbit (anatomy), also known as the ''orbital bone'' * Orbito ...

volume by realigning the zygoma and sphenoid. Failure to correct can result in rotational deformity and increase the volume of the orbit, causing the eye to sink inwards. Fractures with displacement require surgery consisting of fracture reduction with miniplates, microplates and screws. Gillie's approach is used for depressed zygomatic fractures. The prognosis of tripod fractures is generally good. In some cases there may be persistent post-surgical facial asymmetry, which can require further treatment.

References

External links

{{Fractures Oral and maxillofacial surgery Bone fractures