The malar bone plays a unique role in maintaining facial contours and the underlying bony architecture1. Any break in continuity or dislocation of this bone disrupts ocular and mandibular functions, and may cause cosmetic defects. The zygoma is most vulnerable to fracture beyond the dorsum of the nose2. Due to its unique bony architecture, it can withstand blows of significant impact without being fractured. Zygomatic fractures can also lead to disarticulation from the suture line along the four articulation surfaces (i.e., the zygomaticomaxillary complex, the zygomatic complex [ZMC] proper, and the orbitozygomatic complex). Zygomatic fractures should be treated early because they can cause both functional and cosmetic defects. The most important functional defect encountered is reduced mouth opening due to impingement on the coronoid process3. This makes early diagnosis and management important. Zygomatic fractures require appropriate treatment because inadequate skeletal healing can cause reduced malar projection, resulting in facial cosmetic deformities. Accurate positioning of the fractured bone (posterior to the skull base and anterior to the midface) should be performed in order to repair the fragments. The ability to withstand the forces of a blow to the midface comes via a strong attachment of the frontal, maxillary, zygomatic, and sphenoid bones to one another. These bones are enclosed by the thicker bones of the facial buttress, providing strength and stability. The elements of the facial buttress are listed in Table 14.

A handful of classifications for fractures of the zygomatic bone complex are recorded in the literature, but they have not been established for regular clinical application5. The most accepted classification systems are listed in Table 267.

The symptoms of zygomatic bone fractures rely largely upon the pattern and the extent of the fracture line. Possible clinical features are listed in Table 38.

The most accepted radiological procedure for establishing a proper diagnosis for midface fracture and zygomatic fracture is computed tomography (CT) scan. Bony structures, foreign bodies, hematoma, herniation, and emphysema are well depicted by this method8. Injuries can be analyzed in axial, coronal, and sagittal sections. For intricate trauma, three-dimensional reconstruction can be performed to further evaluate injury. Cone-beam computed tomography may be preferred for the three-dimensional presentation of zygomatic bone fractures, but the disadvantage of this procedure is its low significance regarding soft tissue structures. In this respect, the CT diagnostic procedure is superior. Furthermore, the orbit, eye muscles, optic nerve, and retroglobal hematoma can be well assessed with computed tomography9.

The reduction and fixation of fracture fragments should be performed as early as possible to avoid any functional and cosmetic deformities. The two biggest problems encountered are an uncertain repositioning of the fracture gaps, and an inappropriate postoperative stability of the repositioned zygomatic body. A closed reduction of zygomatic fractures is contraindicated if surgical correction of the orbital floor is required11. Closed reduction procedures are less labor-intensive, but still provide appropriate decompression of the infraorbital nerve. For the closed reduction of the zygomatic bone, two transcutaneous approaches are recommended. According to Gillies, the first approach consists of reaching the zygomatic bone through a small temporal incision8. The fascia of the temporalis muscle is incised to insert an elevator below the zygomatic arch. The second approach is performed percutaneously with a bone hook. A small incision is made 2 cm laterally to the temporal canthus, and the hook is inserted through the skin under the zygomatic bone, where it is then repositioned13. Percutaneous insertion of a “Caroll-Girard” screw is a less traditional technique to pull the zygomatic bone into an undislocated position, and to reposition it11. In 2014, Patil and Patil14 used Gillies temporal approach in three cases of left ZMC fracture. They concluded that it is a desirable approach for undisplaced zygomatic fractures due to its simple, effective, and cosmetically acceptable results. In 2013, Salinas et al.15 treated 23 patients with zygomaticomaxillary complex fractures using a closed reduction method with Steinmann-pin fixation. They compared their outcomes (reduction and esthetic) with those of patients who underwent open reduction and internal fixation (ORIF) techniques. They found that the average facial incision length was shorter than that associated with traditional methods, which often require multiple incisions. They concluded that their method of repairing ZMC fractures provided adequate bony alignment and esthetics, shorter operating times, only one small incision, and excellent patient outcomes.

The treatment of facial fractures has undergone several improvements over recent decades. Methods of rigid internal fixation have allowed for accurate repairs of facial fractures and have reduced morbidity. Over the past ten years, surgeons have refined various endoscopic approaches to facial fracture repair in an effort to achieve results similar to traditional open (surgical) approaches, but with less morbidity. These technological advancements can be classified as (1) computer-aided pre-surgical planning; (2) intraoperative navigation; and (3) incision techniques. Computer-aided technology involves transferring CT data onto medical software platforms (CAD/CAM), where information can be analyzed and evaluated in three-dimensional planes. This allows three-dimensional reconstruction and/or reduction as required45. The preferred approaches for the diagnosis and evaluation of malar bone fractures are the transconjunctival approach, the limited blepharoplasty incision, and the transoral approach. Lee et al.46 have introduced an endoscopy-assisted repair procedure for malar bone fractures. This procedure requires a limited-access incision at the anterior margin of the helical crus, extending 2 cm superior to the auricle. This incision is used primarily to gain endoscopic access, and to facilitate the fixation of the proximal zygomatic arch fracture. A 1 cm transverse incision at orbital region I (a skin crease superior to the lateral canthal region) is used to gain access for plate fixation at the FZ and distal arch fracture. An upper buccal sulcus incision is used to directly access and stabilize the zygomaticomaxillary and infraorbital rim fracture.

ZMC fractures are the most common facial fractures after nasal fractures. Recent advances in imaging, incision techniques, and materials for fixation have given promising functional and esthetic outcomes. Surgeons have developed various incision techniques for treating zygomatic fractures. These include coronal, eyebrow, upper eyelid, transconjunctival, infraciliary, and lower eyelid incisions. They also include the maxillary vestibular approach, the temporal approach, and the supraorbital approach. Du Verney et al. have described closed reduction techniques that take advantage of the mechanical forces of the masseter and temporalis muscles on the zygoma23. Another closed reduction technique is Lothrop's transantral approach through the maxillary sinus, below the inferior turbinate. This technique does not provide a complete reduction of the zygomatic bone. The Keen intraoral approach offers the advantage of avoiding skin incisions, thereby avoiding visible scaring. This approach provides minimal dissection and excellent reduction, but it may result in increased rates of infection by introducing oral flora into the infratemporal fossa. Compared to the lateral orbital approach, Gillies temporal approach requires an extra incision to elevate the zygoma. Without this, the temporalis muscle may get injured, resulting in post-reduction trismus and damage to the superficial temporal artery. Dingman and Natvig concluded that most displaced zygomatic fractures should be treated by open reduction and direct wire fixation.23 These authors preferred the suprafrontal approach. Although various methods are available to treat a fractured zygoma, the most common techniques in use are Gillies temporal approach and the intraoral approach. While these methods provide excellent access to reduce fractures of the body and arch, the lateral orbital approach provides simple and rapid access to the lateral orbital rim. The same incision can be used for miniplate fixation at the FZ suture. No functionally important neurovascular structures are at risk in this approach. And, the treatment can be done under local anesthesia. The supraorbital approach can be used to reduce all types of zygoma and arch fractures23. The chosen incision technique depends entirely on the clinical situation of the patient and the surgeon's preference and expertise, although the most popular incision techniques for such fractures are the lateral eyebrow, the buccal sulcus, and the infraorbital incision techniques. To avoid unacceptable scarring and postoperative sequelae, the coronal approach is the preferred method for unhindered exposure of the ZMC, to achieve accurate reduction and fixation of the fracture fragments. This approach has the added advantage of minimal post-surgical complications. For mildly displaced fractures, closed reduction by the temporal (or intraoral) approach is equally good. In cases where an open reduction is required, fixation by miniplates is superior to fixation by wires. Similarly, a 3-point fixation is superior to a 2-point fixation, especially when wires are used as the fixation devices. Various modifications have been developed for these different incisions, to overcome the complications inherent to the different techniques. In conclusion, the selected approach must balance the perioperative risks, a surgeon's particular abilities (in terms of preferred incisions), the requirements of treatment, and the potential postoperative complications.