The zygomatic arch is located at the most prominent position on the lateral aspect of the face and is most susceptible to injury from blows. The bones of the zygomatic arch are thin and narrow, and therefore, more prone to fracture. The zygomatic bone is involved in the formation of the orbital floor wall, maxillary eminence, and temporal fossa, and its weakest area is located at the zygomatic eminence of the temporal bone. After injury, maxillary fractures can occur simultaneously, and in severe cases there is craniofacial injury. The early redefinition after the injury, the postoperative effect is good. Clinical manifestations 1, zygomatic facial collapse zygomatic bone, zygomatic arch fracture after the fracture block displacement direction mainly depends on the direction of the external force, mostly occurred in the inversion of displacement. In the early post-injury period, zygomatic-facial depression can be seen. Subsequently, due to local swelling, the depression deformity is not obvious and is easily mistaken for a simple soft tissue injury. When the swelling subsides after a few days, local collapse occurs again. 2.Mouth opening restriction Due to the internal displacement of the fracture block, it compresses the temporalis and occlusal muscles and hinders the rostral prominence movement, resulting in mouth opening pain and mouth opening restriction. 3, Diplopia The zygomatic bone constitutes most of the lateral wall of the orbit and the inferior orbital rim. After displacement of the zygomatic fracture, diplopia can be found due to displacement of the eye, oozing blood and local edema of the adductor muscle, and the torn inferior oblique muscle embedded in the fracture line, limiting eye movement. 4. Bruising When there is a closed fracture of the orbital wall of the zygoma, there may be hemorrhagic bruises under the periorbital skin, eyelids and conjunctiva. 5. Neurological symptoms A fracture of the maxillary process of the zygoma may damage the infraorbital nerve, resulting in numbness in the innervated area of the nerve. If the zygomatic branch of the facial nerve is also injured during the fracture, incomplete eyelid closure may occur. Examination 1. Physical examination Palpation of the fracture may be localized with pressure pain, collapse of the displaced zygomatic frontal suture zygomatic maxillary suture bone junction, as well as the infraorbital rim may have a step formation, such as palpation from inside the mouth along the vestibular groove to the top posteriorly. The gap between the zygomatic bone and the rostral process of the maxilla can be checked for smallness, and these can help in the diagnosis of zygomatic fracture. X-ray examination X-ray radiographs are often taken in the nasal-chin position and zygomatic arch position or CT radiographs. In the nasal-chin position, the fracture of the zygomatic bone and zygomatic arch can be seen, and the abnormalities of the orbital maxillary sinus and infraorbital foramen can also be observed. In the zygomatic arch position, the fracture and displacement of the zygomatic arch can be clearly shown. Because zygomatic fractures occur in conjunction with fractures of adjacent bones, including the maxilla, temporal bone, zygomatic process, and pterygoid, they are often referred to as zygomatic complex fractures.