According to Kenhub, the skull's two zygomatic bones, also known as the zygoma, support facial tissue, pronounce the shape of the cheeks and form the lower, outer portion of the orbital socket. The zygomatic bones house the insertion points for the masseter muscles, which are one of the four types of muscles required for chewing.
Kenhub describes the zygomatic bone as an oddly shaped portion of the skull that protrudes laterally to form the prominent shape of cheekbones. The level of protrusion from the rest of the skull makes the zygomatic bone prone to fractures. Zygomatic fractures are the second most common type of facial fracture.
The Merck Manual Home Health Handbook states that fractures to the zygomatic bone may result in the inability to open the jaw fully, as well as changes in the way a person's teeth fit together. Irregularities in the bone due to fracture are typically noticeable by running a finger along the bone. Kenhub lists the symptoms of a zygomatic fractures as pain, a flattened cheek area, swelling, bone displacement and subconjunctival hemorrhage, which manifests as a red patch in the white of the eye. According to the Merck Manual Home Health Handbook, treatment of a severely fractured zygomatic bone may require jaw immobilization or surgery to repair the bone with metal plates and screws.