Zygomatic Bones

1. Overview

The zygomatic bones are paired facial bones that form the prominent part of the cheeks and contribute to the lateral wall and floor of the orbit. Often referred to as the “cheekbones,” they are key structural components of the midface and play a critical role in facial aesthetics, articulation with surrounding bones, and protection of orbital contents.

2. Location

The zygomatic bones are located on the lateral aspect of the midface:

• Lateral to: The maxilla and nasal bones.

• Inferior to: The frontal bone and lateral margin of the orbit.

• Anterior to: The temporal bone, with which it forms the zygomatic arch.

Each zygomatic bone articulates with four bones: the frontal, maxilla, sphenoid, and temporal bones.

3. Structure

Each zygomatic bone has a robust and quadrangular shape, with several important features:

• Orbital surface: Forms part of the lateral wall and floor of the orbit.

• Temporal surface: Faces posteriorly to form part of the zygomatic arch.

• Maxillary surface: Articulates with the maxilla, contributing to the infraorbital rim.

• Zygomatic arch: Formed by the zygomatic process of the temporal bone and temporal process of the zygomatic bone; serves as a bridge between face and skull.

• Zygomaticofacial foramen: Allows passage of the zygomaticofacial nerve and vessels to the skin of the cheek.

4. Function

The zygomatic bones serve several structural and functional roles:

• Facial contour: Provide the prominence of the cheeks and define facial width and aesthetics.

• Orbital protection: Form part of the orbit and help shield the eye from lateral impact.

• Muscle attachment: Serve as attachment sites for facial expression muscles (e.g., zygomaticus major and minor).

• Bridge to cranium: Link facial bones with the neurocranium via the zygomatic arch.

5. Physiological role(s)

Though the zygomatic bones are not directly involved in metabolic functions, they contribute indirectly to important physiological roles:

• Facial muscle coordination: Facilitate facial expressions such as smiling and speaking.

• Mechanical load transfer: Distribute masticatory forces from the maxilla to the cranial base through the zygomatic arch.

• Support of orbital structures: Maintain orbital geometry essential for proper ocular alignment and vision.

6. Clinical Significance

Zygomatic bones are frequently involved in facial trauma and reconstructive surgery:

• Zygomatic fractures:

  • Often result from blunt trauma (e.g., sports injuries, vehicle accidents).

  • May cause flattening of the cheek, trismus (jaw movement limitation), diplopia (double vision), or infraorbital nerve injury.

• Tripod fracture:

  • A common type of zygomatic complex fracture involving three points: zygomatic arch, orbital floor, and maxillary articulation.

  • Often requires surgical realignment and fixation.

• Zygomaticomaxillary complex (ZMC) fracture:

  • Involves the zygomatic bone and its articulations; affects aesthetics and function.

• Cosmetic and reconstructive relevance:

  • Important in procedures involving midfacial augmentation or repair after trauma or congenital deformity.

• Infections and tumors:

  • Though rare, the zygomatic bone may be affected by osteomyelitis, fibrous dysplasia, or metastatic lesions.