Odontoid peg

Odontoid Peg

The Odontoid Peg, also known as the dens, is a bony projection found in the axis, which is the second cervical vertebra of the spine. It serves as a pivot point that allows the first cervical vertebra, known as the atlas, to rotate around it.

Anatomy

The odontoid peg is a conical process that projects upwards from the body of the axis. It is held in place by the transverse ligament of atlas, which wraps around the peg and holds it against the anterior arch of the atlas. This arrangement allows for the rotation of the head and neck.

Function

The primary function of the odontoid peg is to provide a pivot point for the rotation of the atlas and the skull. This allows for the "no" motion of the head. The odontoid peg and its ligaments also help to stabilize the cervical spine.

Clinical Significance

Injury to the odontoid peg can lead to serious complications, including spinal cord injury and paralysis. Fractures of the odontoid peg are relatively common and can occur as a result of trauma to the head or neck. These fractures are classified into three types based on their location and severity.

See Also

• Axis (second cervical vertebra)
• Atlas (first cervical vertebra)
• Cervical vertebrae
• Spinal cord injury