Final answer:
An open traumatic brain injury (TBI) occurs when there is a fracture in the skull, resulting in damage to the brain.
Step-by-step explanation:
An open traumatic brain injury (TBI) occurs when there is a fracture in the skull. This can happen when a strong blow to the head causes the skull to break, resulting in damage to the brain. The fracture can be linear, comminuted, depressed, or a contrecoup fracture depending on the nature of the impact.