If a person had deep facial lacerations what cranial nerves would be damaged?

Facial or Trigeminal: You can easily have injury to the facial or trigeminal nerve with facial lacerations. Other cranial nerves can also be involved, though these are the cutaneous nerves, and more easily damaged with superficial injuries.

Facial nerve injury: With any facial laceration there is a possibility if injury to nerves. The facial nerve supplies innervation to the muscles of the face and is cranial nerve 7. The sensory nerves supply sensation to the skin of the face and cons from cranial nerve 3. Any laceration should be evaluated for possible nerve injury at initial and follow up exam.

#7 or #5 typically: A facially laceration that involves a cranial nerve typically effects the facial (cn #7), which is motor to the face, or trigeminal (cn #5), which supplies sensation to the face but also has motor branches to the chewing muscles. If there is involvement of the neck, other nerves can be injured as well.