Final answer:
One possible unusual post-operative complication of mastoidectomy is cephalic tetanus, which can result from otitis media. Cephalic tetanus can cause double vision.
Step-by-step explanation:
One unusual post-operative complication that can result from mastoidectomy is cephalic tetanus. Cephalic tetanus is a rare, localized form of tetanus that is typically associated with wounds on the head or face. In some rare cases, it has been known to occur as a complication of otitis media (middle ear infection).
Cephalic tetanus can cause double vision due to the spasms affecting the muscles responsible for controlling eye movement. It is important for patients to be aware of this potential risk and consult with their healthcare provider if they experience any concerning symptoms after mastoidectomy.