Hopefully you won’t need brain surgery anytime soon, but if you know someone who does, it would be a good idea for him or her to go to the dentist beforehand to prevent issues like pneumonia.
After a major operation (especially brain surgery), the elderly generation runs a 20% risk of getting pneumonia. This is because brain surgery weaknes the gag and coughing reflexes, thus making it easier for patients to breath in bacteria from their mouth and nose.
A research study done among 23 people has found that proper oral hygiene before a surgery makes a difference. There were five people who developed pneumonia within 48 hours of their operation, and each of them had poor oral health, like gingivitis, prior to the surgery. It is estimated that the risk of infection after surgery in those with poor oral health is increased by at least threefold.
Source: New Scientist