The position of wisdom teeth at the back of your mouth makes their extraction a complex procedure that requires some kind of anaesthetic. In some cases, your dentist will use a local anaesthetic, and you'll be awake during the operation; in others, you may sleep through the whole thing under a general anaesthetic. The type of anaesthesia your dentist uses typically dictates whether you can eat or drink before the operation or not.

Fasting and General Anaesthetic

If you're having a general anaesthetic, you'll usually be told not to eat or drink anything for a set period before you have your wisdom tooth extracted. According to the Better Health Channel, this period of fasting ensures that your stomach is empty and helps avoid problems during the procedure. For example, if your stomach was full, you would have no control over vomiting under the anaesthetic, which can be dangerous.

Your dentist will advise the ideal fasting time before you come in for the procedure. According to National Dental Care Australia, you should expect a fasting period of between 6-12 hours before you have the anaesthetic.

Fasting and Local Anaesthetic

If you're having a local anaesthetic and will be awake while you're having your wisdom tooth extracted, you usually won't be expected to fast before the procedure. Local anaesthetics don't have the same potential problems as general anaesthetics, as you remain awake and in control of your body during the operation.

You may even find that your dentist recommends that you make sure to have something small to eat and that you have a drink an hour or so before you come in to the surgery. Although trepidation over the impending operation may make you lose your appetite completely, this is good advice that may be useful later.

It's important to remember that eating may be very painful for a while once you've had your wisdom tooth removed, and you may find it easier to cope with the first few post-surgery hours if you've taken the edge off your appetite before the operation and don't feel the need to eat after it.

Warning: According to BUPA Australia, you should avoid eating or drinking anything hot until the local anaesthetic has completely worn off. If you're still numb, you may burn your mouth with a hot meal or a hot drink. You may also inadvertently chew the inside of your mouth without noticing you're doing it.