What are the pros and cons of extracting asymptomatic, fully impacted wisdom teeth prior to wearing braces?

I can understand your concern as it may seem unnecessary to remove teeth that are not causing any trouble. Why mend what's not broken right? These are some of my thoughts about removing asymptomatic fully impacted wisdom teeth prior to wearing braces.

Pros :

1. Sometimes during braces treatment, teeth may be indicated for extraction due to the need to create space or to remove any obstruction to the path of eruption, or the removal of buried/extra teeth. Some of these teeth may be difficult to remove and general anaesthesia may be needed for the procedure. Although the impacted wisdom teeth may be asymptomatic, it is not of any functional benefit and leaving any impacted teeth may still present a small risk of a cyst forming around the impacted tooth. Hence if general anaesthesia is indicated, an elective removal is justified as I would not want to subject my patient to another general anaesthesia later to remove the wisdom teeth.
2. Your dentist/orthodontist may plan to use the space occupied by the wisdom teeth via a method called distalisation. Distalisation is a process where the teeth are moved backwards into the wisdom teeth space, hence the wisdom teeth will need to be removed prior to starting braces treatment.
3. As mentioned earlier, sometimes teeth are extracted during braces treatment to create space. This may result in the molars drifting forwards during the treatment and cause the wisdom teeth to erupt partially causing food trap and oral hygiene issues. However, the wisdom teeth can also be removed at a later stage should this occur.

Cons:

1. Removal of asymptomatic impacted wisdom teeth will present its own surgical risks, namely risk to the nerves and structures close to the wisdom tooth. Do speak with your dentist/surgeon about this as it will depend on the wisdom tooth's location and proximity to these vital structures.
2. May potentially mean a painful and uncomfortable start to braces treatment and may negatively impact on your experience. No one likes to go through surgery, on top of that braces treatment requires some time to get used to the appliance in the mouth and may often be associated with some pain and discomfort. In my experience, patients do get over this hurdle pretty quickly but do expect some downtime.