Chewing gum has certain oral health benefits. It vitalises the oral mucosa through the act of chewing, as blood will flow to the myriad of capillaries that are in the soft tissues of the mouth. It also induces the production of saliva which lubricates the oral mucosa and the teeth, and boosts the natural immune responses of the mouth, making it more resistant to infection, tooth decay, gum diseases like gingivitis and periodontitis and bacterial colonisation in general. But it is also a food item that is strictly off limits during orthodontic treatment. Here are some of the reasons why:
Dislodging brackets
Chewing gum during orthodontic treatment may cause the brackets to be dislodged or come off of the tooth surfaces altogether. This is because it is sticky, and it can get caught and twisted on the brackets, and then the force off chewing will directly peel the bracket off of the tooth surfaces.
Dislodging the archwire
Just as the brackets can be threatened by chewing gum, the wire can also be caught in the sticky mass and be dislodged or pulled out of its course. This can create injuries in the mouth, and of course causes treatment to be delayed and you need to go and see the orthodontist afterwards.
Heightened chance of tooth decay
If the chewing gum becomes stuck in the spaces between the brackets and the teeth, or between any parts of the device and the teeth, it will feed the bacteria caught in these spaces and create the potential for tooth decay in very hard to reach places. Basically, this is true of all sticky foods, including chewing gum, caramels and all other chewable candy, including laffy taffy and fudge as well. This is why all of them are on the ban list.
Although this last point is not really applicable to sugar free gum, the first two definitely do. But even sugar free gum will cause problems for the teeth if it is stuck to a tooth surface for weeks or even months. This will facilitate decay, as it gives more space for the bacteria to breed in. These are all the reasons why chewing gum during orthodontics is a big no-no. The food related instructions given to you by your orthodontist are not polite requests, they are orders that if you do not follow, you will face tooth decay, lengthened treatment times and possibly will need to get a new device.