What are common reasons to get braces?

Rationale 4 Ortho. Bad bite may contribute to dental caries (cavities-more difficult to keep teeth clean), gum disease (from food entrapment and proximity of roots which are too close together); esthetics (which may also effect self esteem and job opportunities); may contribute to TMJ/Temporomandibular Joint Dysfunction; may effect speech and eating.
Reason 4 Braces. There are many reasons to get braces to correct a malocclussion (bad bite). The obvious reason is esthetics (want your smile to look better). There are functional reasons (your bite is off, have an open bite, an overbite, and underbite, etc..). Ask yourself if you are having any of the above listed issues and speak to you dental professional if an orthodontic consultation is warrented.
Many reasons. There are many reasons why braces are placed, but ultimately, it's often done by moving teeth. (1) crooked teeth to be aligned straight; (2) have a bad bite corrected by repositioning teeth; (3) manipulate bone height where you/dentist wants more/less bone; (4) create space or close space between teeth; (5) get tooth/teeth to be more in/out of bone for restorative/cosmetic reasons. Yes, many...!
Varied. some of our patients have medical reasons for braces. Others simply want to look better. The details as to what braces can fix in both of these cases varies greatly-- underbites, crossbites, impacted teeth-- the list is long. The best bet is to see an orthodontist if you have concerns-- most will give you a free consultation and you can understand what they can do and the options you have.