I have a gap in my front teeth and a lil gum separating them. i got my braces and it's closed but the gums became puffy and big (behind & in front)?

Cosmetic Dentistry: Moving your teeth with braces can happen very fast and it sounds most likely the excess gum tissue that was there before is now more or less pinched. With proper cleaning this may reduce on its own. If it doesn't, your dentists or hygienist can use some laser therapy to return that tissue to optimum health!

Gums: You should see your orthodontist to let him/her see the area; without seeing the area hard to diagnose however it does not sound terrible. Could be just a need for better hygiene in that area or you may have injured the area. Best to let your orthodontist see the area.

Normal usually: this is a normal response when closing gaps and will usually resolve with time and good hygiene. Make sure you talk with your dentist about this issue and follow his advice.

Compressed tissue: Tissue is compressed by teeth moving together. Likely within normal limits. Check with orthodontist.

Gum swelling: Common. Make sure to clean between your teeth daily with Water Pik or dental floss. If inflammation does not subside your treating Dentist or specialist Orthodontist may want to refer you to a specialist Periodontist for revision of shape of gum tissue.