Why is there a lump in my gums by my braces? explanations please?

A number of things: You want to have that evaluated by your dentist. There are several reasons for swollen gums. In your case it might be dental plaque. Dental plaque can build up on your brackets that can turns into a hard deposit called dental tartar. This can irritate your gum and cause it to get inflamed and enlarged. The other possibility is residual cement. Have your dentist evaluate it and provide close care.

Braces Gingivitis: It is very common with braces to see the gums get swollen and infected with gingivitis. Not a big problem. Schedule an appointment for the dental cleaning with your dentist. While in orthodontic treatment you should diligently brush, flossing and rinse your gums around the braces to prevent decay and gum disease.

Infection: A lump in gum tissue usually means infection. Either an infected tooth or infected gums. Please have both your general dentist and your orthodontic specialist examine the area, possibly take x-rays if necessary, and advise proper course of treatment.