Was the braces treatment not completed properly or have the teeth shown relapse due to improper wear of retainer appliance???? There is no such thing as temporary braces, although clear aligners are the latest modality which do not require permanent braces and tooth movement can be achieved by removal transparent plates. They show excellent results even in repeat cases. Consult an orthodontist to evaluate the current condition of your teeth so that the right treatment options can be explained to you. The cost of the treatment also varies according to the condition of the teeth and the experience of the dentist. Regards.