Orthodontics is a specialty of dentistry that is concerned with the study and treatment of improper bites, which may be a result of tooth irregularity, disproportionate jaw improved bite (occlusion).
After a course of active orthodontic treatment, patients will often wear retainers, which will maintain the teeth in their improved position while the surrounding bone reforms around them. The retainers are generally worn full-time for a short period, perhaps 6 months to a year, and then worn periodically (typically nightly during sleep) for as long as the orthodontist recommends. It is possible for the teeth to stay aligned without regular retainer wear.
However, there are many reasons teeth will crowd as a person ages; thus there is no guarantee that teeth, orthodontically treated or otherwise, will stay aligned without retention. For this reason, many orthodontists recommend periodic retainer wear for many years (or indefinitely) after orthodontic treatment.
Full orthodontic treatment takes about two or two and a half years for a typical case. It will take longer with a complicated case or if your do not follow the orthodontist’s instructions.