is able to see the entire process from start to finish during consultation. being that aligners are used, there is a lot of flexibility in fixing the smile. the dentist is able to make any changes that one wants to their treatment. traditional braces require metal brackets; with invisalign, depending on the case, a patient will have "attachments" on the teeth. they are clear little buttons that help move teeth. also, depending on the case, an individual might need interproximal reduction, also known as ipr. the dentist will take a little tool and "shave" off in-between the teeth, to help with overcrowded teeth. the reduction is very minimal, at most 0.3mm. once the individual receives their aligners, they will have to wear them every day for 20–22 hours. one is supposed to remove them when eating and drinking. unlike traditional metal braces, the person is able to eat anything when the aligners are removed; there are no restrictions. after the treatment is complete, the individual will have to wear clear removable retainers. training there are several specialty areas in dentistry, but the specialty of orthodontics was the first to be recognized within dentistry. specifically, the american dental association recognized orthodontics as a specialty in the 1950s. each country has their own system for training and registering orthodontic specialists. australia in australia, to obtain an accredited three-year full-time university degree in orthodontics, one will need to be a qualified dentist (complete an ahpra registered general dental degree) with a minimum of two years of clinical experience. there are several universities in australia that offer orthodontic programs: university of adelaide, university of melbourne, university of sydney, university of queensland, university of western australia, university of otago. orthodontic courses are accredited by the australian dental council and reviewed by the australian society of orthodontists (aso). prospective applicants should obtain information from the relevant institution before applying for admission. after completing a degree in orthodontics, specialists are required to be registered with the australian health practitioner regulation agency (ahpra) in order to practice. bangladesh dhaka dental college in bangladesh is one of the many schools recognized by the bangladesh medical and dental council (bm&dc) that offer post-graduation orthodontic courses. before applying to any post-graduation training courses, an applicant must have completed the bachelor of dental surgery (bds) examination from any dental college. after application, the applicant must take an admissions test held by the specific college. when successful, selected candidates undergo training for six months. canada in canada, obtaining a dental degree, such as a doctor of dental surgery (dds) or doctor of medical dentistry (dmd), would be required before being accepted by a school for orthodontic training. currently, there are 10 schools in the country offering the orthodontic specialty. candidates should contact the individual school directly to obtain the most recent pre-requisites before entry. the canadian dental association expects orthodontists to complete at least two years of post-doctoral, specialty training in orthodontics in an accredited program, after graduating from their dental degree. united states similar to canada, there are several colleges and universities in the united states that offer orthodontic programs. every school has a different enrollment process, but every applicant is required to have graduated with a dds or dmd from an accredited dental school. entrance into an accredited orthodontics program is extremely competitive, and begins by passing a national or state licensing exam. the program generally lasts for two to three years, and by the final year, graduates are to complete the written american board of orthodontics (abo) exam. this exam is also broken down into two components: a written exam and a clinical exam. the written exam is a comprehensive exam that tests for the applicant's knowledge of basic sciences and clinical concepts. the clinical exam, however, consists of a board case oral examination (bcoe), a case report examination (cre), and a case report oral examination (croe). once certified, certification must then be renewed every ten years. orthodontic programs can award the master of science degree, doctor of science degree, or doctor of philosophy degree depending on the school and individual research requirements. united kingdom throughout the united kingdom, there are several orthodontic specialty training registrar posts available. the program is full-time for three years, and upon completion, trainees graduate with a degree at the masters or doctorate level. training may take place within hospital departments that are linked to recognized dental schools. obtaining a certificate of completion of specialty training (ccst) allows an orthodontic specialist to be registered under the general dental council (gdc). an orthodontic specialist can provide care within a primary care setting, but to work at a hospital as an orthodontic consultant, higher-level training is further required as a post-ccst trainee. to work within a university setting, as an academic consultant, completing research toward obtaining a ph.d. is also required.