The period between 10 and 12 months upon fixed appliance removal, and during which teeth gain stability, is defined retention phase. During this period bone tissue surrounding the teeth is mineralised, the teeth get used to new forces exerted by the tongue and cheeks which might move them. Therefore, during the retention period, whose duration varies with ages and the encountered problem, a retaining appliance is worn.
Mobile retention appliances - retainers or bites
After the fixed appliance is removed, a mould is taken and a particular bite is manufactured from a transparent plastic material; it is the retention appliance or retainer. Each patient should be supplied with a retainer within 24 hours after the appliance removal, and this should be used following the orthodontist's indications.
Bites are cleaned by brushing them with toothpaste, eating while wearing a bite is forbidden and when it is not worn it should be store in its original casing.
Fixed retention appliances
Fixed retainers are applied just before the removal of braces by gluing them to the tongue side of the front teeth. They are made with a thin wire which is attached to the teeth with a composite material. Usually, these retainers are used for the lower jaw, as it is more subject to recidivism, but also to prevent disturbance when chewing. Only in particular cases it is used for the upper jaw, and then particular attention has to placed so that it doesn't get in the way of chewing. The so-called 3-3 retainers are used to avoid compression of the canine segment and to maintain the incisors in position.
Fixed retainers are more often used in adults, in cases of incisors compression or when therapy included the closing of interdental spaces. These retainers are used only in certain cases which means that not all patients will need them. Just as with braces, oral hygiene is rendered difficult by these retainers, so particular attention should be paid to it.