Retainers are required following orthodontic treatment in order to hold the alignment of the teeth and the fit of the bite.
Without retainers there are muscle forces and forces within the gum tissue that will try to move the teeth partially back to their original positions. The most common retainers are Hawley retainers, Essix retainers, or Bonded retainers. The Hawley and Essix retainers are removable retainers while the Bonded retainers are glued in place.
Hawley retainers consist of a plastic base that conforms to the shape of your mouth and is connected to a wire that wraps around your teeth to keep them in place.
Essix retainers are made of thin clear plastic that cover your teeth. They are almost invisible and do not cover the palate like Hawley retainers do. They are not as durable as Hawley retainers but many patients find them more comfortable.
Bonded retainers are small wires that are glued to the back of some of the front teeth, usually the front six teeth although sometimes just the front four teeth. These retainers are not visible. These bonded retainers hold the alignment of the front teeth very well but do not hold the alignment of the teeth further back.
Oral hygiene is easier with the removable retainers as they can simply be removed for brushing and flossing. These removable retainers can be easily lost. With the bonded retainer it is necessary to thread the floss through a small gap between the wire and the gum tissue in numerous locations to floss properly. These retainers are convenient in as much as you don’t have to take them in and out and they are not easily lost.
During the braces treatment, pressure is applied on teeth via the braces. The pressure is transferred to the bone around it which makes the bone soft. The teeth move in the soft bone from one position to other. As long as braces and wires are present on teeth, the bones will remain soft. At the end of braces treatment, when the braces are removed from the teeth, the teeth are at a risk of moving out of the corrected positions, as the bones are still “soft”. It takes a few months for the bones to” become hard”. To ensure that the teeth do not move out of their corrected positions, till the”bone hardens” around it, retainers are prescribed. The retainers are the key units responsible for maintaining that healthy beautiful smile on your face.
During braces treatment, as teeth move, there is lot of remodeling of bone that is supporting the teeth. In the process there is transient decrease in the density of the bone. The teeth are attached to the bone with the help of tiny elastic fibres called gingival and periodontal fibres. As the teeth move from one position to the other, these fibres are stretched and they try to pull the teeth back to their former position but presence of braces prevents them from doing so. After your braces are removed, there is no restraining force on these fibres and they start pulling the teeth away from the corrected positions. Additionally, the teeth in their corrected positions, need some time & adjustments to stabilizes itself between the lips & cheeks on one side and the tongue on the other side. If not adequately supported in their corrected positions during this transitional period, teeth tend to move out of line. This phenomenon is called RELAPSE. To prevent relapse, patients are advised to wear a restraining appliance called RETAINER and the period through which the retainers are worn is called RETENTION PERIOD. During the retention period, these fibres relocate their attachments on the teeth roots and adjust their lengths conforming to the new position of the teeth. In the mean time, as the teeth function individually and their position is held constant by the retainers, there is bone deposition around the teeth so that they stabilize in their new position.
There are two types of retainers, removable and fixed.
Generally removable retainers are used for most of the cases.
For certain cases that show more relapse tendency, a fixed retainer is advocated.
It is important that all instructions given by the orthodontist, on the use of retainers is followed strictly.
The period of wear of retainers varies from individual to individual. On an average, the retainers are worn about the same number of months the fixed braces were put, scientific articles published in the "American Journal of Orthodontics and Dentofacial Orthopedics" from 1988 to the present, indicate that orthodontic researchers are unsure how long you need to wear your retainer(s). There is no way to predict how your teeth will react when retainer(s) are removed. About half of the undesired tooth movement takes place in the first two years after you stop wearing your retainer(s). Some crowding of the lower front teeth may be part of the aging process similar to grey hair and wrinkled skin.
The only way to ensure continued alignment EXACTLY AS IT WAS AT THE TIME WHEN BRACES WERE REMOVED, is by the use of retainers to some degree, perhaps for life. The amount of wear will vary from patient to patient. Orthodontists know from experience that you, the patient, actually decide when you think the retainer is unimportant and stop wearing it or ask to have it removed.You must be willing to accept the fact and the risk that the degree of tooth position stability in your mouth is unknown.
In case of any disclosure, kindly report to the office as soon as possible.
Removable retainer is made of an acrylic plate that covers the palate in the upper jaw and the inside portion of the lower jaw. Attached to the acrylic plate are the wire components, which include – clasps on first molars and a labial bow on incisors and canines. The clasps hold the plate on the teeth firmly and the labial bow along with the acrylic plate maintains the stability of the teeth.
Click here to view how to use the removable retainers
Essix retainers are made of transparent resin material. They snugly fit the dental arch and when worn 12 – 18 hrs a day, they do not allow relapse movement of the teeth after the braces treatment.
This is a good alternative for people who do not want fixed ( bonded) retainers or when fixed retainers are not recommended for them and are not comfortable wearing standard removable retainer.
These retainers have to be remade after a certain time since they tend to lose their plasticity during routine wear.
Certain cases, it is observed by the orthodontist that the teeth once aligned and positioned correctly, will need some additional and perhaps, prolonged support to maintain them in the corrected position.
In such cases, (unless the patient resolves to be extremely particular with removable retainers), the Orthodontist advises Fixed retainers as the solution. The Fixed Retainer is made of Stainless Steel, or Titanium wire contoured as per the inside surfaces of the front teeth, fixed on the inside of the front four to eight teeth (varies case to case) with a special dental adhesive.
Though not compulsory, it is always prudent on the part of the patient and Orthodontist to give an additional BACK UP removable retainer to the patient along with the fixed retainer.( In effect the patient gets two retainers per jaw - One - fixed, the other - removable). The Back up retainer is to be worn only at nights.
The rationale behind a Back up removable retainer : If ever the adhesive holding the wire in place comes off, or, the wire breaks, the patient may not realise it. He/She would come to know of the damage only after he/she observes the tooth out of line. If the patient , however, was wearing the Back up retainer every night, the tooth would not move out of place and the damage can be detected by the Orthdontist on the patient's annual follow up visit and repaired easily.