Removable appliances correct crooked teeth. Some of the components within these appliances consist of springs such as T Springs, Cantilever Springs or Palatal Finger Springs. There can also be screws such as expansion screws, piston screws, three dimensional screws etc. in addition to other components to aid retention and provide various movements. All of these are determined, created and fitted ‘in-house’ at Wells Orthodontics.
What does the treatment with Removable appliances involve?
Once we have determined the best treatment path an impression or impressions will have to be taken. Next our dental technician will make the appliance requested; this normally takes about a week. Once the appliance is ready, your orthodontist will arrange an appointment where they will fit the appliance, ensuring that it is as comfortable as possible.
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You will be instructed on how to put the appliance in and take it out correctly, and your orthodontist will check you can manage this easily. The function of various springs, wires or other parts of the appliance e.g. key and screw will also be explained to you or a parent/guardian at this stage. Instructions about care of the appliance and when it is ok to not wear it (usually just for cleaning) will be given both verbally and in writing along with any additional instructions required; for example the patients’ use of a screw and key or use of elastics.
Do the appliances hurt?
Most patients can expect some mild discomfort for a short period of time after an appliance has been fitted or adjusted, speech may also be affected for about a week, but perseverance will overcome these initial inconveniences.
How long does treatment last?
Once we are happy, another appointment will be made for adjustments to be made to the appliance and to review progress made, unless any problems arise, if they do, contact the practice as soon as possible so that they can be dealt with quickly and normal treatment can resume. Appointments will continue, usually at six weekly or monthly intervals where small adjustments are made to the appliance. It is sometimes necessary to take impressions to either record progress or to make new appliances until the next stage of treatment can begin.
Common types of removable appliances
Cantilever Springs are simple and efficient, with several distinct clinical advantages over continuous arch wires. Knowing the force level and the distance between the two attachment sites, we can quickly calculate all the forces and movements involved. Reactivations are needed less frequently. The cantilevers may be utilised in all the planes of space, both buccally (toward the cheeks) and lingually (toward the tongue) to correct the malocclusion.
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Palatal Finger Springs are often used to tip teeth in a mesiodistal (more central) direction.
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T Spring is used for the buccal movement of a single premolar or molar tooth. Good retention is required to resist the displacing effect of the spring. Activation is by pulling the spring away from the acrylic at an angle of 45°.
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Screws are less versatile than springs, as the direction of tooth movement is determined by the position of the screw in the appliance. They are also bulkier. However, a screw appliance may be useful when a number of teeth are to be moved together (for example in an appliance to expand the upper arch). There are basically two types of screw. The most commonly used type consists of two halves on a threaded central cylinder, turned by means of a key which separates the two halves by a predetermined distance, usually about 0.2 mm for each quarter turn. The other variety is the spring-loaded piston screw, which is activated by moving the whole screw assembly forwards by means of a screwdriver.
