Tongue thrusting, tooth size discrepancy, periodontal disease and posterior bite collapse are just a few of the factors that can cause a patient to have excessive space. Only when you identify the cause of the problem can you properly select an appliance that will close the space and allow you to keep it closed.
The most common result of a tongue thrust is the creation of an anterior open bite with flared anteriors. Although the etiology of a tongue thrust is often debated, the need to address the problem early is not. If a thrusting pattern remains past the age of 4 to 5, there is an increasing likelihood that this pattern will remain. When an appliance is used to close excess space caused by a tongue thrust, it is best to choose a design that also addresses the thrusting problem. If this is not done, tongue forces will just cause the problem to re-occur.
Nocturnal grinding or bruxism can break down the protective mechanisms provided by the posterior occlusion. When this occurs, undue forces are placed on the anteriors causing them to flair. Many of the appliances shown in this section can be used to gather the anteriors. However these appliances should only be used after the loss in vertical dimension has been corrected. This is usually accomplished through a combination of orthodontics and restorative therapy.
Periodontal disease can also be a factor causing anterior flaring and the creation of excessive space. An anterior retraction appliance should be used after periodontal therapy is completed. In these cases, it may be necessary to splint the teeth together after retraction and space closure is completed.
Managing space problems caused by a tooth size discrepancy are usually handled by combining small amount of tooth movement with some form of cosmetic restorative therapy. The key to success here is not to impinge upon the space needed for the tongue. Therefore, one must exercise caution when using any form of retraction mechanics to close the excess space.
When choosing an appliance, it is important to remember that fixed appliances are capable of moving the teeth bodily, while removable appliances tend to tip teeth. As with most SML appliance designs, combinations of different components are possible to accomplish any given objective.
Featured Appliances
Diastema Controller U/L
The simplest appliance to bodily move two teeth and close a diastema is the Diastema Controller.
It is composed of two brackets and a segmental guide wire that is tied to the brackets with metal ligature ties. An elastic is then carried from the distal of each bracket to provide an equal force on both teeth in a mesial direction. The guide wire assures bodily movement and prevents unwanted rotations or changes in the axial inclination. Elastics of the appropriate size are provided with each appliance. The patient should be instructed to change them daily for the best results. Note: Metal ligature ties should be tightened just enough to maintain guide wire positioning. Over-tightening these ties will create excess friction and slow the closure process.
Mesial and Lingual Anterior Movement U/L
Sometimes anteriors need to be moved both mesially and lingually to close up excessive space.
This removable Hawley-type appliance features finger springs for mesial movement of the centrals and laterals — and an elastic force over the labial surface of the anteriors to move them lingually. Adjustments are easily accomplished by using finger pressure to activate the spring wires and by changing the elastic every day. Once the desired tooth movement has been accomplished, the labial bow can be adjusted to allow the appliance to be worn as a final retainer. Note: Make sure to relieve the acrylic away from the lingual aspect of the anteriors before attempting to move them lingually.
Removable with Anterior Finger Springs U/L
When space exists between teeth because the teeth are tipped, finger springs can be used to tip the crowns back over the roots and close the space.
Shown here, the finger springs are designed to close up excess space between the centrals by tipping them mesially. Closing the diastema will create the space needed to align the laterals. The labial arch wire, Adams Clasps, and Ball Clasps provide the needed retention for this active appliance.
Posterior Space Closure U/L
Abnormal occlusal forces, periodontal disease and poor restorative work can cause interproximal spacing to occur in the posterior segments.
This often leads to food impaction that is not only annoying, but can also contribute to a worsening of the periodontal condition. This excess space can be easily reversed (shown here). Anchorage is the key to successfully closing this space. The appliance typically requires anterior retention using a combination of bilateral clasping and a labial bow Then, stainless “retraction” screws are placed bilaterally as needed to close the interproximal spaces through mesial movement of molars. Typically, heavy “C” Clasps are placed around the distal of the last molars and the acrylic is removed from the interproximal areas around the teeth needing mesial movement.
Apron Spring Appliance U/L
The Apron Spring Appliance is an alternative to retracting flared anteriors with an elastic force.
This removable appliance uses light spring pressure to gently guide the centrals and laterals lingually. When protrusive position is associated with a habit, tongue or thumb, control loops can readily be incorporated into the palatal area to provide habit control. Note: Minimal adjustment is required to keep the appliance active. Make sure to relieve the acrylic away from the lingual aspect of the anteriors before attempting to move them lingually.
Sliding Buccal Bar U/L
This appliance allows for reciprocal movement of both teeth to close the space between them.
Elastics provide the force, while the bar, extending through the tube soldered to the molar band, keeps the teeth from tipping as movement occurs. Appropriately sized elastics are provided with each appliance and the patient should be instructed to change them daily. When you wish to eliminate the movement of one of the abutment teeth, using a jackscrew with labial/lingual arch wires, will provide the added anchorage needed to accomplish this. A small dab of premixed cold-cure acrylic may also be applied to the threads behind the second nut to further ensure force maintenance and prevent back-up. Note: A popular alternative to the jackscrew is the use of a nickel titanium coil spring activated by an adjustable Gurin Lock.
Sliding Labial Appliance U/L
When the anteriors are not severely proclined, a Sliding Labial Appliance can provide a constant, light lingual pressure sufficient to retract the anteriors and close up a small amount of excess space.
The amount of force is controlled by the size of the elastic stretched between the hooks on the labial wire and the tube soldered to the Adams clasps through which it slides. Note: Make sure to relieve the acrylic away from the lingual aspect of the anteriors before attempting to move them lingually.
Retraction Expansion Screws U/L
The most common area of relapse after finishing a bicuspid extraction case is in the area distal to the cuspids.
This space can be closed and maintained by placing an expansion screw in the open position, between two sections of an acrylic appliance, and drawing the sections together. Extra retention is provided by using both “C” and Adams Clasps bilaterally. Note: This space-closing technique is only to be used after a thorough evaluation of the patient’s vertical dimension and upper and lower anterior relationship have been completed. Care must be taken not to deepen the bite or lock the mandible into a retruded position.
Inman Retraction Appliance
This appliance is used for retracting anterior teeth to close spacing.
The active labial bow provides a continual retractive force by way of the bilateral open coil spring as illustrated.
The appliance comes pre-activated. Additionally, the labial bow has an acrylic facing that provides intimate contact with the labial surface of the anteriors.