Space management refers to the careful supervision of a child's developing jaws and teeth during the period of growth from infancy to adulthood. With appropriately timed maintenance of existing jaw space, the dentist may reduce or eliminate the need for future orthodontic treatment. While many different types of appliances and treatment methods exist to manage space during childhood, this article will focus exclusively on the use of the band and loop space maintainer following the early loss of a first and/or second baby molar.
In the past, space maintenance was often thought of as treatment for a specific problem, that is, the use of an appliance to hold space for a developing unerupted permanent tooth necessitated by the early loss of a baby tooth. Presently, however, space maintenance is seen as an ongoing process that contiues throughout a child's growth period. Therefore, the use of the term space management more accurately describes the fact that the patient's overall mouth and bite should be evaluated and that future growth and development must be considered before an appliance is used.
Even today, from both parents' and various dentists' point of view, space maintenance has created frustration and gained a poor reputation overall. Lost appliances, repeated broken appliances, failure to maintain arch length and unrealistic expectations on the part of certain parents have been the most common complaints. Proper diagnosis and case selection, thoughtful appliance design, and parent education as to the value, limitations and responsibilities with regard to the appliance are the keys for successful space management.
Obviously, the ideal space maintainer is the tooth itself. Fillings and root canal treatments can help preserve baby teeth, but many children still suffer their untimely loss. In these instances of early baby tooth loss, it is important to have the child assessed for the possibility of future space loss as failure to hold space may result in dental crowding or "crooked teeth" that may necessitate future orthodontic treatment.
Once the dentist has determined a child requires a space maintainer, he or she will recommend one of a number of space holding appliances, the most common of which is known as the band and loop.
The steps involved in the fabrication and placement of the band a loop space maintainer are:
- Band selection and placement
- Model fabrication and lab work
The following special instruments are used in the fabrication and placement of the band and loop space maintainer:
- A mouth mirror
- An explorer
- Band seater
- Band burnisher
- Band removing pliers
- A scaler type instrument
- And a sectional impression tray
- Prophylaxis equipment
- Flour of pumice
- And a band cementing material
A preformed stainless steel band is selected to snugly fit the abutment tooth of the space maintainer. Finger pressure may be used for initial band placement while final occlusal-gingival seating is achieved with the use of a band seater. By applying pressure to the occlusal aspect of the band using the band seater and the patient's biting force one is able to drive the band gingivally. A burnisher may then be used to achieve the final adaptation of the band onto the grooved surfaces of the tooth. The correctly fitted preformed stainless steel band is seated out of occlusion, is difficult to displace and displays no voids between the band margin and the abutment tooth surface.
Once the band is selected and appropriately placed, the dentist is required to take an accurate mold. This mold should, at a minimum, include the abutment tooth with the fitted band in place, the space, and the tooth in front of the space. A sectional impression tray is then loaded with impression material and the mold is taken. Once the desired set of the impression material is achieved, the mold may be removed and examined for appropriate detail. If the impression is satisfactory, the band may be removed using a band removing plier or a scaler type instrument. The band should then be placed in the impression and stabilized using wax and a heated wax knife. It is essential that the band is secure within the impression prior to model fabrication as a band that is easily displaced will lead to an ill-fitting space maintainer.
Model and Loop Fabrication
Once the band is stabilized in the mold, a working model is made so that loop fabrication can begin. The loop is comprised of a 0.036 inch stainless wire that is contoured to fit the band and the adjacent space.
A properly contoured loop will:
- parallel the edentulous tissue space,
- lie approximately 1mm above the gingival tissues,
- reach the distal surface of the tooth anterior to the edentulous space just below its contact point,
- have sufficient width buccal lingually to permit unobstructed eruption of the permanent tooth,
- and should not impinge on either the tongue or buccal mucosa.
Once all of these criteria have been satisfied, the loop, initially held in place using sticky wax, can then be permanently soldered to the band and polished.
Prior to cementation, the band and loop should be tried in to ensure that it fits the tooth and space as intended. It should also be confirmed that the band and loop does not interfere with the patient's bite. While minor adjustments may be made to the loop using orthodontic pliers, a grossly ill-fitting space maintainer should not be inserted. In these instances of poor fit, the previous steps should be repeated until a satisfactory result is achieved. Once the appropriate fit is achieved the abutment tooth should then be pumiced, rinsed, dried and isolated. The band is then loaded with cement to cover all internal surfaces and as few as possible external surfaces. On insertion, the band must be positioned onto the abutment tooth in exactly the same manner described in the fitting procedure using both finger pressure and a band seater. Additional burnishing of the band margin against the abutment tooth surface can then be completed following final band seating. Following final adaptation of the band margins excess cement is then removed from all unnecessary surfaces.
Maintenance and Evaluation of Fixed Space Maintainers
Patients with the band and loop space maintainer must be evaluated at recall appointments to reassess the fit and stability of the appliance as well as the patient's oral hygiene. The degree of eruption of the permanent tooth for which the space is being maintained must also be assessed. Parents should be made aware of this and should contact the dentist at the first sign of any looseness, change in the appliance, or complaint from the patient as untreated appliance failure may necessitate more complicated treatment in the future.
The impending eruption of the permanent tooth for which the space is being maintained is an indication for appliance removal. Once desired eruption of the permanent tooth is achieved the band and loop space maintainer can be removed using the band removing pliers.