When considering the subject of space maintainence for children, it must first be acknowledged that most orthodontic problems begin during the period of time when the development of the entire masticatory apparatus (including dental arch and occlusion) proceeds from primary to permanent dentition. Unfortunately, many patients do not see the orthodontic specialist during this time. Why? Because the orthodontist usually has to depend upon a referral from the general dentist.
Because the general dentist is the one who cares for the dental needs of the vast majority of growing children, it is imperative that they be able to recognize growth problems as they occur. This will allow them to either actively intervene or immediately refer these patients to the orthodontist.
For a smooth transition through the stages of occlusal development the following events must occur:
- The eruption of the first permanent molar will be guided by the distal surface of the second primary molar. The location and arrangement of the permanent incisors will be guided by the mesial surface of the primary canine.
- Once the permanent first molar and incisors are in the arch, (The Mixed Dentition Stage) the canine and two premolars will then erupt into the limited space between the mesial surfaces of the first permanent molar and the distal surface of the lateral incisor. This exchange takes about one and a half years to complete.
- The sum of the mesio-distal widths of the primary cuspid and the first and second primary molars is generally larger than that of the permanent cuspid and premolars — by about 1mm per quadrant in the maxilla and 2mm per quadrant in the mandible. This difference is called the leeway (or extra) space…and is a fundamental factor in allowing for an easy exchange of these teeth.
- A normal eruption sequence of the succedaneous teeth must take place in both the mandible and maxilla. In the mandible, the most frequent eruption sequence is the cuspid, first bicuspid, and second bicuspid. In the maxilla, the sequence of eruption typically seen is either the first bicuspid, second bicuspid and cuspid or first bicuspid, cuspid and second bicuspid.
- When the second molars begin to erupt, the distal surface of the first permanent molar will guide them into the arch. In most cases, the eruptive force of the second molar will cause a reduction in the dental arch length using up the leeway space. In fact, the arch circumference of the permanent dentition may become shorter than that of the primary dental arch.
Unfortunately, a smooth transition is often disrupted by the premature loss of teeth. Tooth decay, trauma from a fall, or some other accidental injury are just some of the common causes of early tooth loss. When tooth loss occurs, pediatric space management is the key to preventing a serious malocclusion in the permanent dentition. In the posterior quadrants, the early loss of primary teeth often results in a reduction of arch length. This change can directly affect the normal eruption of the adult teeth. If space loss has not already occurred, rapid intervention with a space-maintaining appliance is of utmost importance. In the anterior region, space maintenance is important to maintain normal speech, function, and esthetics.
When it comes to adults, proper space management is important for the adult patient in a variety of situations. During active restorative treatment, there is often a need for an interim appliance to maintain space. For example, an interim space maintainer is often used in young patients who, because of an accident, rampant caries, or hereditary partial anodontia, are missing either anterior or posterior teeth. Other commonly evidenced indications for an interim space maintainer are:
- to maintain space
- to re-establish occlusion
- to replace visible missing teeth while definitive restorative procedures are being accomplished
- to serve while the patient is undergoing periodontal or other prolonged treatment
- when healing is progressing after an extraction or a traumatic injury
- to maintain function while accomplishing minor tooth movement
Featured Appliances
Space Maintainer
Early loss of a primary molar often allows the adult first molar to tip and move mesially.
The basic unilateral Space Maintainer is used for holding molar position. Note: The forces during eating can cause this Space Maintainer to move gingivally at the loop. This can cause tissue irritation and will allow the banded molar to tip mesially. A better choice would be appliance #2012 or #2072
Lingual Arch U/L
The Lingual Arch is considered the “appliance of choice” to maintain arch length even when the space to be maintained is unilateral.
This simple retainer prevents both mesial and lingual tipping of the molars while maintaining the arch length. The most common design is composed of an arch wire soldered to two bands. When prescribing this appliance, please indicate clearly if you have a wire placement preference on the lingual of the anterior teeth.
Nance U
The Nance appliance is designed to prevent arch length loss by maintaining the position of the maxillary molars.
To accomplish this, it uses an acrylic button in the pre-maxillary region of the palate to add stability. This design is also frequently used during full banding and bracketing to create an anchorage unit. Note – This appliance must be monitored carefully as the acrylic pad can act as a food trap. Left unresolved, the pad could actually become embedded in the tissue. This can easily be controlled with the use of an oral irrigator.
Maxillary Final Retainer U
When you have a cooperative patient, a removable retainer is an excellent way to maintain space.
The basic Hawley retainer features Adams clasps on the first molars and a standard, tightly adapted Hawley type labial arch wire running from the distal of both cuspids. The acrylic should be well adapted to the palate and the lingual aspect of the teeth. Also, every effort should be made to keep it thin for comfort. Don’t forget to let your patient choose a color or design. It’s a great way to motivate your younger patients. Note – Always send the lab both upper and lower casts along with a bite relationship for fabrication of this appliance.
Essix U/L
The Essix Retainer is a popular retainer for the extremely appearance-conscious patient.
Fabricated by thermo-forming a thin sheet of Essix material over the entire arch, this retainer is made of a tough, stain and abrasive-resistant clear acrylic that has the light-reflecting properties to make teeth appear brilliant when the retainer is in place. The appliance covers the buccal, labial, and lingual surfaces and extends onto the gingival tissue. Note: If you have a specific finish in mind, please provide a detailed description when ordering this appliance.
Groper Fixed Anterior Bridge U/L
Esthetics and strength are the key advantages to this popular design.
The Groper Fixed Anterior Bridge is made extra strong by attaching each tooth separately to a specially designed, stainless steel pad (an SML exclusive). Each unit is then welded and soldered to the arch wire. Placing rest seats and bonding rests into place will prevent the patient from bending or breaking the appliance. Note: As with all bridges and partials, opposing models and a bite registration are necessary for proper construction.
NOTE: Replacement teeth are made of ACRYLIC by default. The replacement teeth are also available in COMPOSITE when requested. Composite pedo partials incur an additional fee. Composite material allows the practitioner to add, reduce or repair the device easier than the standard acrylic. Keep in mind that BOTH the acrylic and composite material may discolor over time based upon a number of factors (Diet and life style etc.)
Modified Space Maintainer U/L
The early loss of a primary second molar often allows the adult first molar to tip and move mesially. This Modified Unilateral Space Maintainer features an occlusal rest on the adjacent tooth.
The occlusal rest will prevent the forces of mastication from moving the loop gingivally. Note: Sometimes it will be necessary to prepare a rest seat in the supporting tooth to keep the occlusion clear of any interference. Also, added retention can be gained by bonding the rest into position with composite resin.
Bonded Spacer U/L
When a tooth is not fully erupted, making a custom band for it is impossible and selecting a preformed band that is going to fit is almost as difficult.
However, it still may be possible to place a space maintainer if a sufficient amount of tooth structure is exposed to place an all-bonded unilateral spacer like the one shown here. This appliance is bonded to both the buccal and lingual surface of the partially erupted molar. When the other abutment tooth has a well-defined occlusal surface, a simple wire rest will suffice. Otherwise, bonding with a direct-bond pad (shown) is recommended.
Occlusal Bar U/L
This two-band space maintainer with an occlusal bar is designed to prevent super-eruption of the opposing teeth.
Easy-to-clean design allows patients to maintain desired oral hygiene. IMPORTANT: Before prescribing this appliance, be sure banded teeth have a parallel path of insertion. Note: To place the occlusal bar in the ideal position, the laboratory must be supplied with an opposing model and a bite relationship.
Occlusal Pad U/L
This two-band space maintainer has an acrylic pad over the edentulous region.
It is designed with the occlusal surface of the pad in function with the opposing teeth and the tissue side-cleared to eliminate any interference with the normal eruption of succedaneous teeth. Before choosing this design, be sure the teeth to be banded have a parallel path of insertion. Note: This appliance can act as a food trap. This can be controlled easily with the use of an oral irrigator.
Distal Shoe U/L
A single band — with a distal extension placed through the tissue — can be used to guide the eruption of the six-year molar when the primary second molar has been lost prematurely.
To accomplish this, you must send an x-ray or mark the mesial edge of the six-year molar on the model for correct placement of the guide. Also, indicate the desired depth of the shoe that will extend beneath the tissue to contact the erupting tooth.
REQUIRED MATERIALS:
• Upper or Lower Working Model
• Film* (recommended) or Digital** X-ray
RECOMMENDED PROCEDURE:
Indicate (mark) the location where the Distal Shoe is to be placed.
*FILM X-RAYS: Traditional FILM Bite Wing X-rays provide a “true-to-size” or “1:1 image” — used to accurately measure the distance from the second primary molar to the (yet-to-erupt) six-year molar. The measurement is then transferred to the model to ensure accurate distal extension length.
**DIGITAL X-RAYS: Because Digital Image Files, e.g. x-rays, photographs, etc, can be enlarged or reduced in size almost indefinitely, DIGITAL Bite Wing X-rays do NOT provide a “true-to-size” or “1:1 image” UNLESS ACCOMPANIED BY A REFERENCE SCALE. ALL SUBMITTED DIGITAL X-RAYS MUST INCLUDE A REFERENCE SCALE (in millimeters) to ensure accurate distal extension length measurement. WITHOUT A REFERENCE SCALE PROVIDED, SML CANNOT GUARANTEE THE FINISHED APPLIANCE.
Lingual Arch with Stops U/L
When a primary cuspid is lost prematurely, the anteriors can shift into its position. This causes a loss of arch length in that area.
This can be prevented with the use of a lingual arch wire with stops. In the design shown here, loops have also been added to the arch wire. These loops allow the doctor to adjust the length of the arch wire to gain a small amount of arch length.
Transpalatal U
This appliance is used to hold the position of the maxillary molars, maintain the leeway space, and prevent molar extrusion when the patient is in the transitional stage of development.
By using a wire that follows the vault of the palate, the possibility of a lingual arch wire interfering with the normal eruption of one of the bicuspids is eliminated. The appliance is comfortable and does not interfere with normal speech.
Transpalatal Omega Loop U
By adding a Mid-Palatal Omega Loop to the standard transpalatal design, the Transpalatal Omega Loop appliance not only acts as an anchor, but when carefully activated can be used to rotate, torque, distalize or intrude the molars.
Adjustment techniques are available upon request.
Removable Lingual U/L
Special attachments to the bands permit the construction of a removable Lingual Arch Wire — for easy loop adjustment or adding of attachments.
PICTURED: Horizontal attachment allows the doctor to remove the wire in a mesial direction.
Simple Mandibular Retainer L
Shown here is a removable Simple Mandibular Retainer with standard Hawley type labial arch wire. Adams Clasps and rests are placed on the molars for posterior stability and to keep the appliance from over-seating into the tissue.
Note: For fabrication, always send the lab both upper and lower casts –along with a bite relationship.
Lower Pedo Partial L
Four ‘C’ type clasps provide the retention for the removable Lower Pedo Partial. Any number of teeth may be replaced.
However, as with all bridges and partials, an opposing model and bite registration are necessary for proper construction. As the permanent teeth erupt, an acrylic bur may be used to remove the acrylic pontics. Note: SML has a special shade guide featuring the most common primary shades for a better color match.
Upper Pedo Partial U
This removable appliance features replacement teeth for the four primary anteriors. It is often called a “flipper” because patients tend to play with it, flipping it in and out.
This can easily be avoided by creating extra retention with a combination of additional clasps and/or direct bonded buttons as shown in the insert photo. However, patient cooperation is essential when using removable pedo partials. If cooperation is questionable, we recommend using a fixed approach. Note:As with all bridges and partials, opposing models and a bite registration are necessary for proper construction.
Fixed Banded Temporary Anterior Bridge U/L
By utilizing bands on the molars or premolars and a lingual arch wire, an esthetically pleasing temporary fixed anterior space maintainer may be constructed.
Each anterior tooth (up to four) is fitted to a wire that has been soldered to the arch wire. Acrylic is then applied to bond them into a single unit. Primary or adult replacement teeth are available in the appropriate Bioform™ and Vita shades. This appliance can give the patient very pleasing esthetics, but requires extra care as it is vulnerable to distortion and breakage. Note: We recommend that you always prepare rest seats in the supporting teeth. This will allow you to bond the occlusal rests into position, gaining extra retention while keeping the occlusion clear of any interference.
Pedo Bridge U/L
This patient-pleasing fixed appliance can accommodate up to four primary replacement teeth attached to a maxillary lingual arch. Each tooth is individually reinforced to prevent breakage, which can be a problem with this design.
Placing rest seats and bonding rests into place will prevent the patient from bending or breaking the appliance. Note: As with all bridges and partials, opposing models and a bite registration are necessary for proper construction.
Single Arm Space Maintainer
Early loss of primary dentition needs to be addressed as soon as possible in order to prevent space loss. In situations where it is determined that the yet-to-erupt permanent tooth may be erupting to the buccal or the lingual a Single Arm Space Maintainer is a good solution.
The single arm can be soldered to the buccal or lingual of the band as prescribed in order not to interfere with eruption. Once the erupting tooth has broken the surface a subsequent appliance can be used if deemed necessary to move the tooth into the proper buccal/lingual position.