Product News in August 2023 Issue
Flared mandibular incisors are difficult to correct with a removable appliance. The lingual acrylic must be relieved to retract the incisors, but if the incisor inclination is too great, the labial bow can slip gingivally, causing the acrylic to impinge on the lingual gingivae or the bow to impinge on the labial gingivae. The activation can be negated if the bow slides down the incisors, or if the patient inserts the appliance incorrectly.
The following method eliminates these problems and ensures consistent appliance placement.
Technique
Figure 1 shows a patient whose mandibular incisors flared out after the loss of the maxillary central incisors. Before a fixed partial denture could be placed, the mandibular incisors had to be retracted. A removable appliance was fabricated (Fig. 2), but the labial bow tended to slip gingivally (Fig. 3).
The mandibular incisors were etched, and the bow was placed in the ideal location (Fig. 4).
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Fig. 1 Patient with flared mandibular incisors due to loss of maxillary central incisors.
Fig. 2 Removable appliance fabrication.
Fig. 3 Labial bow slipping gingivally into improper position.
Fig. 4 Bow placed in proper position after etching of mandibular incisors.
Bonding adhesive was added gingival to the bow, leaving a shelf on the teeth after the bow was removed (Fig. 5). The edges of the adhesive were smoothed slightly with a finishing bur, but enough was left so the patient could feel the shelf with the tongue. The patient could then tell exactly where to place the bow, which made a continuous surface with the shelf when inserted properly.
Fig. 5 Shelf of bonding adhesive gingival to bow location on mandibular incisors.
If all four mandibular incisors are not initially touching the bow, the bonding material should be placed only on those teeth that are in contact. Adhesive can be added to the remaining incisors as they make contact with the bow.
If the removable appliance has to be replaced because of loss, breakage, or inadequate activation, the composite does not have to be removed. The impression can be taken and the new appliance fabricated to fit the existing adhesive (Fig. 6).
Once the retraction is completed (Fig. 7), the composite is removed with a finishing bur, and a passive retainer is made.
Fig. 6 New appliance made for same patient over existing adhesive shelf.
Fig. 7 Patient after retraction of incisors and removal of adhesive.
Case Report
A 25-year-old female was referred by the speech therapy department because she thrust her tongue forward in swallowing and placed her tongue between her teeth at rest. She had a Class I occlusion with an anterior open bite (Fig. 8). The maxillary and mandibular anterior teeth were extremely proclined, with multiple anterior spaces in both arches. The maxillary left lateral incisor was rotated and peg-shaped.
Fig. 8 25-year-old female patient with tongue-thrust habit and anterior open bite.
Removable appliances were fabricated to retract the maxillary and mandibular incisors (Fig. 9).
Fig. 9 Removable appliances for retraction of maxillary and mandibular incisors.
Adhesive was added to the mandibular incisors that were in contact with the labial bow--the left lateral and both central incisors (Fig. 10). A month later, adhesive was added to the right lateral incisor.
After three months of wearing the removable appliances, a hook was soldered to the maxillary appliance and a button was bonded to the peg lateral for full-time elastic wear (Fig. 11). After another three months, the patient was referred to the prosthetic department for a porcelain jacket crown on the maxillary left lateral incisor.
Fig. 10 Adhesive added to mandibular left lateral and central incisors to create shelf for labial bow.
Fig. 11 Hook soldered to maxillary appliance for elastic to bonded button on peg lateral.
The final records showed an improvement in the maxillary and mandibular incisor positions, with all spaces closed (Fig. 12). The open bite was closed, and the lip procumbency was slightly reduced. Total active treatment time was only seven months.
Fig. 12 Patient after seven months of treatment.
Conclusion
Treatment with removable appliances can be shortened by adding composite to the facial surfaces of flared mandibular incisors. The force applied will be constant and predictable, because the labial bow can be placed in only one position by the patient.
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DR. CURETON
Dr. Cureton is Staff Orthodontist, Snyder Dental Clinic, Fort Gordon, GA 30905. The opinions contained in this article are those of the author and are not to be construed as official or representing the views of the U.S. Army, Department of Defense, or Government.