Construction of tooth positioners with LTV vinyl silicone rubber and some case reports.
In the orthodontic field, attention has recently begun to center on active treatment with tooth positioners, appliances with elasticity made of rubber materials used for orthodontic force in place of conventional metal wires[1-7]. Tooth positioners were contrived by KESLING as retainers to be used after the use of metal wires in active treatment[8,9]. Nowadays, it is used for closing the spaces due to band removal after active treatment, for the minute regulation of the occlusal relationship and for aftercare as a retainer. Not only that, as it is possible to regulate malocclusion by moving teeth with rubberlike elasticity applied in place of metal wires or brackets, it is beginning to draw attention as a new active treatment appliance to be substituted for conventional metal wires. With regard to the materials for tooth positioners to be used as active treatment appliances, various kinds of materials have been applied since KESLING contrived them[10-12], but few materials satisfy the necessary conditions for tooth positioners[10]; 1) easy manipulability, 2) elasticity and hardness, 3) tastelessness and odorlessness in the oral cavity and 4) durability. Polyurethane rubber and heatvulcanized silicone (HTV) rubber which are tasteless, odorless and superior in elasticity, have recently been developed[1,4-7], but these materials require special mold materials and equipment in the preparation process which is also very complicated, so their use has not been widespread as yet. Therefore, for several years the authors have been studying their practical application and trying to develop a material that is easy to manipulate and superior in physical properties[2,3,13]. As a result, the authors have developed a clinically applicable method of tooth positioners with low temperature vulcanized (LTV) vinyl silicone rubber. The following is an outline of its physical properties, the method for its preparation and some case reports.
Application of the positioner appliance in orthodontic treatment.
Abstract An outline and categorization of some of the types of treatment and tooth movement possible with the positioner have been made. Twenty-nine cases in which successful response to tooth positioner therapy was evident in some phase of orthodontic correction were studied. The degree of movement or improvement of tooth position was limited to 3 mm. or less of tipping movement. Rotational correction of incisors, canines, and premolars was possible in certain instances. Virtually all types of correction of occlusion and tooth movement, with the exception of translation or bodily movement, were evidenced. These were correction in interdigitation of cusp, correction of cross-bites, decrease in overbite and overjet, rotation of anterior and posterior teeth, closing of spaces, improvement of midline deviations, and maintenance and retention of the above.
Orthodontic positioner treatment during orthopedic treatment of scoliosis
Abstract 1. 1. This study was conducted for three and one-half years to determine the value of the dental positioner in conjunction with application of orthopedic casts and braces during orthopedic treatment of spinal scoliosis. The study included forty patients, aged 6 to 19 years, who were treated for intervals of from seven months to thirty-four months. 2. 2. In thirty-five of forty cases treated during this study, satisfactory maintenance or improvement of dental occlusion was possible when positioners were worn properly in conjunction with orthopedic casts and braces placed by orthopedic surgeons treating scoliosis. 3. 3. In two of the five cases in which the patient's occlusion demonstrated greater imbalance during orthopedic-orthodontic treatment, later cooperation from the patient and the parents made it possible for subsequent wearing of positioners to improve the undesirable malocclusion that developed during the first uncooperative part of treatment. 4. 4. In three cases, in which cooperation was completely lacking during orthopedic-orthodontic treatment, satisfactory maintenance of dentofacial relationships and dental occlusion was not possible (Fig. 17). 5. 5. Thirty-five of forty patients satisfactorily treated with orthopedic appliances and dental positioners worn simultaneously showed spinal curvature corrections ranging from 15 to 65 degrees along with constant or improved craniofacial relations and dental occlusion. The patients' cooperation here was satisfactory to excellent. 6. 6. Good cooperation from the patient was a positive factor in cases where facial pattern and dental occlusion showed improvement in this orthopedic positioner treatment of scoliosis. 7. 7. The study demonstrated that the use of a dental positioner for orthopedic patients, along with placement of an orthopedic cast or brace, was highly individual. 8. 8. Results from this treatment procedure were more satisfactory when the dental positioner was inserted prior to placement of the orthopedic cast or brace. 9. 9. A limitation in the extent of tooth movement possible with a dental positioner was recognized in this study. 10. 10. Better gingival tone was noted in orthopedic patients wearing positioners as compared to other patients under similar orthopedic treatment who were not wearing positioners. 11. 11. The patient's comfort is seemingly improved by the wearing of a positioner during placement of a body cast and brace in the orthopedic treatment of scoliosis.