Closed torque spring 0.7 mm spring hard, upper connecting bow 1.0 mm hard, Adams clasp 0.6 and 0.7 mm spring hard
Function:
Treatment of Angle class II-1 malocclusions
Description:
In this functional orthopedic appliance special springs connect the upper plate to the lower plate
The closed torque spring which serves to receive the J-hooks is located with loops distally of 11 and 21, the connecting bow is located directly behind. The Adams clasps over 54 and 64 are bent of 0.6 mm spring hard wire, the Adams clasps over 55 and 65, and also over 16 and 26, are bent of 0.7 mm spring hard wire. The buccal tubes are placed on the second deciduous molars or on the second premolars. The split fan type expansion screw is built in without its joint.
In the mandible, the reduced lower plate is connected with the upper jaw through a labial shield and a pair of especially designed spring bows for this plate. With this spring bow, the mesial retention tag is anchored in the lower plate; the distal tag is anchored into the lateral bite block in height of the occlusal plane. The pair of spring bows should not contact the gingival tissue or teeth.
When all wire elements are bent, the wax layer for the reduced lower plate is added. A slim wax stripe limits the free part of the palate and simultaneously blocks out the connecting bow.
It is advisable to add a wax frame in order to manufacture easier the upper reduced plate. For this purpose, a narrow wax stripe is fixed on the labial side of the upper tooth row. The thickness of this wax stripe is of approximately two wax plates. Finally, to make the application of the acrylic easier, a wax frame is fixed around the previous wax layer. The buccal tubes are also sealed with wax. Prepared this way, the acrylic can be added on the upper plate and it can be finished.
The lower lip shield is bent in average with 6 loops; the retention tag is passed between the canine and the first premolar, or the first deciduous molar, into the lower acrylic base ideally with a mesial direction. The retention tags of the spring bows are bent distally. The retention for the lower jaw lies lingually underneath the tooth row. The other retention, which is anchored in the upper plate, is positioned in height of the lateral bite blocks parallel to the occlusal plane.
The wax lining of the lower model covers the cuspids of the posterior teeth in such a way that the compensation curve is maintained. In the anterior region, the wax is added in the same manner as in the posterior region so that there is no transition between them. Now acrylic can be added separately on the lower plate and it can be finished.
The upper plate is finished first. The lateral and anterior bite planes should have even contact with small impressions for the lower teeth; the torque springs should lie free and the buccal tubes should extend over the lateral bite planes. The connecting bow has to lie free in such a way that it can be activated parallel to the screw. The bite plane should embrace the teeth as far as possible although the Adams clasps should lie free.
The lower plate is also finished separately. The base plate ends on the level of the 2nd. deciduous molar or distally of the 2nd. premolar. In the incisal or lingual area the plate has to be shortened in order avoid interfering with the height determined by the construction bite. This way, the separately finished appliances can be polished without problems.
The finished plates are positioned onto the models to mark the spots where the retentions of the spring bows are anchored into the upper plate. The retentions are integrated into the acrylic of the lateral bite blocks parallel to the occlusal plane. The superfluous acrylic is grinded and polished. In the area of the loops a small groove is milled to make the insertion of the headgear easier. If necessary, the buccal tubes have to be grinded free minimally.
