CASE STUDY Fig. 9 Fig. 10 full time during the day other than when cleaning. It is designed to allow the condyles to approximate the Gelb 4/7 position when the patient is chewing (Fig. 3). The deeply imprinted occlusal table on the appliance allows the cusps of the maxillary bicuspids and molars to seat properly when the patient bites forward (Fig. 5). The splint does not allow the previously posteriorized condyles to relocate backwards and continue to bludgeon the inflamed retrodiscal tissues when the patient is chewing. The splint has buccal walls, which eliminate lateral excursive and other parafunctional jaw movements that are hard on the TM joints and prolong the healing process. Dr. Spahl recommends Futar-D Occlusion manufactured by Ketten-bach Dental 1 as his choice of bite registration material. Any other fast setting polyvinyl siloxane bite regis-tration materials are acceptable as well. From the dispensing syringe inject the bite registration over the posterior occlusal surfaces right and left with the patient biting edge to edge with 1-2mm interincisal clear-ance (Fig. 6). With the bite registra-tion in the mouth, confirm radio-graphically that both condyles approximate the Gelb 4/7 position. A third bite registration segment covering the incisors (Fig. 7) can then be produced that will ensure mounting stability and greatly reduce post-delivery occlusal adjustments. The Bionator 5,6 (Figs. 8 and 9) serves mainly as a joint protective appliance during sleep. Unlike the FACT appliance and other anterior repositioning splints, the Bionator keeps the mandible stable at night. The mandible generally cannot disen-gage from the Bionator while the patient is sleeping. This eliminates the destructive lateral and retrusive movements, which can damage the joints. The Bionator helps in the A-P dimension to correct a Class II neuro-muscular sling towards Class I. The interproxi-mal projections of the acrylic (IPAs) are left in contact with the line angles of the maxillary and mandibular bicuspids (Fig. 10). They are not to be adjusted. Even if the IPAs were ground away from the posterior teeth, in adults these teeth will not erupt or will erupt only Fig. 11 minimally. In children and young adolescents, the posterior teeth will erupt which is desirable in these cases to actively close the posterior open bite and thus place the denti-tion in harmony with ideally located condyles. The bite registration is taken with Shur Wax with the patient biting edge to edge with a 3mm inter-incisal clearance (Fig. 11). How long is this phase of treatment? The progression of TM joint heal-ing and masticatory muscle response to ART mandibular relocation treat-www.orthodontics.com Winter 2022 35
Journal of the American Orthodontic Society Winter 2022: Page 35
