Advances in treatment of transversal discrepancies of the maxilla and class III malocclusions using skeletal anchorage

Morphological features of skeletal class III malocclusion may comprise mandibular prognathism, maxillary retrognathism or a combination of both. Sagittal orthopaedic forces to protract the maxillary complex were commonly applied to the upper dental arch. This approach incurred well-known side effects such as proclination of the upper front teeth, bite opening, mesial movement of the lateral segments, and constriction of unerupted canines. New skeletal anchorage concepts involving surgical mini-plates or mini-implants have been developed to address these problems. Directing orthopaedic forces directly into the bony structures of the midface promised a significant reduction of dental side effects as well as an enhancement of skeletal response. To further increase orthopaedic treatment effects, some maxillary protraction protocols include rapid maxillary expansion (RME) in order to stimulate the midface sutures. RME can be carried out purely bone-borne or with a combination of dental and skeletal anchorage using mini-implants in the anterior palate (Hybrid-Hyrax).