The use of palatal implants for orthodontic anchorage. Design and clinical application of the orthosystem.

This paper presents the Orthosystem (Institute Straumann, Waldenburg/ Switzerland), a new endosseous orthodontic implant anchor system for palatal anchorage. The Orthosystem may replace compliance dependent extraoral anchoring aids for orthodontics and makes a bonding of well aligned mandibular dentition and it's use with class II elastics unnecessary. The fixture is designed for a one-stage application. It consists of an implant of pure titanium with a surface-treated, screw-shaped endosseous part of 3.3 mm diameter and lengths of 4 and 6 mm. Above the polished transmucosal neck follows as abutment where transpalatal arches made of rigid orthodontic wires (0.032 x 0.032 inch) are fixed by means of a clamp-cap. 6 patients with an angle class II malocclusion were implanted with the 6 mm fixture in the proximal midsagittal region of the palate during a pilot study. The treatment goal was extraction of the first maxillary premolars with subsequent retraction of the frontal dentition under maximal anchorage of the lateral teeth. For the implantation a simple surgical procedure of 10 min length was required while no further invasive action are needed until explantation. This way the strain on the patients was reduced to a minimum. They are now at varying stages of active treatment and the most advanced case is demonstrated here. The clinical and radiological findings after 12 months of treatment comprising 3 months of healing revealed no implant mobility or dislocation, favourable periimplant soft tissue conditions, and no marked mesial movement of the implant supported teeth. The frontal dentition was retracted by 8 mm with space closure occurring in a relatively short treatment period.