Skeletal anchorage in the past, today and tomorrow

Abstract

Skeletal anchorage was not introduced as an alternative to conventional anchorage modalities. The first skeletal anchorage was a ligature through a hole in the infrazygomatic crest. This was replaced by surgical screws and finally the TADs, which were optimized with respect to the material and morphology, were developed. A bracket-like head allows for the use of the mini-implant as indirect anchorage, but should not be a tool for lost control resulting from badly planned biomechanics or failing compliance. Skeletal anchorage should serve as an adjunct to correct biomechanics, to enable treatments that could not be performed prior to the introduction of skeletal anchorage. The aim of this study was to test the hypothesis that temporary anchorage mini-screws help maintain bone density, height and width of alveolar processes in the extraction sites, and thus prevent the thinning of the alveolar ridge usually observed. In adult patients with degenerated dentitions the application of skeletal anchorage can allow for the displacement of teeth where no anchorage units are present, but also for the redevelopment and maintenance of atrophic alveolar bone. The basis for the optimal use of skeletal anchorage is that the correct line of action for the desired tooth displacement is defined and the necessary force system constructed either with the skeletal anchorage as direct or as indirect anchorage. After a period, during which osseointegrated implants were used as anchorage for tooth movement and bone maintenance, it was accepted that the mini-implants could serve also as anchorage for skeletal displacements avoiding loading of teeth.