Читать книгу The Orthodontic Mini-implant Clinical Handbook - Richard Cousley - Страница 11

Orthodontic‐specific skeletal fixtures were developed from two distinct sources:

 restorative implants

 maxillofacial surgical plating kits [1].

Orthodontic implants were first produced in the 1990s by modification of dental implant designs, making them shorter (e.g. 4–6 mm length) and wider (e.g. 3 mm diameter). However, they retained the crucial requirement for osseointegration, which is a direct structural and functional union of bone with the implant surface causing clinical ankylosis of the fixture. In contrast, orthodontic miniplates and mini‐implants (miniscrews) are derived from bone fixation technology, and primarily rely on mechanical retention rather than osseointegration. In effect, modification of the maxillofacial bone plate design, adding a transmucosal neck and intraoral head, resulted in the miniplate, whilst adaption of the fixation screw design produced the mini‐implant. Since the start of this millennium, a wide variety of customised orthodontic mini‐implants have been produced and these are now used in the vast majority of orthodontic bone anchorage applications. Orthodontic implants are no longer in standard use and the invasive nature of miniplates tends to limit their use to orthopaedic traction (e.g. Class III) cases or occasionally where the alveolar and palatal sites are too limited for mini‐implant usage (as exemplified in Chapter 8).