Mini-implants in the palatal slope – a retrospective analysis of implant survival and tissue reaction

Setting and Sample Population: The Department of Orthodontics, the University Hospital Münster. Forty-one consecutively started patients treated using mini-implants in the palatal slope. In this retrospective study, 66 JS were evaluated. Patient records were used to obtain data on the mode of utilization and complications. Standardized photographs overlayed with a virtual grid served to test the hypothesis that deviations from the recommended insertion site or the type of mechanics applied might be related to complications regarding bleeding, gingival overgrowth or implant failure.Two implants (3%) were lost, and two implants (3%), both loaded with a laterally directed force, exhibited loosening while still serving for anchorage. Complications that required treatment did not occur, the most severe problem observed being gingival proliferation which was attributable neither to patients’ age nor to applied mechanics or deviations from the ideal implant position.The JS mini-implant is reliable for sagittal and vertical movements or anchorage purposes. Laterally directed forces might be unfavorable. The selection of implant length as well as the insertion procedure should account for the possibility of gingival overgrowth.Potential sites for mini-implant insertion in the maxilla comprise interradicular space, the infrazygomatic crest and the hard palate [1-4].In terms of skeletal anchorage, the anterior hard palate is especially advantageous since root damage is very unlikely in this area. Furthermore, it provides good bony support [1,5-7]. Median and paramedian insertion as well as various mechanics have been described [4,8-13].The Jet Screw (JS) type mini-implant (Figure？1a, Promedia Medizintechnik GmbH, Siegen, Germany) was developed for insertion in areas with thick soft tissue such as the palatal slope. It is advertised for use with the TopJet Distalizer (H. Winsauer, Bregenz, Austria; Promedia Medizintechnik GmbH, Siegen, Germany, Figure？2). However, its applicati