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

Abstract

BackgroundTo identify insertion procedure and force application related complications in Jet Screw (JS) type mini-implants when inserted in the palatal slope.MethodsSetting 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.ResultsTwo 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.ConclusionsThe 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.

Complications reported with the use of orthodontic miniscrews: A systematic review

“…All studies reported side effects and complications associated with the use of orthodontic miniscrews. The studies, as summarized in Figure 2 , were identified as follows: 11 case reports, 13 - 23 8 retrospective longitudinal studies, 24 - 31 3 prospective controlled trials, 32 - 34 1 preliminary study, 35 and 1 case series. 36 All studies were conducted in a university setting and included both male and female participants.…”

“…All the miniscrews were surgically inserted according to the protocol suggested by the respective manufacturer. According to each orthodontic treatment plan, the miniscrews were positioned both in the maxilla and in the mandible, in the interradicular area, 13 , 15 , 18 , 19 , 21 - 24 , 32 , 33 , 36 palatal zone, 16 , 17 , 25 , 26 , 31 infrazygomatic crest, 28 , 36 ascending ramus, 26 or buccal shelf. 20 , 26 , 29 …”

“…17 However, other complications occurred later, such as scars 15 , 29 or exostoses. 13 Other complications described were inflammatory lesions, 26 , 30 , 31 , 35 necrosis of the buccal or palatal mucosa at the insertion site level, 25 or traumatic sores on the soft tissue in direct contact with the miniscrew. 14 , 20 The patient’s pain, during and after the insertion of the miniscrews, was reported in two different studies.…”

“…The risk-of-bias of the 8 included retrospective studies was assessed using the NOS. 24 - 31 The scores of the studies ranged from 3 to 5 stars, as reported in Table 7 . The interreviewer agreements for study selection, data extraction, and risk-of-bias assessment were suitable, with kappa values of 0.931, 0.988, and 0.943, respectively.…”

“…Miniscrew placement can stimulate the surrounding soft tissues and evoke tissue inflammation, small infections, and periimplantitis, especially when placed through the non-keratinized or mobile gingiva. Tissue overgrowth, defined as a partial or total covering of the implant head by the surrounding soft tissues, was reported by Ziebura et al 31 as the most common complication associated with miniscrews placed on the palatal site. To avoid this, several authors have proposed covering the miniscrew head with a healing abutment, wax pellet, or large separation elastic.…”