Skeletal anchorage for tooth movements: mini implants vs osseointegrated implants

Background: The mini-implants are very important for preventing dental, periodontal, esthetical and psychological problems during the combined implant-orthodontic treatment. Aim: The aim of this study was to show the benefits, possibilities and limits of mini-implants to obtain a rigid skeletal anchorage for tooth movements. Material and Methods: The study utilized 51 patients, 28 men and 23 women, aged 20 to 49 years. Were inserted 84 mini-implants and 57 fixtures to control anchorage. The mini-implant system consisted of a pure titanium micro anchor screw and an abutment hook. It had 3 lengths (4, 6, 8 mm) with same diameter of 1.2 mm, and needed of two minimal surgical procedures. Some aspects were considered: screws loss; anchorage failure; abutment loss; pain; perimplantitis; mucosa inflammation; force application time; bleeding; easy removal; force entity. The loading timing after 4, 8, 12, 16 weeks was evaluated. Results: Using osseointegrated implants as anchorage there were more problems because of severity of surgery, the discomfort of initial healing, a longer period of treatment time and they could only be inserted in retromolar, tuber and edentulous areas, evidencing limitations for the direction of force application. The use of mini-implants as anchorage in tooth movement, produced a satisfactory result in a short period of time. Conclusions: The use of mini-implants as temporary anchorage enables to insert an appliance in any aimed position and carries out easily the tooth movement. They are indicated for: dental-skeletal deformities and intermaxillary fixation after orthognathic surgery. About mini-implants complications, no significative differences among 4, 8, 12, 16 weeks loding periods were showed (p<0.01).