Orthodontic repositioning of two retained upper central incisors in the maxilla with the aid of miniscrews. A case report

Background: Over the last few years’ miniscrews have been used as skeletal anchorage in orthodontics allowing the management of wider discrepancies than those treatable by conventional biomechanics. This is due to the fact that the force can be directly applied from the bone-borne anchor unit. A good surgical technique, an appropriate treatment and an adequate inflammation and oral hygiene control are crucial for the establishment of a successful anchorage system during orthodontic treatment. Miniscrews loaded within the normal orthodontic force range do not exceed stress levels that will lead to bone fracture. Material and methods: A 9-year-old male presented to the Department of Pediatric Dentistry of the Dental School, University of Chieti-Pescara, Italy with an orthopantomography showing the presence of three supplementary teeth that prevented the normal eruption of the two upper central incisors. After the surgical extraction of the three supplementary teeth and a follow-up of six months to evaluate the spontaneous eruption of the two retained incisors, two 11 x 1.5 mm miniscrews (Miniscrew Anchorage System, Micerium, Avegno (Ge), Italy) were placed in the anterior region of the maxilla to provide skeletal anchorage for the traction of the incisors. The two retained upper incisor previously surgically exposed received orthodontic buttons and traction through elastomeric chain in order to allow the eruption of the included teeth. Radiographs were performed every month to evaluate the eruption of the incisors. After two months the teeth reached the buccal cavity, the two miniscrews were removed, and the traction has been continued with anchorage provided by a transpalatal bar. The patient is now undergoing to orthodontic tooth alignment. Discussion: miniscrews for skeletal anchorage in orthodontics have advantages such as reduction of the treatment duration; indeed, the orthodontics forces are close to the center of resistance of the teeth, they can be placed directly through the mucosa without the need of bone exposure and they can be easily removed. Furthermore, miniscrews can be placed in various regions of the maxilla and the mandible independently the bone density and they can be immediately loaded. Therefore, miniscrews represent an efficient alternative to the traditional methods of orthodontic anchorage.