Therefore, the possibility of root-contact is significantly higher than orthodontic miniscrews. According to these findings, the following techniques are considered to be effective for avoiding the root damage in clinical application of interradicular miniscrews: (1) minimum local anesthesia (a patient feels pain when a screw touches the periodontal ligament); (2) placement MK-2206 of a screw into the wider interradicular area; (3) choosing a small and short screw as possible; (4) oblique insertion; (5) placing with a self-tapping method; and (6) using a screwdriver with a torque limiter. These are also effective to reduce the possibility of screw fracture and

failure (Table 2). When a screw is inserted with an oblique angle to the bone surface, a clinician has to take care not to slip the screw. To prevent the soft tissue damage by the slippage, a self-tapping method, pre-drilling with a round bar on the cortical bone, selleck chemicals must be effective. Screws placed through the non-keratinized gingiva or movable gingiva stimulate surrounding soft tissue and sometimes evoke the peri-implantitis. Chang et al. [45], reported that miniscrew placement through non-keratinized tissue sometimes caused screw

failure. Moreover, the screws are often covered with surrounding movable mucosa and it will become cause of pain and discomfort (Fig. 5). Therefore, miniscrews had better be implanted in the range of attached/keratinized gingiva. The screw head placed close to the muco-gingival junction irritates the movable mucosa and it becomes cause of ulcer. Auxiliaries attached between the screw head and the

archwire, i.e. coil springs, elastomeric chains, hooks, and ligation wires, should be adjusted click here not to touch the gingiva or oral mucosa to avoid the pain and discomfort a patient (Fig. 6). A palatal miniscrew sometimes induces pain and injury on the surface of tongue. Use of miniscrews makes it possible to distalize the whole dentition, which breaks the methodological limitation of tooth movement. However; an excessive distal movement causes impaction of the second molar under the gingiva and evokes peri-coronitis, especially in the mandible. Proper diagnosis based on the clinical examinations is important in the implant-anchored orthodontics. Tooth movement through bone-deficient areas (e.g., the maxillary sinus, the atrophic alveolar ridge) is a challenging matter for orthodontist. Emergence of implant-anchored orthodontics can clear mechanical considerations, however; environmental factors still remain. Several reports demonstrated that tooth movement to the bone-deficient areas might reduce the alveolar bone height and/or the root length [66] and [67]. In contrast, some reports have suggested that a tooth with normal supporting apparatus height can be orthodontically moved through the maxillary sinus while maintaining pulp vitality and bone support and exhibiting normal width of the periodontal ligament on both the compression and tension sides [68].