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Trends ORTHO TRIBUNE | MAy 20108 screwdrivers and blades in several lengths for the manual insertion of the screws. Because of their dimensions, long blades pose the risk of attain- ing a very high torque during inser- tion. Thus, insertion must be car- ried out carefully to avoid breaking the miniscrew. Torque ratchets are available for use with some systems (e.g. tomas, DENTAURUM; and LOMAS, Mondeal), which provide a certain amount of control over the insertion torque. Machine insertion Machine insertion requires a surgical treatment unit (the torque ofwhichcanbecontrolled)oratleast a low-rpm dual-green handpiece. Accurate setting of the torque and the number of rotations is required; the rotation rate should not exceed 30 rpm–1 , and the torque must be restricted to the maximum load limit of the screw. Machine insertion helps to achieve a consistent torque dur- ing insertion but means that the operator loses perception of the bone. During manual insertion, it is possible to perceive the interaction between the screw and the bone by tactile senses. Insertion by machine is shown in figures 11a–f. Attaching the orthodontic linking elements As no healing phase is required, load may be placed on the miniscrew immediately after insertion. The selected linking element must be prepared accordingly and attached to the head of the screw (Fig. 12). To avoid damage to the teeth to be moved, the load on the linking element should be between 0.5 and 2 N (about 50 and 200 g). Basic post-operative care The healing of the gingival tis- sue and hygiene status after insertion must be regularly reviewed during the entire time the miniscrew remains in place. The patient must be informed that any manipulation of the screw head with the fingers, tongue, lips and/ or cheeks should be avoided; other- wise the screw may be prematurely lost. Removal of the miniscrew A miniscrew can be removed under local anesthetic. After the linking elements have been removed, the miniscrew may be removed with the same tools used for insertion. The resulting wound requires no special care and usually heals with- in a short time. DT Editorial note: A complete list of references is available from the pub- lisher. This article first appeared in Dental Tribune Asia Pacific, No. 3, 2009. The next edition of Ortho Tri- bune will feature “Part III — Clinical examples.” All photos were provided by the authors. AD Figs. 13a–c: Miniscrew in place, after removal, and following a four-week healing period. Dr Björn Ludwig Am Bahnhof 54 56841 Traben-Trarbach Germany Phone: +49 (654) 181-8381 Fax: +49 (654) 181-8394 E-mail: bludwig@kiefer orthopaedie-mosel.de ContactOT f OT page 6 Fig. 13a Fig. 13b Fig. 13c