DTIN0210

trends &applications DeNtaltribuNe|april-June, 201026 stable methods of acquiring more transverse space in the upper jaw. The targeted screw rate should be in the range of 0.2 to 0.6 mm/day. As a rule, the appliance is fixed by means of bands to the molars & premo- lars. The desired transverse width can generally be achieved within 10 to 20 days. There after, a three-month stabilisation phase should be observed, in order to allow ossification of the ruptured palatine suture. The standard anchorage tech- nique with dental support only has several disadvantages. The most significant is the risk of tipping the anchor teeth. Many appliances have been described that distribute the force over more than one tooth. A further problem is apparent here: as it is necessary to leave the appliance in place for a longer period after the active phase, it is only possible to commence further corrective treatment for teeth in the ante- rior region. It is possible to overcome these problems by using the ‘hybrid RPE’ (Figs. 4–6). Bands are employed as usual in the molar region. In the anterior region, the RPE appliance is fixed using two miniscrews. These should be placed on a notional trans- verselineconnectingthecanine/ premolar contact points para- medially. Distraction is achieved using the same method as in standard techniques. There are several advantages to hybrid RPE. Preparation of the appara- tus is much simpler and cheaper, whilst the dental arch, including the premolars, is accessible for additional tooth correction measures. Class II corrections In the case of patients with Class II malocclusion who have completed or are near com- pleting their growth phase, simple techniques for the for- ward positioning of the lower jaw are usually ineffective. Following a thorough initial examination and diagnosis, there are three possible thera- peutic approaches: camouflage, fixed Cass II correctional appli- ances (Herbst splint, Sabbagh Universal Spring, FMA, Jasper Jumper etc.) or orthognathic surgery. The patient must be informed of the advantages and disadvantages of each approach. All fixed Class II Figs. 6a–d: Bilateral cross-bite in a seven-year-old boy (a). X-ray of the hybrid RPE appliance in situ (b). Status after ten days’ use: cross-bite has disappeared and vertical bite has remained stable (c, d). Figs. 8a & b: The miniscrew stabilises the position of the molars to which the Kinzinger FMA is attached. This counteracts any protrusion of the premolars and anterior teeth (a). Class I dental status on completion of treatment (b). Figs. 7a–d: Anchorage of the canine using a miniscrew avoids protrusion of the anterior teeth when using a fixed Class II correction appliance (here: Williams appliance, FORESTADENT). Figs. 10a–d: Missing tooth 12 is to be replaced by an implant-based crown. The initial phase of treatment involves widening the gap (a). The head of the vertically inserted OrthoEasy screw (b) is used to anchor a provisional crown (including bracket), which serves to widen the gap further (c). Fig. 9: The use of miniscrews to attach intermaxillary rubber traction bands means that no other attachments to the teeth are necessary.