The patient indicated that wearing extraoral appliances would be difficult, and she chose not to have brackets in the lower arch, ruling out anchorage with Class II elastics. The upper right third molar was extracted, and a Spider Screw was inserted in the buccal plate between the upper left second premolar and second molar (Fig. 16). Brackets were bonded to the maxillary teeth. An .016" .022" stainless steel archwire was inserted, with two 150g Sentalloy open-coil springs attached between the upper second pre- molars and second molars to upright the second molars and reopen the first molar spaces.
An .012" stainless steel ligature wire was placed from the Spider Screw to the upper left canine to dissipate the reaction force from the coil spring and prevent mesial movement of the premolars and canine (Fig. 17). On the right side, the reaction force moved the premolars and ca- nines into a Class I relationship, closing the ante- rior spaces and correcting the midline deviation.
Interproximal stripping was performed in the mandibular arch, and a spring aligner was used to correct the mild crowding. Total treat- ment time was 10 months (Fig. 18).
Spider Screws can be used to support dif- ferent types of orthodontic mechanics, especially in cases with incomplete arches or limited coop- eration, as shown here. Their ease of application and small size also permit their use in patients with intact dentitions when anchorage recovery is necessary during treatment.
VOLUME XXXVII NUMBER 2
Maino, Bednar, Pagin, and Mura
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