hooks-one between the lower premolar and canines and the other between the canines and lateral incisors-were crimped on a 0.019-by-0.025-inch stainless steel archwire. Initially, elastic chains were activated from the head of the buccal-shelf miniscrews to the distal hook with a force measured at 250 g on each side. After the application of four months of active distalization forces, a positive overjet was achieved with a combination of lower incisor tipping and mandibular distalization. Th e elastic chains were now engaged from the miniscrew head to the mesial hook on the archwire for further activation (Fig. 4). Step 2: Palatal tipping of the upper incisors Brackets were then placed on the upper arch. Th e four maxillary incisor brackets were inverted to generate Fig. 4 more palatal crown torque when a rectangular wire was inserted. Initially, a 0.014-inch NiTi archwire was placed to level the dentition. An intermaxillary 5∕16-inch, 2-ounce elastic was placed from the upper canine bracket to the lower TAD head to begin tipping the upper incisors. A Kobayashi hook was fabricated on the head of the extraradicular TAD to prevent elastic slippage on placement. Th e upper leveling archwires further transitioned from a 0.016-by-0.025-inch thermal NiTi to a 0.017-by-0.025-inch NiTi. Th e thickness of the intermaxillary elastics were also increased with the increase in wire dimensions. Lower distalization was continued along with upper palatal tipping for the next seven months until a satisfactory upper incisor inclination, along with Class I molar and canine relationships, had been achieved (Fig. 5). Fig. 6 Step 3: Finishing and retention A 0.016-inch NiTi wire was reinserted into the upper and lower arches and 1∕8-inch, 4½-ounce settling elastics were used for minor occlusal detailing to develop a better interdigitation. Th e case was retained with an upper fi xed lingual retainer in conjunction with upper and lower Essix clear retainers (Figs. 6-8). One of the main reasons for the pretreatment anterior open bite and the severely proclined incisors after the fi rst orthodontic treatment was the premature and early engagement of the buccal and highly placed canines after extraction of all bicuspids. High ectopic canines have the tendency to pull the anchorage unit away from the occlusal plane and usually cause an open bite.7 It is important to avoid early archwire engagement of high labial canines so unwanted vertical movement of lateral incisors and premolars does Fig. 5 Fig. 7 Fig. 8 JULY/AUGUST 2024 | 33 | ORTHOTOWN.COMhttp://www.ORTHOTOWN.COM