“Buccal tipping is the expected outcome of removable Schwarz appliances. All removable expansion appliances engage the coronal aspect of the teeth without rigid fixation; therefore, from a biomechanical perspective, buccal tipping is the only possible outcome.” allow the upper molars to upright. In Fig. 17, note the upper molar tipping with the appliance in place. As shown in Fig. 18, the upper screw was open on the insertion, allowing normal activation to constrict the upper intermolar dimension. Fig. 18 shows the HYRAX screw was closed after molar uprighting process. In Figs. 19 and 20, the upper molars are upright and the upper arch decompensated. After decompensating the buccal tipping of the upper molars, the MARPE appliance was inserted with activation two times per day until suture separation occurred, and then once a day until completion. As shown in Fig. 21 the two-screw MARPE was inserted with bands on the 6s and 4s and bonding to the 1s. A CBCT sagittal view (Fig. 22) veri-fied bicortical (palate and nasal floor) engagement of the TADs. In Fig. 23, note the posterior cranial rotation secondary to the upper airway restriction. Eight days after the MARPE appliance insertion, midline diastema developed (Fig. 24). Fig. 25 shows an occlusal PA demon-stration of midline palatal suture separation. After five weeks using the appliance, the upper incisors released from the framework after Fig. 26 Fig. 27 the desired expansion was achieved (Fig. 26), and clear palatal midline suture separation with bone fill occurred (Fig. 27). Finally, after 14 weeks, the upper-central incisors were closing (with anterior arms supporting the arch form, see Figs. 28 and 29), and posterior cranial rotation was spontaneously correcting (Fig. 30). outcome of removable Schwarz appliances. All removable expan-sion appliances engage the coronal aspect of the teeth without rigid fixation; therefore, from a biome-chanical perspective, buccal tipping is the only possible outcome. Buccal tipping may be acceptable in patients with excessive lingual tipping of the posterior teeth and will provide improved tongue space when this is the case. However, most patients with narrow dental arches, narrow transverse nasal orthodontics.com Discussion Buccal tipping is the expected Winter 2026 15
Journal of the American Orthodontic Society Winter 2026: Page 15
