Clear Aligner Molar Protraction After Lower Second Premolar Extraction

A 10-year-old female with protrusive lips initially underwent fixed straight-wire appliance therapy involving extraction of upper first premolars and lower second premolars, but later switched to clear aligners. Using only intermaxillary elastics, anterior teeth were retracted and molars were mesially moved, achieving satisfactory outcomes. Clinical diagnosis included Angle Class II malocclusion, skeletal Class II, severe deep overbite (II°),excessive overjet (II°), normodivergent growth pattern, maxillary protrusion, convex facial profile, and a steep Spee curve (4mm).After extractions, treatment transitioned to aligners with elastics designed to close maxillary spaces via anterior retraction and utilize mandibular spaces for molar protraction. No treatment restarts were required. Final results showed neutral molar relationships, skeletal Class I, reduced overbite and overjet, straightened facial profile, and acceptable root inclination. Two-year follow-up demonstrated stable occlusion and facial profile in the patient. Clear aligners excel in molar distalization but struggle with mesial movement. In cases requiring lower second premolar extraction and molar protraction, mesial tipping risks were mitigated by designing mandibular molar anchorage preparation, staging mesial movement steps, and optimizing elastic direction (lingual buttons bonded to the distolingual surfaces of the first molars).Close monitoring prevented restarts. In cases requiring lower second premolar extraction and molar protraction, meticulous control of interarch elastic direction prevents multiple restarts and ensures successful outcomes.