Abstract :
Bimaxillary dentoalveolar protrusion is a common malocclusion marked by forward positioning and proclination of anterior teeth in both arches. It often results in lip incompetence, a convex facial profile, and compromised soft tissue balance. Management typically involves premolar extractions to enable significant anterior tooth retraction.This case report presents the successful orthodontic treatment of a 14-year-old male with Class I bimaxillary dentoalveolar protrusion, using frictionless biomechanics. Following the extraction of all four first premolars, space closure was achieved with titanium molybdenum alloy Opus loops. The patient initially showed proclined incisors (U1 to NA: 28°, L1 to NB: 36°), lip strain, and a convex profile. Treatment aimed to correct incisor proclination, midline deviation, and crowding, while maintaining occlusal relationships and enhancing facial appearance. Levelling and alignment were done with sequential archwires in MBT 0.022” × 0.028” prescription. Anchorage was reinforced using a Nance palatal arch and lingual holding arch.Opus loops, fabricated from 0.017” × 0.025” TMA, were activated initially by 5.5?mm. The high moment-to-force ratio (8:1–9:1) for efficient en-masse retraction with minimal tipping and controlled bodily movement preserving Class I molar and canine relationships and improving facial aesthetics. Treatment concluded in 14 months.Post-treatment cephalometrics showed improved incisor angulations (U1-NA: 20°, L1-NB: 25°). Soft tissue enhancements included a nasolabial angle increase and reductions in upper and lower lip protrusion by 2?mm and 4?mm, respectively (Rickett’s E-line).The case highlights the clinical effectiveness of Opus loops as a precise and efficient tool in contemporary orthodontic biomechanics.
Keyword :
Opus loop, Orthodontic premolar extraction, Bimaxillary protrusion, Frictionless mechanics, Orthodontic space closure, Orthodontic Biomechanics