Abstract
RATIONALE: A digitally planned lingual protocol using a single 2-step offset bend ("digital plus one bend") was developed to substitute first premolars for congenitally missing maxillary canines, aiming for a cost-effective, reproducible approach that avoids customized brackets and robot-bent wires. PATIENT CONCERNS: A 31-year-old woman reported crooked upper teeth and a visible retained "baby tooth," seeking an esthetic, affordable treatment without complex customized appliances. DIAGNOSES: Bilateral congenital absence of maxillary permanent canines, mild maxillary spacing, and severe mandibular crowding; molar relationship initially class I. INTERVENTIONS: Management included extraction of both mandibular second premolars and lingual appliance therapy in the maxilla with stock self-ligating brackets. A virtual setup repositioned the maxillary first premolars buccally to clear bracket interference; in vivo, a manually applied 2-step offset in the working archwire guided the premolars into their planned lingual positions. OUTCOMES: After 14 months, treatment objectives were achieved: resolution of mandibular crowding and maxillary spacing, bilateral class I molar relationships, coincident dental midlines, and functional canine guidance via first-premolar substitution, with a stable facial profile. At 1-year post-debond, occlusion, smile esthetics, and periodontal health remained stable. LESSONS: The digital plus one bend protocol provides a simple, low-cost lingual solution for maxillary canine agenesis, avoiding bulky composite bases and expensive CAD/CAM systems. The technique is readily reproducible in clinics equipped with basic digital tools and competent wire-bending skills.