Archwires are the backbone of fixed orthodontic therapy serving as the primary force-delivering component in tooth movement. Their evolution-from early precious metal alloys to advanced nanotechnology wires-has revolutionized treatment efficiency biomechanics and patient comfort. This book provides a comprehensive overview of archwire materials properties designs and clinical applications highlighting their role in alignment space closure torque control and finishing. It also discusses innovations in surface coatings shape-memory alloys and customized digital solutions offering readers both scientific foundations and practical insights.