Alignment Efficiency of Two Thermal Activated Orthodontic Archwire Sequences

Inclusion Criteria: * Moderate mandibular anterior crowding (crowding: 4 to 6 mm) according to Little's Irregularity Index * Presence of all teeth in lower arch through to the second molars, no indication for extractions in the lower arch * No need for therapeutic interventions (use of inter-maxillary elastic bands, inter-dental wear, open NiTi spine, active lip bumper) * Absence of systemic conditions that could affect tooth movements * Absence of significant tooth size or shape abnormalities * No history of trauma and no history of root resorption or alveolar bone loss. Exclusion Criteria: * Severe mandibular anterior crowding (crowding: up to 7 mm) according to Little's Irregularity Index * Absence of any teeth in lower arch through to the second molars * Indication for extractions in the lower arch * Need for therapeutic interventions (use of inter-maxillary elastic bands, inter-dental wear, open NiTi spine, active lip bumper) * Presence of systemic conditions that could affect tooth movements * Presence of significant tooth size or shape abnormalities * History of trauma and history of root resorption or alveolar bone loss.