Effectiveness of PEEK Fixed Retainer

Inclusion Criteria: * Age: 17-32 years. * Patients with a score of 0-0.5 on Little's irregularity index in the lower arch. * Patients treated with the pre-adjusted orthodontic appliance (both Extraction and non-extraction cases). * Patients who have healthy periodontal condition Exclusion Criteria: * Patients treated with rapid maxillary expansion or surgically assisted rapid maxillary expansion. * Patients with a cleft lip / and or palate. * Patients with a deep overbite and traumatic parafunctional habits such as bruxism and clenching. * Patients with carious, restored, fractured, or missing lower anterior teeth. * Patients with medical health problems that may influence gingival health like uncontrolled type II diabetic patient, patients with hormonal disturbances or systemic drug administration that effect on oral health. * Smokers