Clinical Effectiveness of Cobalt Chromium CAD-CAM Designed Customized Lingual Retainer

Inclusion Criteria: * Completion of a course of fixed appliance therapy. * with a satisfactory correction of malocclusion and dental alignment. * Class I canine relationship based on Andrew's criteria for finishing. * Patients with a history of constant oral hygiene measures daily. * Good general health. * Subjects had a full and normal complement of teeth in the lower labial segments. * Teeth within the labial segments should be regularly sized and shaped. * Subjects willing to consent to the trial. Exclusion Criteria: * Patients with a deep overbite * Patients with 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 patients. * patients under systemic drug administration that affects oral health. * Smokers