Orthodontic Retention and Relapse: Current Concepts and Clinical Management

Abstract

Orthodontic treatment is followed by a period in which the dentition remains vulnerable to positional change. Some of this change represents true relapse toward the pretreatment arrangement, whereas other changes reflect maturation, ageing and continued adaptation of the dentofacial complex. Because these processes are difficult to predict for an individual patient, retention has become an integral part of orthodontic treatment rather than a short terminal stage. This narrative review discusses the biological basis of post-treatment change and the clinical use of removable and fixed retainers. Attention is given to Hawley and vacuum-formed retainers, bonded retainers, patient adherence, periodontal considerations, appliance failure and the duration of retention. Available evidence does not support a single retainer or wear schedule as the best option for every patient. Recent systematic reviews suggest that vacuum-formed and Hawley retainers have broadly comparable effects on arch dimensions, while fixed retainers may offer advantages for maintaining lower anterior alignment but require ongoing supervision. Bonded retainers also have a meaningful risk of failure, and distorted or partially detached wires can produce unwanted tooth movement. Retention should therefore be planned according to the original malocclusion, the extent and direction of tooth movement, periodontal status, anticipated compliance and patient priorities. Clear instructions, regular review and a realistic discussion of long-term retention are essential. In routine practice, the most appropriate strategy is usually not the retainer that appears theoretically superior, but the one that can reliably control the patient's principal stability risks and can be maintained safely over time. Patients should also understand that a retainer does not eliminate all future dental change. Long-term follow-up should therefore focus on both maintenance of alignment and early identification of retainer-related problems, particularly with bonded appliances. The review also emphasizes that retention decisions should be revisited when appliances fail, when the patient's circumstances change, or when clinically relevant tooth movement becomes apparent.

Keywords: orthodontic retention; relapse; orthodontic retainers; fixed retainers; vacuum-formed retainers

Review approach. This narrative review was informed by targeted searches of PubMed and by examination of recent systematic reviews, evidence-based reviews and selected clinical studies concerning orthodontic retention, relapse, fixed and removable retainers, periodontal outcomes, retainer failure and adherence. Priority was given to systematic reviews, randomized clinical trials and recent evidence published through August 2026. The purpose was to synthesize clinically relevant evidence rather than to perform a formal systematic review or meta-analysis.