Morphological Changes of Removable Orthodontic Retainers During the Use
The retention is one of the stages of orthodontic treatment that aims to keep the teeth in the correct positions after orthodontic treatment. Without a retention phase, there is a tendency for the teeth to return to their initial position (relapse). To prevent relapse, at the end of orthodontic therapy the use of retaining devices to keep the teeth in their ideal position is required. The aim of the study is to analyse whether intraoral aging of removable retention devices can lead to morphological or dimensional changes, and whether or not these changes are related to orthodontic relapse, expressed as a change in the Peer Assessment Rating (PAR) index. The PAR index is an index that allows us to evaluate the relapse after orthodontic treatment. In this study the PAR index will be measured at the start of the retention period (T0), at the three-months follow-up (T1) and at the six months follow-up (T2). In particular, two types of thermoformed retainers with different cutouts will be evaluated to determine whether the presence of higher margins in a type of retainers allows to maintain greater stability over time and, therefore, to confer a mechanical and clinical advantage.
- EligibilityCriteria: Inclusion Criteria:  young adult patients: 18-35 years; Caucasian ethnic group; good oral hygiene (evaluated by observing a plaque index < 20% understood as the sum of the indices of the individual dental elements divided by the number of dental elements considered multiplied by 100); patients with normal occlusion Class I occlusion with slight overcrowding and PAR Index less than or equal to 10; patients who have received previous orthodontic treatment, with or without stripping; patients who have received previous orthodontic treatment with < 20 orthodontic aligners; patients who currently use a thermoprinted mask as a restraint, or who do not use any restraint but who would like to receive one.  Exclusion Criteria:  patients with chromosomal defects, specific neuropsychological disorder, epilepsy (1); patients with systemic diseases and comorbidities; bruxist patients; patients with hypertrophy of chewing muscles, occlusal parafunctions or joint disorders; patients with cognitive disabilities with IQ<70; patients undergoing drug therapy. - HealthyVolunteers: Accepts Healthy Volunteers - Gender: All - MinimumAge: 18 Years - MaximumAge: 35 Years - StdAgeList: Adult - StudyPopulation: Undergraduate students - SamplingMethod: Probability Sample