Assessment of tooth movement with different types of orthodontic removable retainers in patients who have had orthodontic treatment

All patients will be randomly allocated one of two commonly used removable orthodontic retainers which will be custom fit to the patients upper and lower dentition, to be worn full time for 3 months and then night time only for the remaining 3 months. The retainers will be prescribed and inserted at the orthodontists’ clinic by fully qualified orthodontists who have over 10 years of clinical experience,. For the patients who have completed clear aligers (Invisalign) they will be randomised into two types of clear removable retainers, Vivera and Essix Ace. The orthodontists involved in the study will meet with the investigator to be briefed of the research protocol prior to recruiting participants. An investigators’ brochure will also be distributed to ensure consistency and adherence to the method proposed. A case report sheet will be provided to the orthodontists, which will be completed for each participant. This form will be retained at the clinic for the 6 month duration and each section will be recorded each time the participant returns to the clinic. The form includes a clinicians’ checklist for each visit such as the inclusion/exclusion criteria which was met, along with the date and details of each intra-oral scan and whether the protocol was adhered to. The clinician will sign this form at every participants' appointment and any deviation from the protocol will be documented on this form at each visit. At the conclusion of 6 months, these case report forms will be provided to the investigator to assess adherence.