Orthodontic treatment goals can be expressed as achieving ideal tooth alignment, esthetic, functional occlusion and stability. Various occlusal changes occur after active phase of orthodontic treatment, these unwanted changes are called relapse. Reitan pointed out that major percentage of changes following active phase of treatment is seen within 24 hours.

To alleviate the effect of relapse, retention is needed. There is little agreement among clinicians about orthodontic retention protocol due to insufficient evidence in the literature on 1. time of retainer delivery 2. unexpected post- treatment changes. 3.quantification of relapse tendency.

The present study will be undertaken to assess the changes and compare if there is any difference in the movement of teeth in post orthodontic treatment cases with immediate and delayed (post 24 hours) retainer delivery.

Thus help in deciding when should the retainer delivery is preffered.

The proposed study will be a prospective, non-pharmacological, single blind, randomized clinical trial to evaluate if there is a difference in transverse (Xaxis), A-P(Y-axis) and Vertical plane(Z-axis) of dentition in two group of post orthodontic treatment patients with immediate retainer delivery in one group and post 24 hours retainer delivery in other group of patients. The present study will be conducted in the Department of Orthodontic and Dentofacial Orthopedics, P.G.I.D.S, Pt. B.D Sharma University of health sciences, Rohtak. The study will be carried out after the institutional approval obtained from ethical committee.

A sample size of 18 patients was calculated keeping confidence interval 95% with power 80%. Accounting for a 10% drop out rate, 20 patients will be enrolled in each group. Patient will be randomly allocated to the study group by a person not involved in the trial using computer generated randomization list. Changes in the tooth movement in transverse(X-axis), A-P(Y-axis), Vertical plane(Zaxis) will be compared in terms of intercanine width, intermolar width, overjet, overbite and contact point displacement between the two groups at following time intervals. These parameters will be charted at T0, T1, T2,T3 and T4 for each patient.Changes in the tooth movement in transverse(X-axis), A-P(Y-axis), Vertical plane(Z-axis) will be compared in terms of intercanine width, intermolar width, overjet, overbite and contact point displacement between the two groups at following time intervals. These parameters will be charted at T0, T1, T2,T3 and T4 for each patient. T0 - Baseline records, at the time of debonding. T1 - Records obtained at the time of retainer delivery. T2 - Records obtained after 1 month of retainer delivery. T3 - Records obtained after 3 months of retainer delivery. T4 - Records obtained after 6 months of retainer delivery

Inclusion Criteria:

• Adult orthodontic patients treated with 022*028 MBT appliance with following sequence of wires- 014, 016, 16*22, 17*25, 19*25 NiTi followed by 19*25 SS.
• Treatment duration of 24-36 months with Optimal functional occlusion at end of treatment (PAR score >70%).
• Class I bimax and Class II div I with pre-treatment Little's irregularity index <6mm in both upper and lower arch.
• Nonsurgical and non-orthopedic patients.
• Non syndromic patients and no impaction of teeth except third molars.
• No previous orthodontic treatment.
• Optimal periodontal condition and Good oral hygiene.
• Good compliance regarding retainer wear (Cases who never missed more than 2 consecutive appointment and who reported with less no of breakages)

Exclusion Criteria:

• Subjects with incomplete orthodontic treatment.
• TMJ disorder patients.
• Any systemic disease affecting bone and general growth.
• Patients with incomplete records.
• Patient who fail to follow up or undergo complete treatment.
• Patient with learning difficulties

Single (Outcomes Assessor)