Comparative evaluation of short term relapse of mandibular anterior teeth in patients using Lingual bonded retainer and Hawley retainer using 3 Dimensional analysis

Background: To evaluate and compare the amount of displacement of mandibular anterior teeth in transverse, sagittal and vertical plane using 3Shape TRIOS3 intraoral scanner in patients using Lingual bonded retainer (LBR) and Hawley retainer at first 3 months and 6 months of retention.Materials and Methods: 16 patients treated with fixed orthodontic appliances using a non-extraction protocol were included.After debonding, they were divided into two groups: Group I (8 patients with Lingual Bonded Retainer) and Group II (8 patients with Hawley Retainer).Intraoral scans were taken using the 3Shape TRIOS 3 scanner at debond (T0), 3 months (T1) and 6 months (T2) post-debond.The T0 scans were superimposed on the T1 and T2 scans for both groups.The study focused on mandibular incisors, using three reference points: Mesioincisal (MI), Distoincisal (DI), and Gingival Zenith (Z).Displacement in transverse, sagittal, and vertical planes was evaluated using the 3Shape Unite Software's cross-section tool, comparing changes between T0-T1, T1-T2, and T0-T2.Group comparisons were done using an unpaired t-test.Results: In the sagittal dimension, significant changes were seen in the mesioincisal point of 42 at both T0-T1 and T0-T2 seen as lingual tipping and rotation.In the transverse dimension, significant changes were seen in the mesioincisal point of 41 at T1-T2, gingival zenith point of 41 at T0-T2 and gingival zenith point of 42 at T1-T2.In vertical dimension the only significant change noted was at the mesioincisal point of tooth 32 at T0-T1.No other significant changes were seen in any tooth at any time interval in all 3 planes.Conclusion: The mandibular incisors contacts are more likely to shift in sagittal and transverse dimension within the first 6 months of retention irrespective of the type of retainer used.