Mostafa A. Mohammed, Kareem M. Gaber And Wael M. Refai,

ABSTRACT
Objective: To Compare The Effect Of Wraparound Retainer And Different Thickness Of Vacuum Formed Retainer (Essix Retainer) On Little?s Irregularity Index During Retention Periods.

Materials and Methods: Forty Patients Of Both Sexes Varying Ages From 12 To 35 Years Were Selected And Randomly Assigned Into Four Equal Groups, Group 1 Wraparound Group (control Group), Group 2 (1 Mm Thickness Essix Retainer), Group 3 (1.5 Mm Thickness Essix Retainer) And Group 4 (2 Mm Thickness Essix Retainer). After Finishin Fixe Orthodontic Treatment And Patients Had Class I Molar And Canine Relationship, Debonding Was Carried Out. Impressions Were Taken After Debonding, 2 For Retainer Fabrication And 1 For Mandibular Irregularity Index Analysis. Patients Asked To Wear The Retainer 24 Hours For 6 Months Except In Eating And 12 Hours For Another 6 Months. All Casts Were Numbered To Avoid Bias And Scanned By Smart Optics 3D Scanner For Getting STL File. Little?s Irregularity Index Was Measured Using 3 Shape Software. The Measurements Were Repeated At T0 (after Debonding), T1 (after 6 Months) And T2 (after 12 Months).

Results: No Significanc Difference Between Essix Groups In Mandibular Irregularity Index. Concerning Wraparound Group, A Significanc Differences Were Found Between T0 And T2. Conclusion: Essix Retainer Is More Effective In Retaining Lower Incisors Alignment Than Wraparound Retainer.