RCT for the Effectiveness of 3 Orthodontic Retention Schemes on Post-treatment Stability and Gingival Recession

Study Overview
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Brief Summary
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The present study aims to assess the effectiveness of three different retention schemes used to maintain tooth position after orthodontic treatment with fixed orthodontic appliances (stability) and to evaluate possible association between retention scheme and gingival recessions on the lingual surfaces of the lower anterior teeth seen for up to 5 years post-treatment. Moreover the possible association between primary relapse tendency and long term occlusal stability will be evaluated.

Detailed Description
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This is a randomized, controlled, single-center, equivalence trial with three parallel groups and an allocation ratio of 1:1:1, that aims to investigate the effectiveness of 3 orthodontic retention schemes on post-treatment mandibular arch stability and gingival recession.

Official Title
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A Single-center, 3-arm, Parallel-group Randomized Controlled Trial to Evaluate the Effectiveness of Three Orthodontic Retention Schemes in Preventing Post-treatment Mandibular Arch Changes and Gingival Recession in Children and Adolescents

Conditions
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Relapse, Gingival Recession

Intervention / Treatment
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* Other: 0.028 bonded to canines
* Other: 0.027 7-strand bonded to all 6
* Other: removable Hawley-type


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Both sexes Age between 10 and 16 years At the finishing stage of orthodontic treatment, programmed for debonding Class I to Class II molar relationship before the beginning of orthodontic treatment Non-extraction treatment plan with fixed straight-wire appliances Space deficiencies and irregularity of no more than 6mm in the maxillary/ mandibular arch (Irregularity Index) Exclusion Criteria: No missing teeth, impacted teeth or other dental anomalies No congenital anomalies/ syndromes

Ages Eligible for Study
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Minimum Age: 10 Years
Maximum Age: 16 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 0.028 bonded to canines<br>lower fixed canine and canine retainer and upper removable Hawley (Intervention A) | Other: 0.028 bonded to canines<br>* lower fixed canine and canine retainer (0.028 stainless steel bonded to canines) and upper removable Hawley (Intervention A)<br>|
| Experimental: 0.027 7-strand bonded to all 6<br>lower fixed canine to canine retainer and upper removable Hawley (Intervention B) | Other: 0.027 7-strand bonded to all 6<br>* lower fixed canine to canine retainer (7-strand Twistflex 0.027 bonded to all six anterior teeth) and upper removable Hawley (Intervention B)<br>|
| Active Comparator: removable Hawley-type<br>lower hawley-type and upper hawley removable retainer (Control) | Other: removable Hawley-type<br>* lower Hawley-type and upper Hawley removable retainer (Control)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in Little's Irregularity Index in the mandible (mm) |  | 1 year in retention, 2 years in retention, 5 years in retention | 
| Changes in Intercanine width in the mandible (mm) |  | 1 year in retention, 2 years in retention, 5 years in retention | 
| Changes in Interpremolar width in the mandible (mm) |  | 1 year in retention, 2 years in retention, 5 years in retention | 
| Changes in Intermolar width in the mandible (mm) |  | 1 year in retention, 2 years in retention, 5 years in retention | 
| Changes in Arch length in the mandible (mm) |  | 1 year in retention, 2 years in retention, 5 years in retention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in Gingival Recessions on the lingual surfaces of the six lower anterior teeth |  | 1 year in retention, 2 years in retention, 5 years in retention | 
| Changes in Intercanine width in the maxilla (mm) |  | 1 year in retention, 2 years in retention, 5 years in retention | 
| Changes in Interpremolar width in the maxilla (mm) |  | 1 year in retention, 2 years in retention, 5 years in retention | 
| Changes in Intermolar width in the maxilla (mm) |  | 1 year in retention, 2 years in retention, 5 years in retention | 
| Changes in Arch length in the maxilla (mm) |  | 1 year in retention, 2 years in retention, 5 years in retention | 
| Changes in Overbite and Overjet (mm) |  | 1 year in retention, 2 years in retention, 5 years in retention | 
| Accidental bond failures of fixed retainers or breakages of removable ones |  | 1 year in retention, 2 years in retention, 5 years in retention | 
| Leveling or torque related problems of the lower anterior teeth |  | 1 year in retention, 2 years in retention, 5 years in retention | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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relapse, irregularity, recession, retention