Stability of Maxillary Anterior Teeth After Two Years of Retention in Adolescents Comparing Two Bonded and a Vacuum-formed Retainer

Study Overview
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Brief Summary
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After orthodontic treatment 3 different retention devices will be compared.Thirty patients in each group; Group 1) Bonded retainer 13-23, Group 2)Bonded retainer 12-22 and Group 3) Vacuum-formed retainer covering all erupted teeth in the maxilla. Retention capacity between these three devices will be compared after 2 years of retention by measuring Contact Point displacements (CPD) between 6 anterior teeth and sum of 5 anterior CPDs called Little´s Irregularity Index (LII).

Detailed Description
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Studies have shown that esthetics, no doubt, is the major motivating factor for orthodontic treatment both in adults and adolescents.Orthodontic relapses are usually described as changes toward the pretreatment status. These changes occur very fast if the teeth are not kept in their new position. That is the reason why, after orthodontic treatment, the result must be stabilized by some kind of retention device to prevent relapse. However, after this first period of remodeling of periodontal structures, comes the later period of changes. Relapse in aesthetic zone (Anterior teeth), is the major reason why patients are dissatisfied with the results and seek for retreatment. There is a gap in our knowledge which kind of retention device is more effective to stabilize achieved alignment after orthodontic treatment. This randomized clinical trial, tries to answer to that question. The investigators shall compare three different retention devices and measure changes after 2 years when retention devices have been in place and later compare the long-term results when the retainers have been removed after 2 years of retention (future study 5 years ptstretention). Randomization Three months before the estimated removal of the fixed appliances, the patients will be invited to take part in the trial. After gaining informed consent from the patient and their custodians, the patients are randomly allocated to one of the three retention groups as follow: A) bonded retainer 13-23, B) bonded retainer 12-22 and C) removable vacuum-formed retainer (VFR) covering the maxillary teeth including the second molars. The randomization process is prepared by an independent person and carried out by three staff members not involved in the trial. The randomization uses blocks of 30. The randomization notes is delivered in a sealed opaque envelope each. Every new participant picked an envelope and reveal the group assignment by opening the envelope. Recruitment is ongoing until the total number of participants meet the estimated sample size.

Official Title
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Stability of Maxillary Anterior Teeth After Two Years of Retention in Adolescents - A Randomized Controlled Trial Comparing Two Bonded and a Vacuum-formed Retainer

Conditions
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Orthodontic Appliance Complication

Intervention / Treatment
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* Other: Measuring changes of Little´s irregularity index ( sum of 5 contact point discrepancies together) measured in mm 2 years after retention have been I place.


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Young children age between 11 to 19 years old undergone orthodontic treatment. Exclusion Criteria: Syndrome patients Skeletal discrepancy missing maxillary anterior teeth Adults

Ages Eligible for Study
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Minimum Age: 11 Years
Maximum Age: 19 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
Interventional Model Description: Three groups with different retention devices
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Bonded retainer 13-23<br>This group have bonded retainer behind six front teeth in the maxilla to keep front teeth stable. | Other: Measuring changes of Little´s irregularity index ( sum of 5 contact point discrepancies together) measured in mm 2 years after retention have been I place.<br>* Measuring changes occurred under 2 years which the retention devices have been in place between the groups<br>* Other names: Measuring changes of 5 single Contact point displacements in mm 2 years after retention have been I place.;|
| Active Comparator: Bonded retainer 12-22<br>This group have bonded retainer behind four front teeth in the maxilla to keep front teeth stable. | Other: Measuring changes of Little´s irregularity index ( sum of 5 contact point discrepancies together) measured in mm 2 years after retention have been I place.<br>* Measuring changes occurred under 2 years which the retention devices have been in place between the groups<br>* Other names: Measuring changes of 5 single Contact point displacements in mm 2 years after retention have been I place.;|
| Active Comparator: Vacuum-formed retainer<br>This group have Vacuum-formed retainer covering all erupted teeth in maxilla to keep front teeth stable | Other: Measuring changes of Little´s irregularity index ( sum of 5 contact point discrepancies together) measured in mm 2 years after retention have been I place.<br>* Measuring changes occurred under 2 years which the retention devices have been in place between the groups<br>* Other names: Measuring changes of 5 single Contact point displacements in mm 2 years after retention have been I place.;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in LII (sum of 5 contact point discrepancy)among 6 maxillary front teeth | Sum of five single contact points of maxillary anterior teeth | 2 years after retention device in place | 
| Changes in CPD | Changes in single contact point discrepancy of five maxillary anterior teeth | 2 years after retention device in place | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Intercanine distance | Measuring the distance between top of the canines in maxilla | 2 years after retention device in place | 
| Intermolar distance | Measuring the distance between cusp tips of first molars | 2 years after retention device in place | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Retention devices, Relapse, Maxillary incisors, Irregularity