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Trial registered on ANZCTR


Registration number
ACTRN12612000670875
Ethics application status
Approved
Date submitted
6/06/2012
Date registered
22/06/2012
Date last updated
22/06/2012
Type of registration
Prospectively registered

Titles & IDs
Public title
A prospective study of orthodontic retention outcomes with different retention strategies
Scientific title
A prospective study of orthodontic treatment outcomes with different treatment strategies in children under 17 years old who have completed orthodontic treatment.
Secondary ID [1] 280610 0
Nil
Universal Trial Number (UTN)
U1111-1131-0946
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
retention outcomes post orthodontic treatment as affected by different retainer types 286622 0
retention outcomes post orthodontic treatment as affected by wisdom tooth extraction after completion of orthodontic treatment 286643 0
Condition category
Condition code
Oral and Gastrointestinal 286898 286898 0 0
Other diseases of the mouth, teeth, oesophagus, digestive system including liver and colon

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Patients will be randomly assigned to one of 2 types of retainer for the upper teeth after orthodontic treatment (Begg or Trutain) and some patients will be issued both. Patients issued with both retainers will be asked to decide for themselves which one to wear.
The patients will also be given one of two types of retainer for the lower teeth after orthodontic treatment (Barrer or Bonded lower 3 to 3).
Patients issued removable retainers (both types of upper retainer are removable, as is the lower Barrer retainer) will be asked to wear them full time for 3 months then night time wear only for 3 months.
Patients issued the bonded lower retainer will be asked to retain it until at least the end of active growth i.e. into the second decade. So all patients issues the lower retainer will be wearing it for the entire duration of the study.
Half of the group will have their wisdom teeth removed immediately following the end of orthodontic treatment and half will have their wisdom teeth removed 3 years after completion of orthodontic treatment.
(so when one takes into account the 3 different possibilities for the upper retainer issue, the two different options for lower retainer issue and the 2 different options relating to wisdom teeth,there are 12 possible combinations of treatment)
Intervention code [1] 285003 0
Treatment: Devices
Intervention code [2] 285004 0
Treatment: Surgery
Comparator / control treatment
Patients will all be issued with retainers but with different types of retainer.
Half the patients will have wisdom teeth extracted immediately after orthodontic treatment and half 3 years after completion of orthodontic treatment
Control group
Active

Outcomes
Primary outcome [1] 287251 0
% with acceptable PAR score. An acceptable PAR score being one which demonstrates that there has not been relapse.
Timepoint [1] 287251 0
T0 is before treatment
T1 is after randomisation and therefore at point of allocation to trial (immediately post treatment)
T2 is one year after allocation to trial, one year post treatment.
T3 is three years after allocation to trial, 3 years after end of treatment.
Secondary outcome [1] 297744 0
Patient preference for retainer, as assessed by a questionnaire.
This particular questionnaire has not been validated
Timepoint [1] 297744 0
3 months after treatment
1 year after end of treatment
3 years after end of treatment

Eligibility
Key inclusion criteria
1. subject to be under the age of 17 years old at the end of treatment
2. subject diagnosed as not having enough space for lower third molar teeth (assessment of this will be made using a late treatment OPG and the Space Width Ratio will be less than 0.8). If the OPG indicates that the teeth are horizontally impacted and therefore at a risk of being closely involved with the inferior dental canal and its contents then the patient would be advised not to participate in the study and to seek early removal of the 8s.

3. subject has a continuous (no unclosed extraction spaces) natural dentition including second molars in occlusion with no retained primary (baby) teeth or complex restorations (crowns, bridges or implant supported crowns or bridges);
4. subject has undergone full fixed orthodontics with or without other phases or adjunctive treatments such as rapid maxillary expansion or extractions; (however no orthognathic surgery cases will be included to avoid the compounding factor of surgical relapse);
5. subject has pre-treatment study models and OPG available (these are standard pre-treatment orthodontic records);
6. subject has end-of-treatment study models, and late treatment OPG (these are standard end-of-treatment orthodontic records);
7. subject agrees, with consent of parent/guardian, to have impressions for study models not only at end-of-treatment, but also at 1 year post-treatment and 3 years post-treatment;
8. subject agrees, with consent of parent/guardian, to undergo oral examination and to complete a patient satisfaction survey at 3 months, 1 year and at 3 years;
9. subject and parent/guardian consents to a randomly assigned retention protocol
Minimum age
No limit
Maximum age
17 Years
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
1. over the age of 17 years
2. Has sufficient space for lower third molar teeth
3. Patient has unclosed extraction spaces
4. Patient has undergone orthognathic surgery
5. Patient does not have complete end of treatment records.
6. Patient does not consent to treatment
7. Patient is not available for review at the time points

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Once patients are nearing completion of their orthodontic treatment they will be asked if they wish to participate in the study. They will be given an information sheet and a consent form. Once they have agreed to take part and consent has been signed then the clinician will draw a blank envelope from the pile given to him by the investigator. The clinician has 24 envelopes each with a different retention regime written inside, which is not visible from the exterior.
Once the patient has been assigned the retention regime they will also be assigned an identification number so that the observer does not know what retention regime the patient was assigned and thus is less likely to be biased when interpreting results.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation. Opaque and unidentifiable envelopes shuffled into random sequence, then given to clinicians.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?



Intervention assignment
Factorial
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
1/07/2012
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
72
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)

Funding & Sponsors
Funding source category [1] 285403 0
Charities/Societies/Foundations
Name [1] 285403 0
Australian Society of Orthodontics Foundation for Research and Education
Country [1] 285403 0
Australia
Primary sponsor type
Charities/Societies/Foundations
Name
Australian Society of Orthodontists Foundation for Research and Education
Address
PO Box 576
Crows Nest
NSW 1585
Country
Australia
Secondary sponsor category [1] 284255 0
University
Name [1] 284255 0
University of Queensland
Address [1] 284255 0
School of Dentistry
200 Turbot Street
Brisbane
QLD
3000
Country [1] 284255 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 287387 0
University of Queensland Medical Research Ethics Committee
Ethics committee address [1] 287387 0
The University of Queensland
Cumbrae Stewart Building
Research Road
Brisbane QLD 4072
Ethics committee country [1] 287387 0
Australia
Date submitted for ethics approval [1] 287387 0
Approval date [1] 287387 0
16/05/2012
Ethics approval number [1] 287387 0
2012000418

Summary
Brief summary
Undesirable tooth movement following orthodontic treatment is common. Retention refers to the period of treatment after your braces have been removed and is required to help prevent teeth from moving back to their original positions.
One method of retention is to use removable or fixed retainers (retainers are orthodontic devices that help to keep your teeth in the correct position and they can either be removable or be glued discreetly onto the teeth). The eruption of second and third molars is sometimes held responsible for unwanted tooth movement and many third molars (wisdom teeth) are removed as part of the orthodontic treatment plan (before treatment, as part of or after orthodontic treatment). The delay in removal of the third molars is not uncommon where the third molars are delayed in development. The aim of this study is to compare some regularly used retention regimes and the following will be tested; Whether there is a difference in outcomes between two commonly used maxillary, top teeth retainers, Whether there is a difference in outcomes of two commonly used mandibular, bottom teeth retainers;whether there is a difference between subjects who retain their third molars and those who have their third molars removed at the completion of treatment
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 34259 0
Address 34259 0
Country 34259 0
Phone 34259 0
Fax 34259 0
Email 34259 0
Contact person for public queries
Name 17506 0
Emily Close
Address 17506 0
University of Queensland Dental School
200 Turbot Street
Brisbane 3000
Country 17506 0
Australia
Phone 17506 0
+61 (0)423512293
Fax 17506 0
Email 17506 0
[email protected]
Contact person for scientific queries
Name 8434 0
Emily Close
Address 8434 0
University of Queensland Dental School
200 Turbot Street
Brisbane 3000
Country 8434 0
Australia
Phone 8434 0
+61 (0) 423512293
Fax 8434 0
Email 8434 0
[email protected]

No information has been provided regarding IPD availability


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

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