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Trial registered on ANZCTR


Registration number
ACTRN12623000984695p
Ethics application status
Submitted, not yet approved
Date submitted
15/08/2023
Date registered
8/09/2023
Date last updated
8/09/2023
Date data sharing statement initially provided
8/09/2023
Type of registration
Prospectively registered

Titles & IDs
Public title
Effects of two different post-expansion retention methods in the mixed dentition
Scientific title
Effects of two different post-expansion retention methods on maxillary arch width, depth and perimeter in children in the mixed dentition
Secondary ID [1] 310331 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Tooth size-arch length discrepancies 331143 0
Condition category
Condition code
Oral and Gastrointestinal 327920 327920 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
Participants will be randomly assigned to a retention appliance after the completion of their expansion treatment. Patients will be assigned one of the two types of retention modalities: use of either a Hawley retainer or maintenance of the expander appliance in situ.

During the expansion treatment, this phase is termed active treatment. After completion of the expansion, both groups will have the expander left in situ for 3 months. One group will then be switched to use of a removable Hawley retainer, and the other group will keep the expander in for an additional 6 months, with the final 3 months retainer free. The Hawley retainer will be in use for a total of 9 months and the overall study will take place over 12 months after the completion of the active expansion treatment phase.

The Hawley retainer will be worn full time during the day and while sleeping. It should be only taken out for eating and cleaning. The retainer must be cleaned twice daily with a toothbrush and toothpaste. The Hawley retainer will be administered by the treating orthodontist. No strategies to monitor adherence will be used.



Intervention code [1] 326795 0
Treatment: Devices
Comparator / control treatment
The comparator is the maintenance of the expander appliance in situ.

During the expansion treatment, this phase is termed active treatment. After completion of the expansion, both groups will have the expander left in situ for 3 months. One group will then be switched to use of a removable Hawley retainer, and the control group will keep the expander in for an additional 6 months, with the final 3 months retainer free.

The key difference between the expander appliance and the Hawley retainer is that the expander appliance is fixed (i.e. cannot be removed by the patient) and the Hawley is removable. Resultantly, patient adherence is not an issue with leaving the expander in situ. As it is fixed, it is in use full time. It must be cleaned with a toothbrush and toothpaste at the same time as cleaning their teeth. The device will be administered by the treating orthodontist prior to the active expansion treatment.
Control group
Active

Outcomes
Primary outcome [1] 335772 0
Any change in arch width, measured as the shortest distance between the centroids of the permanent first molars as assessed by a digital scan of the maxillary arch.
Timepoint [1] 335772 0
Baseline (after completion of the expansion treatment) and 12 months post-baseline
Secondary outcome [1] 425547 0
Nil
Timepoint [1] 425547 0
Nil

Eligibility
Key inclusion criteria
All participants will be selected based on the following criteria:
1. All participants must possess a mixed dentition, with both permanent and primary teeth present
2. All participants must have all permanent first molars and incisors erupted
3. All participants must be about to receive rapid expansion therapy using a Hyrax expander
4. All participants must only be receiving expansion treatment at this point in time
5. All participants must have no craniofacial abnormalities or syndromes
Minimum age
6 Years
Maximum age
13 Years
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
1. Patient is not in the mixed dentition
2. Patient does not have all permanent first molars and incisors
3. Patient is going into another appliance during or immediately after treatment
4. Any craniofacial abnormalities.

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)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Who is / are masked / blinded?



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

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

Funding & Sponsors
Funding source category [1] 314536 0
University
Name [1] 314536 0
Oral Health Centre of Western Australia
Country [1] 314536 0
Australia
Funding source category [2] 314593 0
University
Name [2] 314593 0
Oral Health Centre of Western Australia
Country [2] 314593 0
Australia
Primary sponsor type
Individual
Name
Zoe Thorning
Address
Oral Health Centre of Western Australia 17 Monash Avenue, Nedlands WA 6009
Country
Australia
Secondary sponsor category [1] 316559 0
None
Name [1] 316559 0
Address [1] 316559 0
Country [1] 316559 0

Ethics approval
Ethics application status
Submitted, not yet approved
Ethics committee name [1] 313578 0
The University of Western Australia Human Research Ethics Committee
Ethics committee address [1] 313578 0
The University of Western Australia35 Stirling Highway, Crawley WA 6009
Ethics committee country [1] 313578 0
Australia
Date submitted for ethics approval [1] 313578 0
15/08/2023
Approval date [1] 313578 0
Ethics approval number [1] 313578 0

Summary
Brief summary
To date, there have been no comparative studies of retention methods post-expansion. This study aims to address this gap in the literature, comparing the effects of fixed and removable retention methods following rapid maxillary expansion; placement of a Hawley retainer and maintenance of a fixed expander appliance. Records obtained from prior to expansion, immediately posttreatment and then again at 12 month review will be analysed and interpreted in order to determine the best retention method.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 128618 0
Dr Steven Naoum
Address 128618 0
Oral Health Centre of Western Australia17 Monash Avenue, Nedlands WA 6009
Country 128618 0
Australia
Phone 128618 0
+61 08 6457 4400
Fax 128618 0
Email 128618 0
steven.naoum@uwa.edu.au
Contact person for public queries
Name 128619 0
Dr Zoe Thorning
Address 128619 0
Oral Health Centre of Western Australia17 Monash Avenue, Nedlands WA 6009
Country 128619 0
Australia
Phone 128619 0
+61 08 6457 4400
Fax 128619 0
Email 128619 0
zoe.thorning@uwa.edu.au
Contact person for scientific queries
Name 128620 0
Dr Zoe Thorning
Address 128620 0
Oral Health Centre of Western Australia17 Monash Avenue, Nedlands WA 6009
Country 128620 0
Australia
Phone 128620 0
+61 08 6457 4400
Fax 128620 0
Email 128620 0
zoe.thorning@uwa.edu.au

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment


What supporting documents are/will be available?

Doc. No.TypeCitationLinkEmailOther DetailsAttachment
20022Informed consent form  zoe.thorning@uwa.edu.au
20023Ethical approval  zoe.thorning@uwa.edu.au
20024Study protocol  zoe.thorning@uwa.edu.au



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.