Plain English Summary
Background and study aims
Prominent upper front teeth are associated with poor appearance, inadequate function and psychosocial problems (12.8% prevalence of bullying in adolescents). There is also double the risk of trauma to the teeth and this has been calculated at a global level to 235 million traumatic injuries to teeth.
Bite blocks are removable braces frequently used in treating prominent upper front teeth in adolescents. Whilst patients who wear removable biteblocks on a full-time basis in the presence of active growth inevitably show an excellent treatment result, those who do not wear them as required unfortunately are unsuccessful with treatment. The solution to the problem of compliance is to develop a fixed biteblock appliance that is effective and value for money. The compliance, comfort and speed of treatment with fixed bite block brace treatment remains to be tested.
The aim of our study is to investigate the speed of correction of the overjet (upper front teeth prominence) comparing the fixed and removable Twinblock appliance for correction of prominent upper front teeth, as well as the patient centred psychoscocial aspects of treatment and psychological impact of the associated soft tissue facial changes.
Who can participate?
Children aged 9 – 14 years
What does the study involve?
In this study the participant will either have the fixed or the removable Twinblock fitted to correct their bite. We will then measure how quickly teeth move and how long treatment takes. We are also interested in how jaws and muscles adapt with this brace. To investigate this we will take laser light scans of the teeth, 3D photographs of the face and ask participants to fill in short questionnaires to find out about their experience.
What are the possible benefits and risks of participating?
The outcomes of this study are clinically relevant with major dental health and financial benefits for the population and by investigating if a fixed version of an existing removable appliance can circumvent the issues with compliance and also speed up treatment, hence indirectly assessing cost effectiveness. The study could potentially maximise correction of the malocclusion during growth and negate the challenges of dental trauma and malocclusion associated psychsocial problems in adolescents.
The material used to make this brace has been shown to be safe and is standard laboratory clinical material. Sometimes during the course of brace treatment, participants can be faced with problems related to their treatment. This may require prompt treatment, resulting in unscheduled visits. Also, as the fixed twinblock is a new device, it may not work and if that is the case, the Orthodontist will remove the device and the participant will revert back to standard treatment (removable twinblock).
Where is the study run from?
NHS Tayside (UK)
When is the study starting and how long is it expected to run for?
September 2017 to June 2024
Who is funding the study?
British Orthodontic Society Foundation
Who is the main contact?
Gautham Sivamurthy, g.sivamurthy@dundee.ac.uk
Trial website
Contact information
Type
Public
Primary contact
Mr Gautham Sivamurthy
ORCID ID
http://orcid.org/0000-0003-2481-8862
Contact details
School of Dentistry
University of Dundee
Park Place
Nethergate
Dundee
DD1 4HR
United Kingdom
+44 (0)1382 381607
g.sivamurthy@dundee.ac.uk
Type
Scientific
Additional contact
Mr Gautham Sivamurthy
ORCID ID
http://orcid.org/0000-0003-2481-8862
Contact details
School of Dentistry
University of Dundee
Park Place
Nethergate
Dundee
DD1 4HR
United Kingdom
+44 (0)1382 381607
g.sivamurthy@dundee.ac.uk
Additional identifiers
EudraCT number
Nil known
ClinicalTrials.gov number
Nil known
Protocol/serial number
IRAS 276650
Study information
Scientific title
Fixed versus conventional removable Twinblock for overjet reduction in children – A randomised clinical trial to investigate the burden of care
Acronym
FTB
Study hypothesis
There is no difference between the fixed and removable twinblocks in speed of overjet reduction and skeletal, dental and soft tissue contributions in correction.
Ethics approval
Approval to be submitted to East of Scotland Research Ethics Service in January 2021
Study design
Multicentre randomized clinical trial with two-arm parallel design
Primary study design
Interventional
Secondary study design
Randomised parallel trial
Trial setting
Other
Trial type
Treatment
Patient information sheet
Not available in web format, please use the contact details to request a patient information sheet.
Condition
Functional treatment of Class II division 1 malocclusions
Intervention
The study will have 2 parallel arms. One group will be treated with the removable twinblock appliance and the other group will be treated with fixed twinblock appliance. Following completion of the Twinblock treatment, all participants will continue treatment with fixed orthodontic appliance (train-track braces), which is standard treatment protocol following completion of twinblock treatment. Both groups will be followed up until end of treatment, which can vary for each patient depending on the severity of their initial dental condition. Usually, such clinical treatment varies between 18 - 24 months.
Randomisation will be stratified by gender, overjet measurement and site, using an on-line randomisation system which provides GCP compliant web-based randomisation to produce balanced randomisation allocation based on a minimisation with stratification algorithm.
Intervention type
Device
Phase
Not Applicable
Drug names
Fixed Twinblock
Removable Twinblock
Primary outcome measure
Overjet correction measured by clinical measurement in millimetres at baseline, 3 months, 6 months, 9 months, end of twinblock treatment and end of fixed orthodontic treatment
Secondary outcome measures
1. Skeletal contributions to overjet correction by radiographic measurement (lateral cephalogram) at baseline, end of twinblock treatment and towards end of fixed orthodontic treatment
2. Dental contributions to overjet correction by 3D model measurements at baseline, end of twinblock treatment and end of fixed orthodontic treatment
3. Soft tissue contributions to overjet correction by 3D stereophotogrammetric measurements at baseline, end of twinblock treatment and end of fixed orthodontic treatment
4. Patients’ perception and experience by using three questionnaires to assess the perception of fixed orthodontic therapy before, during and after treatment
Overall trial start date
24/09/2017
Overall trial end date
29/06/2024
Reason abandoned (if study stopped)
Eligibility
Participant inclusion criteria
1. Class II division 1 malocclusion
2. No history of active orthodontic treatment
3. Overjet > 6mm (IOTN 4a/5a)
4. Age 9 - 14 years
5. Child & parent/carer who are able to assent and consent, respectively
Participant type
Patient
Age group
Child
Gender
Both
Target number of participants
88
Participant exclusion criteria
1. Overjet <6mm
2. Mobile/loose deciduous teeth
3. Profound hypodontia affecting the incisor region (>1 missing tooth per quadrant)
4. Subjects taking growth hormone or endocrine disorders
5. Suspected or identifiable syndromes
6. Subjects with cleft lip and palate
7. Anterior open bite
Recruitment start date
01/02/2021
Recruitment end date
30/06/2022
Locations
Countries of recruitment
United Kingdom
Trial participating centre
Ninewells Hospital and Medical School
NHS Tayside
James Arrott Drive
Dundee
DD1 9SY
United Kingdom
Sponsor information
Organisation
University of Dundee
Sponsor details
TASC R&D office
Ninewells Hospital and Medical School
Dundee
DD1 9SY
United Kingdom
+44 (0)1382 383877
TASCgovernance@dundee.ac.uk
Sponsor type
University/education
Website
Funders
Funder type
Charity
Funder name
British Orthodontic Society Foundation
Alternative name(s)
British Orthodontic Society, The BOSF, BOSF
Funding Body Type
private sector organisation
Funding Body Subtype
Trusts, charities, foundations (both public and private)
Location
United Kingdom
Results and Publications
Publication and dissemination plan
Peer reviewed journal publication and presentation at scientific meetings will be prepared to disseminate the data analysed at the end of Twinblock appliance treatment, in addition to using the final clinical trial report for publication in peer reviewed open access journals and presentation at scientific meetings.
IPD sharing statement:
All data generated or analysed during this study will be included in the subsequent results publication.
Intention to publish date
29/06/2025
Participant level data
Other
Basic results (scientific)
Publication list