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Study to Compare Two Functional Appliances for Class II Malocclusions

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT03773783
Recruitment Status : Recruiting
First Posted : December 12, 2018
Last Update Posted : December 12, 2018
Information provided by (Responsible Party):
University of Birmingham

Brief Summary:

A randomised controlled clinical trial to compare the effectiveness of two functional appliances in the correction of a Class II malocclusion. (Class II malocclusions are where upper front teeth bite significantly further forward in relation to lower front teeth).

Null hypothesis:

There is no significant difference between the Button & bead and Twin-block appliances with regard to time taken to reduce the overjet

Condition or disease Intervention/treatment Phase
Malocclusion, Angle Class II Device: Button and Bead appliance Device: Twin Block appliance Not Applicable

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 64 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Effectiveness of Treatment for Class II Malocclusions With the Button & Bead or Twin-block Functional Appliance: A Single Centre Randomised Clinical Trial
Actual Study Start Date : July 10, 2017
Estimated Primary Completion Date : July 2019
Estimated Study Completion Date : July 2020

Arm Intervention/treatment
Active Comparator: Twin Block
Twin Block appliance
Device: Twin Block appliance
Twin Block appliance

Experimental: Button and Bead
Button and Bead appliance
Device: Button and Bead appliance
Button and Bead appliance

Primary Outcome Measures :
  1. Change in overjet reduction [ Time Frame: Overjet measurement recorded at the start of treatment and at completion of functional appliance therapy 1 year later. ]
    How quickly the horizontal discrepancy between upper and lower incisor edges is reduced

Secondary Outcome Measures :
  1. Change in Peer Assessment Rating (PAR) [ Time Frame: PAR score will be Assessed from the start of treatment models and the end of fixed appliance study models ( 2 years later) ]
    PAR score change in terms of percentage and actual score

  2. Drop out [ Time Frame: No. of patients at the start of functional appliance therapy that do not wish to continue within the trial or do not finish functional appliance therapy within 18 months ]
    Percentage of patients dropping out of each arm of the trial

  3. Skeletal changes [ Time Frame: Cephalometric x-rays at start of treatment and at the end of treatment 1 year later ]
    Compare skeletal changes of landmarks in degrees and millimetres using cephalometric x-rays at various time points

  4. 3D soft tissue measures [ Time Frame: 3D photographs at start of treatment and at the end of treatment (approx 1 year later) ]
    Measure changes in soft tissues using 3D photographs

  5. Patient satisfaction [ Time Frame: Patient satisfaction survey at study completion ( 1 year after treament started) ]
    Use of tailored patient satisfaction questionnaire to assess patient satisfaction with both appliances

  6. Child related Oral health quality of life (OHRQoL) questionnaire [ Time Frame: The patient ticked the applicable box for the 16 set questions from the standardised qualitative oral health questionairre. This was undertaken at the start of the trial and again at the end of functional appliance therapy ( approximately 1 year later) ]
    Changes in OHRQoL

  7. Adverse events [ Time Frame: Adverse events over the course of functional appliance treatment ( recorded at every visit and reviewed at 1 year) ]
    Adverse events: decalcification, dental caries, soft tissue trauma, ingestion or aspiration of appliance

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   10 Years to 14 Years   (Child)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • * Overjet ≥ 7mm

    • The normal overjet for a Caucasian population is in the range of 2-4mm. A functional appliance is used to allow for overjet reduction without extractions and/or to reduce the anchorage demands of the subsequent treatment with the Straight Wire Appliance (SWA). Clinically the overjet would need to be significantly increased for the treating clinician to consider the use of a functional appliance. Other similar studies have used an overjet of >6mm or ≥ 7mm. This study has elected for an initial overjet of ≥ 7mm to improve the studies external validity by making it more applicable to day-to-day clinical practice.
    • The initial overjet will be used to select patients. The majority of recent high level trials and systematic reviews that have provided a significant amount of the evidence base in the treatment of Class II malocclusions have defined subjects according to their initial overjet.

      * Age 10 to 14 years

    • This has been selected to match other studies relating to functional appliance treatment and reflect the most common clinical practice. The literature on functional appliance treatment has provided evidence that on average the enhancement of growth is small. Some studies on the timing of functional appliance treatment have suggested that pubertal growth is not a significant factor in the success of functional appliance treatment but it is well know and accepted that functional appliance treatment is assisted during periods of more rapid growth. Numerous studies have also found better co-operation and completion of treatment in younger patients (Banks 2004, KOB 2003a & 2003b)

      * Satisfactory Dental health

    • Patients must be dentally healthy and have a suitable level of oral health that would support orthodontic treatment, as per the British Orthodontic Society guidelines. They must have good oral hygiene with minimal gingivitis or periodontal disease, no dental caries or periapical pathology and no history of dento-alveolar trauma. This is judged by the investigator.

      • Willing to participate in study and provide informed consent

Exclusion Criteria:

  • * No previous orthodontic treatment or premolar extractions

    • This is aimed at reducing any confounding factors within the study as these may affect the success of treatment.

      * No craniofacial syndrome (including Cleft patients)

    • This is aimed at reducing any confounding factors within the study as these conditions may affect the success of treatment. The treatment of this subgroup requires a multi-disciplinary team and is more complex. Their treatment pathway may vary from normal clinical practice.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT03773783

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Contact: Sheena Kotecha, FDS MPhil (+44)07940544164
Contact: Thomas Dietrich

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United Kingdom
Birmingham dental hospital Recruiting
Birmingham, United Kingdom
Contact: Sheena Kotecha         
Sponsors and Collaborators
University of Birmingham
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Principal Investigator: Thomas Dietrich University of Birmingham
Isaacson KG, Reed RT, Stephens CD. Functional orthodontic appliances. Oxford: Blackwell Scientific Publications; 1990.

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Responsible Party: University of Birmingham Identifier: NCT03773783    
Other Study ID Numbers: RG_16-204
First Posted: December 12, 2018    Key Record Dates
Last Update Posted: December 12, 2018
Last Verified: December 2018
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by University of Birmingham:
Myofunctional appliance
Additional relevant MeSH terms:
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Malocclusion, Angle Class II
Tooth Diseases
Stomatognathic Diseases