Class II MalocclusionNCT06116500
Effectiveness of Modified Functional Appliance With Expander
A study testing Modified twin block appliance with expander and Conventional twin block appliance with expander in people with Class II Malocclusion, run by University of Baghdad at 1 site in Iraq.
Trial summary
This clinical trial compares the effectiveness of a myofunctional appliance that uses a clear and modified twin block appliance with an expander made from 2mm biocompatible polyethylene terephthalate modified with Glycol thermoplastic material with a conventional twin block appliance with an expander. Read more about this study
- Who is it for?
- Ages 10 to 13 yearsHealthy volunteers can take part
- Conditions the study is for
- Class II Malocclusion
- What is being tested?
- Modified twin block appliance with expander and Conventional twin block appliance with expander
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 48 participants
- Where
- 1 siteIraq
- Study dates
- 9 May 2023to 9 Jun 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 10 to 13 years
- All sexes
- Healthy volunteers accepted
- Child
Who may be able to join
- Patients' age at the start of treatment: at growth spurt [in stage 2 (Acceleration) - 3 (Transition) of cervical vertebral maturation].
- Skeletal and dental relationships: skeletal class II with normal maxilla and retrognathic mandible. Moderate to severe dental class II division 1 malocclusion with overjet ≥ 8 mm.
- Horizontal/normal growth pattern.
- Convex profile with decreased or normal lower facial height (clinically and radiographically).
- Well-aligned/mild crowding of maxillary and mandibular dental arches.
- Good oral health free from caries and periodontal problems at the start of treatment.
Who cannot join
- Patients with vertical growth pattern or backward mandibular rotation tendency.
- Patients with open bite
- Patients with obvious facial asymmetry.
- Patients with orofacial clefting.
- Patients with bad oral habits.
- Active periodontal disease.
Trial locations and contacts
1 site in 1 country.
Iraq1 site
University of Baghdad, Collage of Dentistry
Baghdad, Al-Rusafa, Bab Al-moadham, 10011
About this study
Official title: A Modified Removable Orthodontic Appliance for Maxillary Expansion and Treatment of Class II Malocclusion: A Randomized Clinical Trial
This clinical trial compares the effectiveness of a myofunctional appliance that uses a clear and modified twin block appliance with an expander made from 2mm biocompatible polyethylene terephthalate modified with Glycol thermoplastic material with a conventional twin block appliance with an expander. The trial will be conducted on adolescent patients with class II division 1.
Read the detailed description
In a multicenter single-blinded randomized clinical trial study with two-arm parallel groups, a computer random generator will develop a simple randomization with an equal allocation ratio (1:1) and without stratification. The investigator will initially assess the patients for eligibility to be included in the study. Those who will meet the inclusion criteria, the parents will be informed about the nature of the study verbally to get the initial approval for participation. Then they will be provided with the patient information sheet and consent form.
According to the sample size calculation, 48 patients will be recruited (24 for each group), and impressions and lateral cephalometric radiography will be taken before treatment and bite registration then the appliance inserted, and the patient will be checked every two weeks for expansion and every four weeks for overjet recording. The treatment will be continuing for 6 months to take final records. The collected data will include cephalometric evaluation, clinical evaluation, scanned upper model evaluation, and finally patient satisfaction from the appliance.
Data will be analyzed using Statistical Package for Social Sciences for Windows, version 26.0 including descriptive statistic (number, mean, and standard deviation), Reliability statistic (interclass correlation coefficient), and Inferential statistics (independent samples t-test).
- Conditions
- Class II Malocclusion
- Being tested
- Modified twin block appliance with expander, Conventional twin block appliance with expander
- Keywords
- twin block, thermoplastic material, clear expander,, adolescent, clinical trial
- Medical subject headings
- Overbite
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Modified twin block appliance with expanderDevice
These appliances are myofunctional appliance used for treating class II division growing adolescents.
Conventional twin block appliance with expanderDevice
These appliances are myofunctional appliances used for treating class II division growing adolescents.
| Study group | Role | What they receive |
|---|---|---|
| Modified twin block appliance with expander group | Experimental | For 24 patients with class II division malocclusion in their growing stages, using a 2 mm biocompatible and rigid PET-G thermoforming material to create two clear appliances for each patient. The material will be adapted separately on maxillary and mandibular casts using a pressure molding vacuum machine. Then, the appliances will be trimmed and finished and transferred to the articulator with the aid of a pre-existing working wax bite. The ramps will be made of cold cure acrylic on the thermoplastic sheets. Next, the expansion screw will be placed in the midline of the maxillary cast, and the maxillary appliance will be split midpalatally to fit the patient's individual needs. Receives: Device: Modified twin block appliance with expander; Device: Conventional twin block appliance with expander |
| Conventional twin block appliance with expander group | Experimental | For 24 patients in a growing stage with class II division 1 malocclusion, these appliances will consist of removable maxillary and mandibular appliances. These will have a labial bow, Adam's clasps on the first molars, ball end clasps with incisal capping and expansion screw. The inclined bite blocks (ramps) will act as a guide to move the mandible forward. Receives: Device: Modified twin block appliance with expander; Device: Conventional twin block appliance with expander |
What is being measured
The primary outcome is the main question the study is designed to answer.
Anteroposterior skeletal changes
Skeletal changes using cephalometric radiographs including different angular measurements to estimate the changes between dental bases before and after treatment.
Measured: T0 (before treatment), T1 (at end of the study) around 6-9 months
Vertical skeletal changes
Skeletal changes using cephalometric radiographs including different linear measurements to estimate the changes between dental bases before and after treatment.
Measured: T0 (before treatment), T1 (at end of the study) around 6-9 months.
Secondary outcomes (4)
Soft tissue change
Measurements using cephalometric radiographs including different angular measurements to estimate the soft tissue changes before and after treatment.
Measured: T0 (before treatment), T1 (at end of the study) around 6-9 months
Dentoalveolar changes
Measurements using cephalometric radiographs include different angular measurements to estimate the changes between teeth before and after treatment.
Measured: T0 (before treatment), T1 (at end of the study) around 6-9 months
Study model evaluation
The scanned upper study model will be used to calculate the amount of expansion before and at the end of the study.
Measured: T0 (before treatment), T1 (at end of the study) around 6-9 months.
Patient satisfaction from the appliance
Patient satisfaction with both appliances will be estimated using a questionnaire at the middle of treatment.
Measured: around 4 months.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Nov 2023
- Study start9 May 2023
- Primary completion9 May 2024 (estimated)
- Study completion9 Jun 2024 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Class II MalocclusionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- The patients will be treated with twin block appliance
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 48 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Baghdad
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Anosh Aram Haik, University of Baghdad
- Investigators
- Yassir A Yassir, Ph.D. (UK), Study chair, Baghdad University, Collage of Dentistry
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06116500
- Sponsor's protocol ID
- 664422
- Status last verified
- Oct 2023
- First submitted
- 21 Oct 2023
- Last updated
- 7 Nov 2023
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Haik AA, Yassir YA. A modified clear twin block appliance for treatment of class II malocclusion: a randomized clinical trial. Eur J Orthod. 2025 Dec 16;48(1):cjaf103. doi: 10.1093/ejo/cjaf103.
PubMed 41692591Haik AA, Yassir YA. Efficiency of Polyethylene Terephthalate Glycol Thermoplastic Material to Functional and Expansion Forces in Orthodontic Applications: An Experimental Study. ScientificWorldJournal. 2025 Jan 10;2025:7232779. doi: 10.1155/tswj/7232779. eCollection 2025.
PubMed 39840371
Study at a glance
From the registry record, last updated by the sponsor on 7 Nov 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Modified Removable Orthodontic Appliance for Maxillary Expansion and Treatment of Class II Malocclusion: A Randomized Clinical Trial
- ClinicalTrials.gov ID
- NCT06116500
- Acronym / sponsor ID
- 664422
- Conditions
- Class II Malocclusion
- Keywords
- twin block, thermoplastic material, clear expander,, adolescent, clinical trial
- Study type
- Interventional
- Recruitment status
- Unknown status
- Enrolment
- 48 participants (estimated)
- Lead sponsor
- University of BaghdadUniversity, hospital or other
- Study start
- 9 May 2023 (actual)
- Primary completion
- 9 May 2024 (estimated)
- Study completion
- 9 Jun 2024 (estimated)
- First posted
- 3 Nov 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This clinical trial compares the effectiveness of a myofunctional appliance that uses a clear and modified twin block appliance with an expander made from 2mm biocompatible polyethylene terephthalate modified with Glycol thermoplastic material with a conventional twin block appliance with an expander. The trial will be conducted on adolescent patients with class II division 1.
Detailed description
In a multicenter single-blinded randomized clinical trial study with two-arm parallel groups, a computer random generator will develop a simple randomization with an equal allocation ratio (1:1) and without stratification. The investigator will initially assess the patients for eligibility to be included in the study. Those who will meet the inclusion criteria, the parents will be informed about the nature of the study verbally to get the initial approval for participation. Then they will be provided with the patient information sheet and consent form.
According to the sample size calculation, 48 patients will be recruited (24 for each group), and impressions and lateral cephalometric radiography will be taken before treatment and bite registration then the appliance inserted, and the patient will be checked every two weeks for expansion and every four weeks for overjet recording. The treatment will be continuing for 6 months to take final records. The collected data will include cephalometric evaluation, clinical evaluation, scanned upper model evaluation, and finally patient satisfaction from the appliance.
Data will be analyzed using Statistical Package for Social Sciences for Windows, version 26.0 including descriptive statistic (number, mean, and standard deviation), Reliability statistic (interclass correlation coefficient), and Inferential statistics (independent samples t-test).
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
- Model description
- The patients will be treated with twin block appliance
| Arm | Type | Receives |
|---|---|---|
| Modified twin block appliance with expander group | Experimental | Device: Modified twin block appliance with expander, Device: Conventional twin block appliance with expanderFor 24 patients with class II division malocclusion in their growing stages, using a 2 mm biocompatible and rigid PET-G thermoforming material to create two clear appliances for each patient. The material will be adapted separately on maxillary and mandibular casts using a pressure molding vacuum machine. Then, the appliances will be trimmed and finished and transferred to the articulator with the aid of a pre-existing working wax bite. The ramps will be made of cold cure acrylic on the thermoplastic sheets. Next, the expansion screw will be placed in the midline of the maxillary cast, and the maxillary appliance will be split midpalatally to fit the patient's individual needs. |
| Conventional twin block appliance with expander group | Experimental | Device: Modified twin block appliance with expander, Device: Conventional twin block appliance with expanderFor 24 patients in a growing stage with class II division 1 malocclusion, these appliances will consist of removable maxillary and mandibular appliances. These will have a labial bow, Adam's clasps on the first molars, ball end clasps with incisal capping and expansion screw. The inclined bite blocks (ramps) will act as a guide to move the mandible forward. |
Who may qualify
- Ages
- 10 to 13 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child
Key inclusion criteria (6 listed)
- Patients' age at the start of treatment: at growth spurt [in stage 2 (Acceleration) - 3 (Transition) of cervical vertebral maturation].
- Skeletal and dental relationships: skeletal class II with normal maxilla and retrognathic mandible. Moderate to severe dental class II division 1 malocclusion with overjet ≥ 8 mm.
- Horizontal/normal growth pattern.
- Convex profile with decreased or normal lower facial height (clinically and radiographically).
- Well-aligned/mild crowding of maxillary and mandibular dental arches.
Key exclusion criteria (6 listed)
- Patients with vertical growth pattern or backward mandibular rotation tendency.
- Patients with open bite
- Patients with obvious facial asymmetry.
- Patients with orofacial clefting.
- Patients with bad oral habits.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Modified twin block appliance with expanderThese appliances are myofunctional appliance used for treating class II division growing adolescents. | Device | Conventional twin block appliance with expander group, Modified twin block appliance with expander group |
| Conventional twin block appliance with expanderThese appliances are myofunctional appliances used for treating class II division growing adolescents. | Device | Conventional twin block appliance with expander group, Modified twin block appliance with expander group |
Primary outcome
Anteroposterior skeletal changes
Time frame: T0 (before treatment), T1 (at end of the study) around 6-9 months
Skeletal changes using cephalometric radiographs including different angular measurements to estimate the changes between dental bases before and after treatment.
Vertical skeletal changes
Time frame: T0 (before treatment), T1 (at end of the study) around 6-9 months.
Skeletal changes using cephalometric radiographs including different linear measurements to estimate the changes between dental bases before and after treatment.
4 secondary outcomes
Soft tissue change
Time frame: T0 (before treatment), T1 (at end of the study) around 6-9 months
Dentoalveolar changes
Time frame: T0 (before treatment), T1 (at end of the study) around 6-9 months
Study model evaluation
Time frame: T0 (before treatment), T1 (at end of the study) around 6-9 months.
Patient satisfaction from the appliance
Time frame: around 4 months.
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 Nov 2023.
- Derived from this study: PubMed 41692591Haik AA, Yassir YA. A modified clear twin block appliance for treatment of class II malocclusion: a randomized clinical trial. Eur J Orthod. 2025 Dec 16;48(1):cjaf103. doi: 10.1093/ejo/cjaf103.
- Derived from this study: PubMed 39840371Haik AA, Yassir YA. Efficiency of Polyethylene Terephthalate Glycol Thermoplastic Material to Functional and Expansion Forces in Orthodontic Applications: An Experimental Study. ScientificWorldJournal. 2025 Jan 10;2025:7232779. doi: 10.1155/tswj/7232779. eCollection 2025.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Yassir A Yassir, Ph.D. (UK) study chair
Baghdad University, Collage of Dentistry
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Modified twin block appliance with expander and Conventional twin block appliance with expander in people with Class II Malocclusion, run by University of Baghdad at 1 site in Iraq.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: status not confirmed, as of the sponsor's last update on 7 Nov 2023. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Iraq. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Anteroposterior skeletal changes (time frame: T0 (before treatment), T1 (at end of the study) around 6-9 months). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06116500, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 7 Nov 2023.