Class II MalocclusionNCT07454694
Comparison Of The Effects Of Clear Aligners And Twinblock Appliances In Functional Treatment Of Class II Malocclusion
A study testing Invisalign Clear Aligners and Twinblock Functional Appliance in people with Class II Malocclusion and Mandibular Retrognathism, run by Bezmialem Vakif University at 1 site in Turkey (Türkiye).
Trial summary
This prospective clinical study aimed to compare the skeletal and dentofacial effects of Twin Block (TWB) and clear aligners with mandibular advancement, and to evaluate mandibular trabecular bone changes through fractal analysis (FA). Read more about this study
- Who is it for?
- Ages 10 to 14 years
- Conditions the study is for
- Class II Malocclusion, Mandibular Retrognathism
- What is being tested?
- Invisalign Clear Aligners and Twinblock Functional Appliance
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 34 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Aug 2023to 1 Aug 2025
- 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 14 years
- All sexes
- No healthy volunteers
- Child
Who may be able to join
- Patients with Angle Class II molar and canine relationship
- Overjet greater than 6 mm
- Patients in the growth spurt period
Who cannot join
- History of orthodontic treatment
- Missing teeth
- Patients in mixed dentition period
- Systemic diseases affecting growth or bone metabolism
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Bezmialem Vakif University
Istanbul, Fatih, 34093
About this study
This prospective clinical study aimed to compare the skeletal and dentofacial effects of Twin Block (TWB) and clear aligners with mandibular advancement, and to evaluate mandibular trabecular bone changes through fractal analysis (FA).
Read the detailed description
A total of 34 patients with dentoskeletal Class II malocclusion were included in the study: 16 patients in the Invisalign® Mandibular Advancement (MA) group and 18 patients in the TWB group .Panoramic and lateral cephalometric radiographs were obtained at baseline(T0) and after functional treatment(T1). Skeletal, dental, and soft tissue structures were evaluated on the pretreatment and posttreatment radiographs using cephalometric analysis, while trabecular bone architecture was assessed by fractal analysis.
- Conditions
- Class II Malocclusion, Mandibular Retrognathism
- Being tested
- Invisalign Clear Aligners, Twinblock Functional Appliance
- Keywords
- Class II malocclusion, Twinblock, clear aligners, mandibular advancement
- Medical subject headings
- Overbite
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Invisalign Clear AlignersDevice
Functional appliances are used for mandibular advancement in the treatment of mandibular retrognathia in orthodontics. The Twinblock is a conventional functional appliance, and nowadays mandibular advancement can also be achieved with clear aligners. In this study, these two appliances were used.
Twinblock Functional ApplianceDevice
Functional appliances are used for mandibular advancement in the treatment of mandibular retrognathia in orthodontics. The Twinblock is a conventional functional appliance, and nowadays mandibular advancement can also be achieved with clear aligners. In this study, these two appliances were used.
| Study group | Role | What they receive |
|---|---|---|
| Clear Aligner Group | Experimental | Mandibular advancement with clear aligners Receives: Device: Invisalign Clear Aligners |
| Twinblock Group | Experimental | Mandibular Advancement with Twinblock Functional Appliance Receives: Device: Twinblock Functional Appliance |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change from Baseline in Cephalometric Measurements (mm and degrees) After Functional Appliance Therapy
Cephalometric measurements will be evaluated on lateral cephalometric radiographs using a customized analysis derived from Steiner, McNamara, Tweed, Ricketts, and Arnett analyses.
A total of 47 skeletal, dental, airway, hyoid, and soft tissue parameters will be assessed. Linear measurements will be recorded in millimeters (mm) and angular measurements in degrees. Landmarks will be manually identified on digital lateral cephalometric radiographs.
Measured: Baseline and after completion of functional appliance therapy (approximately 7-13 months)
Change from Baseline in Mandibular Bone Fractal Dimension Values After Functional Appliance Therapy
Fractal dimension values will be calculated using the box-counting method on panoramic radiographs (mandibular condyle, angulus, and corpus) and lateral cephalometric radiographs (symphysis).
Fractal dimension is a unitless numerical value used to evaluate trabecular bone complexity. Higher values indicate greater trabecular complexity, whereas lower values indicate reduced trabecular structure.
Measured: Baseline and after completion of functional appliance therapy (approximately 7-13 months)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Mar 2026
- Study start1 Aug 2023
- Primary completion22 Jul 2025
- Study completion1 Aug 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Class II MalocclusionStudies of the same condition, open and under way.
- More trials run by Bezmialem Vakif UniversityThe sponsor's other registered studies.
- 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
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 34 participants (actual)
Sponsor and investigators
- Lead sponsor
- Bezmialem Vakif University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Ezgi Sunal Akturk, Assistant Professor, Study chair, Saglik Bilimleri UniversitesiGokmen Kurt, Professor, Study chair, Bezmialem Vakif UniversityAhsen Irem Toktas, Research Assistant, Principal investigator, Bezmialem Vakif University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07454694
- Sponsor's protocol ID
- 118118
- Status last verified
- Mar 2026
- First submitted
- 25 Aug 2025
- Last updated
- 6 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 6 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparison Of The Effects Of Clear Aligners And Twinblock Appliances In Functional Treatment Of Class II Malocclusion
- ClinicalTrials.gov ID
- NCT07454694
- Acronym / sponsor ID
- 118118
- Conditions
- Class II Malocclusion, Mandibular Retrognathism
- Keywords
- Class II malocclusion, Twinblock, clear aligners, mandibular advancement
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 34 participants (actual)
- Lead sponsor
- Bezmialem Vakif UniversityUniversity, hospital or other
- Study start
- 1 Aug 2023 (actual)
- Primary completion
- 22 Jul 2025 (actual)
- Study completion
- 1 Aug 2025 (actual)
- First posted
- 6 Mar 2026 (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 prospective clinical study aimed to compare the skeletal and dentofacial effects of Twin Block (TWB) and clear aligners with mandibular advancement, and to evaluate mandibular trabecular bone changes through fractal analysis (FA).
Detailed description
A total of 34 patients with dentoskeletal Class II malocclusion were included in the study: 16 patients in the Invisalign® Mandibular Advancement (MA) group and 18 patients in the TWB group .Panoramic and lateral cephalometric radiographs were obtained at baseline(T0) and after functional treatment(T1). Skeletal, dental, and soft tissue structures were evaluated on the pretreatment and posttreatment radiographs using cephalometric analysis, while trabecular bone architecture was assessed by fractal analysis.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Clear Aligner Group | Experimental | Device: Invisalign Clear AlignersMandibular advancement with clear aligners |
| Twinblock Group | Experimental | Device: Twinblock Functional ApplianceMandibular Advancement with Twinblock Functional Appliance |
Who may qualify
- Ages
- 10 to 14 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
Key inclusion criteria (3 listed)
- Patients with Angle Class II molar and canine relationship
- Overjet greater than 6 mm
- Patients in the growth spurt period
Key exclusion criteria (4 listed)
- History of orthodontic treatment
- Missing teeth
- Patients in mixed dentition period
- Systemic diseases affecting growth or bone metabolism
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 |
|---|---|---|
| Invisalign Clear AlignersFunctional appliances are used for mandibular advancement in the treatment of mandibular retrognathia in orthodontics. The Twinblock is a conventional functional appliance, and nowadays mandibular advancement can also be achieved with clear aligners. In this study, these two appliances were used. | Device | Clear Aligner Group |
| Twinblock Functional ApplianceFunctional appliances are used for mandibular advancement in the treatment of mandibular retrognathia in orthodontics. The Twinblock is a conventional functional appliance, and nowadays mandibular advancement can also be achieved with clear aligners. In this study, these two appliances were used. | Device | Twinblock Group |
Primary outcome
Change from Baseline in Cephalometric Measurements (mm and degrees) After Functional Appliance Therapy
Time frame: Baseline and after completion of functional appliance therapy (approximately 7-13 months)
Cephalometric measurements will be evaluated on lateral cephalometric radiographs using a customized analysis derived from Steiner, McNamara, Tweed, Ricketts, and Arnett analyses. A total of 47 skeletal, dental, airway, hyoid, and soft tissue parameters will be assessed. Linear measurements will be recorded in millimeters (mm) and angular measurements in degrees. Landmarks will be manually identified on digital lateral cephalometric radiographs.
Change from Baseline in Mandibular Bone Fractal Dimension Values After Functional Appliance Therapy
Time frame: Baseline and after completion of functional appliance therapy (approximately 7-13 months)
Fractal dimension values will be calculated using the box-counting method on panoramic radiographs (mandibular condyle, angulus, and corpus) and lateral cephalometric radiographs (symphysis). Fractal dimension is a unitless numerical value used to evaluate trabecular bone complexity. Higher values indicate greater trabecular complexity, whereas lower values indicate reduced trabecular structure.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Mar 2026.
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Comparing 3D-Printed and Milled Titanium Plates in Jaw Surgery (Le Fort I): Accuracy and Operative Time
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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.
Ezgi Sunal Akturk, Assistant Professor study chair
Saglik Bilimleri Universitesi
Gokmen Kurt, Professor study chair
Bezmialem Vakif University
Ahsen Irem Toktas, Research Assistant principal investigator
Bezmialem Vakif University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Invisalign Clear Aligners and Twinblock Functional Appliance in people with Class II Malocclusion and Mandibular Retrognathism, run by Bezmialem Vakif University at 1 site in Turkey (Türkiye).
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 3 inclusion and 4 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: finished, as of the sponsor's last update on 6 Mar 2026. 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 Turkey (Türkiye). 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Change from Baseline in Cephalometric Measurements (mm and degrees) After Functional Appliance Therapy (time frame: Baseline and after completion of functional appliance therapy (approximately 7-13 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?
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 6 Mar 2026.