Angle Class 2 MalocclusionNCT07714603
Clear Aligners vs Fixed Appliances for Molar Distalization Using Infrazygomatic Crest Screws
A study testing Pitts21® fixed appliance, Invisalign® Clear Aligners and ClearCorrect Clear Aligners in people with Angle Class 2 Malocclusion, run by TC Erciyes University at 1 site in Turkey (Türkiye).
Trial summary
This study compares three different methods of moving upper back teeth backward (distalization) to create space for crowded or protruding teeth, all supported by small temporary screws placed in the cheekbone area (infrazygomatic crest screws). Read more about this study
- Who is it for?
- Ages 13 to 18 years
- Conditions the study is for
- Angle Class 2 Malocclusion
- What is being tested?
- Pitts21® fixed appliance, Invisalign® Clear Aligners and ClearCorrect Clear Aligners
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 37 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 6 Jun 2024to 18 Feb 2026
- 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 13 to 18 years
- All sexes
- No healthy volunteers
- Child, Adult
Who may be able to join
- Skeletal Class I (ANB angle 0-4°), dental Class II malocclusion treatable with molar distalization
- Need for unilateral or bilateral distalization of the first molars in the range of 2-4.5 mm
- Chronological age between 13 and 18 years, regardless of skeletal age
- Normal or hypodivergent growth pattern (SN-GoGn < 39°)
- Mild to moderate maxillary crowding (less than 6 mm) and minimal or no mandibular crowding (less than 3 mm)
- No previously extracted maxillary teeth, excluding third molars
Show all 9Show fewer
- Erupted permanent second molars
- Good oral hygiene
- Healthy periodontal tissues
Who cannot join
- Need for orthodontic tooth extraction or functional appliance therapy
- Presence of systemic disease
- Congenital or acquired craniofacial deformity involving the condyle or mandible
- Poor patient cooperation
- History of allergy to any metal
- Pre-existing root resorption prior to treatment
- Previous orthodontic treatment
- Abnormal position, depth of impaction, or close proximity to adjacent anatomical structures (sinus, neurovascular structures) of the maxillary third molar that would make its surgical extraction risky
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Erciyes University, Faculty of Dentistry, Department of Orthodontics
Kayseri, 38000
About this study
Official title: Evaluation of the Treatment Effects of Different Clear Aligner and Fixed Appliance Systems in Maxillary Posterior Distalization Using Infrazygomatic Crest Screws: An In-Vivo Randomized Clinical Study
This study compares three different methods of moving upper back teeth backward (distalization) to create space for crowded or protruding teeth, all supported by small temporary screws placed in the cheekbone area (infrazygomatic crest screws). Participants were randomly assigned to one of three treatment types: traditional fixed braces (Pitts21 system), Invisalign clear aligners, or ClearCorrect clear aligners. The study measures how effectively each method moves the back teeth, how long treatment takes, and how comfortable and practical each method is for patients. The goal is to help orthodontists and patients choose the most effective and efficient treatment option for this type of tooth movement.
Read the detailed description
This prospective randomized clinical trial included 35 subjects aged 13-18 years with skeletal Class I, dental Class II malocclusion, randomly allocated to Pitts21 fixed appliance (n=12), Invisalign (n=12), or ClearCorrect (n=11) treatment groups. Unilateral or bilateral infrazygomatic crest (IZC) miniscrews were placed in all subjects, and distalization forces were applied via intraoral elastics. Lateral cephalometric radiographs and digital dental models (acquired with a 3Shape TRIOS 3 intraoral scanner) were obtained at the start (T0) and end (T1) of distalization to assess skeletal, dental, and soft tissue changes. Patient-reported outcomes were also collected, including pain (Visual Analog Scale) and anxiety (Çapa Anxiety Scale). Data were analyzed using IBM SPSS v23 and R 4.4.1; normality was assessed with the Shapiro-Wilk test. Between-group comparisons used one-way ANOVA or the Kruskal-Wallis H test, and within-group comparisons over time used paired t-test, Wilcoxon, repeated measures ANOVA, or Friedman test. Group×time and group×tooth interactions were evaluated using Generalized Estimating Equations and Robust Mixed ANOVA, with Bonferroni, Games-Howell, or Holm corrections applied for multiple comparisons.
- Conditions
- Angle Class 2 Malocclusion
- Being tested
- Pitts21® fixed appliance, Invisalign® Clear Aligners, ClearCorrect Clear Aligners
- Keywords
- Clear aligners, Fixed orthodontic appliance, Distalization, Infrazygomatic crest miniscrew, Skeletal anchorage
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Pitts21® fixed applianceDevice
Also called Fixed orthodontic bracket system
Fixed orthodontic brackets (Pitts21 system) used for maxillary posterior distalization, anchored with infrazygomatic crest miniscrews and intraoral elastics.
Invisalign® Clear AlignersDevice
Also called Invisalign Clear Aligner System
Clear aligner system (Invisalign) used for maxillary posterior distalization, anchored with infrazygomatic crest miniscrews and intraoral elastics.
ClearCorrect Clear AlignersDevice
Also called ClearCorrect Clear Aligner System
Clear aligner system (ClearCorrect) used for maxillary posterior distalization, anchored with infrazygomatic crest miniscrews and intraoral elastics.
| Study group | Role | What they receive |
|---|---|---|
| Group A ( Pitts21® Fixed Appliance ) | Active comparator | Participants received maxillary posterior distalization using the Pitts21® fixed orthodontic appliance system, anchored with infrazygomatic crest (IZC) miniscrews and intraoral elastics for distalization force. Receives: Device: Pitts21® fixed appliance |
| Group B ( Invisalign® clear aligners) | Experimental | Participants received maxillary posterior distalization using Invisalign® clear aligners, anchored with infrazygomatic crest (IZC) miniscrews and intraoral elastics for distalization force. Receives: Device: Invisalign® Clear Aligners |
| Group C ( ClearCorrect® clear aligners) | Experimental | Participants received maxillary posterior distalization using ClearCorrect® clear aligners, anchored with infrazygomatic crest (IZC) miniscrews and intraoral elastics for distalization force. Receives: Device: ClearCorrect Clear Aligners |
What is being measured
The primary outcome is the main question the study is designed to answer.
Amount of Maxillary Posterior Tooth Distalization
The amount of distalization of the maxillary premolars and molars (U4, U5, U6, U7) was measured in millimeters using three-dimensional digital dental model analysis, comparing pre-treatment (T0) and post-distalization (T1) records.
Measured: From the date of infrazygomatic crest miniscrew placement and initiation of distalization force (T0) until the end of the active distalization phase (T1), assessed up to 13 months
Secondary outcomes (1)
Total Distalization Duration
The total duration of the distalization phase, calculated as the time interval between the start of force application (T0) and the completion of active distalization (T1).
Measured: From the date of miniscrew placement and start of distalization force (T0) until the date of completion of active distalization (T1), assessed up to 13 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Jul 2026
- Study start6 Jun 2024
- Primary completion12 Jan 2026
- Study completion18 Feb 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Angle Class 2 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
- Participants were randomly assigned to one of three parallel groups: Pitts21® fixed orthodontic system, Invisalign® clear aligner system and ClearCorrect® clear aligner system.
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 37 participants (actual)
Sponsor and investigators
- Lead sponsor
- TC Erciyes University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Ahmet Yağcı, TC Erciyes University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07714603
- Sponsor's protocol ID
- TDH-2025-15402
- Status last verified
- Jul 2026
- First submitted
- 15 Jul 2026
- Last updated
- 20 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 20 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of the Treatment Effects of Different Clear Aligner and Fixed Appliance Systems in Maxillary Posterior Distalization Using Infrazygomatic Crest Screws: An In-Vivo Randomized Clinical Study
- ClinicalTrials.gov ID
- NCT07714603
- Acronym / sponsor ID
- TDH-2025-15402
- Conditions
- Angle Class 2 Malocclusion
- Keywords
- Clear aligners, Fixed orthodontic appliance, Distalization, Infrazygomatic crest miniscrew, Skeletal anchorage
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 37 participants (actual)
- Lead sponsor
- TC Erciyes UniversityUniversity, hospital or other
- Study start
- 6 Jun 2024 (actual)
- Primary completion
- 12 Jan 2026 (actual)
- Study completion
- 18 Feb 2026 (actual)
- First posted
- 20 Jul 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 study compares three different methods of moving upper back teeth backward (distalization) to create space for crowded or protruding teeth, all supported by small temporary screws placed in the cheekbone area (infrazygomatic crest screws). Participants were randomly assigned to one of three treatment types: traditional fixed braces (Pitts21 system), Invisalign clear aligners, or ClearCorrect clear aligners. The study measures how effectively each method moves the back teeth, how long treatment takes, and how comfortable and practical each method is for patients. The goal is to help orthodontists and patients choose the most effective and efficient treatment option for this type of tooth movement.
Detailed description
This prospective randomized clinical trial included 35 subjects aged 13-18 years with skeletal Class I, dental Class II malocclusion, randomly allocated to Pitts21 fixed appliance (n=12), Invisalign (n=12), or ClearCorrect (n=11) treatment groups. Unilateral or bilateral infrazygomatic crest (IZC) miniscrews were placed in all subjects, and distalization forces were applied via intraoral elastics. Lateral cephalometric radiographs and digital dental models (acquired with a 3Shape TRIOS 3 intraoral scanner) were obtained at the start (T0) and end (T1) of distalization to assess skeletal, dental, and soft tissue changes. Patient-reported outcomes were also collected, including pain (Visual Analog Scale) and anxiety (Çapa Anxiety Scale). Data were analyzed using IBM SPSS v23 and R 4.4.1; normality was assessed with the Shapiro-Wilk test. Between-group comparisons used one-way ANOVA or the Kruskal-Wallis H test, and within-group comparisons over time used paired t-test, Wilcoxon, repeated measures ANOVA, or Friedman test. Group×time and group×tooth interactions were evaluated using Generalized Estimating Equations and Robust Mixed ANOVA, with Bonferroni, Games-Howell, or Holm corrections applied for multiple comparisons.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 3
- Model description
- Participants were randomly assigned to one of three parallel groups: Pitts21® fixed orthodontic system, Invisalign® clear aligner system and ClearCorrect® clear aligner system.
| Arm | Type | Receives |
|---|---|---|
| Group A ( Pitts21® Fixed Appliance ) | Active comparator | Device: Pitts21® fixed applianceParticipants received maxillary posterior distalization using the Pitts21® fixed orthodontic appliance system, anchored with infrazygomatic crest (IZC) miniscrews and intraoral elastics for distalization force. |
| Group B ( Invisalign® clear aligners) | Experimental | Device: Invisalign® Clear AlignersParticipants received maxillary posterior distalization using Invisalign® clear aligners, anchored with infrazygomatic crest (IZC) miniscrews and intraoral elastics for distalization force. |
| Group C ( ClearCorrect® clear aligners) | Experimental | Device: ClearCorrect Clear AlignersParticipants received maxillary posterior distalization using ClearCorrect® clear aligners, anchored with infrazygomatic crest (IZC) miniscrews and intraoral elastics for distalization force. |
Who may qualify
- Ages
- 13 to 18 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (9 listed)
- Skeletal Class I (ANB angle 0-4°), dental Class II malocclusion treatable with molar distalization
- Need for unilateral or bilateral distalization of the first molars in the range of 2-4.5 mm
- Chronological age between 13 and 18 years, regardless of skeletal age
- Normal or hypodivergent growth pattern (SN-GoGn < 39°)
- Mild to moderate maxillary crowding (less than 6 mm) and minimal or no mandibular crowding (less than 3 mm)
Key exclusion criteria (8 listed)
- Need for orthodontic tooth extraction or functional appliance therapy
- Presence of systemic disease
- Congenital or acquired craniofacial deformity involving the condyle or mandible
- Poor patient cooperation
- History of allergy to any metal
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 |
|---|---|---|
| Pitts21® fixed applianceAlso: Fixed orthodontic bracket systemFixed orthodontic brackets (Pitts21 system) used for maxillary posterior distalization, anchored with infrazygomatic crest miniscrews and intraoral elastics. | Device | Group A ( Pitts21® Fixed Appliance ) |
| Invisalign® Clear AlignersAlso: Invisalign Clear Aligner SystemClear aligner system (Invisalign) used for maxillary posterior distalization, anchored with infrazygomatic crest miniscrews and intraoral elastics. | Device | Group B ( Invisalign® clear aligners) |
| ClearCorrect Clear AlignersAlso: ClearCorrect Clear Aligner SystemClear aligner system (ClearCorrect) used for maxillary posterior distalization, anchored with infrazygomatic crest miniscrews and intraoral elastics. | Device | Group C ( ClearCorrect® clear aligners) |
Primary outcome
Amount of Maxillary Posterior Tooth Distalization
Time frame: From the date of infrazygomatic crest miniscrew placement and initiation of distalization force (T0) until the end of the active distalization phase (T1), assessed up to 13 months
The amount of distalization of the maxillary premolars and molars (U4, U5, U6, U7) was measured in millimeters using three-dimensional digital dental model analysis, comparing pre-treatment (T0) and post-distalization (T1) records.
1 secondary outcome
Total Distalization Duration
Time frame: From the date of miniscrew placement and start of distalization force (T0) until the date of completion of active distalization (T1), assessed up to 13 months
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 20 Jul 2026.
- Individual participant dataSharing planned: No
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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.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Pitts21® fixed appliance, Invisalign® Clear Aligners and ClearCorrect Clear Aligners in people with Angle Class 2 Malocclusion, run by TC Erciyes 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 9 inclusion and 8 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 20 Jul 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?
Amount of Maxillary Posterior Tooth Distalization (time frame: From the date of infrazygomatic crest miniscrew placement and initiation of distalization force (T0) until the end of the active distalization phase (T1), assessed up to 13 months). 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 20 Jul 2026.