MalocclusionNCT07866976
Effects of Power Arm Application in Maxillary Canine Distalization
A study testing Canine and molar power arms and Conventional canine retraction in people with Malocclusion and Angle Class II, run by Atlas University at 1 site in Turkey (Türkiye).
Trial summary
The aim of this study is to investigate the effects of a canine distalization force applied between power arms placed on the maxillary canine and first molar, in comparison with the classical method without power arms. Read more about this study
- Who is it for?
- Ages 14 to 20 years
- Conditions the study is for
- Malocclusion, Angle Class II, Tooth Movement Techniques
- What is being tested?
- Canine and molar power arms and Conventional canine retraction
- Type of treatment
- Medical device, Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 16 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 22 Jan 2024to 1 Mar 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 14 to 20 years
- All sexes
- No healthy volunteers
- Child, Adult
Who may be able to join
- Maxillary skeletal/dental Angle Class II malocclusion
- Indication for fixed orthodontic treatment with bilateral maxillary first premolar extraction and moderate anchorage requirement
- No systemic disease and no medication use
- No congenitally missing or previously extracted maxillary teeth (third molars excepted)
- Good oral hygiene and healthy periodontal tissues
Who cannot join
- Systemic disease or medication use
- Anomalies of tooth number or shape in the maxillary dentition
- Inadequate oral hygiene
- Pubertal growth spurt not yet completed
- Previous orthodontic treatment
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Ondokuz Mayıs University, Faculty of Dentistry, Department of Orthodontics
Samsun, 55139
About this study
Official title: Investigation of the Effects of Power Arm Application in Canine Distalization: A Randomized Split-Mouth Clinical Trial
The aim of this study is to investigate the effects of a canine distalization force applied between power arms placed on the maxillary canine and first molar, in comparison with the classical method without power arms. Following maxillary first premolar extraction, canine distalization is commonly accompanied by undesirable effects such as distal tipping and distopalatal rotation of the canine and mesial movement (anchorage loss) of the first molar. By bringing the applied force closer to the teeth's centers of resistance through power arms, the study seeks to move the canine into the extraction space as close to parallel (bodily) movement as possible. The hypothesis is that applying force with Ni-Ti closed-coil springs between power arms placed on the molar and canine teeth reduces undesirable dental effects such as rotation, tipping and anchorage loss during distalization compared with the classical method. In a split-mouth design, 16 patients with maxillary first premolar extractions and moderate anchorage requirement receive power-arm mechanics on one randomly selected side (study side) and conventional mechanics on the other side (control side), with a 150 g force on both sides, over three months of canine distalization.
Read the detailed description
Design and setting: Prospective, randomized, controlled, split-mouth in vivo clinical study conducted as a specialty (residency) thesis at the Department of Orthodontics, Faculty of Dentistry, Ondokuz Mayis University, Samsun, Turkey. Sixteen patients (11 female, 5 male; mean age at treatment start 16 years 1 month) with Angle Class II malocclusion requiring extraction of the maxillary right and left first premolars and fixed appliance treatment with moderate anchorage were included. The right and left maxillary quadrants of each patient form the study and control groups (16 sides per group).
Randomization: At bracket bonding, the side receiving the molar tube with a power arm was selected at random using a computer program; the other side received a standard molar tube. The side with the power arm forms the study group and the side without it the control group.
Treatment: Brackets were bonded one week after extraction of the maxillary first premolars (37% orthophosphoric acid, Transbond XT primer and adhesive, 3M) using 0.022 x 0.028-inch vertical-slot metal brackets (Mini Master V-Slot, American Orthodontics). Leveling and alignment were completed with 0.014-, 0.016- and 0.019 x 0.025-inch copper Ni-Ti archwires at 4-week intervals; no laceback ligatures were used. A 0.019 x 0.025-inch stainless steel archwire was then placed and left for one month without active force to allow bracket torque expression, after which baseline (T0) impressions and photographs were taken. On the study side, a U-shaped canine power arm was bent from 0.016 x 0.022-inch stainless steel wire with its gingival opening facing mesially, its height matched to the molar power arm. One end of a 9-mm Ni-Ti closed-coil spring (American Orthodontics) was attached to the molar power-arm hook and the other to the canine power-arm hook with a 0.010-inch long ligature wire, at the level at which a force gauge (Loyka ATG-500) read 150 g. On the control side, the spring was attached in the same way between the molar tube hook and the canine bracket hook, activated to 150 g.
Records and measurements: Patients were recalled every 4 weeks for three months. At each visit the maxillary archwire was removed and intraoral photographs and alginate impressions were taken at the start of distalization (T0) and at the 1st (T1), 2nd (T2) and 3rd (T3) months. Plaster casts were scanned with a 3D model scanner (3Shape) and the digital models were superimposed (T0-T1, T0-T2, T0-T3) in OrthoAnalyzer (3Shape) using the medial and lateral points of the third palatal ruga and the medial point of the second palatal ruga. Canine distalization (mm), canine rotation (degrees), canine tipping (degrees) and first molar anchorage loss (mm) were measured separately for each side relative to the occlusal plane and a sagittal plane through and parallel to the midpalatal suture. Impressions, casts, scanning and all measurements were performed by the same investigator. Method error was assessed by repeating 104 measurements after 2 weeks (Dahlberg formula).
Sample size: Based on data from Leethanakul et al., a power analysis in G*Power 3.1.9.7 (alpha = 0.05, power = 95%) indicated 6 subjects per group; considering possible attrition during active orthodontic treatment, 8 per group (16 individuals in total) were included.
This record was registered retrospectively after completion of the trial.
- Being tested
- Canine and molar power arms, Conventional canine retraction
- Keywords
- canine retraction, power arm, anchorage loss, split-mouth, closed-coil spring, center of resistance
- Medical subject headings
- Malocclusion, Malocclusion, Angle Class II
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Canine and molar power armsDevice
Molar tube with a power arm and a U-shaped canine power arm bent from 0.016 x 0.022-inch stainless steel wire (gingival opening facing mesially), adjusted to the molar power-arm height; a 9-mm Ni-Ti closed-coil spring is attached between the two power-arm hooks via a 0.010-inch long ligature wire and activated to 150 g measured with a force gauge.
Conventional canine retractionProcedure or surgery
Also called Sliding mechanics canine retraction
9-mm Ni-Ti closed-coil spring delivering 150 g attached directly between the molar tube hook and the canine bracket hook.
| Study group | Role | What they receive |
|---|---|---|
| Study side (power arms) | Experimental | Study side (power arms) Receives: Device: Canine and molar power arms |
| Control side (classical method) | Active comparator | Contralateral maxillary canine retracted on the same archwire with a 150 g Ni-Ti closed-coil spring activated between the molar tube hook and the canine bracket hook, without power arms. Receives: Procedure: Conventional canine retraction |
What is being measured
The primary outcome is the main question the study is designed to answer.
Canine distalization
Distal movement of the maxillary canine cusp tip (mm), measured on superimposed 3D digital models as the distance between successive cusp-tip projections on a reference line parallel to the midpalatal raphe. Reported per month and cumulatively.
Measured: Baseline (T0), 1, 2 and 3 months of retraction; cumulative T0 to 3 months
Secondary outcomes (3)
First molar anchorage loss
Mesial movement of the maxillary first molar (mm), measured at the mesial contact point between the first molar and second premolar, projected on the same reference line on superimposed models.
Measured: Baseline (T0), 1, 2 and 3 months; cumulative T0 to 3 months
Canine rotation
Distopalatal rotation of the maxillary canine (degrees): angle between a line through the canine cusp tip and palatal ridge and a line parallel to the midpalatal raphe.
Measured: Baseline (T0), 1, 2 and 3 months; cumulative T0 to 3 months
Canine tipping
Mesiodistal crown tipping of the maxillary canine (degrees): angle between a line from the disto-incisal bracket corner to the canine cusp tip and the horizontal reference of the midsagittal plane.
Measured: Baseline (T0), 1, 2 and 3 months; cumulative T0 to 3 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Oct 2026
- Study start22 Jan 2024
- Primary completion1 Mar 2025
- Study completion1 Mar 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for 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
- Split-mouth design: within each participant, the right and left maxillary quadrants were randomly allocated to the experimental (power arm) or control (conventional) canine retraction mechanics. Each of the 16 participants contributes one quadrant to each arm.
- Masking
- None (open label)
- Enrolment
- 16 participants (actual)
Sponsor and investigators
- Lead sponsor
- Atlas University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Selim Arici, Ondokuz Mayıs University
- Investigators
- Selim Arici, DDS, PhD, Study director, Atlas University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07866976
- Sponsor's protocol ID
- OMU-KAEK-2023/260
- Status last verified
- Oct 2026
- First submitted
- 5 Oct 2026
- Last updated
- 9 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data are not deposited in a public repository; de-identified data are available from the corresponding author on reasonable request.
Study at a glance
From the registry record, last updated by the sponsor on 9 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Investigation of the Effects of Power Arm Application in Canine Distalization: A Randomized Split-Mouth Clinical Trial
- ClinicalTrials.gov ID
- NCT07866976
- Acronym / sponsor ID
- OMU-KAEK-2023/260
- Keywords
- canine retraction, power arm, anchorage loss, split-mouth, closed-coil spring, center of resistance
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 16 participants (actual)
- Lead sponsor
- Atlas UniversityUniversity, hospital or other
- Study start
- 22 Jan 2024 (actual)
- Primary completion
- 1 Mar 2025 (actual)
- Study completion
- 1 Mar 2025 (actual)
- First posted
- 9 Oct 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.
The aim of this study is to investigate the effects of a canine distalization force applied between power arms placed on the maxillary canine and first molar, in comparison with the classical method without power arms. Following maxillary first premolar extraction, canine distalization is commonly accompanied by undesirable effects such as distal tipping and distopalatal rotation of the canine and mesial movement (anchorage loss) of the first molar. By bringing the applied force closer to the teeth's centers of resistance through power arms, the study seeks to move the canine into the extraction space as close to parallel (bodily) movement as possible. The hypothesis is that applying force with Ni-Ti closed-coil springs between power arms placed on the molar and canine teeth reduces undesirable dental effects such as rotation, tipping and anchorage loss during distalization compared with the classical method. In a split-mouth design, 16 patients with maxillary first premolar extractions and moderate anchorage requirement receive power-arm mechanics on one randomly selected side (study side) and conventional mechanics on the other side (control side), with a 150 g force on both sides, over three months of canine distalization.
Detailed description
Design and setting: Prospective, randomized, controlled, split-mouth in vivo clinical study conducted as a specialty (residency) thesis at the Department of Orthodontics, Faculty of Dentistry, Ondokuz Mayis University, Samsun, Turkey. Sixteen patients (11 female, 5 male; mean age at treatment start 16 years 1 month) with Angle Class II malocclusion requiring extraction of the maxillary right and left first premolars and fixed appliance treatment with moderate anchorage were included. The right and left maxillary quadrants of each patient form the study and control groups (16 sides per group).
Randomization: At bracket bonding, the side receiving the molar tube with a power arm was selected at random using a computer program; the other side received a standard molar tube. The side with the power arm forms the study group and the side without it the control group.
Treatment: Brackets were bonded one week after extraction of the maxillary first premolars (37% orthophosphoric acid, Transbond XT primer and adhesive, 3M) using 0.022 x 0.028-inch vertical-slot metal brackets (Mini Master V-Slot, American Orthodontics). Leveling and alignment were completed with 0.014-, 0.016- and 0.019 x 0.025-inch copper Ni-Ti archwires at 4-week intervals; no laceback ligatures were used. A 0.019 x 0.025-inch stainless steel archwire was then placed and left for one month without active force to allow bracket torque expression, after which baseline (T0) impressions and photographs were taken. On the study side, a U-shaped canine power arm was bent from 0.016 x 0.022-inch stainless steel wire with its gingival opening facing mesially, its height matched to the molar power arm. One end of a 9-mm Ni-Ti closed-coil spring (American Orthodontics) was attached to the molar power-arm hook and the other to the canine power-arm hook with a 0.010-inch long ligature wire, at the level at which a force gauge (Loyka ATG-500) read 150 g. On the control side, the spring was attached in the same way between the molar tube hook and the canine bracket hook, activated to 150 g.
Records and measurements: Patients were recalled every 4 weeks for three months. At each visit the maxillary archwire was removed and intraoral photographs and alginate impressions were taken at the start of distalization (T0) and at the 1st (T1), 2nd (T2) and 3rd (T3) months. Plaster casts were scanned with a 3D model scanner (3Shape) and the digital models were superimposed (T0-T1, T0-T2, T0-T3) in OrthoAnalyzer (3Shape) using the medial and lateral points of the third palatal ruga and the medial point of the second palatal ruga. Canine distalization (mm), canine rotation (degrees), canine tipping (degrees) and first molar anchorage loss (mm) were measured separately for each side relative to the occlusal plane and a sagittal plane through and parallel to the midpalatal suture. Impressions, casts, scanning and all measurements were performed by the same investigator. Method error was assessed by repeating 104 measurements after 2 weeks (Dahlberg formula).
Sample size: Based on data from Leethanakul et al., a power analysis in G*Power 3.1.9.7 (alpha = 0.05, power = 95%) indicated 6 subjects per group; considering possible attrition during active orthodontic treatment, 8 per group (16 individuals in total) were included.
This record was registered retrospectively after completion of the trial.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Split-mouth design: within each participant, the right and left maxillary quadrants were randomly allocated to the experimental (power arm) or control (conventional) canine retraction mechanics. Each of the 16 participants contributes one quadrant to each arm.
| Arm | Type | Receives |
|---|---|---|
| Study side (power arms) | Experimental | Device: Canine and molar power armsStudy side (power arms) |
| Control side (classical method) | Active comparator | Procedure: Conventional canine retractionContralateral maxillary canine retracted on the same archwire with a 150 g Ni-Ti closed-coil spring activated between the molar tube hook and the canine bracket hook, without power arms. |
Who may qualify
- Ages
- 14 to 20 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (5 listed)
- Maxillary skeletal/dental Angle Class II malocclusion
- Indication for fixed orthodontic treatment with bilateral maxillary first premolar extraction and moderate anchorage requirement
- No systemic disease and no medication use
- No congenitally missing or previously extracted maxillary teeth (third molars excepted)
- Good oral hygiene and healthy periodontal tissues
Key exclusion criteria (5 listed)
- Systemic disease or medication use
- Anomalies of tooth number or shape in the maxillary dentition
- Inadequate oral hygiene
- Pubertal growth spurt not yet completed
- Previous orthodontic treatment
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 |
|---|---|---|
| Canine and molar power armsMolar tube with a power arm and a U-shaped canine power arm bent from 0.016 x 0.022-inch stainless steel wire (gingival opening facing mesially), adjusted to the molar power-arm height; a 9-mm Ni-Ti closed-coil spring is attached between the two power-arm hooks via a 0.010-inch long ligature wire and activated to 150 g measured with a force gauge. | Device | Study side (power arms) |
| Conventional canine retractionAlso: Sliding mechanics canine retraction9-mm Ni-Ti closed-coil spring delivering 150 g attached directly between the molar tube hook and the canine bracket hook. | Procedure or surgery | Control side (classical method) |
Primary outcome
Canine distalization
Time frame: Baseline (T0), 1, 2 and 3 months of retraction; cumulative T0 to 3 months
Distal movement of the maxillary canine cusp tip (mm), measured on superimposed 3D digital models as the distance between successive cusp-tip projections on a reference line parallel to the midpalatal raphe. Reported per month and cumulatively.
3 secondary outcomes
First molar anchorage loss
Time frame: Baseline (T0), 1, 2 and 3 months; cumulative T0 to 3 months
Canine rotation
Time frame: Baseline (T0), 1, 2 and 3 months; cumulative T0 to 3 months
Canine tipping
Time frame: Baseline (T0), 1, 2 and 3 months; cumulative T0 to 3 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 9 Oct 2026.
- Individual participant dataSharing planned: No. Individual participant data are not deposited in a public repository; de-identified data are available from the corresponding author on reasonable request.
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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.
Selim Arici, DDS, PhD study director
Atlas 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 Canine and molar power arms and Conventional canine retraction in people with Malocclusion and Angle Class II, run by Atlas 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 5 inclusion and 5 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 9 Oct 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?
Canine distalization (time frame: Baseline (T0), 1, 2 and 3 months of retraction; cumulative T0 to 3 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 9 Oct 2026.