MalocclusionNCT07862790
Additional Palatal Force in Maxillary Canine Distalization
A study testing Combined buccal and palatal distalizing force and Buccal distalizing force in people with Malocclusion and Tooth Movement, run by Atlas University at 1 site in Turkey (Türkiye).
Trial summary
In orthodontic treatment involving extraction of the maxillary first premolars, the canine is distalized into the extraction space using sliding mechanics. Because the retraction force is applied at bracket level and therefore at a distance from the centre of resistance of the tooth, the canine tends to rotate… Read more about this study
- Who is it for?
- Ages 12 to 18 years
- Conditions the study is for
- Malocclusion, Tooth Movement
- What is being tested?
- Combined buccal and palatal distalizing force and Buccal distalizing force
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 16 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 15 Jan 2024to 4 Nov 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 12 to 18 years
- All sexes
- No healthy volunteers
- Child, Adult
Who may be able to join
- Indication for fixed orthodontic treatment with bilateral extraction of the maxillary first premolars
- Moderate anchorage requirement
- Complete permanent dentition with radiographically closed maxillary canine apices
- Good oral hygiene, with the ability to maintain it throughout treatment
- Good cooperation with treatment
Who cannot join
- Previous extraction of any permanent tooth other than third molars
- Congenitally missing or impacted teeth
- Systemic disease, or regular use of medication, capable of influencing orthodontic tooth movement
- Asymmetry, occlusal discrepancy, jaw trauma or developmental disturbance of a degree requiring orthognathic surgery
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 Additional Palatal Force Application in Canine Tooth Distalization: A Split-Mouth Randomized Controlled Trial
In orthodontic treatment involving extraction of the maxillary first premolars, the canine is distalized into the extraction space using sliding mechanics. Because the retraction force is applied at bracket level and therefore at a distance from the centre of resistance of the tooth, the canine tends to rotate distopalatally and to tip in the sagittal plane instead of translating bodily. These side effects lengthen treatment and increase the load on the posterior anchorage teeth.
Power arms are used to bring the line of action of the force closer to the centre of resistance. In addition, because the centre of resistance of the maxillary canine lies palatal to the mid-buccolingual axis of the crown, a force applied from the palatal surface generates a rotational moment opposite in direction to that produced by a buccal force.
Read more
This trial tested whether dividing a constant total distalizing force between the buccal and the palatal surfaces of the canine, so that the two rotational moments oppose one another, produces a more bodily canine movement than applying the whole force from the buccal side alone.
The trial used a split-mouth design: in each participant one maxillary quadrant received the whole force from the buccal side and the contralateral quadrant received half the force buccally and half palatally, with the total force identical on both sides. Canine displacement, rotation, tipping and first molar anchorage loss were measured on superimposed digital models over 12 weeks.
Read the detailed description
Background. Distalization of the maxillary canine is the first stage of two-step space closure in first premolar extraction cases. In sliding mechanics the retraction force acts at bracket level, occlusal and buccal to the centre of resistance of the canine, producing a couple that tips the crown distally in the sagittal plane and rotates it distopalatally in the occlusal plane. These movements increase bracket-archwire binding, convert the canine segment into a site of resistance, transfer load to the anchorage unit and require additional appointments for correction. Power arms reduce these effects by displacing the line of action apically toward the centre of resistance, but published trials indicate that this is achieved at the cost of a slower rate of retraction. Lingual mechanics have separately been credited with less canine rotation, because the centre of resistance lies palatal to the mid-buccolingual axis of the crown. In previous comparisons, however, buccal and lingual forces were always applied alternately and never simultaneously to the same tooth.
Objective. To compare canine distalization, canine distopalatal rotation, canine mesiodistal tipping and first molar anchorage loss between a quadrant in which the distalizing force was applied only from the buccal surface and a contralateral quadrant in which the same total force was divided equally between the buccal and palatal surfaces, in both cases delivered through canine and first molar power arms.
Design. Single-centre, split-mouth (within-person) randomized controlled trial with 1:1 allocation of the two maxillary quadrants of each participant. Both interventions were applied simultaneously in every participant, so each participant contributed one quadrant to each intervention. The unit of randomization and of analysis was the maxillary quadrant, and the two observations from each participant are paired.
Interventions. After levelling and alignment on a 0.019 x 0.025 inch stainless steel archwire left passive for four weeks, distalizing force was delivered by 9 mm nickel-titanium closed-coil springs acting between a 7 mm canine power arm placed in the vertical slot of the canine bracket and a power arm incorporated into the first molar tube. On the control quadrant a single spring delivered 200 g from the buccal side. On the experimental quadrant two springs delivered 100 g from the buccal side and 100 g from the palatal side, giving the same 200 g total; an additional vertical-slotted bracket was bonded to the palatal surface of the canine and a power-arm tube to the palatal surface of the first molar, and the bite was raised with glass ionomer on the mandibular first molars to prevent occlusal interference. Forces were re-measured with a dynamometer and reset to baseline at every four-week visit.
Assessment. Alginate impressions were taken at the start of distalization and at 4, 8 and 12 weeks. Casts were scanned and the digital models of each participant were superimposed on three palatal rugae landmarks. Linear measurements (canine distalization, first molar anchorage loss) were made on a plane parallel to the occlusal plane, and angular measurements (canine rotation, canine tipping) on the occlusal and sagittal planes respectively. Intra-examiner error was assessed by repeating 80 measurements after two weeks and calculating the Dahlberg error.
- Conditions
- Malocclusion, Tooth Movement
- Being tested
- Combined buccal and palatal distalizing force, Buccal distalizing force
- Keywords
- canine distalization, canine retraction, power arm, palatal force, lingual force, sliding mechanics, otrthodontic anchorage, split-mouth
- Medical subject headings
- Malocclusion
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Combined buccal and palatal distalizing forceDevice
Canine distalization on a 0.019 x 0.025 inch stainless steel archwire using two 9 mm nickel-titanium closed-coil springs. One spring delivers 100 g between a 7 mm buccal canine power arm in the bracket vertical slot and the power arm of the first molar tube; the second delivers 100 g between a palatal canine power arm, placed in the vertical slot of a bracket bonded to the palatal surface of the canine, and a power-arm tube bonded to the palatal surface of the first molar. Total force 200 g. Forces re-measured and reset every four weeks.
Buccal distalizing forceDevice
Canine distalization on a 0.019 x 0.025 inch stainless steel archwire using a single 9 mm nickel-titanium closed-coil spring delivering 200 g between a 7 mm buccal canine power arm in the bracket vertical slot and the power arm of the first molar tube. Force re-measured and reset every four weeks.
| Study group | Role | What they receive |
|---|---|---|
| Buccal plus palatal force | Experimental | The maxillary quadrant randomly allocated to receive the distalizing force from both the buccal and the palatal surfaces. A nickel-titanium closed-coil spring delivered 100 g between the buccal canine power arm and the buccal first molar power arm, and a second spring delivered 100 g between a palatal canine power arm and a palatal first molar power arm, giving 200 g in total. Sixteen quadrants, one in each participant. Receives: Device: Combined buccal and palatal distalizing force |
| Buccal force only | Active comparator | The contralateral maxillary quadrant, in which the distalizing force was applied only from the buccal surface. A single nickel-titanium closed-coil spring delivered 200 g between the buccal canine power arm and the buccal first molar power arm. Sixteen quadrants, one in each participant. Receives: Device: Buccal distalizing force |
What is being measured
The primary outcome is the main question the study is designed to answer.
Cumulative maxillary canine distalization
Linear distance, in millimetres, travelled by the maxillary canine cusp tip in the sagittal direction, measured as the distance between the projections of the cusp tip onto a reference line parallel to the midpalatal suture on digital models superimposed on three palatal rugae landmarks.
Measured: From the start of distalization to 3 months
Secondary outcomes (3)
Maxillary canine distopalatal rotation
Angle, in degrees, between the line running from the canine cusp tip along the palatal ridge and a reference line parallel to the midpalatal suture, measured on the occlusal plane. Positive values denote distopalatal rotation.
Measured: From the start of distalization to 3 months
Maxillary canine mesiodistal tipping
Distoocclusal angle, in degrees, between the line joining the distoincisal corner of the canine bracket to the cusp tip and the horizontal reference grid of the sagittal plane. Positive values denote mesial crown tipping, that is distal movement of the root; negative values denote distal crown tipping.
Measured: From the start of distalization to 3 months
Maxillary first molar anchorage loss
Linear mesial displacement, in millimetres, of the most buccal point of the contact between the maxillary first molar and the mesial surface of the second premolar, projected onto a reference line parallel to the midpalatal suture.
Measured: From the start of distalization 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 posted7 Oct 2026
- Study start15 Jan 2024
- Primary completion4 Nov 2024
- Study completion4 Nov 2024
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
- Crossover
- Model description
- Split-mouth (within-person) design. Both interventions were applied simultaneously in every participant, one to each maxillary quadrant, rather than in successive periods. The unit of randomization and analysis was the maxillary quadrant, and the two quadrants of each participant provide paired observations. There was no washout period, as the interventions ran concurrently on anatomically separate sites.
- 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, Principal investigator, Ondokuz Mayıs University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07862790
- Sponsor's protocol ID
- OMU-ORT-2023-261
- Other IDs
- 2023/261
- Status last verified
- Sep 2026
- First submitted
- 2 Oct 2026
- Last updated
- 7 Oct 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 7 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Investigation of the Effects of Additional Palatal Force Application in Canine Tooth Distalization: A Split-Mouth Randomized Controlled Trial
- ClinicalTrials.gov ID
- NCT07862790
- Acronym / sponsor ID
- OMU-ORT-2023-261
- Conditions
- Malocclusion, Tooth Movement
- Keywords
- canine distalization, canine retraction, power arm, palatal force, lingual force, sliding mechanics, otrthodontic anchorage, split-mouth
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 16 participants (actual)
- Lead sponsor
- Atlas UniversityUniversity, hospital or other
- Study start
- 15 Jan 2024 (actual)
- Primary completion
- 4 Nov 2024 (actual)
- Study completion
- 4 Nov 2024 (actual)
- First posted
- 7 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.
In orthodontic treatment involving extraction of the maxillary first premolars, the canine is distalized into the extraction space using sliding mechanics. Because the retraction force is applied at bracket level and therefore at a distance from the centre of resistance of the tooth, the canine tends to rotate distopalatally and to tip in the sagittal plane instead of translating bodily. These side effects lengthen treatment and increase the load on the posterior anchorage teeth.
Power arms are used to bring the line of action of the force closer to the centre of resistance. In addition, because the centre of resistance of the maxillary canine lies palatal to the mid-buccolingual axis of the crown, a force applied from the palatal surface generates a rotational moment opposite in direction to that produced by a buccal force.
This trial tested whether dividing a constant total distalizing force between the buccal and the palatal surfaces of the canine, so that the two rotational moments oppose one another, produces a more bodily canine movement than applying the whole force from the buccal side alone.
The trial used a split-mouth design: in each participant one maxillary quadrant received the whole force from the buccal side and the contralateral quadrant received half the force buccally and half palatally, with the total force identical on both sides. Canine displacement, rotation, tipping and first molar anchorage loss were measured on superimposed digital models over 12 weeks.
Detailed description
Background. Distalization of the maxillary canine is the first stage of two-step space closure in first premolar extraction cases. In sliding mechanics the retraction force acts at bracket level, occlusal and buccal to the centre of resistance of the canine, producing a couple that tips the crown distally in the sagittal plane and rotates it distopalatally in the occlusal plane. These movements increase bracket-archwire binding, convert the canine segment into a site of resistance, transfer load to the anchorage unit and require additional appointments for correction. Power arms reduce these effects by displacing the line of action apically toward the centre of resistance, but published trials indicate that this is achieved at the cost of a slower rate of retraction. Lingual mechanics have separately been credited with less canine rotation, because the centre of resistance lies palatal to the mid-buccolingual axis of the crown. In previous comparisons, however, buccal and lingual forces were always applied alternately and never simultaneously to the same tooth.
Objective. To compare canine distalization, canine distopalatal rotation, canine mesiodistal tipping and first molar anchorage loss between a quadrant in which the distalizing force was applied only from the buccal surface and a contralateral quadrant in which the same total force was divided equally between the buccal and palatal surfaces, in both cases delivered through canine and first molar power arms.
Design. Single-centre, split-mouth (within-person) randomized controlled trial with 1:1 allocation of the two maxillary quadrants of each participant. Both interventions were applied simultaneously in every participant, so each participant contributed one quadrant to each intervention. The unit of randomization and of analysis was the maxillary quadrant, and the two observations from each participant are paired.
Interventions. After levelling and alignment on a 0.019 x 0.025 inch stainless steel archwire left passive for four weeks, distalizing force was delivered by 9 mm nickel-titanium closed-coil springs acting between a 7 mm canine power arm placed in the vertical slot of the canine bracket and a power arm incorporated into the first molar tube. On the control quadrant a single spring delivered 200 g from the buccal side. On the experimental quadrant two springs delivered 100 g from the buccal side and 100 g from the palatal side, giving the same 200 g total; an additional vertical-slotted bracket was bonded to the palatal surface of the canine and a power-arm tube to the palatal surface of the first molar, and the bite was raised with glass ionomer on the mandibular first molars to prevent occlusal interference. Forces were re-measured with a dynamometer and reset to baseline at every four-week visit.
Assessment. Alginate impressions were taken at the start of distalization and at 4, 8 and 12 weeks. Casts were scanned and the digital models of each participant were superimposed on three palatal rugae landmarks. Linear measurements (canine distalization, first molar anchorage loss) were made on a plane parallel to the occlusal plane, and angular measurements (canine rotation, canine tipping) on the occlusal and sagittal planes respectively. Intra-examiner error was assessed by repeating 80 measurements after two weeks and calculating the Dahlberg error.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Split-mouth (within-person) design. Both interventions were applied simultaneously in every participant, one to each maxillary quadrant, rather than in successive periods. The unit of randomization and analysis was the maxillary quadrant, and the two quadrants of each participant provide paired observations. There was no washout period, as the interventions ran concurrently on anatomically separate sites.
| Arm | Type | Receives |
|---|---|---|
| Buccal plus palatal force | Experimental | Device: Combined buccal and palatal distalizing forceThe maxillary quadrant randomly allocated to receive the distalizing force from both the buccal and the palatal surfaces. A nickel-titanium closed-coil spring delivered 100 g between the buccal canine power arm and the buccal first molar power arm, and a second spring delivered 100 g between a palatal canine power arm and a palatal first molar power arm, giving 200 g in total. Sixteen quadrants, one in each participant. |
| Buccal force only | Active comparator | Device: Buccal distalizing forceThe contralateral maxillary quadrant, in which the distalizing force was applied only from the buccal surface. A single nickel-titanium closed-coil spring delivered 200 g between the buccal canine power arm and the buccal first molar power arm. Sixteen quadrants, one in each participant. |
Who may qualify
- Ages
- 12 to 18 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (5 listed)
- Indication for fixed orthodontic treatment with bilateral extraction of the maxillary first premolars
- Moderate anchorage requirement
- Complete permanent dentition with radiographically closed maxillary canine apices
- Good oral hygiene, with the ability to maintain it throughout treatment
- Good cooperation with treatment
Key exclusion criteria (4 listed)
- Previous extraction of any permanent tooth other than third molars
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 |
|---|---|---|
| Combined buccal and palatal distalizing forceCanine distalization on a 0.019 x 0.025 inch stainless steel archwire using two 9 mm nickel-titanium closed-coil springs. One spring delivers 100 g between a 7 mm buccal canine power arm in the bracket vertical slot and the power arm of the first molar tube; the second delivers 100 g between a palatal canine power arm, placed in the vertical slot of a bracket bonded to the palatal surface of the canine, and a power-arm tube bonded to the palatal surface of the first molar. Total force 200 g. Forces re-measured and reset every four weeks. | Device | Buccal plus palatal force |
| Buccal distalizing forceCanine distalization on a 0.019 x 0.025 inch stainless steel archwire using a single 9 mm nickel-titanium closed-coil spring delivering 200 g between a 7 mm buccal canine power arm in the bracket vertical slot and the power arm of the first molar tube. Force re-measured and reset every four weeks. | Device | Buccal force only |
Primary outcome
Cumulative maxillary canine distalization
Time frame: From the start of distalization to 3 months
Linear distance, in millimetres, travelled by the maxillary canine cusp tip in the sagittal direction, measured as the distance between the projections of the cusp tip onto a reference line parallel to the midpalatal suture on digital models superimposed on three palatal rugae landmarks.
3 secondary outcomes
Maxillary canine distopalatal rotation
Time frame: From the start of distalization to 3 months
Maxillary canine mesiodistal tipping
Time frame: From the start of distalization to 3 months
Maxillary first molar anchorage loss
Time frame: From the start of distalization 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 7 Oct 2026.
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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 principal investigator
Ondokuz Mayıs 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 Combined buccal and palatal distalizing force and Buccal distalizing force in people with Malocclusion and Tooth Movement, 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 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 7 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?
Cumulative maxillary canine distalization (time frame: From the start of distalization 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 7 Oct 2026.