Angle Class ILam Le NguyênNCT06928896
Friction or Frictionless: What is the Most Effective Method for Retracting Anterior Teeth?
A study testing This interventional trial enrolled a total of 42 patients, dividing them into two age groups: group 1. Using the friction and group 2. Using the frictionless in people with Angle Class I and Alveolar Bone Loss, run by Can Tho University of Medicine and Pharmacy at 1 site in Vietnam.
Trial summary
Objective:To evaluate the effectiveness of the friction (sliding mechanism with elastomeric chains) and frictionless (T-loop) methods for retracting anterior teeth in Angle Class I malocclusion. Read more about this study
- Who is it for?
- Ages 16 years and olderHealthy volunteers can take part
- Conditions the study is for
- Angle Class I, Alveolar Bone Loss
- What is being tested?
- This interventional trial enrolled a total of 42 patients, dividing them into two age groups: group 1. Using the friction and group 2. Using the frictionless
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 50 participants
- Where
- 1 siteVietnam
- Study dates
- 1 Aug 2022to 1 Aug 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 16 years and older
- All sexes
- Healthy volunteers accepted
- Child, Adult, Older adult
Who may be able to join
- Angle class I malocclusion on one or both sides
- Without any previous orthodontic treatment
- Indications for fixed appliances, premolar extraction to create space during treatment
- Consented to participate in the study
Who cannot join
- History of craniofacial traumas, anomalies, congenital defects, or systemic diseases related to osteogenic metabolisms, e.g. diabetes mellitus, kidney diseases, osseous diseases
- Patients took anticoagulant drugs that affected bone metabolism (eg., for example, heparin, warfarin, NSAIDs, cyclosporine, glucocorticoids, medroxyprogesterone acetate, etc.)
- Mini screw, and hook failure
Trial locations and contacts
1 site in 1 country.
Vietnam1 site
Can Tho University of Medicine and Pharmacy
Can Tho, Can Tho City, 90000
About this study
Objective:To evaluate the effectiveness of the friction (sliding mechanism with elastomeric chains) and frictionless (T-loop) methods for retracting anterior teeth in Angle Class I malocclusion.
Methods: This clinical intervention study examined the duration of maxillary incisor retraction from August 2022 to August 2024 in 42 adult patients who had completed canine retraction. The process involved resolving horizontal and vertical discrepancies, establishing a Class I relationship between the canines, and altering the overbite (the interproximal space between the lateral incisors and canines) until an ideal overbite index of 2 mm was achieved. Cone beam computed tomography (CBCT) was conducted before and after retraction to evaluate alveolar changes and speed.
Read the detailed description
Step 1. The following data were collected: general information, clinical examination, classification of facial symmetry while facing forward, profile, state of the temporomandibular joint, relationships between the first molar teeth, and canine relationship. Patients with bilateral type I angle malocclusion were selected. The PAR(W) index was calculated using the model cast as a measurement. Subsequently, the patients' model casts, standardized intraoral and extraoral photographs, panoramic films, and cephalometric films were used to make the second selection. A patient's upper first premolar was removed if orthodontic treatment was indicated. All cephalometric films that met the study's requirements were analyzed using the customized software WebCeph. Before beginning orthodontic therapy, the bleeding time, clotting time, and platelet count were tested in the patients who met the inclusion criteria. Before participating in the study, patients signed a permission form and received information about the study's goals and methods.
Step 2. The TransbondTM XT Light Cure Adhesive and the Victory Series Metal Bracket System (MBT 0.022 slot, 3M Unitek®, USA) were employed. This study used a two-step space closure method for tooth extraction, in which the canine is moved backward to obtain a Class I canine relationship, and the relationship between the molars is changed if necessary. Subsequently, CTCB was performed before the procedure of retracting the four incisors. At this stage, the patient's group allocation was determined randomly. IZC mini-screws (8 x 1.6 mm, 3M UnitekTAD, St. Paul, Minn.) were used in both groups .
In group 1 (sliding mechanism: using elastomeric chains combined with mini-screws), 3M elastomeric chains were used to retract the four maxillary incisors toward the mini-screws with 160 g of force.
In group 2 (loop mechanism), the T-loop was measured and bent using TMA wire (0.016 × 0.022 inches, 3M, USA) to conform to the patient's arch. The loop was positioned distal to the lateral incisor to initiate the force and modify the loop. Weingart forceps were utilized to retract the archwire posterior to the first premolar, expanding the loop by about 4 mm (150 g) and securing the tail to initiate activation. The loop force was adjusted to fully close space at each subsequent visit. To enhance anchoring, the mini-screw was placed identically on both sides of the arch (the screw positioning resembled that of group 1). Subsequently, the upper first molar was secured to the mini-screws using a 0.012-inch diameter ligature wire.
After the retraction of four incisors, post-retraction CBCT scans were obtained, and the retraction of the four upper incisors was analyzed (overbite achieved 2 mm, Class I canine relationship). CBCT images were generated in DICOM format and imported into Ondemand3Ddental software (Cybermed, Korea, version 1.0.11.1007) for data measurement. The teeth were identified using axial navigation guidance from the multi-planar reconstruction (axial, sagittal, and coronal) of the CBCT, following the measurement method in Le's study (2023) , while ensuring that radiation exposure was kept as low as reasonably achievable (ALARA Guidelines)
- Conditions
- Angle Class I, Alveolar Bone Loss
- Being tested
- This interventional trial enrolled a total of 42 patients, dividing them into two age groups: group 1. Using the friction and group 2. Using the frictionless
- Keywords
- alveolar bone, elastomeric chains, friction, frictionless
- Medical subject headings
- Malocclusion, Angle Class I, Alveolar Bone Loss
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
This interventional trial enrolled a total of 42 patients, dividing them into two age groups: group 1. Using the friction and group 2. Using the frictionlessProcedure or surgery
Cone beam computed tomography (CBCT) was conducted before and after retraction to evaluate alveolar changes and speed.
| Study group | Role | What they receive |
|---|---|---|
| Group 1. Using the friction | Experimental | Not described Receives: Procedure: This interventional trial enrolled a total of 42 patients, dividing them into two age groups: group 1. Using the friction and group 2. Using the frictionless |
| Group 2. Using the frictionless | Experimental | Not described Receives: Procedure: This interventional trial enrolled a total of 42 patients, dividing them into two age groups: group 1. Using the friction and group 2. Using the frictionless |
What is being measured
The primary outcome is the main question the study is designed to answer.
To evaluate the effectiveness of the friction (sliding mechanism with elastomeric chains) and frictionless (T-loop) methods for retracting anterior teeth in Angle Class I malocclusion.
This interventional trial enrolled a total of 42 patients, dividing them into two age groups: group 1. Using the friction (sliding mechanism-elastomeric chains) and group 2. Using the frictionless (T-loop). For each patient, cone beam computed tomography (CBCT) was taken before and after retraction to evaluate alveolar changes.
Study variables measured on CBCT. The palatal plane (PP) represents the magnetic connection between the PNS (posterior nasal spine) and the ANS (anterior nasal spine), V: a vertical reference line perpendicular to the ANS-PNS line, H: a vertical reference line parallel to the ANS-PNS line. Four lines perpendicular to the V line (L0, L1, L2, L3, 2 mm apart). Line L0 passes through the cementoenamel junction (CEJ) on the buccal side. Measure the alveolar bone thickness at 3 positions (S1, S2, S3, lingual, and buccal) at T1 and T2.
Measured: 6 months after enrollment
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Apr 2025
- Study start1 Aug 2022
- Primary completion1 Aug 2024
- Study completion1 Aug 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Angle Class IStudies 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
- Masking
- None (open label)
- Enrolment
- 50 participants (actual)
Sponsor and investigators
- Lead sponsor
- Can Tho University of Medicine and Pharmacy
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Assoc.Prof.Dr. Nguyen Ngoc Rang, Can Tho University of Medicine and Pharmacy
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06928896
- Sponsor's protocol ID
- Le nguyên lâm ctump
- Acronym
- Lam Le Nguyên
- Status last verified
- Oct 2024
- First submitted
- 15 Oct 2024
- Last updated
- 15 Apr 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Attia AM, Shibl LA, Dehis HM, Mostafa YA, El-Beialy AR. Evaluation of anchorage loss after en masse retraction in orthodontic patients with maxillary protrusion using friction vs frictionless mechanics: randomized clinical trial. Angle Orthod. 2024 Sep 1;94(5):532-540. doi: 10.2319/113023-791.1.
PubMed 39230024
Study at a glance
From the registry record, last updated by the sponsor on 15 Apr 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Friction or Frictionless: What is the Most Effective Method for Retracting Anterior Teeth?
- ClinicalTrials.gov ID
- NCT06928896
- Acronym / sponsor ID
- Lam Le Nguyên / Le nguyên lâm ctump
- Conditions
- Angle Class I, Alveolar Bone Loss
- Keywords
- alveolar bone, elastomeric chains, friction, frictionless
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 50 participants (actual)
- Lead sponsor
- Can Tho University of Medicine and PharmacyUniversity, hospital or other
- Study start
- 1 Aug 2022 (actual)
- Primary completion
- 1 Aug 2024 (actual)
- Study completion
- 1 Aug 2024 (actual)
- First posted
- 15 Apr 2025 (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.
Objective:To evaluate the effectiveness of the friction (sliding mechanism with elastomeric chains) and frictionless (T-loop) methods for retracting anterior teeth in Angle Class I malocclusion.
Methods: This clinical intervention study examined the duration of maxillary incisor retraction from August 2022 to August 2024 in 42 adult patients who had completed canine retraction. The process involved resolving horizontal and vertical discrepancies, establishing a Class I relationship between the canines, and altering the overbite (the interproximal space between the lateral incisors and canines) until an ideal overbite index of 2 mm was achieved. Cone beam computed tomography (CBCT) was conducted before and after retraction to evaluate alveolar changes and speed.
Detailed description
Step 1. The following data were collected: general information, clinical examination, classification of facial symmetry while facing forward, profile, state of the temporomandibular joint, relationships between the first molar teeth, and canine relationship. Patients with bilateral type I angle malocclusion were selected. The PAR(W) index was calculated using the model cast as a measurement. Subsequently, the patients' model casts, standardized intraoral and extraoral photographs, panoramic films, and cephalometric films were used to make the second selection. A patient's upper first premolar was removed if orthodontic treatment was indicated. All cephalometric films that met the study's requirements were analyzed using the customized software WebCeph. Before beginning orthodontic therapy, the bleeding time, clotting time, and platelet count were tested in the patients who met the inclusion criteria. Before participating in the study, patients signed a permission form and received information about the study's goals and methods.
Step 2. The TransbondTM XT Light Cure Adhesive and the Victory Series Metal Bracket System (MBT 0.022 slot, 3M Unitek®, USA) were employed. This study used a two-step space closure method for tooth extraction, in which the canine is moved backward to obtain a Class I canine relationship, and the relationship between the molars is changed if necessary. Subsequently, CTCB was performed before the procedure of retracting the four incisors. At this stage, the patient's group allocation was determined randomly. IZC mini-screws (8 x 1.6 mm, 3M UnitekTAD, St. Paul, Minn.) were used in both groups .
In group 1 (sliding mechanism: using elastomeric chains combined with mini-screws), 3M elastomeric chains were used to retract the four maxillary incisors toward the mini-screws with 160 g of force.
In group 2 (loop mechanism), the T-loop was measured and bent using TMA wire (0.016 × 0.022 inches, 3M, USA) to conform to the patient's arch. The loop was positioned distal to the lateral incisor to initiate the force and modify the loop. Weingart forceps were utilized to retract the archwire posterior to the first premolar, expanding the loop by about 4 mm (150 g) and securing the tail to initiate activation. The loop force was adjusted to fully close space at each subsequent visit. To enhance anchoring, the mini-screw was placed identically on both sides of the arch (the screw positioning resembled that of group 1). Subsequently, the upper first molar was secured to the mini-screws using a 0.012-inch diameter ligature wire.
After the retraction of four incisors, post-retraction CBCT scans were obtained, and the retraction of the four upper incisors was analyzed (overbite achieved 2 mm, Class I canine relationship). CBCT images were generated in DICOM format and imported into Ondemand3Ddental software (Cybermed, Korea, version 1.0.11.1007) for data measurement. The teeth were identified using axial navigation guidance from the multi-planar reconstruction (axial, sagittal, and coronal) of the CBCT, following the measurement method in Le's study (2023) , while ensuring that radiation exposure was kept as low as reasonably achievable (ALARA Guidelines)
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Group 1. Using the friction | Experimental | Procedure: This interventional trial enrolled a total of 42 patients, dividing them into two age groups: group 1. Using the friction and group 2. Using the frictionless |
| Group 2. Using the frictionless | Experimental | Procedure: This interventional trial enrolled a total of 42 patients, dividing them into two age groups: group 1. Using the friction and group 2. Using the frictionless |
Who may qualify
- Ages
- 16 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (4 listed)
- Angle class I malocclusion on one or both sides
- Without any previous orthodontic treatment
- Indications for fixed appliances, premolar extraction to create space during treatment
- Consented to participate in the study
Key exclusion criteria (3 listed)
- History of craniofacial traumas, anomalies, congenital defects, or systemic diseases related to osteogenic metabolisms, e.g. diabetes mellitus, kidney diseases, osseous diseases
- Patients took anticoagulant drugs that affected bone metabolism (eg., for example, heparin, warfarin, NSAIDs, cyclosporine, glucocorticoids, medroxyprogesterone acetate, etc.)
- Mini screw, and hook failure
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 |
|---|---|---|
| This interventional trial enrolled a total of 42 patients, dividing them into two age groups: group 1. Using the friction and group 2. Using the frictionlessCone beam computed tomography (CBCT) was conducted before and after retraction to evaluate alveolar changes and speed. | Procedure or surgery | Group 1. Using the friction, Group 2. Using the frictionless |
Primary outcome
To evaluate the effectiveness of the friction (sliding mechanism with elastomeric chains) and frictionless (T-loop) methods for retracting anterior teeth in Angle Class I malocclusion.
Time frame: 6 months after enrollment
This interventional trial enrolled a total of 42 patients, dividing them into two age groups: group 1. Using the friction (sliding mechanism-elastomeric chains) and group 2. Using the frictionless (T-loop). For each patient, cone beam computed tomography (CBCT) was taken before and after retraction to evaluate alveolar changes. Study variables measured on CBCT. The palatal plane (PP) represents the magnetic connection between the PNS (posterior nasal spine) and the ANS (anterior nasal spine), V: a vertical reference line perpendicular to the ANS-PNS line, H: a vertical reference line parallel to the ANS-PNS line. Four lines perpendicular to the V line (L0, L1, L2, L3, 2 mm apart). Line L0 passes through the cementoenamel junction (CEJ) on the buccal side. Measure the alveolar bone thickness at 3 positions (S1, S2, S3, lingual, and buccal) at T1 and T2.
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 15 Apr 2025.
- Results publication: PubMed 39230024Attia AM, Shibl LA, Dehis HM, Mostafa YA, El-Beialy AR. Evaluation of anchorage loss after en masse retraction in orthodontic patients with maxillary protrusion using friction vs frictionless mechanics: randomized clinical trial. Angle Orthod. 2024 Sep 1;94(5):532-540. doi: 10.2319/113023-791.1.
- Related InfoLink provided by the sponsor.
- 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 This interventional trial enrolled a total of 42 patients, dividing them into two age groups: group 1. Using the friction and group 2. Using the frictionless in people with Angle Class I and Alveolar Bone Loss, run by Can Tho University of Medicine and Pharmacy at 1 site in Vietnam.
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 4 inclusion and 3 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 15 Apr 2025. 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 Vietnam. 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?
To evaluate the effectiveness of the friction (sliding mechanism with elastomeric chains) and frictionless (T-loop) methods for retracting anterior teeth in Angle Class I malocclusion. (time frame: 6 months after enrollment). 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 NCT06928896, which also lists 1 linked publication.
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 15 Apr 2025; AzTrials last refreshed its copy on 3 Nov 2026.