Skeletal Class II MalocclusionMTB-CTBNCT07608406
Modified Versus Clear Twin Block for Skeletal Class II Malocclusion
A study testing Modified Twin Block Appliance and Conventional Clear Twin Block Appliance in people with Skeletal Class II Malocclusion, run by University of Aleppo at 1 site in Syria.
Trial summary
This study aims to evaluate the effectiveness of a modified Twin Block appliance compared to a conventional clear Twin Block appliance in the treatment of skeletal Class II malocclusion caused by mandibular retrusion in growing patients. Read more about this study
- Who is it for?
- Ages 10 to 13 years
- Conditions the study is for
- Skeletal Class II Malocclusion
- What is being tested?
- Modified Twin Block Appliance and Conventional Clear Twin Block Appliance
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 40 participants
- Where
- 1 siteSyria
- Study dates
- 17 May 2026to Dec 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 13 years
- All sexes
- No healthy volunteers
- Child
Who may be able to join
- Systemically healthy patients.
- Patients willing to accept removable functional appliance therapy.
- Skeletal Class II malocclusion (Angle Class II Division 1).
- Skeletal Class II due to mandibular retrusion (ANB ≥ 5°, 6 mm ≤ OJ ≤ 13 mm , SNB ≤ 78°, with normal maxillary position).
- Growth stage corresponding to MP3 stage or pre-pubertal peak according to hand-wrist radiograph (Björk and Helm, 1967).
- No severe dental crowding in the dental arches and no significant maxillary dental protrusion.
- Absence of congenital anomalies, trauma, burns, or surgical scars affecting the temporomandibular joint or craniofacial structures.
- Absence of systemic or rheumatologic diseases affecting the temporomandibular joint.
Who cannot join
- Presence of clinical signs or symptoms of temporomandibular joint disorders.
- Functional mandibular deviation.
- Previous orthodontic treatment.
Trial locations and contacts
1 site in 1 country.
Syria1 site
Faculty of Dentistry, University of Aleppo
Aleppo, Aleppo Governorate
About this study
Official title: Evaluation of the Efficacy of Functional Therapy Using Modified Twin Block Versus Clear Twin Block in Class II Skeletal Patients: A Randomized Controlled Clinical Trial
This study aims to evaluate the effectiveness of a modified Twin Block appliance compared to a conventional clear Twin Block appliance in the treatment of skeletal Class II malocclusion caused by mandibular retrusion in growing patients.
This is a two-arm randomized controlled clinical trial including patients aged 10-13 years diagnosed with skeletal Class II malocclusion. Participants will be randomly allocated into two equal groups.
Read more
Skeletal, dental, and soft tissue changes will be assessed using lateral cephalometric analysis and cone-beam computed tomography (CBCT). Additionally, temporomandibular joint (TMJ) health, pain perception, and functional tolerance will be evaluated using standardized clinical indices and patient-reported outcome measures.
The study aims to compare the modified appliance with the conventional design in terms of skeletal improvement, TMJ safety, and patient acceptance.
Read the detailed description
Skeletal and dentofacial anomalies, particularly Class II malocclusion due to mandibular retrusion, represent one of the most prevalent orthodontic problems during growth. Functional appliances, especially the Twin Block appliance, are widely used to enhance mandibular development and correct jaw discrepancies. However, variations in treatment protocols, particularly regarding advancement mechanics and appliance modifications, may influence both skeletal outcomes and temporomandibular joint (TMJ) response.
This study aims to investigate the effects of a modified Twin Block appliance, incorporating progressive mandibular advancement and additional design modifications such as lower lip pads intended to influence muscular activity, compared to a conventional clear Twin Block appliance.
A two-arm randomized controlled trial will be conducted on growing patients aged 10-13 years diagnosed with skeletal Class II malocclusion due to mandibular retrusion. Participants will be randomly allocated into two equal groups using a computer-generated randomization sequence with allocation concealment.
Skeletal and dental changes will be evaluated using lateral cephalometric radiographs and cone-beam computed tomography (CBCT), with particular attention to condylar morphology, joint space dimensions, and craniofacial skeletal relationships. TMJ health will be assessed using the Helkimo Index. Patient comfort, pain perception, and functional adaptation will be evaluated using validated questionnaires administered at multiple time points throughout the treatment period.
Radiographic and clinical assessments will be performed at baseline (T0) and after 7 months of functional appliance therapy (T1). Repeated patient-reported outcome measures will be collected at predefined intervals during treatment.
The objective of this study is to determine whether the modified Twin Block appliance provides superior skeletal and functional outcomes while maintaining temporomandibular joint safety and improving patient tolerance compared to the conventional appliance.
- Conditions
- Skeletal Class II Malocclusion
- Being tested
- Modified Twin Block Appliance, Conventional Clear Twin Block Appliance
- Keywords
- Twin Block appliance, Class II malocclusion, Mandibular advancement, Functional orthopedic treatment, CBCT
- Medical subject headings
- Overbite
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Modified Twin Block ApplianceDevice
Also called Progressive Twin Block
A modified Twin Block functional appliance incorporating progressive mandibular advancement and lower lip pads designed to modify muscular activity and enhance mandibular growth. The appliance is used for the treatment of skeletal Class II malocclusion due to mandibular retrusion in growing patients.
Conventional Clear Twin Block ApplianceDevice
Also called Clear Twin Block
A conventional clear Twin Block functional appliance used for correction of skeletal Class II malocclusion in growing patients. The appliance acts by posturing the mandible forward to stimulate functional and skeletal adaptation.
| Study group | Role | What they receive |
|---|---|---|
| Modified Twin Block Group | Experimental | Patients in this group will be treated using a modified Twin Block appliance incorporating progressive mandibular advancement and lower lip pads designed to influence muscular activity and enhance skeletal effects. Receives: Device: Modified Twin Block Appliance |
| Conventional Clear Twin Block Group | Active comparator | Patients in this group will be treated using a conventional clear Twin Block functional appliance for correction of skeletal Class II malocclusion. Receives: Device: Conventional Clear Twin Block Appliance |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in mandibular skeletal position measured by SNB angle on lateral cephalometric radiographs
Assessment of sagittal mandibular skeletal position using the SNB angle (degrees) measured on standardized lateral cephalometric radiographs.
Measured: Baseline (T0) and after 7 months of treatment (T1)
Change in effective mandibular length measured by Co-Gn distance on lateral cephalometric radiographs
Assessment of mandibular length using the Condylion-Gnathion (Co-Gn) linear measurement in millimeters obtained from lateral cephalometric analysis.
Measured: Baseline (T0) and after 7 months of treatment (T1)
Change in condylar dimensions assessed using cone-beam computed tomography (CBCT)
Assessment of temporomandibular condylar morphology using CBCT, including condylar length, condylar width, and condylar height measured in millimeters.
Measured: Baseline (T0) and after 7 months of treatment (T1)
Change in temporomandibular joint spaces assessed using CBCT
Assessment of condylar position within the glenoid fossa using CBCT measurements of anterior joint space (AJS), superior joint space (SJS), posterior joint space (PJS), and medial joint space (MJS), measured in millimeters.
Measured: Baseline (T0) and after 7 months of treatment (T1)
Secondary outcomes (8)
Temporomandibular joint dysfunction symptoms assessed using the Helkimo Anamnestic Index (Ai)
Assessment of temporomandibular joint dysfunction symptoms using the Helkimo Anamnestic Index questionnaire. The index classifies patients into:
- Ai0: no symptoms
- Ai1: mild symptoms
- Ai2: severe symptoms Higher scores indicate greater temporomandibular dysfunction severity.
Measured: Baseline (T0) and after 7 months of treatment (T1)
Patient-reported pain intensity assessed using a Numeric Rating Scale (NRS)
Assessment of pain intensity reported by patients using a numeric rating scale ranging from 0 to 10, where 0 indicates no pain and 10 indicates maximum pain.
Measured: 1 week, 2 weeks, 6 weeks, 3 months, and 6 months after appliance insertion
Patient-reported discomfort and functional limitation assessed using a validated questionnaire
Assessment of appliance-related discomfort and functional or social impairment using a validated questionnaire adapted from Sergl and Zentner (1998), modified by Idris et al. (2012). The questionnaire evaluates pressure sensation, tooth sensitivity, speech impairment, swallowing difficulty, mouth restriction sensation, and social confidence using a numeric rating scale from 0 to 10. Higher scores indicate greater discomfort and poorer appliance acceptance.
Measured: 1 week, 2 weeks, 6 weeks, 3 months, and 6 months after appliance insertion
Change in lower incisor inclination measured by IMPA on lateral cephalometric radiographs
Assessment of lower incisor inclination using the Incisor Mandibular Plane Angle (IMPA) measured in degrees on lateral cephalometric radiographs.
Measured: Baseline (T0) and after 7 months of treatment (T1)
Change in upper incisor inclination measured by U1-SN angle on lateral cephalometric radiographs
Assessment of upper incisor inclination using the upper incisor to SN plane angle (U1-SN) measured in degrees on lateral cephalometric radiographs.
Measured: Baseline (T0) and after 7 months of treatment (T1)
Change in overjet measured on lateral cephalometric radiographs
Assessment of overjet as the horizontal distance between upper and lower incisors measured in millimeters on lateral cephalometric radiographs.
Measured: Baseline (T0) and after 7 months of treatment (T1)
Change in overbite measured on lateral cephalometric radiographs
Assessment of overbite as the vertical overlap between upper and lower incisors measured in millimeters on lateral cephalometric radiographs.
Measured: Baseline (T0) and after 7 months of treatment (T1)
Change in sagittal molar relationship measured on lateral cephalometric radiographs
Assessment of sagittal molar relationship using linear measurements in millimeters between upper and lower first molars on lateral cephalometric radiographs.
Measured: Baseline (T0) and after 7 months of treatment (T1)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 May 2026
- Study start17 May 2026
- Primary completionDec 2026 (estimated)
- Study completionDec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (9)Papers the sponsor has linked to this study.
- Other trials for Skeletal Class II 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 will be randomly assigned into two parallel groups receiving either a modified Twin Block appliance or a conventional clear Twin Block appliance.
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 40 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Aleppo
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Feras baba, University of Aleppo
- Investigators
- Abdulmalek Majanni, PhD, Study director, Faculty of Dentistry, University of Aleppo
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07608406
- Sponsor's protocol ID
- MClearTB
- Other IDs
- UADS-3478-26052024/SRC-1994
- Acronym
- MTB-CTB
- Status last verified
- Jul 2026
- First submitted
- 12 May 2026
- Last updated
- 14 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data will not be shared due to patient privacy and confidentiality considerations. The study involves pediatric orthodontic patients, and data will be reported in aggregate form only.
Publications
Wu Y, Yu Q, Xia Y, Wang B, Chen S, Gu K, Zhang B, Zhu M. Does mandibular advancement with clear aligners have the same skeletal and dentoalveolar effects as traditional functional appliances? BMC Oral Health. 2023 Feb 2;23(1):65. doi: 10.1186/s12903-023-02709-5.
PubMed 36732724Lombardo EC, Lione R, Franchi L, Gaffuri F, Maspero C, Cozza P, Pavoni C. Dentoskeletal effects of clear aligner vs twin block-a short-term study of functional appliances. J Orofac Orthop. 2024 Sep;85(5):317-326. doi: 10.1007/s00056-022-00443-1. Epub 2023 Jan 18.
PubMed 36651930Caruso S, Nota A, Caruso S, Severino M, Gatto R, Meuli S, Mattei A, Tecco S. Mandibular advancement with clear aligners in the treatment of skeletal Class II. A retrospective controlled study. Eur J Paediatr Dent. 2021;22(1):26-30. doi: 10.23804/ejpd.2021.22.01.05.
PubMed 33719479Tripathi T, Singh N, Rai P, Gupta P. Comparison of Dentoskeletal Changes, Esthetic, and Functional Efficacy of Conventional and Novel Esthetic Twin Block Appliances among Class II Growing Patients: A Pilot Study. Turk J Orthod. 2020 Jun 1;33(2):77-84. doi: 10.5152/TurkJOrthod.2020.19030. eCollection 2020 Jun.
PubMed 32637187Golfeshan F, Soltani MK, Zohrei A, Poorolajal J. Comparison between Classic Twin-block and a Modified Clear Twin-block in Class II, Division 1 Malocclusions: A Randomized Clinical Trial. J Contemp Dent Pract. 2018 Dec 1;19(12):1455-1462.
PubMed 30713173Gill DS, Lee RT. Prospective clinical trial comparing the effects of conventional Twin-block and mini-block appliances: Part 1. Hard tissue changes. Am J Orthod Dentofacial Orthop. 2005 Apr;127(4):465-72; quiz 517. doi: 10.1016/j.ajodo.2004.11.012.
PubMed 15821691Banks P, Wright J, O'Brien K. Incremental versus maximum bite advancement during twin-block therapy: a randomized controlled clinical trial. Am J Orthod Dentofacial Orthop. 2004 Nov;126(5):583-8. doi: 10.1016/j.ajodo.2004.03.024.
PubMed 15520691Kyburz KS, Eliades T, Papageorgiou SN. What effect does functional appliance treatment have on the temporomandibular joint? A systematic review with meta-analysis. Prog Orthod. 2019 Aug 12;20(1):32. doi: 10.1186/s40510-019-0286-9.
PubMed 31402395Chadwick SM, Banks P, Wright JL. The use of myofunctional appliances in the UK: a survey of British orthodontists. Dent Update. 1998 Sep;25(7):302-8.
PubMed 10478026
Study at a glance
From the registry record, last updated by the sponsor on 14 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of the Efficacy of Functional Therapy Using Modified Twin Block Versus Clear Twin Block in Class II Skeletal Patients: A Randomized Controlled Clinical Trial
- ClinicalTrials.gov ID
- NCT07608406
- Acronym / sponsor ID
- MTB-CTB / MClearTB
- Conditions
- Skeletal Class II Malocclusion
- Keywords
- Twin Block appliance, Class II malocclusion, Mandibular advancement, Functional orthopedic treatment, CBCT
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 40 participants (estimated)
- Lead sponsor
- University of AleppoUniversity, hospital or other
- Study start
- 17 May 2026 (actual)
- Primary completion
- Dec 2026 (estimated)
- Study completion
- Dec 2026 (estimated)
- First posted
- 27 May 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 aims to evaluate the effectiveness of a modified Twin Block appliance compared to a conventional clear Twin Block appliance in the treatment of skeletal Class II malocclusion caused by mandibular retrusion in growing patients.
This is a two-arm randomized controlled clinical trial including patients aged 10-13 years diagnosed with skeletal Class II malocclusion. Participants will be randomly allocated into two equal groups.
Skeletal, dental, and soft tissue changes will be assessed using lateral cephalometric analysis and cone-beam computed tomography (CBCT). Additionally, temporomandibular joint (TMJ) health, pain perception, and functional tolerance will be evaluated using standardized clinical indices and patient-reported outcome measures.
The study aims to compare the modified appliance with the conventional design in terms of skeletal improvement, TMJ safety, and patient acceptance.
Detailed description
Skeletal and dentofacial anomalies, particularly Class II malocclusion due to mandibular retrusion, represent one of the most prevalent orthodontic problems during growth. Functional appliances, especially the Twin Block appliance, are widely used to enhance mandibular development and correct jaw discrepancies. However, variations in treatment protocols, particularly regarding advancement mechanics and appliance modifications, may influence both skeletal outcomes and temporomandibular joint (TMJ) response.
This study aims to investigate the effects of a modified Twin Block appliance, incorporating progressive mandibular advancement and additional design modifications such as lower lip pads intended to influence muscular activity, compared to a conventional clear Twin Block appliance.
A two-arm randomized controlled trial will be conducted on growing patients aged 10-13 years diagnosed with skeletal Class II malocclusion due to mandibular retrusion. Participants will be randomly allocated into two equal groups using a computer-generated randomization sequence with allocation concealment.
Skeletal and dental changes will be evaluated using lateral cephalometric radiographs and cone-beam computed tomography (CBCT), with particular attention to condylar morphology, joint space dimensions, and craniofacial skeletal relationships. TMJ health will be assessed using the Helkimo Index. Patient comfort, pain perception, and functional adaptation will be evaluated using validated questionnaires administered at multiple time points throughout the treatment period.
Radiographic and clinical assessments will be performed at baseline (T0) and after 7 months of functional appliance therapy (T1). Repeated patient-reported outcome measures will be collected at predefined intervals during treatment.
The objective of this study is to determine whether the modified Twin Block appliance provides superior skeletal and functional outcomes while maintaining temporomandibular joint safety and improving patient tolerance compared to the conventional appliance.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
- Model description
- Participants will be randomly assigned into two parallel groups receiving either a modified Twin Block appliance or a conventional clear Twin Block appliance.
| Arm | Type | Receives |
|---|---|---|
| Modified Twin Block Group | Experimental | Device: Modified Twin Block AppliancePatients in this group will be treated using a modified Twin Block appliance incorporating progressive mandibular advancement and lower lip pads designed to influence muscular activity and enhance skeletal effects. |
| Conventional Clear Twin Block Group | Active comparator | Device: Conventional Clear Twin Block AppliancePatients in this group will be treated using a conventional clear Twin Block functional appliance for correction of skeletal Class II malocclusion. |
Who may qualify
- Ages
- 10 to 13 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
Key inclusion criteria (8 listed)
- Systemically healthy patients.
- Patients willing to accept removable functional appliance therapy.
- Skeletal Class II malocclusion (Angle Class II Division 1).
- Skeletal Class II due to mandibular retrusion (ANB ≥ 5°, 6 mm ≤ OJ ≤ 13 mm , SNB ≤ 78°, with normal maxillary position).
- Growth stage corresponding to MP3 stage or pre-pubertal peak according to hand-wrist radiograph (Björk and Helm, 1967).
Key exclusion criteria (3 listed)
- Presence of clinical signs or symptoms of temporomandibular joint disorders.
- Functional mandibular deviation.
- 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 |
|---|---|---|
| Modified Twin Block ApplianceAlso: Progressive Twin BlockA modified Twin Block functional appliance incorporating progressive mandibular advancement and lower lip pads designed to modify muscular activity and enhance mandibular growth. The appliance is used for the treatment of skeletal Class II malocclusion due to mandibular retrusion in growing patients. | Device | Modified Twin Block Group |
| Conventional Clear Twin Block ApplianceAlso: Clear Twin BlockA conventional clear Twin Block functional appliance used for correction of skeletal Class II malocclusion in growing patients. The appliance acts by posturing the mandible forward to stimulate functional and skeletal adaptation. | Device | Conventional Clear Twin Block Group |
Primary outcome
Change in mandibular skeletal position measured by SNB angle on lateral cephalometric radiographs
Time frame: Baseline (T0) and after 7 months of treatment (T1)
Assessment of sagittal mandibular skeletal position using the SNB angle (degrees) measured on standardized lateral cephalometric radiographs.
Change in effective mandibular length measured by Co-Gn distance on lateral cephalometric radiographs
Time frame: Baseline (T0) and after 7 months of treatment (T1)
Assessment of mandibular length using the Condylion-Gnathion (Co-Gn) linear measurement in millimeters obtained from lateral cephalometric analysis.
Change in condylar dimensions assessed using cone-beam computed tomography (CBCT)
Time frame: Baseline (T0) and after 7 months of treatment (T1)
Assessment of temporomandibular condylar morphology using CBCT, including condylar length, condylar width, and condylar height measured in millimeters.
Change in temporomandibular joint spaces assessed using CBCT
Time frame: Baseline (T0) and after 7 months of treatment (T1)
Assessment of condylar position within the glenoid fossa using CBCT measurements of anterior joint space (AJS), superior joint space (SJS), posterior joint space (PJS), and medial joint space (MJS), measured in millimeters.
8 secondary outcomes
Temporomandibular joint dysfunction symptoms assessed using the Helkimo Anamnestic Index (Ai)
Time frame: Baseline (T0) and after 7 months of treatment (T1)
Patient-reported pain intensity assessed using a Numeric Rating Scale (NRS)
Time frame: 1 week, 2 weeks, 6 weeks, 3 months, and 6 months after appliance insertion
Patient-reported discomfort and functional limitation assessed using a validated questionnaire
Time frame: 1 week, 2 weeks, 6 weeks, 3 months, and 6 months after appliance insertion
Change in lower incisor inclination measured by IMPA on lateral cephalometric radiographs
Time frame: Baseline (T0) and after 7 months of treatment (T1)
Change in upper incisor inclination measured by U1-SN angle on lateral cephalometric radiographs
Time frame: Baseline (T0) and after 7 months of treatment (T1)
Change in overjet measured on lateral cephalometric radiographs
Time frame: Baseline (T0) and after 7 months of treatment (T1)
Change in overbite measured on lateral cephalometric radiographs
Time frame: Baseline (T0) and after 7 months of treatment (T1)
Change in sagittal molar relationship measured on lateral cephalometric radiographs
Time frame: Baseline (T0) and after 7 months of treatment (T1)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 Jul 2026.
- Results publication: PubMed 36732724Wu Y, Yu Q, Xia Y, Wang B, Chen S, Gu K, Zhang B, Zhu M. Does mandibular advancement with clear aligners have the same skeletal and dentoalveolar effects as traditional functional appliances? BMC Oral Health. 2023 Feb 2;23(1):65. doi: 10.1186/s12903-023-02709-5.
- Results publication: PubMed 36651930Lombardo EC, Lione R, Franchi L, Gaffuri F, Maspero C, Cozza P, Pavoni C. Dentoskeletal effects of clear aligner vs twin block-a short-term study of functional appliances. J Orofac Orthop. 2024 Sep;85(5):317-326. doi: 10.1007/s00056-022-00443-1. Epub 2023 Jan 18.
- Results publication: PubMed 33719479Caruso S, Nota A, Caruso S, Severino M, Gatto R, Meuli S, Mattei A, Tecco S. Mandibular advancement with clear aligners in the treatment of skeletal Class II. A retrospective controlled study. Eur J Paediatr Dent. 2021;22(1):26-30. doi: 10.23804/ejpd.2021.22.01.05.
- Results publication: PubMed 32637187Tripathi T, Singh N, Rai P, Gupta P. Comparison of Dentoskeletal Changes, Esthetic, and Functional Efficacy of Conventional and Novel Esthetic Twin Block Appliances among Class II Growing Patients: A Pilot Study. Turk J Orthod. 2020 Jun 1;33(2):77-84. doi: 10.5152/TurkJOrthod.2020.19030. eCollection 2020 Jun.
- Results publication: PubMed 30713173Golfeshan F, Soltani MK, Zohrei A, Poorolajal J. Comparison between Classic Twin-block and a Modified Clear Twin-block in Class II, Division 1 Malocclusions: A Randomized Clinical Trial. J Contemp Dent Pract. 2018 Dec 1;19(12):1455-1462.
- Results publication: PubMed 15821691Gill DS, Lee RT. Prospective clinical trial comparing the effects of conventional Twin-block and mini-block appliances: Part 1. Hard tissue changes. Am J Orthod Dentofacial Orthop. 2005 Apr;127(4):465-72; quiz 517. doi: 10.1016/j.ajodo.2004.11.012.
- Results publication: PubMed 15520691Banks P, Wright J, O'Brien K. Incremental versus maximum bite advancement during twin-block therapy: a randomized controlled clinical trial. Am J Orthod Dentofacial Orthop. 2004 Nov;126(5):583-8. doi: 10.1016/j.ajodo.2004.03.024.
- Results publication: PubMed 31402395Kyburz KS, Eliades T, Papageorgiou SN. What effect does functional appliance treatment have on the temporomandibular joint? A systematic review with meta-analysis. Prog Orthod. 2019 Aug 12;20(1):32. doi: 10.1186/s40510-019-0286-9.
- Results publication: PubMed 10478026Chadwick SM, Banks P, Wright JL. The use of myofunctional appliances in the UK: a survey of British orthodontists. Dent Update. 1998 Sep;25(7):302-8.
- Individual participant dataSharing planned: No. Individual participant data will not be shared due to patient privacy and confidentiality considerations. The study involves pediatric orthodontic patients, and data will be reported in aggregate form only.
Related trials for Skeletal Class II Malocclusion
Recruiting
Maxillary Arch Distalization With Infrazygomatic Crest Miniscrews for Class II Malocclusion
Class II Malocclusion
Recruiting
Treatment of Skeletal Class II Malocclusion With Modified Twin-Block Appliance With Clear Plates
Malocclusion, Angle Class II
Not yet recruiting
Clinical and Radiographic Evaluation of Low Sagittal Medial Ramus Osteotomy for Treatment of Skeletal Class II and Class III Malocclusion
Skeletal Class II Malocclusion, Skeletal Class III Malocclusion
Recruiting
Twin-Block and LIPUS for TMJ Outcomes in Skeletal Class II Patients
CLASS II DIVISION 1 MALOCCLUSION
Recruiting
"Sliding Jigs vs Retraction Hooks for Maxillary Dentition Distalization Using IZC Miniscrews"
Skeletal Class II Malocclusion
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.
Abdulmalek Majanni, PhD study director
Faculty of Dentistry, University of Aleppo
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Modified Twin Block Appliance and Conventional Clear Twin Block Appliance in people with Skeletal Class II Malocclusion, run by University of Aleppo at 1 site in Syria.
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 8 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: under way, not looking for participants, as of the sponsor's last update on 14 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 Syria. 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?
This study is still under way. Results are not available in the source record yet.
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 in mandibular skeletal position measured by SNB angle on lateral cephalometric radiographs (time frame: Baseline (T0) and after 7 months of treatment (T1)). The study lists 4 primary outcomes in all. 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 NCT07608406, which also lists 9 linked publications.
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 14 Jul 2026.