Malocclusion, Angle Class IINCT05950581
Treatment of Skeletal Class II Malocclusion With Modified Twin-Block Appliance With Clear Plates
A study testing Modified Twin-Block Appliance with Clear Plates. and Traditional Twin-Block appliance in people with Malocclusion, Angle Class II, run by Hama University at 1 site in Syria.
Trial summary
Patients with skeletal class II malocclusion who have a retracted lower jaw will be treated in this study. The efficacy of clear Plates in the treatment of Skeletal Class II Malocclusion will be assessed. Read more about this study
- Who is it for?
- Ages 10 to 13 years
- Conditions the study is for
- Malocclusion, Angle Class II
- What is being tested?
- Modified Twin-Block Appliance with Clear Plates. and Traditional Twin-Block appliance
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 32 participants
- Where
- 1 siteSyria
- Study dates
- 15 Mar 2027to 15 Sep 2027
- 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
- - Patients with mixed dentition at age 10.5-13 years.
- The patient has Skeletal class II malocclusion caused by mandibular retraction ANB > 5, 8 mm >O.J> 5 mm, SNB<78, angle (NSAr) ≥ ° 125 and normal placement of the upper jaw.
- The patient is willing to accept treatment with a removable device.
- No previous orthodontic treatment
- the growth model is within the normal or horizontal maxillary opening angle of 30 >MM or angle of 400 > Björk
- patients do not have an upper alveolar dental protrusion.
Who cannot join
- -Patients with periodontal disease.
- patients with a neuromuscular disorder.
- patients of class I or III of malocclusion.
- Patients with temporomandibular joint disorder.
- Patients with Skeletal open bite.
- Patients with poor oral and gingival health
Show all 9Show fewer
- the presence of a unilateral or bilateral posterior crossbite.
- patients who have upper jaw stenosis and need to be prepared by expansion before functional treatment.
- any patient who does not meet one or more of the Inclusion criteria will be removed from the study.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Fadi Jnaid contact
Syria1 site, 1 recruiting
- Recruiting
Hama University
Hama
Fadi Jnaid, 988499015, Drfadijnaid@gmail.com
About this study
Official title: Treatment Skeletal Class II Malocclusion With Modified Twin-Block Appliance With Clear Plates VS Traditional Twin Block
Patients with skeletal class II malocclusion who have a retracted lower jaw will be treated in this study. The efficacy of clear Plates in the treatment of Skeletal Class II Malocclusion will be assessed. The skeletal, dental and soft tissues changes resulted by this intervention will be studied and compared with the results of Traditional treatment with fixed appliances.
Read the detailed description
There are two group:
- a group of patients in which participants will be undergo to Modified Twin-Block Appliance with Clear Plates.
- a group of patients in which participants will be undergo to the traditional Twin-Block Appliance. phase Intervention/treatment Condition or disease
Not applicable Other:
Modified Twin-Block Appliance with Clear Plates.
Other:
Traditional Twin-Block Appliance. Skeletal class II Malocclusion
- Conditions
- Malocclusion, Angle Class II
- Being tested
- Modified Twin-Block Appliance with Clear Plates., Traditional Twin-Block appliance
- Medical subject headings
- Malocclusion, Angle Class II
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Modified Twin-Block Appliance with Clear Plates.Device
Clear plates technique A group of patients in which participants will be undergo to clear plates treatment will be applied to the upper and lower arch 17 hours daily
Traditional Twin-Block applianceDevice
Traditional Twin-Block appliance A group of patients in which participants will undergo to the Traditional Twin-Block appliance Treatment, appliances will be applied to the upper and lower arch 17 hours daily
| Study group | Role | What they receive |
|---|---|---|
| : Modified Twin-Block Appliance with Clear Plates. | Experimental | Clear plates technique A group of patients in which participants will be undergo to clear plates treatment will be applied to the upper and lower arch 17 hours daily Experimental : Modified Twin-Block Appliance with Clear Plates. Receives: Device: Modified Twin-Block Appliance with Clear Plates. |
| Traditional Twin-Block appliance | Experimental | Traditional Twin-Block appliance A group of patients in which participants will undergo to the Traditional Twin-Block appliance Treatment, appliances will be applied to the upper and lower arch 17 hours daily Receives: Device: Traditional Twin-Block appliance |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in the SNA angle[
This angle the represents the position of the upper jaw in the cephalometric analysis in the anteroposterior direction. Lateral cephalograms will be taken and this angle is going to be measured in degrees.
Measured: : T0:1 day before the beginning of treatment . T1: when a normal overjet and canines class I relationships achieved (expected to be within 6-9 months in the exp. Group and control group)
change in the SNB angle [
This angle the represents the position of the lower jaw in the cephalometric analysis in the anteroposterior direction. Lateral cephalograms will be taken and this angle is going to be measured in degrees.
Measured: : T0:1 day before the beginning of treatment . T1: when a normal overjet and canines class I relationships achieved (expected to be within 6-9 months in the exp. Group and control group)
change in the mandibular length
Amount of distance measured from the Co point to Gn point in the cephalometric analysis. Lateral cephalograms will be taken and this angle is going to be measured in degrees.
Measured: T0: 1day before the beginning of treatment . T1: when a normal overjet and canines class I relationships achieved (expected to be within 6-9 months in the exp. Group and control group)
change in overjet
Represents The distance between the most anterior point on the lower incisor to the most anterior point on the upper incisor in the cephalometric analysis.
Measured: T0: 1 day before the beginning of treatment . T1: when a normal overjet and canines class I relationships achieved (expected to be within 6-9 months in the exp. Group and control group)
change in the vertical position of incisors
The vertical distance from the edge of the lower incisor to the mandibular plane.
Measured: : T0: 1 day before the beginning of treatment . T1: when a normal overjet and canines class I relationships achieved (expected to be within 6-9 months in the exp. Group and control group)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Jul 2023
- Study start15 Mar 2027 (estimated)
- Primary completion15 Jul 2027 (estimated)
- Study completion15 Sep 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (7)Papers the sponsor has linked to this study.
- Other trials for Malocclusion, Angle Class IIStudies 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
- Single blind
- Who is masked
- Investigator
- Enrolment
- 32 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Hama University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Rabab Alsabbagh,, DDS MSc PhD, Study director, Professor of Orthodontics, University of Hama Dental School, Hama, Syria.ANAS FAKHOURI, Principal investigator, Student in Orthodontics, University of Hama Dental School, Hama.
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05950581
- Sponsor's protocol ID
- Hama University -Orthdontic.
- Status last verified
- Sep 2025
- First submitted
- 10 Jul 2023
- Last updated
- 16 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Buschang PH, Stroud J, Alexander RG. Differences in dental arch morphology among adult females with untreated Class I and Class II malocclusion. Eur J Orthod. 1994 Feb;16(1):47-52. doi: 10.1093/ejo/16.1.47.
PubMed 8181550Clark WJ. The twin block technique. A functional orthopedic appliance system. Am J Orthod Dentofacial Orthop. 1988 Jan;93(1):1-18. doi: 10.1016/0889-5406(88)90188-6. No abstract available.
PubMed 3422118Cozza P, Baccetti T, Franchi L, De Toffol L, McNamara JA Jr. Mandibular changes produced by functional appliances in Class II malocclusion: a systematic review. Am J Orthod Dentofacial Orthop. 2006 May;129(5):599.e1-12; discussion e1-6. doi: 10.1016/j.ajodo.2005.11.010.
PubMed 16679196de Lira Ade L, de Moura WL, Artese F, Bittencourt MA, Nojima LI. Surgical prediction of skeletal and soft tissue changes in treatment of Class II. J Craniomaxillofac Surg. 2013 Apr;41(3):198-203. doi: 10.1016/j.jcms.2012.07.009. Epub 2012 Nov 30.
PubMed 23201327Jung MH, Yang WS, Nahm DS. Maximum closing force of mentolabial muscles and type of malocclusion. Angle Orthod. 2010 Jan;80(1):72-9. doi: 10.2319/020509-78.1.
PubMed 19852643Trenouth MJ. Cephalometric evaluation of the Twin-block appliance in the treatment of Class II Division 1 malocclusion with matched normative growth data. Am J Orthod Dentofacial Orthop. 2000 Jan;117(1):54-9. doi: 10.1016/s0889-5406(00)70248-4.
PubMed 10629520Tulloch JF, Medland W, Tuncay OC. Methods used to evaluate growth modification in Class II malocclusion. Am J Orthod Dentofacial Orthop. 1990 Oct;98(4):340-7. doi: 10.1016/S0889-5406(05)81491-X.
PubMed 2220695
Study at a glance
From the registry record, last updated by the sponsor on 16 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Treatment Skeletal Class II Malocclusion With Modified Twin-Block Appliance With Clear Plates VS Traditional Twin Block
- ClinicalTrials.gov ID
- NCT05950581
- Acronym / sponsor ID
- Hama University -Orthdontic.
- Conditions
- Malocclusion, Angle Class II
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 32 participants (estimated)
- Lead sponsor
- Hama UniversityUniversity, hospital or other
- Study start
- 15 Mar 2027 (estimated)
- Primary completion
- 15 Jul 2027 (estimated)
- Study completion
- 15 Sep 2027 (estimated)
- First posted
- 18 Jul 2023 (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.
Patients with skeletal class II malocclusion who have a retracted lower jaw will be treated in this study. The efficacy of clear Plates in the treatment of Skeletal Class II Malocclusion will be assessed. The skeletal, dental and soft tissues changes resulted by this intervention will be studied and compared with the results of Traditional treatment with fixed appliances.
Detailed description
There are two group:
- a group of patients in which participants will be undergo to Modified Twin-Block Appliance with Clear Plates.
- a group of patients in which participants will be undergo to the traditional Twin-Block Appliance. phase Intervention/treatment Condition or disease
Not applicable Other:
Modified Twin-Block Appliance with Clear Plates.
Other:
Traditional Twin-Block Appliance. Skeletal class II Malocclusion
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| : Modified Twin-Block Appliance with Clear Plates. | Experimental | Device: Modified Twin-Block Appliance with Clear Plates.Clear plates technique A group of patients in which participants will be undergo to clear plates treatment will be applied to the upper and lower arch 17 hours daily Experimental : Modified Twin-Block Appliance with Clear Plates. |
| Traditional Twin-Block appliance | Experimental | Device: Traditional Twin-Block applianceTraditional Twin-Block appliance A group of patients in which participants will undergo to the Traditional Twin-Block appliance Treatment, appliances will be applied to the upper and lower arch 17 hours daily |
Who may qualify
- Ages
- 10 to 13 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
Key inclusion criteria (6 listed)
- - Patients with mixed dentition at age 10.5-13 years.
- The patient has Skeletal class II malocclusion caused by mandibular retraction ANB > 5, 8 mm >O.J> 5 mm, SNB<78, angle (NSAr) ≥ ° 125 and normal placement of the upper jaw.
- The patient is willing to accept treatment with a removable device.
- No previous orthodontic treatment
- the growth model is within the normal or horizontal maxillary opening angle of 30 >MM or angle of 400 > Björk
Key exclusion criteria (9 listed)
- -Patients with periodontal disease.
- patients with a neuromuscular disorder.
- patients of class I or III of malocclusion.
- Patients with temporomandibular joint disorder.
- Patients with Skeletal open bite.
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 Appliance with Clear Plates.Clear plates technique A group of patients in which participants will be undergo to clear plates treatment will be applied to the upper and lower arch 17 hours daily | Device | : Modified Twin-Block Appliance with Clear Plates. |
| Traditional Twin-Block applianceTraditional Twin-Block appliance A group of patients in which participants will undergo to the Traditional Twin-Block appliance Treatment, appliances will be applied to the upper and lower arch 17 hours daily | Device | Traditional Twin-Block appliance |
Primary outcome
Change in the SNA angle[
Time frame: : T0:1 day before the beginning of treatment . T1: when a normal overjet and canines class I relationships achieved (expected to be within 6-9 months in the exp. Group and control group)
This angle the represents the position of the upper jaw in the cephalometric analysis in the anteroposterior direction. Lateral cephalograms will be taken and this angle is going to be measured in degrees.
change in the SNB angle [
Time frame: : T0:1 day before the beginning of treatment . T1: when a normal overjet and canines class I relationships achieved (expected to be within 6-9 months in the exp. Group and control group)
This angle the represents the position of the lower jaw in the cephalometric analysis in the anteroposterior direction. Lateral cephalograms will be taken and this angle is going to be measured in degrees.
change in the mandibular length
Time frame: T0: 1day before the beginning of treatment . T1: when a normal overjet and canines class I relationships achieved (expected to be within 6-9 months in the exp. Group and control group)
Amount of distance measured from the Co point to Gn point in the cephalometric analysis. Lateral cephalograms will be taken and this angle is going to be measured in degrees.
change in overjet
Time frame: T0: 1 day before the beginning of treatment . T1: when a normal overjet and canines class I relationships achieved (expected to be within 6-9 months in the exp. Group and control group)
Represents The distance between the most anterior point on the lower incisor to the most anterior point on the upper incisor in the cephalometric analysis.
change in the vertical position of incisors
Time frame: : T0: 1 day before the beginning of treatment . T1: when a normal overjet and canines class I relationships achieved (expected to be within 6-9 months in the exp. Group and control group)
The vertical distance from the edge of the lower incisor to the mandibular plane.
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 16 Sep 2026.
- Background: PubMed 8181550Buschang PH, Stroud J, Alexander RG. Differences in dental arch morphology among adult females with untreated Class I and Class II malocclusion. Eur J Orthod. 1994 Feb;16(1):47-52. doi: 10.1093/ejo/16.1.47.
- Background: PubMed 3422118Clark WJ. The twin block technique. A functional orthopedic appliance system. Am J Orthod Dentofacial Orthop. 1988 Jan;93(1):1-18. doi: 10.1016/0889-5406(88)90188-6. No abstract available.
- Background: PubMed 16679196Cozza P, Baccetti T, Franchi L, De Toffol L, McNamara JA Jr. Mandibular changes produced by functional appliances in Class II malocclusion: a systematic review. Am J Orthod Dentofacial Orthop. 2006 May;129(5):599.e1-12; discussion e1-6. doi: 10.1016/j.ajodo.2005.11.010.
- Background: PubMed 23201327de Lira Ade L, de Moura WL, Artese F, Bittencourt MA, Nojima LI. Surgical prediction of skeletal and soft tissue changes in treatment of Class II. J Craniomaxillofac Surg. 2013 Apr;41(3):198-203. doi: 10.1016/j.jcms.2012.07.009. Epub 2012 Nov 30.
- Background: PubMed 19852643Jung MH, Yang WS, Nahm DS. Maximum closing force of mentolabial muscles and type of malocclusion. Angle Orthod. 2010 Jan;80(1):72-9. doi: 10.2319/020509-78.1.
- Background: PubMed 10629520Trenouth MJ. Cephalometric evaluation of the Twin-block appliance in the treatment of Class II Division 1 malocclusion with matched normative growth data. Am J Orthod Dentofacial Orthop. 2000 Jan;117(1):54-9. doi: 10.1016/s0889-5406(00)70248-4.
- Background: PubMed 2220695Tulloch JF, Medland W, Tuncay OC. Methods used to evaluate growth modification in Class II malocclusion. Am J Orthod Dentofacial Orthop. 1990 Oct;98(4):340-7. doi: 10.1016/S0889-5406(05)81491-X.
- 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.
Fadi Jnaid contact
Rabab Alsabbagh,, DDS MSc PhD study director
Professor of Orthodontics, University of Hama Dental School, Hama, Syria.
ANAS FAKHOURI principal investigator
Student in Orthodontics, University of Hama Dental School, Hama.
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 with Clear Plates. and Traditional Twin-Block appliance in people with Malocclusion, Angle Class II, run by Hama University 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 6 inclusion and 9 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: looking for participants now, as of the sponsor's last update on 16 Sep 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?
Contact Fadi Jnaid (988499015, Drfadijnaid@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in the SNA angle[ (time frame: : T0:1 day before the beginning of treatment . T1: when a normal overjet and canines class I relationships achieved (expected to be within 6-9 months in the exp. Group and control group)). The study lists 5 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 NCT05950581, which also lists 7 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 16 Sep 2026.