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RecruitingNCT05950581Updated Sep 16, 2026

Treatment of Skeletal Class II Malocclusion With Modified Twin-Block Appliance With Clear Plates

An interventional study of Modified Twin-Block Appliance with Clear Plates. and Traditional Twin-Block appliance in Malocclusion, Angle Class II, sponsored by Hama University. Recruiting at 1 site in Syria. Open to participants aged 10 Years to 13 Years. Per ClinicalTrials.gov, last updated 2026-09-16.

Sponsored by Hama University · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
32
Allocation
Randomized
Ages
10 Years to 13 Years
Sex
All
01

Study 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. 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:

  1. a group of patients in which participants will be undergo to Modified Twin-Block Appliance with Clear Plates.
  2. 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

02

Conditions studied

  • Malocclusion, Angle Class II
03

In context

Malocclusion, Angle Class II

124 studies on the registry are indexed under Malocclusion, Angle Class II; 19 are open to participants now.

This study's planned enrollment of 32 is close to the median of 34 across 115 interventional studies indexed under Malocclusion, Angle Class II.

Browse Malocclusion, Angle Class II studies →

Lead sponsor

Hama University is the lead sponsor of 9 studies on the registry; 4 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
10 Years to 13 Years
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • - 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.

Exclusion criteria

Exclusion Criteria:

  • -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
  • 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.
05

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Single (Investigator)
Enrollment
32 participants (estimated)

Study arms

  • Experimental
    : 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.

    Device: Modified Twin-Block Appliance with Clear Plates.

  • Experimental
    Traditional Twin-Block appliance

    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

    Device: Traditional Twin-Block appliance

Interventions

  • DeviceModified 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

  • DeviceTraditional Twin-Block appliance

    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

06

What researchers measure

Primary outcomes

  1. 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.

    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)

  2. 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.

    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)

  3. 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.

    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)

  4. 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.

    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)

  5. change in the vertical position of incisors

    The vertical distance from the edge of the lower incisor to the mandibular plane.

    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)

07

Study locations

1 of 1 sites recruiting
08

References and documents

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 8181550 ↗
  • Clark 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 3422118 ↗
  • Cozza 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 16679196 ↗
  • de 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 23201327 ↗
  • Jung 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 19852643 ↗
  • Trenouth 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 10629520 ↗
  • Tulloch 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 ↗

Individual participant data

Plan to share: No

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Sep 16, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT05950581
Lead sponsor
Hama University
Responsible party
Sponsor
First posted
Jul 18, 2023
Start date
Mar 15, 2027 (estimated)
Primary completion
Jul 15, 2027 (estimated)
Completion
Sep 15, 2027 (estimated)
Last update
Sep 16, 2026

Study contacts

Fadi Jnaid
Contact
Drfadijnaid@gmail.com
988499015
Fadi Jnaid
Contact
fadijnaid@hama-univ.edu.sy
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.

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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