CClinicalTrials.gg
RecruitingNCT077103913DRTBUpdated Jul 21, 2026

3D Printed Reverse Twin Block for Class III Malocclusion

An interventional study of 3D printed Reverse Twin Block appliance and Conventional Reverse Twin Block appliance in Class III Malocclusion, sponsored by University of Baghdad. Recruiting at 1 site in Iraq. Open to participants aged 8 Years to 13 Years. Per ClinicalTrials.gov, last updated 2026-07-21.

Sponsored by University of Baghdad · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
30
Allocation
Randomized
Ages
8 Years to 13 Years
Sex
All
01

Study summary

This RCT aims to evaluate the effectiveness of a novel 3D printed reverse twin block appliance in the management of maxillary deficiency in growing patients having class III malocclusion. The clinical outcomes of this appliance will be compared with the conventional reverse twin block appliance over 6 months treatment period.

primary objective is evaluating of the effectiveness of 3DRTB in correcting sagittal discrepancies due to maxillary deficiency in class III malocclusion compared to conventional one while secondary objectives are assessment of transverse and vertical jaw relationship produced by 3DRTB compared to CRTB and to evaluate the soft tissue profile of class III patients and to evaluate the maxillary and mandibular incisor inclination, also assessment of patient perception with both appliances by using questionnaire and finally to assess the impact of 3DRTB on oral health compared to CRTB by using oral hygiene index.

02

Conditions studied

  • Class III Malocclusion
03

Who can participate

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

Inclusion criteria

  1. The age group selected is mixed dentition group 8-13 years with residual potential maxillary growth. Patient maturity will be assessed using the Cervical Vertebral Maturation (CVM) method on lateral cephalogram, patients in CS1-CS3 stages will be included to ensure remaining maxillary growth.
  2. Presence of permanent first molar with lower anterior teeth to retain the appliance.
  3. Skeletal/dental class III tendency with anterior cross bite or reverse overjet: a. Clinically the overjet is equal or less than zero up to -3 mm.

    b. Cephalometric ANB angle equal or less than zero up to -3 degrees and Wits appraisal ≤ -2.

  4. Prescence of unilateral or bilateral posterior crossbite.
  5. Mild to moderate anterior crowding.
  6. Acceptable oral hygiene baseline defined by oral hygiene index (OHI). -

Exclusion criteria

Exclusion Criteria:

  1. Patients with cleft lip and palate and/or craniofacial anomalies.
  2. History of previous orthopedic and/or orthodontic treatment.
  3. Presence of uncontrolled systemic disease or medically compromised status.
  4. Uncooperative patient/parents.
04

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
30 participants (estimated)

Study arms

  • Experimental
    3D printed Reverse Twin Block appliance

    patients with class III malocclusion will receive a novel 3D printed reverse twin block with expansion screw for expansion and protraction of maxilla and will be digitally designed using CAD software and fabricated using photopolymer resin.

    Device: 3D printed Reverse Twin Block appliance

  • Active comparator
    Conventional Reverse Twin Block appliance

    patients with class III malocclusion will receive a conventional reverse twin block with expansion screw for expansion and protraction of maxilla and will be fabricated from acrylic resin.

    Device: Conventional Reverse Twin Block appliance

Interventions

  • Device3D printed Reverse Twin Block appliance

    a CAD-CAM novel reverse twin block appliance will be used for orthopedic management of maxillary deficiency in growing patients with class III malocclusion.

  • DeviceConventional Reverse Twin Block appliance

    a conventionally fabricated Reverse Twin Block appliance will be used for correction of maxillary deficiency in growing patients with class III malocclusion

05

What researchers measure

Primary outcomes

  1. Changes in sagittal relation using lateral cephalometric radiograph.

    By using cephalometric radiograph skeletal changes in sagittal plane will be measured like: 1. SNA angle in degrees. 2. SNB angle in degrees. 3. ANB angle in degrees. 4. Wits appraisal in degrees. 5. SN-Pog angle

    Time frame: T0 baseline records T1 3 months after initiation of treatment T2 6 months after initiation of treatment

Secondary outcomes

  1. Transverse relationship by Study model

    This will measure by scanned digital study model to calculate the amount of expansion at T0, T1, T2. 1. Intermolar width: which is the distance between the mesiobuccal cusp tips of the right and left maxillary first molars. 2. Arch length: Arch length will be achieved by measuring the summation of right and left lines that passing through the midpoint between the distal surfaces of the deciduous second molar or the first permanent molar to the midpoint between the central incisors.

    Time frame: T0 baseline records T1 after 3 months T2 after 6 months

Other outcomes

  1. Oral hygiene index-children (OHI-C) will be measured

    The six index teeth that will be included: 1. 16/55: Maxillary right permanent first molar or maxillary right primary second molar. 2. 11/51: Maxillary right permanent central incisor or maxillary right primary central incisor. 3. 26/65: Maxillary left permanent first molar or maxillary left primary second molar. 4. 36/75: Mandibular left permanent first molar or mandibular left primary second molar. 5. 31/71: Mandibular left permanent central incisor or mandibular left primary central incisor. 6. 46/85: Mandibular right permanent first molar or mandibular right primary second molar.

    Time frame: T0 baseline record T1 after 3 months T2 after 6 months

06

Study locations

1 of 1 sites recruiting
  • Collage of Dentistry, University of Baghdad
    Baghdad, Iraq
    Recruiting
07

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

08

Registry details

Key details

Study ID
NCT07710391
Lead sponsor
University of Baghdad
Responsible party
Linda Basim (principal investigator, University of Baghdad) — Principal investigator
First posted
Jul 17, 2026
Start date
Jun 10, 2026
Primary completion
Dec 31, 2026 (estimated)
Completion
Jun 30, 2027 (estimated)
Last update
Jul 21, 2026

Study contacts

Linda Basim, PhD
Contact
landa.hadi2403@codental.uobaghdad.edu.iq
+9647812867005

Oversight

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

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