3D Printed Reverse Twin Block for Class III Malocclusion (3DRTB)

Effectiveness of a Novel 3D Printed Reverse Twin Block in The Management of Maxillary Deficiency of Class III Malocclusion: A Randomized Clinical Trial

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.

Study Overview

• Status: Recruiting
• Conditions: Class III Malocclusion
• Intervention / Treatment: Device: 3D printed Reverse Twin Block appliance; Device: Conventional Reverse Twin Block appliance

• Study Type: Interventional
• Enrollment (Estimated): 30
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Linda Basim, PhD; Phone Number: +9647812867005; Email: landa.hadi2403@codental.uobaghdad.edu.iq

Study Locations

• Iraq
  • Baghdad, Iraq
    • Recruiting
    • Collage of Dentistry, University of Baghdad

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: No

Description

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:

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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
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; a CAD-CAM novel reverse twin block appliance will be used for orthopedic management of maxillary deficiency in growing patients with class III malocclusion.
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; a conventionally fabricated Reverse Twin Block appliance will be used for correction of maxillary deficiency in growing patients with class III malocclusion

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Sagittal and vertical relationship by cephalometric radiograph.	Skeletal changes (SNA, SNB, ANB, Wits appraisal, SN-Pog angle TAFH, TPFH, mandibular plane angle, facial plane angle, facial taper angle, facial axis angle, maxillary convexity, saddle angle).	T0 baseline records T1 3 months after initiation of treatment T2 6 months after initiation of treatment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Transverse relationship by Study model	This will measure by scanned digital study model to calculate the amount of expansion at T0, T1, T2.; Intermolar width: which is the distance between the mesiobuccal cusp tips of the right and left maxillary first molars.; 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.	T0 baseline records T1 after 3 months T2 after 6 months

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Oral hygiene index-children (OHI-C) will be measured	The six index teeth that will be included: 16/55: Maxillary right permanent first molar or maxillary right primary second molar.; 11/51: Maxillary right permanent central incisor or maxillary right primary central incisor.; 26/65: Maxillary left permanent first molar or maxillary left primary second molar.; 36/75: Mandibular left permanent first molar or mandibular left primary second molar.; 31/71: Mandibular left permanent central incisor or mandibular left primary central incisor.; 46/85: Mandibular right permanent first molar or mandibular right primary second molar.	T0 baseline record T1 after 3 months T2 after 6 months

Collaborators and Investigators

• Sponsor: University of Baghdad

Study record dates

Study Major Dates

• Study Start (Actual): June 10, 2026
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): June 30, 2027

Study Registration Dates

• First Submitted: July 1, 2026
• First Submitted That Met QC Criteria: July 14, 2026
• First Posted (Actual): July 17, 2026

Study Record Updates

• Last Update Posted (Actual): July 17, 2026
• Last Update Submitted That Met QC Criteria: July 14, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Stomatognathic Diseases; Tooth Diseases; Malocclusion; Malocclusion, Angle Class III
• Other Study ID Numbers: 1213426

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No