3D-printed fixed twin block versus MARA to help correct an underdeveloped lower jaw in Class II malocclusion

Dentoskeletal Effects of CAD/CAM 3D-Printed Fixed Twin Block Versus MARA Appliances in the Management of Skeletal Class II Due to Mandibular Deficiency in Preadolescence: A Randomized Controlled Trial

This research will test whether a CAD/CAM 3D-printed fixed twin block or a MARA appliance better improves dental alignment and jaw relationships in preadolescents with Class II due to a small lower jaw.

Quick facts

• Phase: Not applicable
• Study type: Interventional
• Enrollment: 60 (estimated)
• Ages: 9 Years to 14 Years
• Sex: All
• Sponsor: Mansoura University (Academic / other)
• Locations: 1 site (Al Mansurah, Dakahlia Governorate)
• Trial ID: NCT07340242 on ClinicalTrials.gov

What this trial studies

This is a randomized, parallel-group controlled trial enrolling 60 preadolescent patients with Class II malocclusion due to mandibular retrusion, randomized 1:1:1 into three groups. Participants will receive either a CAD/CAM 3D-printed fixed twin block, a MARA appliance, or serve in a comparator group, with dentoskeletal outcomes tracked over the treatment period. Outcomes will include dental and skeletal measurements (likely cephalometric analyses) to quantify changes in jaw position and tooth relationships. Eligibility focuses on circumpubertal growth patients (CVMI 2–4) with overjet ≥ 6 mm and minimal mandibular crowding.

Who should consider this trial

Good fit: Ideal candidates are preadolescent patients in the circumpubertal growth phase (CVMI 2–4) with Class II malocclusion from mandibular retrusion, overjet ≥ 6 mm, normal or low-angle growth pattern, minimal lower‑arch crowding, and no prior orthodontic treatment.

Not a fit: Patients with Class II caused primarily by maxillary excess, significant mandibular crowding, prior orthodontic treatment, craniofacial anomalies, cleft conditions, systemic growth disorders, or active temporomandibular disorder are unlikely to benefit from these appliances.

Why it matters

Potential benefit: If successful, the approach could improve lower-jaw growth and dental alignment in affected children, potentially reducing the need for more invasive procedures later.

How similar studies have performed: Traditional functional appliances like twin-block and MARA have shown consistent dental changes and variable modest skeletal effects, while the CAD/CAM 3D-printed fixed twin block approach is newer and less extensively studied.

Eligibility criteria

Inclusion Criteria:

1. Skeletal Class II malocclusion due to mandibular retrusion.
2. Overjet ≥ 6.0 mm.
3. Normal or low-angle growth pattern.
4. Minimum crowding in the mandibular arch.
5. Undergoing circumpubertal phase of skeletal development (CVMI 2, 3, and 4)

Exclusion Criteria:

1. Clinical signs and symptoms of temporomandibular disorder.
2. Systemic disease affecting bone and general growth.
3. Previous orthodontic treatment
4. Cleft lip or palate.
5. Congenital craniofacial deformity.
6. Abnormal oral habits.

Where this trial is running

Al Mansurah, Dakahlia Governorate

• Faculty of dentistry, Mansoura university — Al Mansurah, Dakahlia Governorate, Egypt (Recruiting)

Study contacts

• Study coordinator: Yasmin s Ghaly, phd

Conditions Class II Malocclusion; Mandibular Deficiency