Comparison Between Mandibular Advancement With Aligners and Twin Block in Class II Malocclusion in Growing Patients

Analysis of the Efficacy of AngelAligner A6 Mandibular Advancer and Twin Block in the Treatment of Class II Malocclusion in Growing Patients: a Prospective Clinical Study

To analyze mandibular advancement between the traditional Twin Block and the Angel Aligner A6 mandibular advancement clear aligners using cephalometric analysis in growing patients and a repeatable and reproducible digital measurement technique.

Study Overview

• Status: Completed
• Conditions: Malocclusion Class II
• Intervention / Treatment: Device: AngelAligner A6 Mandibular Advancer; Device: Twin Block; Device: Clear aligners

Detailed Description

This study compared three early orthodontic treatments for Class II division 1 malocclusion in 60 growing patients (mean age: 12.4 ± 1.3 years): Twin Block, standard Angel Aligner, and Angel Aligner A6 with mandibular advancement.

After 10 months, both Twin Block and A6 showed greater skeletal correction and mandibular advancement than standard aligners, achieving higher rates of Class I correction. The A6 group also had the shortest overall treatment time.

Cephalometric analyses were performed using a digital and reproducible measurement technique. For each patient, lateral cephalograms were taken before treatment (T0) and after treatment (T1, after the functional phase or aligner completion). Thus, a total of 120 lateral cephalograms were analysed. The following skeletal, dental, and soft tissue parameters were analysed.

• Study Type: Interventional
• Enrollment (Actual): 60
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Spain
  • Salamanca
    • Salamanca, Salamanca, Spain, 37008
      • University of Salamanca

Participation Criteria

Eligibility Criteria

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

Description

Inclusion criteria:

• Aged between 9 and 14 years with late mixed or early permanent dentition
• Class II/1 malocclusion (molar relationship ≥ half-cusp Class II and overjet ≥ 5 mm)
• ANB angle greater than 5º
• SNB lower than 78º
• CVMS 2-3, a growing patients.

Exclusion criteria:

• Previous orthodontic treatment or orthognathic surgery
• Patients with severe malformations or syndromes
• Extraction treatment.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: AngelAligner A6 Mandibular Advancer; Mandibular advancement with aligners uses specially designed appliances to position the lower jaw forward, improving jaw alignment and correcting Class II malocclusion in growing patients. Aligner replacement was performed at 10-day intervals.	Device: AngelAligner A6 Mandibular Advancer; Mandibular advancement with aligners is achieved using specially designed orthodontic aligners that incorporate built-in mandibular advancement features. These appliances posture the lower jaw forward in a controlled and incremental manner while simultaneously aligning the teeth. The forward positioning of the mandible helps stimulate mandibular growth in growing patients and improves the correction of Class II malocclusion by enhancing sagittal jaw relationship. Aligner replacement was performed at 10-day intervals.; Other Names: GA6
Active Comparator: Twin block; The Twin Block is a removable functional orthodontic appliance used to correct Class II malocclusion by advancing the mandible. It consists of upper and lower acrylic plates with bite blocks that interlock at a specific angle, guiding the lower jaw forward during closure. It is most effective in growing patients to improve jaw relationship and facial profile. The Twin Block appliance was worn for a period of 10 months, with a minimum of 14-16 hours per day, including night hours.	Device: Twin Block; The Twin Block is a removable functional orthodontic appliance used to correct Class II malocclusion by advancing the mandible. It consists of upper and lower acrylic plates with bite blocks that interlock at a specific angle, guiding the lower jaw forward during closure. It is most effective in growing patients to improve jaw relationship and facial profile. The Twin Block appliance, used for mandibular advancement (correction of skeletal class II), was usually worn for a period of 10 months, with a minimum of 14-16 hours per day, including night hours.
Active Comparator: Clear aligners; Class II correction with aligners (without mandibular advancement) involves the use of clear sequential aligners to improve dental alignment and occlusion by moving teeth into a more favorable position. The correction is achieved through controlled tooth movements without actively repositioning the mandible forward. Aligner replacement was performed at 10-day intervals.	Device: Clear aligners; Class II correction with aligners (without mandibular advancement) involves the use of clear sequential aligners to improve dental alignment and occlusion by moving teeth into a more favorable position. The correction is achieved through controlled tooth movements such as distalization, interproximal reduction, and vertical control, without actively repositioning the mandible forward.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
ANB (°)	Point A-nasion-point B angle (ANB): relationship between the upper and lower jaws	10 months
Wits appraisal (AO-BO)	projecting points A and B in two perpendicular lines, along the functional occlusal plane	10 months

Collaborators and Investigators

• Sponsor: University of Salamanca

Study record dates

Study Major Dates

• Study Start (Actual): October 18, 2022
• Primary Completion (Actual): October 18, 2022
• Study Completion (Actual): July 14, 2025

Study Registration Dates

• First Submitted: May 6, 2026
• First Submitted That Met QC Criteria: May 12, 2026
• First Posted (Actual): May 15, 2026

Study Record Updates

• Last Update Posted (Actual): May 15, 2026
• Last Update Submitted That Met QC Criteria: May 12, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Class II; mandibular advancement; clear aligners; growing patients; twin block
• Other Study ID Numbers: UniversidadDeSalamanca

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