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Completed

NCT Number: NCT07591025

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

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.

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Key information

Conditions

Malocclusion Class II

Age range

9 year–14 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Salamanca

Salamanca, 37008, Spain

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

AngelAligner A6 Mandibular Advancer

Device

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

Twin Block

Device

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.

Clear aligners

Device

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.

Primary outcomes

  1. ANB (°)

    Time frame: 10 months

    Point A-nasion-point B angle (ANB): relationship between the upper and lower jaws

  2. Wits appraisal (AO-BO)

    Time frame: 10 months

    projecting points A and B in two perpendicular lines, along the functional occlusal plane

Sponsors and collaborators

Lead sponsor

University of Salamanca

Other

Registry information

Official study title

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

Important dates

Study start
2022
Primary completion
2022
Study completion
2025
First posted
May 15, 2026
Registry last updated
May 15, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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