An observational study in CLASS II DIVISION 1 MALOCCLUSION, sponsored by Sichuan University. Completed at 1 site in China. Open to participants aged 10 Years to 13 Years. Per ClinicalTrials.gov, last updated 2024-09-24.
Sponsored by Sichuan University · Observational
The goal of this retrospective observational study is to compare the effects of Clear Aligner Mandibular Advancement (MA) and Twin Block (TB) appliances in treating Class II malocclusion, a condition where the lower jaw is underdeveloped. The main questions it aims to answer are:
Researchers will compare MA and TB appliances to an untreated control group to evaluate their impact on skeletal, dental, and soft tissue outcomes. Participants in the study underwent cephalometric analysis (X-ray measurements) both before and after treatment to assess changes in jaw positioning, overbite, and overjet. The study focuses on how each treatment affects facial aesthetics and dental function.
Participants in the study will:
Supplementary information for Study Design It was a retrospective study that collected patients' routine treatment X-rays (before and after treatment) to measure some angular and linear parameters from the X-rays.
124 studies on the registry are indexed under Malocclusion, Angle Class II; 19 are open to participants now.
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The study population consists of patients from the Orthodontics Department at West China Hospital of Stomatology, Sichuan University. This population includes individuals diagnosed with Class II malocclusion who are undergoing or have completed treatment with Mandibular Advancement (MA) or Twin Block (TB) appliances. Eligible participants for the treatment group are those in the mixed dentition or early permanent dentition stages, showing specific cephalometric characteristics such as an ANB angle greater than 4 degrees and an SNB angle less than or equal to 78 degrees.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Patients receiving routine care for Class II malocclusion, which may include the use of Clear Aligner with Mandibular Advancement (MA) function appliances
Device: Clear aligner with mandibular function
Patients receiving routine care for Class II malocclusion, which may include the use of Twin Block (TB) appliances
Device: Twin block
The TB group used a single appliance continuously, with appropriate reduction of occlusal surface height by 1 mm when clinically indicated. Both groups had follow-up appointments every 6 weeks.
The MA group underwent stepwise mandibular forward movement with clear aligners (Invisalign, Align Inc, CA, USA) worn for 22 hours/day and replaced every 7 days.
Changes in Skeletal Measurements ( SNB angle)
This study assesses skeletal changes in patients treated for Class II malocclusion with Twin Block (TB) or Mandibular Advancement (MA) appliances at West China School of Stomatology, Sichuan University. The evaluation focuses on the measurement of the SNB angle, a critical skeletal parameter, using cephalometric radiographs. These radiographs are taken as a routine part of the treatment to capture skeletal positioning before the treatment starts and after the treatment concludes. This allows for an analysis of the angular changes due to the orthodontic intervention, providing insights into the effectiveness of the appliances in correcting malocclusions.
Time frame: Baseline and post-treatment cephalometric radiographs will be taken 1-2 weeks pre and 1-2 weeks post the 12-month treatment at West China School of Stomatology, Sichuan University.
Changes in Soft Tissue Measurements ( soft tissue chin thickness)
This study assesses skeletal changes in patients treated for Class II malocclusion with Twin Block (TB) or Mandibular Advancement (MA) appliances at West China School of Stomatology, Sichuan University. The evaluation focuses on the measurement of the soft tissue chin thickness, using cephalometric radiographs. These radiographs are taken as a routine part of the treatment to capture skeletal positioning before the treatment starts (baseline) and after the treatment concludes (1-2 weeks post the 12-month treatment). This allows for an analysis of the angular changes due to the orthodontic intervention, providing insights into the effectiveness of the appliances in correcting malocclusions.
Time frame: Baseline and post-treatment cephalometric radiographs will be taken 1-2 weeks pre and 1-2 weeks post the 12-month treatment at West China School of Stomatology, Sichuan University.
Changes in Skeletal Measurements (ANB angle)
This study assesses skeletal changes in patients treated for Class II malocclusion with Twin Block (TB) or Mandibular Advancement (MA) appliances at West China School of Stomatology, Sichuan University. The evaluation focuses on the measurement of the ANB angle, a critical skeletal parameter, using cephalometric radiographs. These radiographs are taken as a routine part of the treatment to capture skeletal positioning before the treatment starts and after the treatment concludes. This allows for an analysis of the angular changes due to the orthodontic intervention, providing insights into the effectiveness of the appliances in correcting malocclusions.
Time frame: Baseline and post-treatment cephalometric radiographs will be taken 1-2 weeks pre and 1-2 weeks post the 12-month treatment at West China School of Stomatology, Sichuan University.
Changes in Skeletal Measurements ( mandibular length)
This study assesses skeletal changes in patients treated for Class II malocclusion with Twin Block (TB) or Mandibular Advancement (MA) appliances at West China School of Stomatology, Sichuan University. The evaluation focuses on the measurement of the mandibular length (mm), a critical skeletal parameter, using cephalometric radiographs. These radiographs are taken as a routine part of the treatment to capture skeletal positioning before the treatment starts and after the treatment concludes. This allows for an analysis of the angular changes due to the orthodontic intervention, providing insights into the effectiveness of the appliances in correcting malocclusions.
Time frame: Baseline and post-treatment cephalometric radiographs will be taken 1-2 weeks pre and 1-2 weeks post the 12-month treatment at West China School of Stomatology, Sichuan University
Plan to share: No — confidential
Ran from Aug 2021 to primary completion in Aug 2022, 12 months.
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This study is completed, as verified in Sep 2024. You cannot join it, but the record below documents what was studied.
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Malocclusion, Angle Class II →