CLASS II DIVISION 1 MALOCCLUSION
Conditions
Brief summary
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: 1. Does mandibular advancement with clear aligners improve jaw and dental alignment as effectively as Twin Block appliances? 2. What are the differences in soft tissue changes, such as chin advancement and lip position, between these two treatments? 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: * Undergo treatment with either clear aligner mandibular advancement or Twin Block appliances. * Attend follow-up appointments to monitor progress and assess treatment outcomes.
Detailed description
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.
Interventions
DEVICETwin 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.
DEVICEClear aligner with mandibular function
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.
Sponsors
Sichuan University
Study design
Observational model
CASE_CONTROL
Time perspective
RETROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
10 Years to 13 Years
Healthy volunteers
No
Inclusion criteria
* Patients who have completed MA or TB treatment at the West China Hospital of Stomatology Orthodontic Department. * Pretreatment lateral cephalometric radiographs showing cervical vertebral maturation stage (CVSM) II or III. * Patients in the mixed dentition or early permanent dentition stages. * Class II Division 1 malocclusion according to Angle's classification * ANB angle > 4°; SNB ≤ 78°. * Comprehensive medical records and necessary data available pre- and post-treatment.
Exclusion criteria
* Missing teeth, supernumerary teeth, or severe dental malformations affecting function. * Poor oral hygiene. * Systemic diseases or congenital deformities. * History of dental or maxillofacial trauma. * Incomplete or missing records.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Changes in Skeletal Measurements ( SNB angle) | 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. | 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. |
| Changes in Soft Tissue Measurements ( soft tissue chin thickness) | 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. | 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. |
| Changes in Skeletal Measurements (ANB angle) | 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. | 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. |
| Changes in Skeletal Measurements ( mandibular length) | 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 | 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. |
Countries
China
Outcome results
None listed