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Published on: January 28, 2020
[Non-extraction treatment in borderline class III malocclusion].
Lin-ling Chen1, Qing-ling You, Yi-ming Yang
1Department of Orthodontics, Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai 200011, China. chenlinling100@yahoo.com.cn
Summary
This study shows that a non-extraction orthodontic treatment, including rapid palatal expansion and lower molar distalization, effectively corrects borderline Class III malocclusion in adolescents. The protocol improves jaw alignment and lip profile.
Area of Science:
- Orthodontics
- Craniofacial Development
- Dental Malocclusion
Background:
- Borderline Class III malocclusion presents a diagnostic and treatment challenge in adolescents.
- Non-extraction protocols are sought to manage such cases while optimizing facial aesthetics and skeletal relationships.
Purpose of the Study:
- To evaluate the efficacy of a non-extraction treatment combining rapid palatal expansion and lower molar distalization.
- To assess the effects on skeletal and dental parameters in adolescents with borderline Class III malocclusion.
Main Methods:
- Nine adolescent patients (mean age 13.4 years) with borderline Class III malocclusion (ANB > -3°) underwent the described non-extraction protocol.
- Lateral cephalograms were analyzed pre- and post-treatment to evaluate changes in skeletal and dental relationships.
- Paired t-tests were used to determine statistical significance of observed changes.
Main Results:
- Significant forward movement of the maxilla (A-point: +1.69 mm, SNA: +1°) and inhibition of mandibular growth (B-point: -1.88 mm, SNB: -0.69°) were observed.
- The treatment resulted in a significant increase in the ANB angle (+1.69°), indicating correction of the sagittal jaw discrepancy.
- Improvements in maxillary incisor position and upper-lower lip relationship were also noted, alongside clockwise mandibular rotation.
Conclusions:
- The evaluated non-extraction treatment protocol is effective in improving sagittal jaw discrepancies in borderline Class III malocclusion.
- This approach also leads to a favorable upper-lower lip relationship, enhancing facial aesthetics.
