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A retrospective study of Angle Class I malocclusions treated orthodontically without extractions using two palatal
M Azizi1, M K Shrout, A J Haas
1Orthodontic Department, School of Dentistry, Medical College of Georgia, Augusta 30912-1241, USA.
Summary
Orthodontic treatment for Angle Class I malocclusion without tooth extraction effectively corrected crowding. While some minor relapse occurred after an average of 8 years post-retention, the overall orthodontic correction was maintained.
Area of Science:
- Orthodontics
- Dental Arch Development
- Malocclusion Correction
Background:
- Mandibular anterior crowding is a common orthodontic concern.
- Correction and long-term stability of orthodontic treatment outcomes are crucial for patient satisfaction.
- Understanding relapse patterns after non-extraction treatment is essential for predicting long-term results.
Purpose of the Study:
- To evaluate the correction and post-retention relapse of mandibular anterior crowding in Angle Class I malocclusion patients treated without permanent tooth extraction.
- To compare the effectiveness of two orthopedic treatment approaches for maxillary apical base development in conjunction with orthodontic mechanics.
Main Methods:
- Retrospective evaluation of 58 patients with Angle Class I malocclusion treated orthodontically without extraction.
- Two groups received orthopedic treatment for maxillary apical base development (Kloehn face bow vs. Haas palatal expansion), followed by tandem mechanics.
- Measurements included overbite, overjet, intercanine distance, intermolar distance, and irregularity index, assessed pre-treatment, post-treatment, and post-retention (average 8 years).
Main Results:
- Both treatment groups showed significant improvements in overbite, overjet, and irregularity index, with increased intermolar distance. Intercanine distance remained stable.
- Post-retention follow-up revealed slight changes towards pre-treatment values, but overall orthodontic correction was largely maintained.
- The irregularity index showed minimal increase in the post-retention period for both groups, indicating small relapse.
Conclusions:
- Orthodontic treatment without extraction effectively corrects mandibular anterior crowding in Angle Class I malocclusion.
- A small degree of relapse in mandibular anterior crowding is expected post-retention, but it does not compromise the overall orthodontic correction.
- Neither pre-treatment nor post-treatment variables predicted the extent of relapse in this study population.