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Extraction vs nonextraction orthodontic treatment: a systematic review and meta-analysis
The Angle Orthodontist
|October 29, 2023
Summary
Four first premolar extraction decreases arch width, while nonextraction treatment shortens overall treatment time. Both approaches show no significant difference in smile aesthetics or maxillary intercanine width, warranting further research.
Area of Science:
- Orthodontics
- Dental Research
Background:
- Comparing the effects of four first premolar extraction versus nonextraction in orthodontic treatment is crucial for optimizing patient outcomes.
- Understanding the impact on intra-arch width, facial profile, treatment duration, occlusal results, smile aesthetics, and stability is essential.
Approach:
- A comprehensive literature search was conducted up to June 2, 2023, including health science databases and gray literature.
- Included studies involved nonsurgical patients with fixed appliances, with data extraction and quality assessment using ROBINS-I and Cochrane RoB 2 tools.
- The certainty of evidence was evaluated using the GRADE framework.
Key Points:
- Four first premolar extraction led to a decrease in maxillary and mandibular inter-first molar width.
- Nonextraction treatment resulted in an increase in mandibular intercanine width and a shorter treatment duration.
- Evidence for effects on lip-E plane, American Board of Orthodontics Objective Grading System, and Little's irregularity index was inconclusive.
Conclusions:
- Four first premolar extraction causes maxillary and mandibular inter-first molar width reduction and upper/lower lip retraction.
- Nonextraction treatment increases mandibular intercanine width and reduces treatment time.
- No significant differences were found between the groups for maxillary intercanine width, US PAR score, or posttreatment smile aesthetics.
