Related Experiment Video
Updated: Apr 23, 2026
04:19
The Establishment of a Murine Mandibular Molar Extraction Socket Healing Model
Published on: January 13, 2023
5.3K
Mandibular incisor re-crowding: is it different in extraction and non-extraction cases?
A Hamid Zafarmand1, Ali Qamari, M Mahdi Zafarmand
1Department of Orthodontics, Shahid Beheshti University of Medical Sciences, School of Dentistry, Evin, Tehran, Iran; Tel: +98-2122421813;
Oral Health and Dental Management
|October 7, 2014
Summary
Orthodontic treatment involving tooth extraction or non-extraction methods shows similar rates of anterior crowding relapse. Both approaches result in statistically significant changes, but neither offers a clear advantage in preventing incisor relapse post-treatment.
Area of Science:
- Orthodontics
- Dental Arch Analysis
- Treatment Outcomes
Background:
- Anterior crowding relapse is a common and unpredictable complication following orthodontic treatment.
- Understanding relapse patterns is crucial for effective long-term orthodontic care.
Purpose of the Study:
- To compare the relapse of anterior crowding in patients treated with non-extraction versus extraction of first premolars.
- To evaluate the influence of treatment modality on incisor stability after retention.
Main Methods:
- A comparative study involving 40 patients, divided into extraction (n=21) and non-extraction (n=19) groups.
- Measurement of the "Irregularity Index" on dental models at pre-treatment, post-treatment, and post-retention phases.
- Statistical analysis using Wilcoxon and Mann-Whitney tests to assess intra-group and inter-group changes.
Main Results:
- Initial irregularity indices were 7.23 mm (extraction) and 6.13 mm (non-extraction), reduced to 0 mm post-treatment.
- Post-retention relapse was observed at 2.11 mm (extraction) and 1.65 mm (non-extraction).
- Statistically significant changes were noted within both groups (P=0.001), with no significant difference in relapse between groups (P=0.138).
Conclusions:
- Both extraction and non-extraction orthodontic treatment protocols exhibit similar tendencies for anterior incisor relapse.
- The choice between extraction and non-extraction does not significantly influence the degree of incisor relapse after retention.
