Mandibular second premolar extraction--postretention evaluation of stability and relapse

Area of Science:

• Dentistry
• Orthodontics
• Dental Arch Stability

Background:

• Mandibular second premolar extraction is a common orthodontic procedure.
• Assessing long-term stability after this treatment is crucial for clinical practice.

Purpose of the Study:

• To evaluate the long-term stability of orthodontic treatment involving mandibular second premolar extraction.
• To compare stability between early (mixed dentition) and late (permanent dentition) extraction timing.

Main Methods:

• Analysis of dental casts and cephalometric radiographs from 46 patients over a minimum 10-year postretention period.
• Comparison of treatment outcomes based on extraction timing (early vs. late).
• Regrouping patients based on postretention incisor irregularity for cephalometric analysis.

Main Results:

• No significant difference in long-term stability was found between early and late mandibular second premolar extraction groups.
• Arch length and width showed a decrease over time.
• Incisor irregularity increased throughout the postretention period.
• Cephalometric differences were noted between minimally and moderately to severely crowded groups postretention.

Conclusions:

• Extraction timing of mandibular second premolars does not appear to influence long-term orthodontic stability.
• Progressive changes like arch dimension reduction and increased incisor irregularity occur post-treatment.
• Further research is needed to identify predictors for long-term stability.