Stability of first and second premolars extraction space closure

Area of Science:

• Orthodontics
• Dental Arch Stability
• Tooth Movement

Background:

• Premolar extractions are common in orthodontics to resolve crowding and protrusion.
• Maintaining extraction space closure is crucial for long-term treatment success.
• Some studies indicate a tendency for relapse even with adequate occlusion post-treatment.

Purpose of the Study:

• To compare the long-term stability of extraction space closure between first and second premolar teeth.
• To evaluate the rate of extraction space reopening after orthodontic treatment.

Main Methods:

• Digitized dental casts from 72 patients were analyzed using a 3D scanner.
• Patients were divided into two groups: first premolar extractions (n=29) and second premolar extractions (n=43).
• Chi-square and t-tests compared space closure stability post-treatment and long-term.

Main Results:

• Overall, both first and second premolar extraction groups showed similar rates of extraction site reopening.
• The tendency for space reopening was comparable between the two groups.
• However, in patients with initially closed spaces, maxillary space reopening was greater after first premolar extractions.

Conclusions:

• The stability of orthodontic extraction space closure is similar for both first and second premolar extractions.
• Both extraction patterns demonstrate comparable long-term stability, with a slight caveat for maxillary first premolar sites.