Korean J Orthod.  2005 Oct;35(5):371-380.

Spatial changes of the upper dentition following en-masse space closure: A comparison between first and second premolar extraction

• Kim HJ
• Chun YS
• Jung SH

Abstract

The purpose of this experimental study was to evaluate and compare maxillary arch dimensional and positional changes between first and second premolar extraction groups. The Calorific Machine was used to illustrate tooth movement in three dimensions. The experimental teeth except the first or second premolars were embedded in artificial alveolar bone. The extraction space was closed using arch wires with bull loops into which 15 degree gable bends were placed. Before and after space closure, radiographs were taken in the sagittal and occlusal directions using occlusal films. The results showed greater mean maxillary incisor retraction and less anchorage loss in the maxillary first premolar extraction group than in the maxillary second premolar extraction group. Mesiopalatal rotation of anchor teeth was greater after extraction of a maxillary second premolar than a maxillary first premolar (p<.001).

Keyword

Premolar extraction; Space closure; Bull loop; Rotation

MeSH Terms

Bicuspid*
Decompression Sickness
Dentition*
Incisor
Tooth
Tooth Movement