Korean J Orthod.  2007 Dec;37(6):407-420.

Comparison of finite element analysis of the closing patterns between first and second premolar extraction spaces

• Koh SA
• Im WH
• Park SH
• Chun YS

Abstract

OBJECTIVE
The aim of this study was to compare the differences in closing extraction spaces between maxillary first premolar and second premolar extractions using 3-dimensional finite element analysis (FEA).
METHODS
Maxillary artificial teeth were selected according to Wheeler's dental anatomy. The size and shape of each tooth, bracket and archwire were made from captured real images by a 3D laser scanner and FEA was performed with a 10-noded tetrahedron. A 10 degrees gable bend was placed behind the bull loop on a 0.017" x 0.025" archwire. The extraction space was then closed through 12 repeated activating processes for each 2 mm of space.
RESULTS
AND CONCLUSIONS: The study demonstrated that the retraction of anterior teeth was less for the second premolar extraction than for the first premolar extraction. The anterior teeth showed a controlled tipping movement with slight extrusion, and the posterior teeth showed a mesial-in rotational movement. For the second premolar extraction, buccal movement of posterior teeth was highly increased.

Keyword

FEA; Premolar extraction; Space closure; Rotation

MeSH Terms

Bicuspid*
Finite Element Analysis*
Tooth
Tooth, Artificial