In order to examine the three dimensional displacement for those abutment teeth having lost occlusal and proximal contacts, a measuring device was designed enabling one to simultaneously record the mesiodistal, buccolingual, and axial movements. The measurements were taken during a 7 days span, and the amount along with the direction of abutment tooth displacements were studied.
The results were as follows;
1. Three dimentional displacement was observed immediately after the loss of occlusal and proximal contacts, and the amount of displacement kept increasing along with time.
2. The abutment tooth displaced towards the distal, coronal and lingual direction.
3. Compared to the buccolingual and axial directions, the mesiodistal direction showed the greatest amount of abutment tooth displacement, with the maximum displacement being 240μm.