Upper second premolar and first and second molars were splinted without any changes of occlusal tooth contacts and interdental proximal contact relations. Each of 4 subjects was instructed to clench, bite 4 or 8 articulating papers and masticate a piece of pretzel. The displacement of upper second premolar and first molar was recorded on a horizontal plane at the same point before and after splinting.
As a result, the amount of displacements of upper second premolars of the 4 subjects was changed -25-+27μm in length and -22-+8° in angle by splinting. That of first molars was changed 1-29μm in length and -10-+31° in angle. These changes, however, were not remarkable compared with the range of physiological tooth displacement. Thus, splinting of approximately three teeth does not disturb periodontium.