Influence of circadian periodicity on reproducibility of centric relation records for edentulous patients.

Complete dentures were made for 30 edentulous patients. The patients were divided into three groups and the dentures were remounted twice on the same day in a Vericheck instrument. The dentures for 10 patients were remounted twice in the morning (AM group), for 10 patients twice in the afternoon (PM group), and for 10 patients once in the morning and again in the afternoon (AM-PM group). Changes in position between the interocclusal records were measured on both the right and left horizontal X and Y axes and the sagittal Y and Z axes. No significant changes were noted when horizontal versus sagittal or right versus left positions were compared, but significant changes were noted between the AM versus AM-PM time groups, and between the PM versus AM-PM time groups.