Methods: Ten subjects at UTHSCSA were selected. Alginate impressions were made. On each patient a true hinge axis was established using a Denar (D) kinematic facebow. A Whipmix (W) arbitrary facebow was also used to transfer this relationship to a (W) articulator. A maxillary casts were mounted on a (D) articulator and a (W) articulator. Mandibular casts were mounted at centric relation using a Aquaseal polyvinylsiloxane record made using the leaf gauge at a thickness of 3.00mm and 1.50mm. Occlusal differences for each patient were identified and compared on the two different articulators. The differences were marked on the right and left side on the first molars and in the anterior marking the right central incisor.
Results: There were no statistical differences with p greater than 0.05 between the two facebows. The mean and SD for the (D) were right 0.32 ± 0.51, left 0.35±0.48, and anterior 0.08±0.15 for the 3.00mm record; and right 0.26±0.38, left 0.32±0.41 and anterior 0.20±0.29 for the 1.50mm record. The mean difference for the (W) were right 0.42±0.61, left 0.35±0.44 and anterior 0.15±0.20 for the 3.00mm; and right 0.41±0.58, left 0.58±0.72, and anterior 0.12±0.28 for the 1.50mm.
Conclusions: Changing vertical dimension when using both the kinematic and an arbitrary facebow showed no statistical difference, however clinically significant differences in occlusion were apparent. The study suggests that when changing vertical dimension a new centric relation record should be made at that vertical dimension.