Methods: Ten patients (4 men - 6 women, ages 25 - 47) at UTHSCSA were selected. Alginate impressions were made for each patient and poured in Microstone. Facebow registrations were made as described by the manufacturers [Denar(D) and Whipmix(W)]. The third point of reference for the (D) kinematic facebow was a point 43mm superior to the distal incisal line angle of the maxillary right central incisor and Nasion was used as the third point of reference for the (W) articulator. Also a third point of reference on a (W) articulator using an occlusal plate with the horizontal relationship established by the manufacturer was used. A maxillary cast of each patient was mounted on a (D) articulator and two (W) articulators and compared.
Results: There was no statistically significant difference p less than 0.05 using paired t-tests observed among the Denar kinematic facebow and the Whipmix arbitrary facebow and the mounting plate. The mean angle developed by the third points of reference with the Denar kinematic facebow was 13.6 with a STD Dev 2.41 to the horizontal plane. The mean for the angles created by the Whipmix arbitrary facebow was 16.1 with a STD Dev 3.41, while the angle created by the mounting plate was 10.0 STD Dev 0.0.
Conclusions: The (D) kinematic facebow and the (W) arbitrary facebow are similar, but because of the differences between the location on the face of Nasion and the third point of reference 43mm superior to the central incisor, and the mounting plate there was still a distinct clinical difference when mounting a maxillary cast on an articulator.