Methods: Ten patients(4 men - 6 women, ages 25 to 47)at the University of Texas Health Science Center at San Antonio 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 for the (W) articulator Nasion was used. A maxillary cast of each patient was mounted on a (D) articulator and a (W) articulator with the facebow and a (W) articulator using a mounting plate. A maxillary cast on the mounting plate was placed with the midline of the central incisors exactly at the middle of the incisal pin The midline of the maxillary cast mounted from the (D) facebow and the cast mounted from the (W) facebow was measured to the center of the incisal pin using a digital caliper.
Results: A statistical significant difference p < 0.05 using unpaired t-tests was observed between the Denar kinematic facebow and the pin; and the Whipmix arbitrary facebow and the pin. The distance of the exact sagittal plane of the articulator to sagittal plane of the (D) facebow was 0.00 to 21.70mm and for the (W) facebow 1.70mm to 6.24mm.
Conclusions: Although one mounted maxillary cast for the (D) facebow had an exact sagittal position of 0.00mm from the pin, it also had the greatest variation of 21.70 mm Most of the recordings were close to the exact sagittal position on both of the articulators, while some recordings showed a statistical and clinical difference.