Aim: The present study is part of an extensive investigation on the positions and distances of the mandibular condyles. We wanted to know if and how the positions of the condyles in centric relation (CR) vary from each other using different CR records.
Materials and methods: The condylar positions in CR were repeatedly recorded by four licensed colleagues on 81 stomatognathically healthy, fully dentate subjects with six different types of CR records. The maxillary casts were mounted in Dentatus articulators after individual facebow transfer, and the mandibular casts were mounted with a central-bearing point (CBP) registration on the tip of the Gothic arch. From three registrations of the centric condylar positions with each of the six registrations, we built mean values with which the comparative calculations were made.
Results: The median spatial distances of the condylar positions between the CBP and all the other CR records were 0.73 ± 0.24 mm (0 to 3.19 mm). The spatial median values between the condylar positions of the different CR records ranged from 0.48 to 0.79 mm. Statistically, the positions of almost all types of registrations were slightly different from each other.
Conclusions: Different CR records reproduce slightly different positions of the mandible, which is especially true for the CBP registration, whereas reproducibilities and standard deviations between the registrations are similar. The unrefined wax wafer registrations using bimanual manipulation according to Dawson have proved particularly successful with regard to precision and time requirements, as has the CBP registration with regard to the condylar position.
Keywords: variation of centric relation registration, centric relation, centric relation records, Lauritzen grip, Dawson grip, bimanual manipulation, frontal jig, wax wafer, acrylic wafer, registration material
