Objective: The method and consistency of finding centric relation (CR) is highly controversial. This study evaluated the relative condylar locations generated by five different CR interocclusal recording techniques.
Materials and methods: Condylar location was measured using the Measures Condylar Displacement (MCD) instrument of the AD2 articulator on five symptom free subjects between 26-36 years of age. The five CR interocclusal recording techniques studied were the Roth Power Bite, Tongue Tip to Soft Palate, Leaf Gauge, Chin Point Guidance, and Bimanual Manipulation. Five different CR registrations on each patient were made at five time points.
Results: Small intra- and inter-technique variations were found in the condylar positions generated by the five CR registration techniques. The Roth Power Bite and Leaf Gauge methods positioned more condyles in an upward and forward location relative to other techniques. The Chin Point Guidance, Tongue Tip to Soft Palate, and Bimanual Manipulation Techniques tended to position condyles slightly more inferior and posterior than other methods.
Conclusions: All methods of CR registration resulted in a very small range of variation indicating a high degree of intra-technique repeatability. However, location within the condylar fossa varied between the different techniques with the Roth Power Bite and Leaf Gauge Techniques positioning condyles slightly more anterior-superior than other techniques studied.
Keywords: Centric relation, adult, dental occlusion, humans, reproducibility of results, temporomandibular joint/physiology, dental articulators