Rotation coordinating device for improving condylar guidance settings of nonarcon articulators: Part 1

Background: Setting of condylar inclination is inaccurate in nonarcon articulators because of alteration of the angle between the upper member and condylar track. This article presents a device which can be attached to a nonarcon articulator to rectify errors related to alterations of maxillary occlusal plane-horizontal condylar guidance relation in nonarcon articulators. Materials and Methods: The device provides tight connection of condylar axis to condylar track by mechanical interdigitation of fragments which are placed on condylar axis and condylar track. Condylar track rotates coordinated with condylar axis. Fragments consist of medial fragments placed on medial surface of articular fossa analogs, lateral fragments placed on lateral surface of articular fossa analogs, and condylar axis fragments placed on condylar axis. The device can be used during condylar inclination adjustment by interocclusal records, changing vertical dimension of occlusion, and occlusal adjustment of restorations. Initial evaluation of the device was performed during an opening hinge movement in a single experiment. The angle between condylar track and the upper member of the articulator was determined by calculation before and after applying hinge movement and with and without the device. Results: When the device was not used, the postexperimental condylar inclination was 7.31° higher than preexperimental value. Using the device, discrepancy reached 2.17°. Conclusion: Using this device may lead to more accurate condylar inclination adjustment which is followed by more accurate prosthetic teeth.