Complete denture displacement following open-mouth reline

In 21 complete denture wearers, six upper and 15 lower denture relines were performed with the open-mouth technique. The centric relation (CR) was recorded with the Central-Bearing-Point (CBP) method three times before and three times after the reline. For each registration, the right and left condylar position was recorded in three dimensions using a custom-made measuring device. The average denture displacement from an initial reference position (CR) was calculated for each registration. An upper denture reline leads to a mean displacement of 2.5 mm, both in the right and left condylar area. With an average of 2.0 mm, this displacement was smaller following a lower denture reline (right and left mean, 1.6 mm). The precision of the CBP-registrations proved 0.5 mm before and 0.3 mm after reline; hence, the measured condylar displacement after reline could not attribute to a methodological bias. This clinical-experimental study demonstrates that relining complete dentures with the open-mouth technique may lead to a substantial denture shift and thus imply inevitably clinically relevant occlusal discrepancies. It is therefore important to carefully check the occlusion at denture delivery and remount the prostheses if necessary.