The relationship between occlusion and jaw dysfunction is not well understood because of a lack of accurate, quantitative measures of occlusal parameters. Objective: Measure, in a laboratory simulation, the accuracy of occlusal contact parameters calculated from three-dimensional interocclusal record images. Method: Ten interocclusal records were made of a calibrated standard using an experimental vinyl polysiloxane impression material. The standard consisted of 7 precision ball bearings (Diameter: 9.522 mm) arranged to simulate a maxillary arch and an opposing flat plane. Three bearings defined the "occlusal plane". The remaining four bearings were offset from the plane in steps of 0.025 mm. Interocclusal records were digitized using a Comet 100 optical scanner (accuracy: 0.040 mm). Three-dimensional virtual models of the interocclusal records were made, analyzed and rendered on a computer PC monitor using the Virtual Dental Patient (VDP) software. A contact was defined as a set of points on one model, with each point in the set within a specified distance (tolerance) of at least one point in the opposing model. Contact location, area, and orientation were calculated for 9 tolerances ranging from 0.013 mm to 0.200 mm. Accuracy was calculated as the mean difference between the VDP and standard for the three contact parameters. Results: Sensitivity/specificity for contact identification were 1.00/0.95; 0.95/1.00; and 0.98/1.00 for the 0.013, 0.025, 0.075 mm tolerances, and 1.00/1.00 for all others. All tolerances provided clinically useful parameters; however, the 0.050 mm tolerance provided the best overall accuracy. Mean errors for contact location, area, and orientation, were 0.07±0.03 mm, 0.4±0.2 mm2, and 1.1±0.4 degrees, respectively. Conclusions: This laboratory study showed that virtual interocclusal records could provide accurate quantitative measures of occlusal parameters. This work was supported in part by the Minnesota Dental Research Center for Biomaterials and Biomechanics and NIH/NIDCR grant RO1 DE12225.

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