Using Electromagnetic Articulography to Measure Denture Micromovement during Chewing with and without Denture Adhesive.

Purpose To study the effects of denture adhesive upon denture micromovements in three dimensions during the chewing of hard, sticky, and tough food items observed using a novel method involving an electromagnetic articulograph (EMA) speech research system. Materials and Methods Ten volunteers (mean age 60.9 +/- 10.4 years) with fair- or poor-fitting complete maxillary dentures were enrolled. Chewing experiments were conducted using two treatments (adhesive or no-adhesive control) and three foods: carrots (hard), raisins (sticky), and processed meat stick (tough). Denture micromovement was measured through a novel application of a Northern Digital Wave EMA System. Three-dimensional denture position was captured during mastication using three sensors embedded into a replica denture for each subject. Following individual characterization of a "home" reference position, the Euclidean Distances from Home (DfH) were calculated for each recorded sample of the chewing experiments. The DfH at each sample represented the denture movement for that 1/100th of a second of the activity. The DfH data were then summarized as the mean DfH, the maximum DfH, and total distance traveled by the denture. Several thresholds were also analyzed, including the percent of time that the DfH >= 1.5 mm, >= 2.0 mm, and >= 2.5 mm. Results With adhesive treatment, the mean DfH of dentures during chewing was reduced by 26.8% for carrot, 30.3% for raisin, and 31.0% for meat stick, when compared with no-adhesive treatment (p < 0.001 for all comparisons). Similar results were also seen for the maximum DfH and total distance travelled endpoints across foods. For the threshold endpoints, adhesive treatment was associated with a statistically significant reduction in denture micromovements at all three thresholds across foods. At the threshold of DfH >= 1.5 mm, adhesive treatment was associated with a reduction in micromovement by 61.6%, 56.2%, and 70.0% with carrot, raisin, and meat stick, respectively (p <= 0.004 for all comparisons). Conclusions Observations of denture movement using the Wave EMA System were able to differentiate systematically between adhesive treatment and no-adhesive treatment for denture micromovements during different chewing challenges. Use of adhesive was associated with statistically significant reductions in denture micromovements for hard, sticky, and tough foods as measured with both distance and threshold endpoints.