Evaluation of psychological effect of prosthetic treatment using Emotion Spectrum Analysis Method (ESAM)

The aim of this pilot study was to consider evaluation of the psychological effects of dental prosthetic treatments using ESAM.

We examined gum chewing with and without an occlusal interference device that simulated a negative change in oral sensation in four subjects. First, we analyzed the temporal components of mandibular movement trajectories as indices for evaluating the degree to which chewing is actually impaired by occlusal interference. Subsequently, we measured brain activity before and after chewing for each of the two conditions (with or without the occlusal interference device). For brain activity, we used the four emotional indices of stress, sadness, joy and relaxation based on ESAM to estimate psychological states before and after chewing, and made a comparison between the two conditions. Statistical analyses were performed with Mann-Whitney's U-test (p<0.05).

The opening phase and chewing cycle were shorter when wearing the occlusal interference device in every subject. There was a significant difference for all subjects (p<0.05) in the closing cycle. Therefore, because a significant difference occurred for at least one temporal component of the mandibular movement trajectory for every subject, we concluded that normal chewing in subjects was impaired by wearing the occlusal interference device. Similarly, in ESAM analyses using EEG, stress tended to increase due to occlusal interference in every subject. In addition, relaxation decreased due to occlusal interference in three subjects.

The results suggested the potential for evaluating the psychological effects of dental prostheses using emotional indices based on ESAM.