Examining the Relationship between Masticatory Indices Improvement and Prosthetic Treatment Difficulty

Abstract

This study examined changes in masticatory function indices, maximum occlusal force, masticatory performance, and masticatory score before and after removable prosthesis treatment, taking into account the prosthetic difficulty level, which assesses factors such as the shape of the residual ridge and properties of the mucous membrane. Participants（n=40, mean age 75.0±6.8 years）seeking prosthetic treatment were evaluated. Significant improvements in maximum occlusal force were observed in Classifications I and III, while masticatory performance improved significantly in Classification III. Multiple regression analysis indicated that post-treatment maximum occlusal force was significantly influenced by pre-treatment maximum occlusal force（p = 0.01）, with marginal significance in the number of remaining teeth（p = 0.06）（adjusted R² = 0.38）. Factors significantly associated with post-treatment masticatory performance included pre-treatment masticatory performance（p = 0.03）（adjusted R² = 0.27）. Additionally, the post-treatment masticatory score was significantly associated with the pre-treatment masticatory score（p < 0.00）（adjusted R² = 0.55）. The findings suggest challenges in improving masticatory indices, particularly at Level IV, the most difficult index. Post-treatment maximum occlusal force, masticatory performance, and masticatory score significantly correlate with the pre-treatment status of each index. These results propose the utility of prosthetic difficulty level and masticatory indice（msasticatory performance, maximum occlusal force, and masticatory score）as predictive indicators for patients seeking denture treatment.