A masticatory function evaluation system and a mastication function that allow a user to easily detect periodontal disease and to easily determine whether or not a denture being used is suitable by using an artificial bolus containing fine particles. A function evaluation method and a chewing function evaluation program are provided. SOLUTION: Among the fine particles included in the image data of the rolled artificial bolus for evaluating the masticatory function, a small-diameter fine particle having an outer diameter smaller than a predetermined outer diameter and a large-diameter fine particle having an outer diameter larger than a predetermined outer diameter. The number of microparticles is counted, and based on the reference number of microparticles contained in the artificial bolus for evaluating the masticatory function and the number of microparticles counted, the chewing rate of the microparticles is calculated, and the chewing function is evaluated. Based on the reference number of large-diameter fine particles contained in the artificial bolus and the counted number of large-diameter fine particles, a large-diameter fine-particle mastication rate is calculated. [Selection diagram] Fig. 1【課題】微粒子を含む人工食塊を用いて、歯周病の早期発見や、使用している入れ歯が合っているか否かを、ユーザー自身によって簡易的に知ることができる咀嚼機能評価システム及び咀嚼機能評価方法並びに咀嚼機能評価プログラムを提供する。【解決手段】圧延された咀嚼機能評価用人工食塊の画像データに含まれる微粒子のうち、外径が所定の外径よりも小さい小径微粒子と、外径が所定の外径よりも大きい大径微粒子の数をそれぞれ計数し、咀嚼機能評価用人工食塊に含まれる小径微粒子の基準数と、計数された小径微粒子の数とに基づいて、小径微粒子咀嚼率を算出するとともに、咀嚼機能評価用人工食塊に含まれる大径微粒子の基準数と、計数された大径微粒子の数とに基づいて、大径微粒子咀嚼率を算出する。【選択図】図１
