This study aimed to quantify oxidative metabolism in masseter muscle using near-infrared spectroscopy, in particular for denture wearers. Fourteen normal dentate subjects without malocclusion (ND group, 25–50 years) participated in the quantification of oxidative metabolism. Eleven partially edentulous patients without occlusal stops (PD group, 64–80 years) and ten edentulous patients (CD group, 57–84 years) also participated after prosthodontic treatment. Oxidative metabolism was recorded during gum chewing, maximum clenching and regulated clenching at 5 kgf. The oxygenated hemoglobin at 5 kgf clenching level was normalized to the oxygenated hemoglobin at the lowest blood flow and expressed as oxygen consumption rate (OCR). The relationship of the OCR to the maximum clenching force was analyzed using Pearsons correlation coefficient, and differences between the PD and CD groups were tested by unpaired Students t-test. The OCR showed a significant negative correlation with maximum clenching force in the ND group. The OCR of the PD group was significantly greater than that of the CD group, although the difference in maximum clenching force was not significant between both groups. These results suggest that the aerobic ability of masseter muscle in complete denture wearers is relatively greater than in partial denture wearers with same age level.