This research found that the loss of occlusal support significantly increased the risk of mortality over a 10-year period, particularly among women. The participants were grouped into EI classes A/B (those with adequate occlusal support) and class C (those lacking occlusal support). Of these, 203 were in EI class A/B and 94 in EI class C. The survival analysis found individuals with sufficient tooth support (class A/B) had a cumulative survival rate of 79.8%, when compared with just 66.0% among those with limited support (class C). Also, being in EI class C also independently increased the risk of mortality (HR: 1.88; CI: 1.08–3.36). In women, lack of occlusal support (class C) was a particularly powerful predictor, with an HR of 4.17 (CI: 1.47–11.79).