Your mouth is not just a hole used for eating and talking! Your mouth is truly a portal to your entire body, and health problems in the oral cavity can contribute, and are related, to health problems throughout the body.
For example, periodontal disease, or the loss of attachment of teeth, has been linked to heart disease, low birth weight of children, and other serious systemic diseases.
Whether it is the mouth causing the systemic problem, or vice versa, is difficult to discern. But this is irrelevant as any of these conditions should make you aware of possibly underlying health problems.
Therefore, it is again essential to visit your doctor AND dentist regularly so that you can not only keep your teeth and mouth healthy, but also so you can keep yourself in the best overall physical condition.
Let me know in the comments if you have any questions on this topic as I have only skimmed the surface about the oral-systemic link here.