This diagram helps illustrate the hidden damage caused by gum disease. The tissue on the left side of the diagram is healthy and normal, while the tissue on the right is diseased. Notice that the signs or symptoms that would be visible to most lay people are quite subtle and easy to miss.
The reduced bone level below the gumline would cause the tooth to feel loose in its socket. Visible tartar is also a sign that you are in need of a cleaning, as tartar buildup contributes greatly to the development of gum disease.