"Feline lymphocytic, plasmacytic gingivitis (LPG) is a condition unique to cats that is seen fairly frequently. This condition is characterized by an exaggerated inflammation of the gum tissue in response to a relatively mild accumulation of plaque. The gingival tissue is also very thickened and painful. Sometimes the affected tissue may extend all the way back to the tonsillar area. These patients should be checked for Feline Leukemia, Feline Immunodefiency Virus, and other possible metabolic disease (kidney failure). Most cases of LPG are thought to be some form of immune reaction to relatively low concentrations of bacteria in the plaque. Early cases can sometimes be managed with frequent cleaning, steroids, and antibiotics. Eventually most cases become chronic and non-responsive to this form of treatment. Therefore, the best current long-term treatment for this is total extraction. Although this may sound extreme, by eliminating the surfaces on which plaque is allowed to accumulate, the gingival reaction ceases. Furthermore, by stopping the chronic inflammation, the potential systemic effects are also limited. "

This is the only information I found that sounds like what you are describing! This explains why all the teeth had to be extracted!