Cat peridontitis. Illustration of the mouth and teeth of a cat with peridontitis (inflammation of the periodontium). The periodontium is the tissues that surround and support the teeth, including the gums and jaw bones. This condition progresses from gingivitis (inflammation of the gums) and is caused by the accumulation of dental plaque (bacterial biofilms). If not treated, the condition can lead to tooth loss. For a sequence of images on cat dental diseases, see images C029/9568 to C029/9571.