Poor dental hygiene can result in a buildup of calculus, or tartar, on the teeth. If enough calculus is allowed to accumulate, the periodontium, or supporting structures of the tooth, can become inflamed. This condition is known as periodontitis, and may be classified according to its severity. This disease is manifested by inflammation of the gingiva, loss of alveolar bone tissue, degeneration of the periodontal membrane or ligament, and the formation of pockets between the teeth and surrounding bone, which can result in increased tooth mobility and eventual tooth loss.