Inflammation of the gingiva was induced in 29 subjects ranging in age from 20 to 29 by discontinuing all forms of oral hygiene for three weeks. The course of the inflammation was followed during the developmental period and the following therapy phase with the PMA index, the plaque index, and monophotogrammetry. The results tend to indicate that gingival swelling develops more gradually and recedes more rapidly after treatment has been instituted than could be assumed from the current standard periodontal indexes.