Fig. 4

Five cases demonstrate considerable individual variability. a In Subject 6, a single vessel can be seen, and b ischemia developed in the attached gingiva, distal to the compression with a minor effect on the papilla. c In Subject 11, no single vessel can be seen, and d ischemia developed in the attached gingiva mesial to the compression with a minor effect on papilla. e In Subject 8, a single small vessel was compressed, and f only the papilla appears ischemic. g In Subject 7, a single large vessel was seen, and h a wide, symmetrical ischemic area with complete papillary involvement was developed. i In Subject 25, a diffuse reddish area can be seen, and j a wide, symmetrical ischemic area with papillary involvement was developed