Fig. 5

The ability of the novel method for gingival shape analysis using surface curvature to detect subtle differences in soft tissue dynamics undetectable by volumetric assessment. Baseline (T0) and three-month follow-up (T1) intraoral scans associated with the non-surgical periodontal treatment (upper row) of two anatomically different regions, i.e., central (a) and interdental (b). The scans were superimposed and evaluated in terms of tissue thickness changes (middle row) and with a novel gingival shape analysis (bottom row). Changes in the interdental regions are already apparent when comparing the scans side by side and even more pronounced with the volumetric colour-coded map. Changes are also confirmed with the gingival shape analysis using mean curvature measure (b). It should be outlined that the region for gingival shape analysis also shifted in the apical direction with the loss of the tissues. However, the regions were defined wide enough to capture the local maximum. In contrast, changes in central regions are subtle and barely visible with direct observation but are demonstrated by gingival shape analysis using minimum curvature measure (a)