The sulcus
A healthy crevice between tooth and gum. Probing depth ≤ 3 mm, bleeding on probing under 10%, no attachment loss. The probe stops here — in health, there is nowhere deeper to go.
The descent
Periodontal disease is measured in millimetres of depth. Scroll — you are the probe.
scroll to descend
skip the descent
0–3 mm
≤ 3 mm
4–5 mm
6–7 mm
8+ mm
Gingivitis
The depth barely changes; the bleeding gives it away. BoP ≥ 10% with no attachment loss: inflammation of the gum alone. Fully reversible — this is the last easy exit.
“bleeding”
Periodontitis, Stage I–II
Now the attachment itself is lost — 1 to 4 mm of it. Bone begins to recede in the coronal third of the root. Nothing about this heals on its own anymore.
“distal four”
Stage III
Pockets of 6 mm and beyond, vertical bone loss, furcations opening under the molars. Teeth begin to be lost — up to four of them.
“distal six — bleeding”
Stage IV
Lesions reach the apical part of the root. Teeth loosen, drift, flare; the bite itself collapses. Five or more teeth lost. Chewing becomes the emergency.
PerioCast charts every one of these depths.
By voice. In seconds.
Educational visualization. Criteria: 2017 World Workshop classification, as taught at Istanbul Aydın University Periodontology.