Position/level of the gingival margin/referred as gingival recession (GR) is measured as the distance from the cemento-enamel junction (CEJ) or the margins of restoration to the gingival margin (GM) and is also measured to the nearest mm.
Gingival recession (GR) definition
Gingival recession recording
Regarding position of the gingival margin relative to the CEJ we can have four clinical situations:
Diagram 1 Clinical positions of the gingival margin
Gingival margin is apical to the CEJ. The CEJ and a portion of the root are visible. In this case we measure GR as distance from the CEJ to the gingival margin (GM) and register it as a positive number.
Diagram 2 Gingival margin is apical to CEJ
Clinical image 1
2. Gingival margin is at the level of the CEJ.
The CEJ is just visible.
In this situation we have slight gingival recession (GR) as the gingival margin is at the level of the CEJ. We register it as GR = 0mm.
Diagram 3 Gingival margin at the level of CEJ
Clinical image 2
Gingival margin is in its normal/natural position up to 3mm coronal to the CEJ.
In this case gingival recession is absent and we leave the recession box of the periodontal chart empty.
Diagram 4 Gingival margin slightly coronal (1-3mm) to the CEJ
Clinical image 3
4. Gingival margin is significantly coronal to the CEJ due to enlargement
(oedema, fibrotic overgrowth, or combination). In this case, position of the gingival margin measured from the CEJ to the gingival margin is labeled as a negative value “-“.
Diagram 5 Gingival enlargement with the gingival margin >3mm coronal to the CEJ