Gingival biotypes are of two types. They are scalloped and thin or flat and thick gingiva. They proposed that the contour of the gingiva closely followed the contour of the underlying bone. The gingiva was categorized into “thick – flat” and “thin – scalloped” biotypes. A gingival thickness of ⩾2 mm (measurements of 1.6–1.9 mm were not accounted for) was considered as thick tissue biotype and a gingival thickness of <1.5 mm was referred as thin tissue biotype.
Fig. 1. Photographs of patients with the thin biotype (A) and the thick biotype (B). (A) The probe tip is visible in the thin gingival biotype. (B) The probe tip is invisible in the thick gingival biotype.
Fig. 2. Measurements of the amount of bone scallop. The distance between the mesial contact point (CP) and the alveolar bone crest (BC) (CP~BC, ①) and the distance between the extension of contact points and the alveolar crest (MID~BC, ②) were measured. The difference in distance between ① and ② was calculated and is defined as the scalloped distance