Tissue biotype and its relation to the underlying bone morphology.

Background: Tissue biotypes have been linked to the outcomes of periodontal and implant therapy. The purpose of this study is to determine the dimensions of the gingiva and underlying alveolar bone in the maxillary anterior region and to establish their association.

Methods: Tissue biotypes of 22 fresh cadaver heads were assessed clinically and radiographically with cone-beam computed tomography (CBCT) scans. Maxillary anterior teeth were atraumatically extracted. The thickness of both soft tissue and bone were measured using a caliper to the nearest 0.1 mm by two calibrated examiners. Probing depths and gingival recession were measured at two points (mid-labial and mid-palatal). Clinical and CBCT measurements of both soft tissue and bone thickness were subsequently compared and correlated.

Results: No statistically significant differences were observed between the clinical and CBCT measurements of both soft tissue and bone thickness except the palatal soft tissue measurements. The labial gingival thickness was moderately associated with the underlying bone thickness measured with CBCT (R = 0.429; P <0.05). Gingival recession was not associated with the thickness of both labial gingiva and bone.

Conclusions: CBCT measurements were an accurate representation of the clinical thickness of both labial gingiva and bone. In addition, the thickness of the labial gingiva had a moderate association with the underlying bone radiographically.