The gingival biotype assessed by experienced and inexperienced clinicians

A recent cluster analysis has identified three gingival biotypes among 100 periodontally healthy subjects based on different combinations of morphometric data related to maxillary front teeth and surrounding soft tissues. Patients with a thin-scalloped biotype are considered at risk because they have been associated with a compromised soft tissue response following surgical and/or restorative therapy. Hence, an accurate identification of these high-risk patients is warranted. The purpose of the present study was to evaluate the precision of simple visual inspection as a method to identify the gingival biotype by experienced and inexperienced clinicians.

Fifteen clinicians (five Restorative Dentists, five Periodontists and five Students) were invited to assess the gingival biotype (thin-scalloped, thick-flat, thick-scalloped) of 100 periodontally healthy subjects based on clinical slides. Cluster analysis on these subjects was used as the gold standard and the accuracy in identifying the gingival biotype was determined using percentile agreement and kappa statistics. Intra- and inter-examiner reliability were also calculated.

The gingival biotype was accurately identified only in about half of the cases irrespective of the clinician's experience. The thick-flat biotype was mostly recognized especially by experienced clinicians (> or =70% of the cases). Nearly half of the thin-scalloped cases were misclassified. The intra-examiner repeatability was fair to substantial (kappa: 0.328-0.670) and the inter-examiner reproducibility was slight to moderate (kappa: 0.127-0.547).

Simple visual inspection may not be considered a valuable method to identify the gingival biotype as nearly half of the high-risk patients are overlooked.