This study evaluated the reliability of assessing visually the facial gingival biotype of maxillary anterior teeth with and without the use of a periodontal probe in comparison with direct measurements. Forty-eight patients (20 men, 28 women) with a single failing maxillary anterior tooth participated in this study. Three methods were used to evaluate the thickness of the gingival biotype of the failing tooth: visual, periodontal probing, and direct measurement. Prior to extraction, the gingival biotype was identified as either thick or thin via visual assessment and assessment with a periodontal probe. After tooth extraction, direct measurement of the gingival thickness was performed to the nearest 0.1 mm using a tension-free caliper. The gingival biotype was considered thin if the measurement was =or<1.0 mm and thick if it measured>1.0 mm. The assessment methods were compared using the McNemar test at a significance level of a=.05. The mean gingival thickness obtained from direct measurements was 1.06+/-0.27 mm, with an equal distribution (50%) of sites with gingival thicknesses of =or<1 mm and >1 mm. The McNemar test showed a statistically significant difference when comparing the visual assessment with assessment using a periodontal probe (P=.0117) and direct measurement (P=.0001). However, there was no statistically significant difference when comparing assessment with a periodontal probe and direct measurement (P=.146). Assessment with a periodontal probe is an adequately reliable and objective method in evaluating gingival biotype, whereas visual assessment of the gingival biotype by itself is not sufficiently reliable compared to direct measurement.