Purpose: To evaluate the relevance of the probe test in classifying the gingival biotype and to determine if differences exist between maxillary and mandibular gingival biotypes in the same patient. Materials and Methods: 53 subjects were included. The gingival thickness was evaluated as thick or thin. This evaluation was based on the transparency of the periodontal probe through the gingival margin while probing the sulcus. In another hand, 124 clinicians were asked to identify the gingival biotype in the same 53 subjects based on visual inspection on pictures. For each examiner, the accuracy in identifying the gingival biotype was assessed using the percentage of cases correctly identified. Results: the percentile of agreement is greater than 70% in maxilla as well as in mandible. An imbalance was observed on the maxillary pictures concerning the gingival biotype and on the thin biotype between maxilla and mandible despite there being no statistical difference (p < 0.0001). The percentile of agreement is quite similar in the mandible for both thin (74%) and thick (70%) gingival biotypes. Agreement between mandibular probe and maxilla probe results demonstrates a weak percentile of agreement of gingival biotypes between maxillary and mandibular anterior teeth (57%). Conclusion: The use of probe transparency through the gingival margin is an accurate and simple method for gingival biotype diagnosis to discriminate a thin gingival from a thick gingival. Furthermore, individualizing the gingival biotype for each of the arches appears to be a new outcome that needs further investigation.