Background: The physiologic dentogingival unit (DGU), also known as the biologic width, is considered to be essential for longevity of the teeth as well as of restorations. Although the clinical relevance of determining the dimensions of DGU is obvious, there is no description in the literature of any simple, standardized, and noninvasive technique for the measurement of DGU in humans. Aim: This study was undertaken to evaluate an innovative radiographic exploration technique (parallel profile radiography [PPRx]) for measuring the dimensions of the DGU on the labial surfaces of maxillary anterior teeth and to provide additional information on the dimensions of the DGU in humans. Methodology: In this study, two radiographs were made in fifty periodontally healthy volunteers, one in frontal projection, while the second radiograph was a PPRx obtained from a lateral position. The dimensions of the DGU were measured radiographically over these images. All data analyses were performed using SPSS 14.0. Results: PPRx was a highly reproducible exploratory technique. Mean dentogingival measurements on the labial surface of right maxillary central incisor were 1.76 ± 0.87 mm for cementoenamel junction (CEJ)-bone crest distance, 1.39 ± 0.50 for gingival sulcus depth, 1.56 ± 0.28 mm for thickness of connective tissue attachment at CEJ, 1.09 ± 0.28 mm for thickness of free gingiva at its base, 1.95 ± 0.43 mm for biologic width, 0.47 ± 0.22 mm for thickness of bone plate at crest level, and 1.76 ± 0.67 mm for gingival overlap on enamel surface. A statistically significant relationship was observed between gingival width and gingival sulcus depth (P = 0.06). These results suggest that the dimensions of DGU are highly variable in humans. Conclusions: We conclude that the dimensions of the DGU in humans can be measured with the PPRx technique, and this technique offers a simple, concise, noninvasive, inexpensive, and reproducible method that can be used in the clinical setup to measure both the length and thickness of the DGU with accuracy. Clinical Relevance to Interdisciplinary Dentistry The dimensions and relationships of the structures of the DGU are essential aspects in many fields of dentistry, and our study strengthen the view that parallel profile radiography can be used as a noninvasive and reliable procedure for measuring the dimensions of the DGU.