Dimensions of the dentogingival unit in maxillary anterior teeth: a new exploration technique (parallel profile radiograph)

This study sought to develop and evaluate a radiographic exploration technique (parallel profile radiograph [PPRx]) for measuring the dentogingival unit on the buccal surfaces of anterior teeth, and to provide additional information on the dimensions of the dentogingival unit in humans. In 88 periodontally healthy individuals, a PPRx was made of the maxillary left central incisor. Over these images, the components of the dentogingival unit were measured. PPRx was a highly reproducible exploratory technique. Mean dentogingival measurements on the buccal surfaces of the teeth were 2.05 +/- 0.87 mm for distance between the CEJ and bone crest; 2.00 +/- 0.72 mm for biologic width; 1.75 +/- 0.24 mm for thickness of connective tissue attachment; 1.12 +/- 0.24 mm for thickness of free gingiva at its base; 0.45 +/- 0.20 mm for thickness of bone plate at crest level; and 1.41 +/- 0.62 mm for gingival overlap on enamel surface. A statistically significant relationship was observed between free gingival width and thickness of connective attachment, and the depth of the gingival sulcus. These results corroborate the notion that the dimensions of the dentogingival unit are highly variable in humans. The thicknesses of both the connective tissue attachment and free gingiva, however, showed less variability than did the thickness of the bone crest, distance between CEJ and bone crest, and biologic width. The results suggest that gingival dimensions are correlated to dentogingival unit dimensions.