A quantitative evaluation of the spatial displacement of the gingival zenith in the maxillary anterior dentition

The appearance of gingival tissues plays an important role in the esthetics of the anterior maxillary region of the mouth. The gingival zenith (GZ) is defined as the most apical point of the marginal gingival scallop; however, its quantitative orientation in the apico-coronal (AC) and mesio-distal (MD) directions has not been reported. Thus, this study aimed to quantify the specific spatial displacement of the GZ in the maxillary anterior dentition.

Bilateral measurements, taken with a digital caliper in maxillary stone casts from periodontally healthy volunteers, were recorded to the nearest 1/100th millimeter in the canine (C), lateral incisor (LI), and central incisor (CI) teeth to evaluate the MD displacement of the GZ in relation to the long axis of the crowns and the AC displacement of the GZ of LI teeth in relation to CI and C teeth. Intermeasurement differences were analyzed with the chi(2) or paired t test, with significance set at alpha <0.05.

The GZ was distally displaced between 0.06 and 0.96 mm in 12%, 70%, and 96% of the C, LI, and CI teeth, respectively. The majority of the population (70%) presented with the GZ of LI teeth positioned 0.75 +/- 0.60 mm coronally to the GZ of the ipsilateral C and CI.

The GZ is not universally displaced toward the distal aspect. The frequency and magnitude of distal displacement is tooth-dependent and larger in CI than in LI, which, in turn, is larger than in C. Consideration of these findings may improve clinical management of the dentogingival complex and enhance periodontal and restorative procedures in the anterior maxillary dentition.