[Comparative study on the morphology of crown, alveolar ridge crest and gingival in maxillary anterior region]

To investigate the correlation among the morphology of crown, alveolar ridge crest and gingiva in maxillary anterior region of adults and to provide anatomical basis for clinical implant esthetics.

Sixty Han-Chinese with healthy peridontium were selected in this study. The curvature of labial alveolar crest, the length and height of inter-proximal bone were measured on 3-D model reconstructed from cone-beam CT (CBCT) images, and the curvature of free gingiva, the width and height of inter-dental papilla and central incisor crown were evaluated on casts. The ratio of crown width to height was ranked and the 10 ranked highest were categorized as group Short-Wide (SW), the 10 ranked lowest were selected as group Long-Narrow (LN).

In maxillary anterior region, the curvature angle of both alveolar crest and marginal gingiva were significantly different among different tooth regions, but the alveolar and gingival curvature was significantly correlated in the same region (P < 0.05). The morphology of inter-proximal bone and papilla was significantly correlated (P < 0.01), except the region between central and lateral incisors (P = 0.625, P > 0.05). Compared to group SW, group LN formed a pronounced scalloped contour of gingival margin (P = 0.002) and slender inter-dental papilla (P = 0.000).

The free gingival curvature and inter-dental papillary morphology are significantly correlated with the morphology of crown and alveolar ridge crest in maxillary anterior region of Han-Chinese. Individuals with long-narrow crown, pronounced scalloped marginal gingiva and slender inter-dental papilla are susceptible to risk implant esthetics.