A photographic evaluation of smile characteristics in different dental and skeletal patterns: A cross-sectional study

Objectives: The aim of this study was to assess smile characteristics – maxillary incisor display, upper lip length (ULL), and gingival display – in individuals with Class I and Class II malocclusions across normodivergent, hyperdivergent, and hypodivergent skeletal growth patterns. Material and Methods: A total of 102 participants (aged 15–25 years) were enrolled. Molar relationship determined Class I versus Class II; cephalometric measurements (Sella-Nasion to Mandibular Plane, Frankfurt Mandibular Plane angle, and Jarabak ratio) classified skeletal patterns. Videography captured posed smiles, and static frames were selected to measure (1) maxillary incisor display at rest and on smiling, (2) ULL at rest and on smiling, and (3) gingival display on smiling. Data analysis used Statistical Package for the Social Sciences (v. 20), with significance set at P < 0.05. Results: Hyperdivergent individuals showed significantly greater incisor display at rest and on smiling ( P = 0.001) and shorter ULL on smiling ( P = 0.001) compared to normodivergent and hypodivergent groups. Gingival display was higher in hyperdivergent participants but not significantly ( P = 0.387). No significant differences were observed between Class I and Class II malocclusions ( P > 0.05). Conclusion: Vertical growth patterns, particularly hyperdivergence, are associated with increased incisor display, shorter ULL on smiling, and greater gingival display. Sagittal classification alone did not significantly affect these characteristics. Orthodontic treatment planning should prioritize skeletal growth pattern assessment to optimize smile esthetics.