Digital Assessment of Gingival Display During Different Facial Expressions Using AutoCAD Software: An Exploratory Clinical Study

Objective: To explore and compare the extent of maximal gingival display among four different facial expressions, including the requested smile, Duchenne smile, grimace of disgust, and funnel-shaped expression, using AutoCAD software. Materials and methods: This exploratory cross-sectional study was conducted in the department of Prosthodontics, Islamic International Dental Hospital, Islamabad, Pakistan, from December 2024 to March 2025. A total of 36 adults (20 females and 16 males), fulfilling the inclusion criteria, were randomly selected. Four different facial expressions, including a ‘requested smile’, a ‘Duchenne smile’, a ‘grimace of disgust’, and a ‘funnel-shaped’ expression, were explained to each participant. A digital camera was then used to capture four standardised photographs for every subject, each photograph showing a specific facial expression. Every photograph was then analysed using AutoCAD software to determine the height of gingival display at all maxillary anterior teeth and first premolars from the lower edge of the upper lip to the gingival zenith point of each tooth. Data analysis was done using SPSS Version 27. The Friedman test with post hoc comparison was used to assess and compare the amount of gingival tissue revealed across the four facial expressions. Results: Within the limitations of this exploratory clinical analysis, the most gingival display was produced at the central and lateral incisors by the Duchenne, grimace and funnel-shaped expressions. Similarly, both the Grimace and Duchenne smiles showed the most gingival display among the four facial expressions at the canines and the first premolars. Conclusions: The Duchenne smile showed more gingival display above all maxillary anterior teeth compared to the other expressions. Clinical relevance: Assessing gingival display across various facial expressions offers objective direction for prosthodontic and aesthetic treatment planning, encompassing smile line evaluation, anterior restoration and implant margin positioning, as well as enhancing aesthetic results and patient satisfaction.