Date: March 2026.
Source: Asian Pacific Journal of Dentistry; 26. doi: 10.47416/apjod.25-0010.
Objective: This study aimed to examine how positioning a simulated canine exhibiting infralabioversion affects the three-dimensional morphology of the upper lip, both at rest and during smiling.
Materials and Methods: This study included 20 adult female Japanese participants. Bilateral simulated canines with infralabioversion (experimental canines) were fabricated and attached to the labial surface between the maxillary lateral incisor and the canine. Three-dimensional facial soft tissue morphology was captured before and after applying the experimental canine, both at rest and during the three distinct smile types. Smiles were classified as small, medium, or large when the inferior margin of the upper lip was aligned with the cusp tip, widest buccolingual contour, and cervical portion of the experimental canine, respectively. The upper lip surface area and volume surrounding the experimental canine were measured. Differences in variables before and after experimental canine placement were evaluated statistically using a paired t-test. The average facial models before and after the procedure were superimposed to visualize shape differences.
Results: The upper lip surface area and volume around the experimental canine at rest and in small and medium smiles were significantly increased. In large smiles, the upper lip surface area and volume did not differ significantly before and after the addition of the experimental canine.
Conclusions: Placement of a simulated canine with infralabioversion altered the three-dimensional morphology of the upper lip at rest and during small and medium smiles.
Article: Influence of the placement of a simulated canine with infralabioversion on the three-dimensional morphology of the upper lip.
Authors: Wakako Tome, Maiko Kazuo, Noriyuki Kitai. Department of Orthodontics, School of Dentistry, Asahi University, Hozumi, Mizuho, Japan.