Deep Learning for Gummy Smile Segmentation

Deep Learning-Based Evaluation of Gummy Smile: Development and Validation of a Segmentation Model

A gummy smile (excessive visibility of the gums when smiling) is not merely an aesthetic issue but also an important parameter in terms of periodontal health. Current evaluation methods are subjective and non-standardized, leading to limitations in both clinical accuracy and patient communication. In recent years, AI-based models have begun to be effectively used in dental image analysis and diagnostic processes. This study aims to develop an AI-supported objective and reproducible analysis model capable of evaluating gummy smile from both aesthetic and periodontal perspectives using a unique dataset composed of images obtained through standard clinical protocols and labeled by the same expert.

Individuals aged 12 years or older with no maxillary anterior (teeth #13-23) tooth loss will be included in the study. Patients with missing anterior maxillary teeth (teeth #13-23), significant anatomical pathologies, or smile-interfering factors (e.g., facial piercings, orthodontic appliances, facial hair) will be excluded.

Standardized frontal photographs will be taken using a single device (iPhone 15) to ensure consistency in resolution, lighting, and color balance. Images will be captured from a fixed distance of 15 cm with participants in an upright position, eyes facing forward, and heads aligned to the Frankfurt Horizontal Plane. To maintain standardization, the smartphone's grid lines will be used to align the horizontal line with the pupils and vertical lines with the nasal alae.

Images of high, average, and low smile lines will be labeled by a periodontist using the web-based annotation tool MakeSense. Visible gingival areas will be annotated as polygons bounded superiorly by the lower border of the upper lip and inferiorly by the gingival margin. For participants with high smile lines, gingival display will be measured using ImageJ (National Institutes of Health, Bethesda, MD, USA), with calibration performed via a periodontal probe embedded in each photo. A pixel-to-millimeter conversion factor will be derived and applied to measurements between the upper lip and gingival margin in the anterior maxillary sextant (teeth #13-23). Distances between paired landmarks (points 7-13, 8-14, 9-15, 10-16, 11-17, 12-18) will be measured in millimeters. AI-based segmentation outputs (via MakeSense) will be statistically compared to ImageJ measurements to assess correlation.

Study Overview

• Status: Recruiting
• Conditions: Gummy Smile

• Study Type: Observational
• Enrollment (Estimated): 1740

Contacts and Locations

• Study Contact: Name: Zeynep Turgut Cankaya, Associate Professor; Phone Number: +90 5333899618; Email: zeynepturgut@gazi.edu.tr
• Study Contact Backup: Name: Gulenay Colak, Research Assistant; Phone Number: +905072637113; Email: gulenaycolak@gazi.edu.tr

Study Locations

• Turkey
  • Cankaya
    • Ankara, Cankaya, Turkey, 06490
      • Recruiting
      • Gazi University
      • Contact: Zeynep Turgut Cankaya, Associate Professor; Phone Number: +905333899618; Email: zeynepturgut@gazi.edu.tr
      • Principal Investigator: Gülenay Colak, Research Assistant

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Patients who presented to the Department of Periodontology, Faculty of Dentistry, Gazi University, for routine dental evaluation and treatment

Description

Inclusion Criteria:

• Individuals aged 12 years or older with no maxillary anterior (teeth #13-23) tooth loss will be included in the study.

Exclusion Criteria:

• Patients with missing anterior maxillary teeth (teeth #13-23), significant anatomical pathologies, or smile-interfering factors (e.g., facial piercings, orthodontic appliances, facial hair) will be excluded.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
• High smile; Gingival margins and cervical areas are clearly visible above the upper lip line.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Evaluation of gummy samples using artificial intelligence	From enrollment to the end of treatment at 4 months

Collaborators and Investigators

• Sponsor: Gazi University
• Collaborators: The Scientific and Technological Research Council of Turkey
• Investigators: Study Director: Zeynep Turgut Cankaya, Associate Professor, Gazi University

Study record dates

Study Major Dates

• Study Start (Actual): January 12, 2025
• Primary Completion (Estimated): May 15, 2025
• Study Completion (Estimated): May 20, 2025

Study Registration Dates

• First Submitted: May 2, 2025
• First Submitted That Met QC Criteria: May 2, 2025
• First Posted (Actual): May 11, 2025

Study Record Updates

• Last Update Posted (Actual): May 21, 2025
• Last Update Submitted That Met QC Criteria: May 16, 2025
• Last Verified: May 1, 2025

More Information

Terms related to this study

• Other Study ID Numbers: E-77082166-604.01-881629

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No