Accuracy of digital photographs for assessing inflammatory gum disease in epidemiologic studies

Paul D. Terry^1*O Lee Wilson²Matthew L Heaton³Orpheus Triplett³Robert Eric Heidel¹Rajiv Dhand¹

• ¹College of Medicine, University of Tennessee Health Science Center (UTHSC), Memphis, United States
• ²Department of General Dentistry, University of Tennessee Medical Center-Knoxville, Knoxville, United States
• ³The University of Tennessee Health Science Center College of Dentistry, Memphis, United States

ABSTRACT Background: Incorporating gum disease assessment into epidemiologic studies would facilitate investigations of disease etiology. Objective: We evaluated the accuracy and inter-rater reliability of experienced dental health professionals’ visual assessments of digital photographs to determine inflammatory gum disease. Methods: Raters viewed anonymized photographs of the teeth and gums of 30 adult patients and were asked to distinguish “healthy” gingiva from “gum disease” and to assess disease severity. Frequency, percentage, and cross-tabulation statistics were used to perform diagnostic calculations including sensitivity, specificity, and overall accuracy. Fleiss’ Kappa, with a 95% confidence interval, was used to test for interrater reliability amongst the four raters. Cohen’s Kappa was then calculated for each potential pairing of the four raters. Results: The accuracy of determining active inflammatory gum disease from digital photographs ranged from 76.7% to 96.7% (mean 85.9%) across the four raters. Sensitivity ranged from 70% to 95% (mean 82.5%), and specificity ranged from 80% to 100% (mean 92.5%). However, inter-rater reliability for disease severity was only fair, with Fleiss’s Kappa for gingivitis and periodontitis 0.25 (0.00-0.51) and 0.28 (0.03-0.54), respectively. Conclusion: Our findings show that digital photographs could be useful for assessing inflammatory gum disease in epidemiologic studies of inflammation-mediated chronic systemic diseases.