Development and validation of a photonumeric scale for evaluation of volume deficit of the temple

Background: A validated scale is needed for objective and reproducible comparisons of temple appearance before and after aesthetic treatment in practice and clinical studies. Objective: To describe the development and validation of the 5-point photonumeric Allergan Temple Hollowing Scale. Methods: The scale was developed to include an assessment guide, verbal descriptors, morphed images, and real subject images for each grade. The clinical significance of a 1-point score difference was evaluated in a review of image pairs representing varying differences in severity. Interrater and intrarater reliability was evaluated in a live-subject validation study (N = 298) completed during 2 sessions occurring 3 weeks apart. Results: A score difference of ≥1 point was shown to reflect a clinically significant difference (mean [95% confidence interval] absolute score difference, 1.1 [0.94-1.26] for clinically different image pairs and 0.67 [0.51-0.83] for not clinically different pairs). Intrarater agreement between the 2 validation sessions was almost perfect (mean weighted kappa = 0.86). Interrater agreement was almost perfect during the second session (0.81, primary endpoint). Conclusion: The Allergan Temple Hollowing Scale is a validated and reliable scale for physician rating of temple volume deficit.