# Development and Validation of a Standardized Lip Fullness Grading Scale

## TL;DR

This study created and validated a new scale to objectively measure lip fullness, showing it is reliable and agrees well with an existing scale.

## Contribution

The development and validation of a new standardized lip fullness grading scale with high reliability.

## Key findings

- Intra-rater reliability was perfect (Cohen's Kappa = 1.0000).
- Inter-rater reliability was high (0.9682).
- Agreement between the Humedix and Allergan scales was strong (Cohen's Kappa = 0.8456).

## Abstract

Lip augmentation is a common cosmetic procedure that requires an objective and validated scale to assess treatment outcomes. Existing lip fullness scales may not be universally applicable across ethnic groups. This study aimed to develop and validate the Humedix Lip Fullness Scale and assess its agreement with the Allergan Lip Fullness Scale.

A total of 53 females were photographed under standardized conditions. Five dermatologists independently evaluated lip fullness using the Humedix scale and analyzed intra‐ and inter‐rater reliability using Cohen's and Fleiss' Kappa, respectively. The same evaluators reassessed the images using the Allergan scale after 6 months, and agreement between the scales was analyzed using Cohen's Kappa.

Intra‐rater reliability was perfect (Cohen's Kappa = 1.0000), and inter‐rater reliability was high (0.9682, 95% confidence interval: 0.9377–0.9987). Agreement between the Humedix and Allergan scales was strong (Cohen's Kappa = 0.8456, weighted Kappa = 0.9056).

The Humedix Lip Fullness Scale demonstrated excellent reliability and strong agreement with the Allergan scale, validating its use as an objective tool for assessing lip volume.