Functional and social limitations after facial palsy: expanded and independent validation of the Italian version of the facial disability index.

Background: The Facial Disability Index (FDI) is widely used for self-assessment of functional impairment and quality of life in patients with facial palsy.

Objective: The study aim was to complete the validation of the FDI by generating an Italian version (IT-FDI) and evaluating its clinimetric properties.

Design: This was a longitudinal, observational measurement study.