Lon Chaney was originally cast as Gwynplaine, but at the last minute, he withdrew.
Gwynplaine's fixed grin and disturbing clown-like appearance was a key inspiration for comic book talents Bob Kane and Jerry Robinson in creating Batman's greatest enemy, The Joker.
Gwynplaine's grotesque grin was achieved with prosthesis. Conrad Veidt was fitted with a set of dentures that had metal hooks to pull back the corners of his mouth. The only scene in which he did not wear the prosthesis is the scene where he is ravished by the Duchess Josiana.