Actor JAKE GYLLENHAAL suffered for his art while making his new war movie JARHEAD - he knocked out one of his own teeth.

The actor, who plays real-life US Marine ANTHONY SWOFFORD in the Gulf War drama, injured himself while filming an intense fight scene.

He says, "I jammed a gun into my mouth, and I guess I did this really, really hard because I was so into the emotions of the scene.

"Suddenly, I looked down and saw my tooth had been knocked out - it was in my hand - and blood was starting to flow... but I didn't even care at that moment."

Despite the mess, Gyllenhaal finished the scene toothless. He has since had the tooth re-inserted.