Grigorieva's alleged injuries are raising "serious questions" about her story that Gibson struck her.
Law enforcement sources who have analyzed the pictures and video -- yes, we've learned she had video shot as well -- tell TMZ there is "no evidence of external or internal damage," making it inconsistent with being punched in the face.
As we have already reported, Oksana's teeth were not damaged -- they were intact. The dentist has submitted a sworn declaration saying one veneer was out and one was cut in half, but the teeth were not damaged.
Furthermore, several experts who have examined the photos and video say there is no evidence of any soft tissue damage, which would be present if someone were struck in the mouth, and it would be "highly irresponsible" for the dentist to so quickly replace Oksana's veneers.
We're told law enforcement is investigating the scenario that the damage to the veneers could have been self-inflicted. We're told at least one expert who has evaluated the photos and video believes it's a self-inflicted injury.
As we first reported, Gibson's lawyers will make a presentation to the Sheriff's Department ... in part arguing that Oksana made false statements to authorities.