An 18-year-old girl was pushed to the ground and kicked in the mouth in an attack in Boston town centre that saw four of her teeth knocked out.
The incident happened at about 9.45pm on Christmas Eve inside the Waterfront Pub in the Market Place and detectives have now chosen to issue an appeal to try to trace the female attacker.
The victim, from Fosdyke, required extensive dental treatment at hospital.
DC Sue-Ellen Wilson is appealing for witnesses to call her on 101, asking for extension 2234 and quoting incident 413 of December 24.
You can also report crimes anonymously by contacting Crimestoppers on 0800 555 111.