Detectives are appealing for witnesses after 18-year-old woman was assaulted following a night out in Chelmsford.
She had been to Evoke with her friends celebrating New Year's Eve.
On their way home they were walking in Tindal Street at around 2.30am when there was a large disturbance.
She was assaulted and ended up receiving serious facial injuries which required hospital treatment.
Investigating Officer, Pc Chris Abbott, said: "The victim has lost one tooth and will need extensive dental work to save others that have been loosened and moved in the attack.
"She also suffered a bruised and cut lip which needed four stitches as well sustaining bruises to her face, arm and back."
The victim, who lives in Rayleigh, did not see the suspect and neither did her friends.
It is believed they may have been part of a mixed group of about seven white men and women who were in their late teens or early 20s.
Anybody who witnessed the incident, or anyone who has any information, is asked to contact Pc Chris Abbott at Chelmsford CID on Essex Police 101.
