A 21-year-old dental nurse was violently attacked after defending her Jewish friends during an antisemitic tirade.

But one year on, police are no nearer to finding her attacker, and this week they offered an unprecedented £10,000 reward for information which leads to an arrest.

Chanelle O'Malley was hit so hard that the suspect broke her jaw in two places, smashed her teeth out and caused deep gashes to her face, which required plastic surgery, 30 stitches in her head and lip, a metal plate and bolts in her jaw and permanent scarring.

Ms O'Malley waived her right to anonymity this week by appealing for information on the man who attacked her.

Ms O'Malley, from Edgware, north west London, was travelling back from Camden on a night bus with four Jewish friends in the early hours of May 24 last year when a man approached them.

“He started being rude and making racist comments,” she said. “He was saying: ‘You ****ing Jews, you little Jewish princesses.’ It went on for a while and I told him to shut up.

“I was the only non-Jewish one in the group. He was being racist and it was the first time I’d experienced that kind of thing. I think it’s disgusting to use those words. He was with three or four friends — and they were all laughing.”

The gang left the bus one stop before she and two of her friends got off at Edgware tube station. Her friends had to wait for a taxi, which arrived just as the gang reached the station.

The friends got in but before she could join them, the man grabbed her neck and punched her in the face. Due to the size and depth of her injuries, police believe he was wearing heavy rings.

“I remember waking up on the floor,” she said. “I didn’t know what had happened and I was on my hands and knees looking for my teeth. I was in complete shock and was scared.

“My friends were in the cab and didn’t see what had happened, it was all so quick. They were in total shock. One said she has had nightmares and wakes up with the image of me, all cut up.”

Off-duty police officers intervened but failed to catch the gang as they ran off. Ms O’Malley was taken to hospital.

She said: “I couldn’t remember that he had grabbed me around my neck but my sister noticed the handprint which brought it back to me.”

Her sister, Hayley, 27, said: “I was shocked when I saw her. I fainted. The injuries were too much for me. I wouldn’t let her look in the mirror for ages.”

Chanelle remained in hospital for two days and returned to work three weeks later after the swelling began to subside.

“The cuts were bad but it was the teeth that really got me,” she said.

“The attack really knocked my confidence at first. When I was going out months later, I was quite nervous and didn’t like speaking to people.

“And now, whenever I’m out, my mum rings me every hour to see if I’m ok. I take cabs now and haven’t been on a night bus since.”

She said she would behave differently if faced with the same situation. “Next time, I think I’ll keep my mouth shut,” she said.

Detective Constable Aileen Davies said: “The level of violence displayed in this attack on a defenceless girl is nothing short of extreme. This man will offend again. The behaviour this thug has displayed should not be tolerated in civil society and the whole community should act together to find him.”