Police are appealing for information after a man was injured in a glassing incident on Sydney’s lower north shore.

About 2.15am today (Sunday 29 July 2012), a 20-year-old man was walking across the dance-floor in a hotel on Willoughby Road, Crows Nest, when he was spoken to by a man and woman.

The 20-year-old went to walk away and felt a push to his back, before the female allegedly threw a glass at him.

The glass hit the man’s mouth, knocking out a tooth and cutting his upper lip.

Hotel staff rendered first aid to the injured man and police were notified of the incident.

Officers from Harbourside Local Area Command are investigating and would like to speak to two people who may be able to assist with their inquiries.

The first person is described as being a female of Caucasian appearance, about 25-30 years of age, with long dark hair.

The second person is only described as a male with slight facial hair.

Any witnesses who have not yet been spoken to by investigators, or anyone with information is asked to contact police.