A man was knocked to the ground and had his head stood on during an attack in Belfast city centre, the High Court has heard.
Two assailants also allegedly kicked him about the face before they boarded a nearby bus, prosecutors claimed.
The victim later underwent surgery to have six metal plates inserted into his head and cheeks.
Details emerged as one of the two men accused of carrying out the attack was refused bail.
James Jelley (45) of Antrim Close in Belfast, faces a charge of causing grievous bodily harm with intent to Leonard Williams in April last year.
Crown counsel Kate McKay said Mr Williams got into an argument with two men outside Office shoe shop on High Street.
Witnesses then heard a thud as one of the attackers allegedly banged his head off the reinforced glass window, according to the barrister.
She claimed Mr Williams was repeatedly punched and kicked about the face and head after he fell to the ground.
"He was noted to be bleeding heavily from his mouth, (and) one of them stood on his head in effect," Mrs McKay said.
After being challenged by members of the public, the two attackers left and got onto a bus on Royal Avenue.
"A witness on the bus overheard them taking about the assault," Mrs McKay added.
"One of them was noted to have blood on his trainers and hands."
She said the victim suffered multiple facial fractures, broken teeth and had to have his jaws wired shut during the healing process.
It was also revealed during the hearing that Jelley's co-accused has since died.
Jelley is also separately charged with burgling a woman's home in Newcastle, Co Down last December.
Confining his submissions to that alleged incident, defence counsel Dennis Boyd said Jelley denies any involvement.
Mr Boyd stressed there is no forensic evidence linking his client to the burglary at the Golf Links Road address.
But Lord Chief Justice Sir Declan Morgan held that a prima facie, circumstantial case has been established against him.
Describing delays in getting the earlier assault case to trial as "shocking", the judge stressed the need for the case to be prioritised.
Sir Declan refused bail, however, based on the risk of the defendant reoffending.