Wayne County medical examiner's office spokesman Dennis Niemiec says an autopsy conducted Friday determined that Paul Cannon died from blunt force trauma to the head.
Niemiec says the man's dentures were "not an issue" in the death. An earlier report said the punch may have caused the older man to choke on his dentures.
Police say Cannon was reportedly causing a disturbance Thursday afternoon at the restaurant on the city's east side and tried to hit the worker, who swung back.
The worker was in police custody Friday.