John Henry Jones, from Trevor, near Llangollen, went missing in 1970.
His family came forward after the reconstructed face of a man found buried in Staffordshire in 1971 was shown on the BBC's Crimewatch.
But Det Insp Dan Ison, of Staffordshire Police, said DNA tests showed the man was not Mr Jones.
Work had been carried out by a dental expert which suggested similarities between Mr Jones's teeth and the man found in Burton-upon-Trent.
"While the DNA test has not resulted in an identification of the body found in Burton, we have been able to rule Mr Jones out of our enquiries," Det Insp Ison said.
"Forty-six years have passed, but the investigation remains open and we'd ask people to check the image and contact us if they have new information."
An unidentified body found buried in a shallow grave 46 years ago is not a missing man from Denbighshire, detectives have said.