The street robbery occurred at California and Kearny streets around 4 p.m. Thursday when the two attackers came up from behind the victim and punched him in the face, knocking him down, police said.
The attackers also took the victim's cell phone and ripped the gold caps out of his mouth before fleeing the scene on foot, according to police.
The victim also suffered a swollen eye and abrasions to the knee and was taken to the hospital.
Police have yet to make any arrests.
Source: SF Chronicle