Green’s Dictionary of Slang

(US black) teeth, real or false.

1902		B. Baynton ‘Billy Skywonkie’ Bush Studies 105: Le’ss get away afore she sees us, or she’ll make yer swallow yer chewers.
1944		‘Jiver’s Bible’ in D. Burley Orig. Hbk of Harlem Jive.