Green’s Dictionary of Slang

railings n.

the teeth.

1845		York Herald 5 Apr. 7/5: The long hair of the woman had been cut off and sold [...] ‘rails’ (teeth) have been taken from every corpse.
1855		(con. 1846) Fights for the Championship 212: His front railings have been displaced in by-gone battles.
1921		(ref. to mid-19C) Essex Newsman 10 Sept. 1/3: I was [...] amused by the quaint language used by my predecessors in the Ring [...] ‘The Nobbler dashed in his left mawley and landed on the British Oak’s kissing-trap [...] knocking out two of his front rails’.
1958		F. Norman Bang To Rights 124: They took him into the Hospital and pulled out all his railings.
1962		F. Norman Guntz 78: They [...] call each other ‘doooling’ through their railings.
1976		(ref. to 1930s–70s) R. Barnes Coronation Cups and Jam Jars.
1984		Partridge DSUE (8th edn) 956/2: since 1910 at latest.
1999		Indep. Rev. 22 July 8: Clean yer railings.