Pop, crackle, snap

SIR – I see that “rogue kernels” in popcorn are now demonised for damaging teeth (report, October 8).

Many years ago when I was working at a dental practice in Birmingham, a session was always left vacant in the appointment book on a Monday to accommodate emergency treatment of fractured teeth caused by pork scratchings eaten in a public house over the weekend. J D Price

Sheffield, South Yorkshire