Teeth are a curious evolutionary life-over from when the average life-expectancy of a human-being was around “20-years-old” or perhaps a little older (early humans used to breed in there early teens due to a very narrow fertility window). However, as human intelligence grew, and human labour made life less difficult – the life-expectancy slowly creeped-up – but teeth development appears to have lagged behind. Far behind – in fact. We can live to 80 – but our teeth give-up the ghost at about 20 – or at least they would without modern dentistry and regular cleaning. Remember – you can die from an infected tooth – so look after yourselves!