sweet tooth

an eye for an eye, a tooth for a tooth

compensation for injury caused by a person, in the form of inflicting of an identical injury on that person.

clean as a hound's tooth

Very clean.

hen's tooth

Anything not naturally occurring.

home sweet home

Expressing contentment or relief at residing in or returning to one's own home.

keep someone sweet

To keep someone friendly or satisfied by complying with their wishes or preferences.

long in the tooth

Old; aged.

salty tooth

A liking for foods that are salty.

sour tooth

A liking for foods that are sour.