Your English: Idioms: teeth

When somebody has treated you badly in an already bad situation, it can be described as being a kick in the teeth. For example, ’After the increase in workload, the pay cut came as a real kick in the teeth.’ In this case, you may be fed up to the back teeth (feel very frustrated) with the situation, but you may have no option but to grit your teeth (put up with the situation) and bear it.

In various industries and professions, people cut their teeth (gain their first experience) in a particular job or activity, as in ‘Many famous actors cut their teeth in regional theatre before moving on to television or film’.Such people often get positions in the teeth of fierce competition (when there are lots of people also wanting that position), and sometimes may only get a job by the skin of their teeth (by luck, very nearly being unsuccessful). However, as in all professions, sometimes you just have to be a little aggressive and show your teeth in order to get what you want. 

If you put a lot of time and energy into something that is interesting because it requires a lot of effort and skill, you can be said to get your teeth into it, as in ‘I’d like a project that I can really get my teeth into’. 

If a sound sets your teeth on edge, it is very unpleasant or annoying, as in ‘That whining voice of his always sets my teeth on edge’.