get one's teeth into (something), to

Fig. to begin to do something; to get completely involved in something. I can't wait to get my teeth into that Wallace job. Here, sink your teeth into this and see if you can't manage this project. He'll find it easier when he sinks in his teeth.

To come to grips with something; to work energetically at something. Though the image of sinking one’s teeth into something is surely much older, the expression appears to come from the early twentieth century. In Dorothy Sayers’s wonderful mystery Gaudy Night (1935), one of the women says, “If one could work here . . . getting one’s teeth into something dull and durable.”