The tongue has the strength and ability to ‘mould’ not only the shape of the dental arch but also the shape and size of the jaws themselves. As I mentioned, the tongue should rest against the palate – that is, at the upper jaw. If it doesn't sit there, the upper jaw stays narrow and underdeveloped. If the tongue rests down by the lower teeth, it drives the growth of the lower jaw, which becomes the wider of the two. All these changes are possible while the jaws are still growing. Once growth has finished, the tongue affects only the position of the teeth. More often than not, the incorrect tongue position starts in childhood, and the changes we see in patients are in the jaws.
This answer is for general information. Your own case needs an examination by an orthodontist.