Tooth marks on the tongue may be caused by the following reasons: the first reason is that the teeth are not aligned too narrow arch, there is a disorder of bite, narrow arch, crowded teeth without timely correction, the tongue does not have enough space will have very obvious tooth marks. In the second case, the patient has serious psychological problems or serious mental stress, and often the tongue is tightly pressed against the teeth, and even in sleep, it is still not relaxed, and tooth marks are likely to appear. In the third case, the patient is too obese, too obese tongue body is too big, the oral environment can not completely accommodate the tongue body, there is a high probability of tooth marks when sleeping at night.