Bites on one side of the big and small generally due to bad chewing habits, dental disease, drug side effects, patients can be improved through general treatment, surgical treatment. 1. Bad chewing habits: bad chewing habits can lead to different size of biting muscles on both sides, when eating, patients should try to use both sides of the biting muscles to chew, to avoid long-term use of one side of the biting muscles to chew food, so as to gradually improve the biting muscles on both sides of the size of the situation. 2. Dental diseases: Wisdom tooth pericoronitis, missing back teeth are also prone to bite muscle hypertrophy on one side, the patient can be surgically removed or the missing teeth will be repaired, which can effectively improve the bite muscle on both sides of the size of the situation. 3. Drug side effects: after injecting botulinum toxin in the face, adverse reactions can also lead to the situation of bite muscle size, the patient can be appropriate for the face of hot compresses, or under the guidance of the doctor local re-injection of botulinum toxin, to achieve symmetry of the two sides of the effect. The size of the bite muscle is not the same on both sides, may also be due to oral tumors and other reasons, the patient should consult a doctor for examination in a timely manner.