⒈ on the teeth itself is not good: long-term chewing betel nut, on the teeth abrasion serious. \x0d\\peculiar to the periodontium is not good: betel nut juice mixed with lime, easy to form dental calculus, not only affects the aesthetic, but also affects the periodontal health. Betel nut fibers are coarse and hard, and may also puncture the gums or block the gaps between the teeth, resulting in inflammation of the gums due to compression. \x0d\\\310 is not good for the oral mucosa: lightly, it may cause mucosal lesions, or more seriously, it may evolve into oral cancer. \x0d\ sunglasses are not good for TMJ: long term chewing will increase the weight bearing of TMJ, causing joint popping, pain and other symptoms. In severe cases, it can also lead to perforation of the joint disk. \x0d\ Careful on digestive system: Some of the components of betel nut can impair the taste nerve and salivary secretion, affecting the digestive function. In addition, betel nut residue also irritates the stomach lining, which can seriously lead to inflammation or even perforation of the gastric mucosa.