The white particles inside the mouth may be caused by sebaceous ectasia, lichen planus and other diseases, which need to be removed by medication and physical therapy. 1. Sebaceous ectasia: white particles inside the mouth may be caused by sebaceous ectasia. Patients can take physical therapy under the guidance of the doctor, such as electrocoagulation therapy, cryotherapy, laser therapy. Most of the patients after treatment, can play a role in removing the white particles inside the mouth. 2. Lichen planus: white particles inside the mouth may also be caused by lichen planus. Patients can take oral glucocorticoid drugs, such as prednisone, dexamethasone, etc., or oral antifungal drugs, such as ashwagandha, etc., under the guidance of the doctor. As well as inhaled glucocorticoid drugs, such as clobetamethasone valerate aerosol. If necessary, optical therapy, laser therapy, and cryotherapy can also be used, which can help to remove small white particles from the mouth. There are many causes of white particles inside the mouth, it is recommended that patients identify the cause of the disease, actively take treatment measures, the use of drugs need to comply with medical advice.