Advanced soft palate cancer may present with dysphagia and produce voice changes, and fixation, destruction, and perforation of the soft palate may lead to food reflux into the nasal cavity. Its surgical complications are open nasal voice and food reflux into the nasal cavity. Soft palate cancer should be differentiated from the following diseases: 1. mixed tumor Benign mixed tumor of small salivary glands in palate is more common than malignant, with no conscious symptoms, slow growth, normal mucosa on the surface of most masses and no bone destruction, which can be identified by puncture cytology or frozen section during surgery. 2.Maxillary sinus cancer, especially the primary one at the bottom wall, often causes oral symptoms, and sometimes it is not easy to distinguish from palate cancer invading maxillary sinus, which often has nasal symptoms and abnormal exudate first, and the teeth loosening and falling off early and in large number. 3.Tongue cancer Tongue cancer is the most common oral cancer, with more men than women. Most tongue cancers are squamous cancers, especially in the first 2/3 of the tongue, while adenocarcinoma is less common and mostly located at the root of the tongue. Tongue cancer mostly occurs at the edge of the tongue, followed by the tip of the tongue, the back of the tongue and the root of the tongue, and is often ulcerative or infiltrative. Generally, it has higher malignancy, fast growth and strong infiltration, and often affects the tongue muscle, resulting in restricted tongue movement and difficulty in speaking, eating and swallowing. 4.Gum cancer Gum cancer is mostly highly differentiated squamous cell carcinoma, with ulcerated type being the most common. Lower gingiva is more frequent than upper gingiva, and the tumor grows slowly, more in men than in women, and can be clinically manifested as ulceration or papillary protrusion. In the early stage, the tumor invades the alveolar process and jawbone, resulting in loosening, displacement and even loss of teeth. The localities are accompanied by pain. Maxillary gum cancer can invade maxillary sinus, and mandibular gum cancer can invade the floor of mouth and chin, and when it invades posterior area of molar and pharynx, it can cause difficulty in opening mouth.