Postoperative care of mandibular angle is as follows: Before waking up from general anesthesia, if frequent swallowing movements are found, attention should be paid to wound bleeding. Because the surgical incision is in the oral cavity, it is easy to pollute the incision, which may increase the chance of postoperative infection. It is particularly important to keep your mouth clean after jaw surgery. Rinse your mouth after meals, and scrub the gingival sulcus 2 ~ 3 times a day with normal saline cotton balls to prevent food residues from entering the incision by mistake and causing infection. Keep the drainage tube unobstructed, observe the color and quantity of drainage, and record it accurately. Observe whether there is bleeding in the operating department and the tightness of dressing, and choose antibiotics according to the condition. The negative pressure drainage tube is usually removed 1 ~ 2 days after lower frontal angle surgery.