For oral and maxillofacial malignant tumors requiring surgical treatment, the surgeon must first face the following problems, make a scientific and comprehensive evaluation of the condition, discuss the patient’s disease diagnosis, pathological nature, biological behavior of the tumor, developmental stage of the tumor, impact of surgical treatment on the patient, prognosis and other issues, and make a relatively personalized surgical plan. I. Whether patients can tolerate surgery and whether there are contraindications to surgery It should be realized that with the overall development of medicine, the absolute contraindications to surgery are gradually decreasing, and most of the concomitant systemic diseases are relative contraindications that can be controlled or adjusted, such as anemia, malnutrition, hypertension, diabetes, most heart diseases, liver and kidney diseases, etc. After detailed preoperative preparation, surgery can be performed, and the surgeon should clearly The bottom line of surgery for patients with concomitant systemic diseases, and a full understanding of the tolerability and possible complications of surgery can ensure the success of surgery. Blood pressure above 26/14 kPa (200/108 mmHg) should be lowered before surgery. In hypertensive patients, the administration of oral antihypertensive medication will not interfere with the administration of anesthesia, although diet must be abstained before general anesthesia surgery. Patients with hypertension should have their blood pressure monitored daily starting three days before surgery for antihypertensive treatment, and if necessary, a cardiology consultation should be requested. Blood pressure persistently higher than 200/108 mmHg should delay surgery. Those who have had recent myocardial infarction or currently have significant symptoms of congestive heart failure are the greatest risk factors. Stable angina pectoris, distant myocardial infarction, electrocardiographic T-wave and S-T segment changes, and bundle branch conduction block, although all are non-negligible red flags, do not pose a serious threat if attended to. Table 1 shows the scoring criteria for non-cardiac surgical cardiac disease, listing the degree of risk for surgery. Patients with very poor pulmonary function, with maximum ventilation below 60%, are absolute contraindications to surgery. In acute hepatitis, the patient’s liver should be transferred to the infectious disease department for treatment as soon as hepatitis is detected, and surgery should not be considered for the time being. If there is bleeding tendency, detailed examination should be done and platelets and fresh blood should be input; if there is ascites, internal medicine consultation should be requested, liver preservation treatment, restriction of sodium and water intake, diuresis, albumin input should be given, and non-emergency surgery should be referred to internal medicine for treatment. Diabetes mellitus, blood glucose should be controlled below 8 mmol/L. Anemia, with hemoglobin below 100g/L, should be corrected before surgery. Every 300ml of whole blood can raise hemoglobin by about 10g, and the amount of blood transfusion needed can be derived by calculation. Hemophilia is a contraindication to surgery, and surgery must be performed after detailed preoperative preparation with the assistance of an internist, including anti-hemoglobin and fresh blood transfusion preparation. Thrombocytopenia, with platelets below 80,000/mm3, should be corrected before surgery. Renal disease, renal dysfunction is not a contraindication to surgery. Elective surgery is possible as long as new damage and aggravated renal injury are avoided. Intraoperatively and postoperatively, blood pressure should be kept stable, the amount of blood and fluid transfusion should be controlled, and attention should be paid to adjust fluid balance, electrolyte balance, and acid-base balance. For patients who will undergo cancer surgery, nutritional support should be given when two of the following indicators occur: (1) weight loss more than 10% of the original weight; (2) weight/height index less than 90% of normal; (3) serum albumin less than 35g/L; (4) serum transferrin less than 1.5g/L; (5) peripheral blood lymphocytes less than 1.5×109/L; (6) pre-treatment lymphocytes less than 1.5×109/L. L; (6) non-responsiveness to recall skin antigen tests, such as delayed skin hypersensitivity test reactions, prior to treatment; (7) being in a catabolic state. Nutritional support should be given 7-10 days before surgery to adjust the imbalance of water-electrolyte balance and correct hypoproteinemia, which is very effective in reducing postoperative incisional dehiscence, infection, and mortality. Nutritional supplementation can be done by three means: oral, tube feeding and intravenous. It is recommended to use total nutritional elements to insert nasal gastric tube, and patients with poor gastrointestinal absorption function can use intravenous nutrition to ensure daily caloric calories above 30-35 calories/Kg.d, and avoid negative nitrogen balance, with nitrogen: calories higher than 1:300 and protein requirement of 6.25X nitrogen. Although the malignant tumors that can be completely removed may not necessarily achieve the effect of cure, theoretically speaking, the malignant tumors that cannot be completely removed can definitely not be cured by surgery, and for almost all oral and maxillofacial malignant tumors, partial removal is not only detrimental to the health of the patient, but also to the health of the patient. For almost all oral and maxillofacial malignant tumors, partial excision is not only detrimental to the treatment of tumor, but also impossible to improve the function, and there is no benefit of tumor reduction. Therefore, if oral and maxillofacial malignant tumors cannot be completely surgically removed, in principle, surgery should be abandoned, therefore, judging whether complete surgery can be performed is a basic requirement for surgical treatment. With the development of modern clinical examination technology, most of the oral and maxillofacial malignant tumors can be judged whether they can be completely resected before surgery. The commonly used means include intensive CT and MRI for judging the precise boundary of the tumor; CTA and MRA for judging the relationship between the tumor and large blood vessels; PET-CT, ECT and other examination means for judging the systemic metastasis and so on. The following are several cases that need to give up surgical treatment. 1.Tumor encircling carotid artery, if the encircling part is located in the carotid segment, it can be surgically removed based on the preparation of carotid reconstruction, but if the encircling part is close to the skull base, the risk of surgery is higher and the success rate is lower, so our opinion is to give up the surgical treatment. Similarly, malignant tumor encircling the skull base and invading the internal jugular vein should also be abandoned for surgery. 2.Tumor directly destroys the skull base and enters into the skull. If tumor destroys the midline structure of skull base, such as the upper wall of pterygoid sinus, slope, tip of temporal bone and enters the brain parenchyma, surgery should be abandoned. 3.Tumor invades cervical spine, no matter the metastasis or primary foci in the neck, as long as the bone structure of cervical spine is damaged and the tumor cannot be operated completely, the surgical treatment should be abandoned. 4.Distant metastasis of tumor occurs. Tumor with distant metastasis is usually multiple, even if there are only isolated metastases in the clinic, surgery should be given up. At present, for cases of adenoid cystic carcinoma with isolated lung metastases and relatively limited primary foci, separate surgical treatment of primary foci and metastases is attempted, but the long-term effect remains to be further observed. Whether induction chemotherapy or radiation therapy is needed before surgery For the treatment of oral and maxillofacial malignant tumors, we should have the concept of comprehensive treatment, and pure surgical treatment has certain limitations. Comprehensive treatment is not a haphazard accumulation of various treatment methods, but a personalized treatment plan should be formulated before starting treatment. Preoperative chemotherapy can reduce the size of tumor and create conditions for surgical treatment, and it can reduce the chance of intraoperative metastasis and the trauma of surgery. At present, the preferred chemotherapy can reduce the incidence of incomplete surgery for oral and maxillofacial malignancies: oropharyngeal cancer, tongue root cancer, etc. Preoperative induction chemotherapy can be used as a reference for later treatment selection. If the primary foci are CR, adjuvant chemotherapy can be continued after surgery, and for those whose lymph nodes do not reach CR, surgery plus radiation therapy is appropriate for the neck. It should be clearly understood that although preoperative induction chemotherapy is often used in clinical practice, and the remission rate is high for intermediate and advanced oral and maxillofacial squamous carcinoma, it is still controversial whether it can improve the survival rate, and a lot of clinical experiments are needed for further confirmation. 2. Pre-operative radiotherapy and post-operative radiotherapy Most surgeons do not accept pre-operative radiotherapy because it may increase the occurrence of post-operative complications and cause incision non-healing and necrosis. However, for maxillary sinus cancer, it is more acceptable to have half course of radiotherapy each before and after surgery, especially for maxillary sinus cancer with posterior lateral wall and superior wall invasion, radiotherapy before and after surgery can significantly improve the cure rate. Pre-operative chemotherapy and post-operative chemotherapy are mainly applied to malignant tumors prone to distant metastasis, such as malignant melanoma, osteosarcoma, soft tissue sarcoma, etc. Chemotherapy before and after surgery is useful to prevent metastasis and treat micro metastasis, thus improving the cure rate. What kind of shape and function changes will be brought after resection The oral and maxillofacial region has complex anatomical features and functional shape requirements, and the surgical treatment of oral and maxillofacial malignant tumors is very destructive or even destructive, so the surgeon is required to make predictions about the destruction of shape and function before the surgical treatment, so as to communicate well with the patient before the operation. The oral and maxillofacial surfaces should have a symmetrical shape and harmonious proportions. The loss of bone and soft tissues caused by tumor resection can cause corresponding shape changes and disrupt the harmonious appearance of the face. The face has complex expressive movements and it is unlikely that it will be stiff or have varying degrees of restricted expressive activity after surgery. The scars left in the neck after surgery may affect the patient’s social life and social psychology. The oral cavity has the functions of eating, speech, chewing, swallowing, and taste, etc. Changes in oral structure and tissue defects can seriously affect these functions, such as jaw bone defects, dental defects, tongue defects, palate defects, cavernous defects of the oral and maxillofacial surfaces, etc. The effects caused by these defects are often not single, such as tongue defects, which not only affect the swallowing function of the oral cavity, but also have serious effects on pronunciation, stirring of food during chewing, taste and even digestion. The total tongue defect even has a serious impact on eating, and the function of aversion is often lost after a total tongue defect, and if the larynx is not treated, eating will cause choking and aspiration pneumonia, affecting the life of the patient. There are complex nerve distribution in the face and neck, such as the trigeminal nerve and cervical plexus nerve are sensory nerves, which may cause numbness and abnormal sensation after surgery; facial palsy caused by injury or defect of facial nerve will cause changes in facial appearance; injury or defect of paracentral nerve will cause difficulty in lifting the shoulder after surgery; injury of vagus nerve will cause hoarseness and choking and coughing after surgery; injury of hypoglossal nerve will cause tongue palsy after surgery, which will seriously affect language and eating etc. In the past, when considering the surgical treatment of oral and maxillofacial tumors, especially malignant tumors, more consideration was given to the preservation of function and less emphasis was placed on the appearance. The choice should be made according to the actual situation and the patient’s requirements. In the past, the principle of simplicity was emphasized in restoration and reconstruction, and vascularized flaps were not used if they could be used with a tip. However, the principle of simplicity should not be completely abandoned, and it should be as simple as possible on the basis of pursuing the best results, because after all, what we are facing is not purely plastic surgery, but the treatment of malignant tumors, and once the oral and maxillofacial malignant tumors need to be rectified, it is often a relatively complicated project and takes relatively long time. However, a reasonable treatment plan should be formulated before the first-stage surgery, and appropriate repair means should be selected to ensure the healing of the wound and not to affect the later functional repair and reconstruction. The tissue defects caused by different sites, different patients and different tumors are all different, not only the size of the defect, but also the shape and amount of the defect are different. Before surgery, we should have a clear understanding of the extent of tumor resection, the size, shape and tissue nature of the defects in the oral cavity, face and neck, and make good measurements so that we can choose the repair method, the size and shape of the tissue flap, the length of the blood vessels in the donor area and the selection of the blood vessels in the recipient area before surgery. For complex jaw reconstruction, computerized design is required to restore the shape of the jaw bone and to design the number and location of implants for simultaneous implant placement. Rapid prototyping (RP) and reverse engineering (RE) is a new technology developed by the rapid development of computers and imaging. In the 1990s, they were used in clinical practice abroad. In the beginning of this century, some units in China have also started to apply it. The advantage of this technique is that the patient can obtain a 3D cephalometric rapid prototype in the laboratory by clinical CT scan; on this basis, various grafts can be created and surgical plans can be designed on an individual basis. This technology is fully compatible with the modern concept of “individualized” medicine and facilitates the development of “individualized” prosthetic surgery.