total mandibular subapical osteotomy

Total mandibular apical osteotomy for surgical correction of mandibular deformities. Total mandibular apical osteotomy is also called submandibular osteotomy. There are generally two ways: one is the sagittal subapical osteotomy of the sagittal subtotal. In 1976, Diets reported a clinical case using this procedure, which is characterized by a combination of ascending sagittal split and total mandibular apical osteotomy to maintain the integrity of the inferior alveolar vascular bundle. The blood supply is better. The other is the complete mandibular subapical osteotomy, or the subtotal apical osteotomy after the mandibular molar. This procedure often requires the inferior alveolar neurovascular bundle to be exposed and protected, but the full dentition osteotomy has been lost above or below the inferior alveolar nerve vascular bundle. The direct blood supply from the inferior alveolar nerve vascular bundle, and only the soft tissue attached to the buccal and lingual side of the blood supply, is worse than the former. Treatment of diseases: temporomandibular joint disease Indication Total mandibular apical osteotomy for: 1. Class II malformation with low mandibular plane angle and anterior anterior humerus position. 2. In the short face syndrome, the mandibular height of the maxillary and labial teeth is normal. 3. It is necessary to simultaneously migrate the entire mandibular alveolar bone and level the Spee curve. 4. Some open deformities. Contraindications 1. The general condition is poor, or there are organic diseases without cure, such as tuberculosis. 2. People with emotional instability or a history of mental illness. Preoperative preparation 1. Learn more about the patient's psychological state and requirements for deformity. 2. Take the full-thoracic tomographic X-ray film and the standard lateral slice of the cranial jaw, and perform cephalometric prediction. 3. Take two pairs of plaster molds and do a careful model surgery to determine the location and size of the osteotomy. 4. Check whether the jaw arch and dentition require preoperative orthodontic treatment. 5. Photo face, side position and bite photo for postoperative comparison. 6. Heart, lung, liver and kidney function tests. Because orthognathic surgery is a plastic surgery category, the general condition should be stricter. 7. Preoperative oral cleaning, cleansing, treatment of the lesions. Prefabricated panels or prepared dental arch splints. Surgical procedure Incision Using a physiological saline containing appropriate amount of epinephrine, submucosal injection was performed in the entire lower jaw and buccal sulcus. The visceral sulcus was attached to the vestibular sulcus and the 5 to 10 mm lip and buccal mucosa was incision. After incision of the mucosa in the pupil area, blunt dissection, revealing the phrenic nerve vascular bundle, and then incision of the periosteum; after incision of the mucosa in the anterior mandibular section, the tangential oblique oblique alveolar bone, so that part of the labial sacral muscle remains in the alveolar space At the bone surface. The mandibular lateral bone surface was separated from the subperiosteal to the median joint and the inferior mandibular border. In general, the median joint and the lower mandible margin were not removed. The periosteum and soft tissue of the sacral vascular bundle are loosened at the pupil so that there is a certain degree of lifting during the operation. The incision extends posteriorly to the leading edge of the ascending branch, using the same incision and exposure as the sagittal split of the ascending branch. 2. Osteotomy According to the position of the pupil and the X-ray of the whole jaw, the distance between the inferior alveolar nerve vascular bundle and the root tip and the lower mandible was measured. The lower apical horizontal osteotomy of the submandibular apical osteotomy is performed between the inferior alveolar nerve vascular bundle and the lower mandibular margin. According to the measurement, the osteotomy mark line was made to the 5 mm after the second molar. The horizontal osteotomy line under the apex is connected to the vertical osteotomy line of the buccal sagittal split. Use a split drill or a complex saw for horizontal osteotomy. When cutting the buccal cortical bone, it should be inclined to the lingual side at an angle of about 45°. The neurovascular bundle should be protected at the iliac nerve bundle. When operating, there must be a fulcrum to prevent the instrument from slipping off, and use the finger to set the side of the tongue to the bottom of the mouth, to feel the depth of the osteotomy device, to avoid damage to the soft tissue of the lingual side. After the molars, the vertical osteotomy and the ascending branch sagittal splitting were performed, and only the buccal cortical bone was cut and connected with the horizontal osteotomy line. The ascending branch osteotomy is the same as the ascending branch sagittal splitting. The front edge of the ascending branch is cut to about 1/2 of the leading edge, which is convenient for exposure, but not too much. The incision is too easy to cause the buccal fat pad to escape. The condylar root was revealed, and the position of the medial bone incision was determined. The subperiosteal separation was about 1.0 cm wide, and it stopped posterior to the lingual groove in front of the posterior margin of the ascending branch. After the medial osteotomy of the ascending branch, the leading edge is connected with the vertical bone incision after the lower molar and the horizontal osteotomy line under the apical root of the dentition. The inner and outer bone plates of the ascending branch are opened with a thin bone chisel. 3. The bone segment is in place, fixed, and sutured After loosening the cement segment, the design site moves to the preoperative site. The plate was fixed on the maxillary arch splint and the intermaxillary traction was temporarily performed. Check the osteotomy line for bone interference. If there is bone interference, protect the lingual soft tissue and carefully remove it with a split drill. According to the preoperative design, the bone was implanted at the osteotomy of the full dentition. The cortical bone was implanted at the canine and median joints on both sides to determine the required height, and then the cancellous bone was used to complete the bone graft. The micro-titanium plate was fixed in the bilateral pupil area and the posterior vertical osteotomy area. Or use stainless steel wire bone to fix. Postoperative intermaxillary traction fixation and mandibular braking. The wound was completely hemostasis, washed with physiological saline containing appropriate amount of chloramphenicol or gentamicin, and the incision was sutured by the muscle layer and the periosteum. Pressure bandaging outside the mouth. The simple mandibular dentition under the apex of the mandibular trochanter is also called the submaxillary osteotomy after the mandibular molar. The osteotomy is performed only 5mm after the molar and the lower apical osteotomy. It is generally necessary to open a window on the lateral bone plate of the mandible to expose the inferior alveolar nerve vascular bundle, and lift the vascular nerve bundle during osteotomy to protect it. Simple mandibular dentition osteotomy is performed above or below the inferior alveolar nerve vascular bundle, and the whole dentition is unable to obtain blood supply directly from the vascular bundle, but relies on the lingual and buccal sides. Nutritional pedicle attached to soft tissue. After the vertical osteotomy and the trabecular root osteotomy line were connected after the molar grinding, the dental bone segment was loosened and moved forward to the preoperative design position. The bone was implanted in the osteotomy space to improve the height of the mandible and the micro titanium plate was fixed. complication See the mandibular anterior and posterior apical osteotomy: 1. Oral mucosal wounds open, infected The main reason is that the contusion of the wound margin is larger in the operation. Before the suture, the wound is also washed with the appropriate amount of chloramphenicol or gentamicin physiological saline, and the suture is not layered well, and the suture is too tight. Once the mucosal wound is found to be split, it is necessary to strengthen the dressing, rinse with 3% hydrogen peroxide and normal saline every day, usually healed in about 3 weeks. 2. Osteonecrosis and delayed bone healing The anterior segment of the anterior submandibular osteotomy is to supply blood from the lingual muscle mucosa and the labial sacral mucosal flap. Therefore, attention should be paid during the operation. A small area of osteonecrosis can occur at the edge of the osteotomy, where the soft tissue is not adequately covered, and does not cause chronic osteitis or diffuse osteomyelitis after shedding. Pay attention to the periodontal, endodontic, and apical conditions of the teeth on both sides of the osteotomy line. If there is pulp necrosis and apical inflammation, root canal treatment should be done in time; patients with periodontal disease should be treated with periodontal disease. In addition to the above reasons, delayed bone healing is also caused by incorrect design, excessive osteotomy, poor contact or inaccurate fixation. The source of infection should be removed, adjusted and strengthened, and generally healed. 3. radial nerve injury Mainly for pulling or direct damage during operation. Pay attention to the position of the pupil when cutting and peeling to avoid damage. The iliac nerve vascular bundle can be properly released and the traction can be reduced. If the sacral nerve injury and numbness of the lower lip are caused by traction, it can be recovered 2 to 3 months after surgery. 4. Airway obstruction Acute obstruction of the respiratory tract and even suffocation are the most serious complications. During general anesthesia, due to vomiting aspiration, secretion obstruction, improper position, tongue fall, tracheal edema after tracheal intubation, and subsequent local tissue edema, plus intermaxillary fixation and other factors may cause respiratory obstruction. Measures should be taken to prevent it from happening. Close observation of the condition and elimination of factors that may cause acute obstruction of the respiratory tract. If signs of dyspnea appear (such as nasal agitation, three concave signs, etc.), it should be treated in time to prevent the occurrence of asphyxiating complications. 5. Bleeding Intraoperative injury to larger blood vessels during surgery can cause severe bleeding, and damage to the inferior alveolar artery during osteotomy of the mandible. The osteotomy line should remain behind the mandibular hole to prevent damage to the inferior alveolar artery. 6. Nerve damage For example, the alveolar nerve may be accidentally injured during surgery. Precautions during osteotomy are the same as prevention of damage to the inferior alveolar artery. When the osteotomy and the moving bone segment are completed for fixation, care should be taken to avoid the occurrence of postoperative nerve injury symptoms caused by the compression of the inferior alveolar nerve by the bone segment. 7. Segmental necrosis The reason is mostly caused by excessive peeling of soft tissue or damage to the supply of blood vessels. Therefore, the separation and exposure of the bone surface should not be too large, especially in the distal heart segment (the bone segment near the gingival direction), the surface soft tissue should not be excessively separated, but the soft tissue should be kept as much as possible to maintain blood circulation and ensure bone. Healing. 8. Damaged root tip and pulp necrosis The root is simultaneously cut off because the transverse osteotomy line is too low (too close to the cutting edge or face). Therefore, the possible position of the root tip should be judged. The method includes: preoperative photographing of the X-ray film to detect the position and length of the root, and referring to the data of the normal normal root length, the intraoperative observation shows that the alveolar bone surrounded by the root has a slight elevation. After estimating the root length and the position of the root tip, a transverse osteotomy line is designed in the telecentric direction of the root tip of 4 to 5 mm (the maxilla is above the apex of the maxillary root and the mandible is below the root tip of the mandible). 9. Unconnected bone or poor bone healing Mainly due to poor fixation, insufficient contact of the bone segment, and poor blood supply. Therefore, the bone must be well fixed during and after surgery. Generally, inter-bone fixation (ligation fixation or micro-plate strong internal fixation) is used, supplemented by intermaxillary fixation, suspension fixation, and external stent fixation. In addition, the osteotomy design should consider maximizing the contact wounds when the bone segments (blocks) are connected, and prevent excessive peeling of the soft tissue and the like during the operation.