 In the previous lecture we had dealt in detail the closed reduction of mandibular fractures. Today we shall be discussing about the open reduction and fixation of mandibular fractures and the different surgical approaches to mandible. In open reduction there is direct visualization and access to the fracture through an incision or a facial wound. There are certain indications for open reduction. Let's see each of them one by one. Open reduction is indicated in displaced unfavorable fractures through the angle of the mandible because the proximal segment that is the fragment containing the condyle is displaced superiorly and medially and cannot be reduced without any bone implants. In displaced unfavorable fractures of the body or the panosymphoesial region of the mandible again the suprahyoid muscles tend to displace the fragments posteriorly and inferiorly. Therefore if you attempt closed reduction in symphysis the inferior border tends to open or flare. This mechanism will be explained in subsequent videos. Therefore open reduction is the mode of choice here. It was told in the previous lecture that in multiple facial fractures the mandible is reconstructed first because it provides a stable base to realign the rest of the bones. Therefore open reduction is very much required in multiple or panfacial fractures. A combination of mid-face and bilateral condyle fracture will necessitate opening of at least one of the condyle fractures. This is done in order to establish the vertical dimension of face. If you don't perform an open reduction there are chances of producing a shortened facial appearance. In edentulous mandible fractures with severe displacement of the fragments open reduction should be considered to maintain the continuity of mandible. The outcome will be better in a non-etrophied mandible with sufficient vascular supply. Like in a dentate mandible occlusion is not an immediate concern in edentulous patients. When a maxilla opposing a mandible fracture is edentulous or contains insufficient teeth to allow intermaxillary fixation then open reduction should be considered. But if the patient's condition demands closed reduction then you may first fabricate a denture for the maxilla which is stabilized with palatal screws and then the routine intermaxillary fixation could be used. When treatment has been delayed in instances like head injury or other serious medical conditions, connective tissue grows between the bone fragments thus inhibiting osteogenesis. This condition demands open reduction where the scar tissue is first removed and then the fracture is reduced and stabilized. In cases where a malunion or a poor result is obtained after mandibular fracture treatment a research is performed via open approach. In patients with difficulty to control seizures, psychiatric problems, compromised pulmonary function or gastrointestinal disorders all fall under the category of conditions contraindicating intermaxillary fixation. Therefore these patients can only benefit from open reduction. Patients in whom general anesthesia cannot be administered, severely infected fracture sites, comminuted fracture with gross loss of soft tissues are all contraindications of open reduction. Before going into the various techniques of open reduction and fixation we shall discuss the various approaches to the fracture site. There are both extra oral and intraoral approaches taken to gain access to the fracture. You decide the approach depending on the location, favorability, the soft tissue nature and fixation method. Extra oral approaches are performed always under general anesthesia. The first approach is the submandibular or residence approach. This particular incision is used for gaining access to the fractures in the ascending ramus, the angle and body of the mandible as far forward as premolar region. The skin incision is 4 to 5 centimeter in length. Marginal mandibular nerve runs 1.5 centimeter below the angle of mandible. Therefore the incision is placed at least 2 centimeters below the angle. Try to position the incision in an existing skin crease so that it hides the scar. Subcutaneous fat and superficial fascia is dissected to reach the platysma muscle. Platysma is then sharply incised to reach the superficial layer of deep cervical fascia. It is in this superficial layer of deep cervical fascia or just below it the marginal mandibular branch of facial nerve is visible. Carefully dissect through the deep cervical fascia to reach the bone. So you can identify the submandibular gland and the tail of parotid as you expose the mandible posteriorly. The section continues till the inferior border of the mandible and from here to the masseter. Once the muscle is encountered, sharply divide it at the inferior border to expose the bone. You know that the masseter is attached to the lateral aspect of the ramus. So you cut the masseter muscle to gain access and visibility to the angle and the lateral aspect of the ramus. The muscle, the periosteum and other soft tissues along with the marginal mandibular nerve is then retracted superiorly as you can see in the diagram. So this is how you expose the fracture site. The second extraural approach is the rectomandibular approach described by Heinz. It is only a variation of the submandibular incision and it is used to gain access to the angle, the ramus and subcondylar region. This incision will curve behind the angle and is placed at least 3 cm above the submandibular incision. Here also you encounter the parotid, the masseter and the deep cervical fascia as you proceed with the dissection. There are other incisions as well used specifically to approach the condyle which will be discussed in detail when discussing condylar fractures. The most common and technically easier approach is the intraoral approach. For fractures of anterior mandible, first the incision region is infiltrated with local anaesthetic solution. The lip is then retracted and a curvilinear incision is made leaving at least 1 cm of mucosa attached to the gingiva. The mentalis muscle is incised and the section is carried subperiostally to identify the mental nerve. The nerve is then preserved, the fracture site is identified, reduced and fixed. The incision is then closed in layers. So basically you give a de-loving incision or an anterior vestibular incision to gain access to the fractures at pedosimphysis and simphysis region. In body, angle and ramus fractures, the incision is made 5 mm from the mucogengival junction. It extends anteriorly from the first molar region and along the external oblique ridge as high as the mandibular occlusal plane. Extending the incision higher means you are prolapsing the buckle fat pad into the surgical field. The anterior surface of the ramus can be exposed after dissecting through the buccinator and temporalis tendon. A notched retractor and a cocker's clamp can be used to retract in the coronal region. A jay stripper can be used to elevate the mesater and a ball retractor can be used in the sigmoid notch and anti-gonial notch. Let us now move on to the different techniques of open reduction and internal fixation. Once you have opened and exposed the fracture site, first you reduce the fracture in its anatomical position. After reduction, you may use any of these techniques to achieve stabilization. Osteosynthesis can be done with or without IMF. What does the term osteosynthesis mean? It simply means stabilization or joining of the two fracture ends using a bone implant. Be it a plate, screw, pin, clamp or wire, you are using a bone implant to stabilize or fix the fracture ends. This is called osteosynthesis. Osteosynthesis can be done in two ways. The techniques given on the left will need an additional intermaxillary fixation to be performed for immobilization of the fracture. So here, even though you perform an osteosynthesis, that means you place a bone implant. It is followed by a duration of intermaxillary fixation, that is to provide immobilization to the fracture site. Whereas the techniques on the right are self-sufficient to provide stabilization as well as immobilization of the fracture site, thus eliminating the need of intermaxillary fixation. In today's lecture, we shall be discussing about the methods of osteosynthesis with intermaxillary fixation. The first technique is trans-ocious wiring. It is also known as direct wiring of the mandible and is usually used in combination with interdental eyelet wiring, cap splints or gunning type splints. Few indications are the fracture of identulous mandible and grossly comminuted mandibular fractures. It is also used to stabilize the inferior border of mandible in case of a fracture where the superior border has already been stabilized with other means. The term trans-ocious means across the bone. Here direct wiring is performed across the fracture line. Moving on to the technique. As you can see in this diagram, holes are drilled across the fracture lines and soft stainless steel wire of 0.45 mm diameter is passed through the holes across the fracture. Accurate reduction of the fractured segments is done by twisting the wires tightly and the twisted wire is stuck into one of the holes. The reduction of the fractured segments should be done with the teeth in occlusion. It is very important to keep the dentition in occlusion while performing fracture fixation. The wires are applied either at the superior border or at the lower border or at both the borders depending on the type of fracture. The superior border can be approached through an intra-oral incision whereas it is always better to approach the lower border extra-orally. It is sufficient for the upper border wire to pass through the outer cortical plate alone as the fixation is always combined with inter-maxillary fixation. Usually a single lower border wire is not sufficient to stabilize the fracture. Especially when the fracture line is oblique or multiple or in case of a comminuted fracture. The segments here tend to override. So in such cases a figure of 8 wiring along with the conventional wiring is performed. This is a conventional type of wiring. This fixation is reinforced by a figure of 8 wiring as you can see in this diagram. There are two kinds of wiring techniques performed here. Transocious wiring can be performed for any kind of mandibular fractures as you can see in the diagram. This is the wiring performed for a sub-condyler fracture. This is a figure of 8 wiring performed for angled fracture. And these are the wiring performed on the body and symphysis regions. It was told that for superior border wiring only dwelling through the buckle cortical plate is sufficient. As you can see in the second diagram here. Here the holes are drilled only on the buckled cortex. Whereas in the first diagram both the cortical plates, the buckle and the lingual cortical plates are drilled for the wiring. The next type of osteosynthesis with intermaxillary fixation is the circumferential wiring. This wiring is done through open reduction and used to create fractures at the angle and the body of mandible. Here the wiring is done by passing a 0.5 mm diameter stainless steel wire circumferentially around the mandible. As you can see in this diagram, this is the fracture and the wire goes around it thus stabilizing the fracture. The technique shall be explained in short. Imagine this sagittal view is that of the fracture at the anterior mandible. You place a stab incision on the skin in the sub-mandibular or sub-mental region depending on the location of the fracture. A catheter needle or a bone awl is pierced in through the stab incision and taken out intra-orally in the flow of the mouth just lingual to the fracture site. A stainless steel wire is passed in through the needle lumen. The needle is then gently withdrawn till the needle tip is just inferior to the mandible border. The tip is just beyond the inferior border. Take care not to withdraw the needle completely out through the incision. Just beyond the inferior border, change the direction of the tip labily and advance the needle superiorly so that it comes out through the labile aspect of the fracture site. Intra-orally it comes out at the labile aspect of the fracture. All this while one end of the wire which is on the lingual aspect is still secured with an artery forcep or a wire holder. Once the tip is out labily, the wire is pulled out thus circumferencing the mandible in this manner. The catheter is then retrieved out through the same incision and in this way circumferential wiring stabilizes the fracture and it is then followed by inter-maxillary fixation. This is how a completed wiring looks like. Bone clamp is an external type of fixation for mandibular fractures and is very rarely used these days. Here the fragmented segments are secured by clamps attached to the lower border of the mandible and from these clamps the pins project out. This is very similar to that of external pin fixation. This system is known as Brenthurst Splint and was used in the past instead of the stainless steel external pin fixation. K-virus another technique of osteosynthesis with IMF which is not very common these days. The fracture segments are held together in position and after reduction a virus dwelt through the cortex on one side of the fracture through an extra-oil approach. It is then passed through the medullary cavity of the undamaged bone on either side of the fracture. As you can see in these diagrams K-virus can be used at almost every site of the mandible. It can be used at the angle, the ramus, the sub-condyle even in multiple fractures of mandible. Several modifications has also been made to the K-virus design. So this is all about open reduction and fixation and osteosynthesis with IMF. In the next lecture we will discuss osteosynthesis without IMF and the different bone plating techniques used for mandibular fractures. Thanks for watching.