 Another topic of OMFS lecture series management of mandibular fractures. The surgical anatomy of mandible is of utmost importance while treating its injury or fracture. In this lecture we shall brush up the basics for a better and easy understanding of fracture management. Here we go. Cancelous is the largest and strongest of the facial bones which is basically a tubular long bone which is bent into a blunt V shape. It has an outer dense cortical bone and loose cancelous bone within. The cortical bone is thicker anteriorly and at the lower border whereas it weakens as it moves posteriorly. It becomes thinner. So it means that the mandible is stronger in the anterior region in the midline and weakens as it moves posteriorly. Even though the mandible is basically V shaped it has been modified to four functional processes namely the angle, the coronoid process, the condylar process and the angular process. Now let us discuss each part of the mandible in detail. The superior border is the angular process which contains the bendation. The inferior border is made up of thick cortical bone. The mandible has two surfaces the outer lateral surface and an inner medial surface. The body of mandible joins the ramus at angle. The two bodies on either side fuse at the center called the symphysis. At the symphysis there is a thickened cortical area which is known as mental propellance. Mental foramen is present on either side of the mandible either side on the lateral aspect of the mandible and it is present between the roots of the first and second primolors. An oblique ridge runs from just inferior to the mental foramen posteriorly and superiorly to the ascending ramus. This is about the lateral aspect of mandible. Now coming to the inner surface. The inner cortical surface at the midline shows two pairs of bony prominences. Here you have two pairs of small bony prominence which is termed the genial tubercles. The genio hyoid muscle originates from the inferior genial tubercle and the genioblossus muscle originates from the superior genio genial tubercle. Then running horizontally backward is an oblique ridge which is called the mylohyoid line or mylohyoid ridge to which mylohyoid muscle is attached. So the mylohyoid line is the submandibular fossa which lodges the submandibular gland and above is the sublingual fossa which lodges sublingual gland. The quadrilateral structure that you see here is the ramus of the mandible. The lateral surface is rough and thick at the angle region by the insertion of masseter muscle as you can see in this diagram. On the medial surface is the mandibular foramen that continues downward and forward into the mandibular canal and transmits inferior alveolar nerve and vessels. Lingular is a medial bony projection at the opening of the mandibular foramen to which sphenomandibular ligament is attached. Mylohyoid line is an extension from this lingular. Mylohyoid line extends from the tip of lingular downward and forward on the medial aspect of mandible. Below the mylohyoid line in the ramal area you can see rough surface here. This is due to the insertion of medial tergoid. So you have attachment of medial tergoid on the medial aspect of ramus in the inferior part and masseter on the lateral aspect of the ramus. This is a notch you can see a notch over here. This is found at the superior edge of the ramus, it is called the mandibular notch. It is bounded by two processes, coronoid process anteriorly and condylar process posteriorly. The fan shaped temporalis muscle attaches to the tip of the coronoid here. The temporalis attaches to the tip of the coronoid process and the attachment of lateral tergoid muscle is at the anterior portion of the neck of the condylar. So this is the condylar head, this is the, this stalk is called the neck of the condyle and on the anterior aspect of the neck of the condyle you have a small depression called the tergoid fovea to which lateral tergoid muscle attaches. A detailed description of condylar head anatomy as well as its fracture management shall be discussed separately in subsequent lectures. Now moving on to one of the most complicated regions of mandible in terms of both anatomy and management that is the angle. After condyle angle region is the commonest site of mandibular fracture. What could be the reasons one could think of? The anatomy of the angle itself will explain it. Angle is a junction and a junction or a joint is always weaker when compared to the adjoining parts. Angle is a junction formed by the adjoining ramus and body. Every bone has a specific pattern of calcification lines. In case of mandible the direction of calcification suddenly changes from horizontal at the body to vertical at the ramus and the transition happens at the angle region. Thus angle has a comparatively thinner cross section than most of the other areas of mandible. In addition presence of wisdom tooth which could be an erupted or an unerupted one. Angles of inferior alveolar nerve canal and constant opposing muscle actions of the elevators and depressors make angle a difficult area in fracture management. Mantibulus 1 bone whose muscle attachments have a continuous function be it mastication, speech, facial expressions, swallowing, yawning. So you cannot expect the fracture to remain still once it has occurred. Angle is a very common feature of a fracture and it is important to understand the action of each muscle on a fracture. The first group of muscles is formed by the supra hyalurid muscles which exerts a force in the posterior, medial and inferior direction. So if there is a fracture segment in the anterior mandible it is displaced, inward, backward and downward direction as you can see in this diagram. The next important muscle group is the tergomassetric sling. You know that the ramus has attachments to massacre muscle on the external surface and medial tergoid on the internal surface. Therefore at the most posterior inferior aspect of the ramus there is a tendon or a sling which is formed by both the masseter and the medial tergoid which is called the tergomassetric sling. So in case of an angle fracture it is this muscle action that causes the posterior fragment to move in a supiromedial and anterior direction. So if there is a fracture at the angle region like this, imagine there is a fracture like this. In this case the segment containing the condyle is called the posterior segment and the segment containing the dentition is the anterior segment. Therefore the tergomassetric sling will tend to displace or move the fracture in a supiromedial and anterior direction. This is the superior upward medial means inward and forward direction. The next muscle of concern is the temporalis. You know that the temporalis has an elevating and protruding action. This is attached to the tip of the coronal process. Therefore in a fracture it tends to displace the segment in a posterior and superior direction that is backward and upward. Similarly lateral tergoid also has two sets of actions each produced by the two separate components of lateral tergoid. It has an internal and an external component. The internal component is responsible for the anterior medial displacement, anterior medial displacement of the condylar head in a supirid direction. Both the components move the segment in anterior and medial direction. But the internal component moves the condylar head in a supirid direction and the external component in an inferior direction. The direction of the fracture at the angle can vary due to various peculiarities of the angle discussed earlier. Here you need to understand the terms favorable and unfavorable in context of mandibular fractures. If the direction or angulation of a fracture is such that it can resist the displacement of the posterior segment due to muscle actions then the condition of the fracture is favorable. That means if this is the fracture and if the posterior segment can resist its upward pull by the tergomassetrix link then the condition of the fracture is favorable. In the previous section we have seen the action of different muscles on a fracture. So keeping the same in mind we will now have a look at the horizontal and vertical favorability of mandibular angle fractures. This diagram shows the horizontal viewing of a fracture and this diagram shows the vertical viewing. Here the terms horizontal or vertical are defined from the viewpoint of the observer. Hence it is a traditional but not very practical terms. Thus a horizontal favorable fracture extends from the upper border downward and forward. This is the direction of a horizontally favorable fracture. This pattern of fracture is termed favorable because of the locking effect at the fracture side. The locking effect is produced by the anterior segment. So when the tergomassetrix link tries to pull the posterior segment upward it is locked at this region or at the fracture side by the anterior segment. Hence it is termed favorable fracture whereas in a horizontally unfavorable fracture the fracture line extends downward and backward. Unlike in a favorable condition here the fracture line extends downward and backward and thus here the locking effect is absent. The tergomassetrix link can freely pull the posterior segment superiorly. So this is how a horizontally favorable and unfavorable fracture looks like. Likewise a vertically favorable fracture runs from the buckle plate posteriorly and medially. Here also you can appreciate the locking effect at the fracture side. Whereas in a vertically unfavorable fracture the fracture runs from the buckle plate anteriorly and medially. It moves forward and inward. There is no locking effect present here and this enables unopposed action of the tergomassetrix link thus displacing the posterior segment. One more thing that needs mentioning here is the patient's airway compromise associated with mandibular fractures. Fractures of bilateral subcondyle and bilateral parasymphysis may create an unstable situation for the tongue because the fracture segment tends to fall behind. So here there is a need for immediate consideration or intervention. To sum up it's been told that mandible is the strongest of the facial bones but still mandibular fractures occur twice as often as mid-face fractures. The reasons being the unique osteology of mandible and the various muscle attachments that causes fracture displacement. Another reason is the presence of dentation. The socket is a weak zone especially if the teeth are impacted or unelected. So does it make children more susceptible to mandibular fractures? Actually not because a child's bone is more flexible and resilient. Therefore the incidence of a complete fracture is lesser in children when compared to adults. So that's all about the basics of mandibular fractures. We shall be discussing the management in detail in the next lecture. Thank you. Hello everyone, welcome back to OMFS lecture series. In the previous lecture we had discussed about the basic anatomy of mandible and how the masticatory muscles act upon mandibular fractures. Today's lecture will deal with the general principles of mandibular fracture management and closed reduction technique. The very first principle is to carefully evaluate the patient's general physical status because any force large enough to cause mandibular fracture is capable of injuring other organ systems as well. Therefore examine the patient for concomitant head and spinal injuries, pneumothorax, fracture of limbs, ruptured spleen or other facial injuries. The next principle is to diagnose and manage the fracture methodically. What does it mean? Patients rarely die of mandibular fractures. Hence do a thorough evaluation of patient history, local, physical and radiological examination. It is not an emergency if the patient's general status is satisfactory. But it doesn't mean that you unnecessarily delay the treatment either. Prevented dental injuries are common findings which needs to be evaluated and treated along with the fracture. We shall discuss on the management of tooth in the line of fracture later in this lecture. Re-establishment of occlusion is the primary goal in the treatment of mandibular fractures because an improper treatment results in malocclusion and function can be seriously compromised. Another principle is to treat the mandibular fractures first in case of multiple facial fractures. This is because to assemble and arrange the facial bones in position reconstruction of mandible is considered necessary. Intermaxillary fixation time should vary according to the type, location, number, severity of mandibular fractures, the patient's age, health and also the methods used for reduction and fixation. Therefore, IMF duration is in the same for every patient and for every fracture. Prophylactic antibiotics should be used for compound fractures. Compound fractures are the ones which communicate with the external environment through a wound in the skin, mucosa or periodontal ligament. Therefore, Prophylactic antibiotics can control the spread of infection. The nutritional needs of the patient also have to be taken care of because the treatment might fail if the patient's metabolism is not normal. Let us now move on to the steps or principles of fracture management. There are four steps, the reduction, fixation, immobilization and rehabilitation. The term reduction means to recreate the normal anatomy of the fractured bone. By reducing a fracture, we are realigning the fracture fragments that they heal in their original positions. After reduction, even though the bone fragments are aligned in the anatomical position, they are still potentially unstable. So, we do a fixation of the fracture. That means the fracture fragments are held together and stabilized using special implants like plates, screws or wires. The third step immobilization refers to the process of holding the bone in place to prevent the injured areas from moving as it heals. Like you wear a cast or splint in case of limb fractures, various immobilization techniques are used in mandibular fractures also. The final step is the rehabilitation or to restore the normal function of the bone. This is done through physiotherapy and exercises. Before moving on to the various treatment options of fractured mandible, let us quickly have a look at how to deal with a tooth that is within the fracture line. As you can see in this radiograph, canine and third molar lie within the fracture line. There are a few complications associated with tooth in the line of fracture. This tooth is a potential impediment to fracture healing. It converts a simple fracture into a compound one because through the tooth, the fracture is exposed to the external environment. Through the tooth, this is the fracture. So through the tooth, it gets exposed to the oral cavity, which is an external environment. Hence it is a potential nidus of infection. The tooth may be damaged and it subsequently becomes necrotic. Also if there is a pre-existing pathology associated with the tooth, it can aggravate or invade the mandible. There are a few indications for removal of tooth in the line of fracture. Longitudinal tooth fracture, subluxation or dislocation of the tooth, pediapical infection, infected fracture line and acute pedicoronitis are all in absolute favor of removing the tooth from fracture line. In one of the initial slides, it was mentioned that the duration of inter-maxillary fixation depends on various factors. So here is a guideline for the time of immobilization for fractures of tooth bearing area of the mandible. According to this guideline, the period of immobilization for a young adult with fracture of the body of the mandible, receiving an early treatment and in which the tooth is removed from fracture line is 3 weeks. So in this particular scenario, the time period of inter-maxillary fixation is 3 weeks. Any deviation from this will alter the IMF period. Just like you add one more week, if the tooth is retained in the fracture line and if the fracture is at the symphysis. You may add a week or more if the patient is over 40 years of age. Whereas in children, immobilize the fracture site in 2 weeks. Having discussed the basic principles of fracture management, we shall now move on to closed reduction. You know that fracture reduction is nothing but realigning the fracture fragments into their normal anatomical position. By closed reduction, you are reducing the fracture without directly seeing it. There is no incision made to access or visualize the fracture and not every fracture is meant for closed reduction. There are certain relative indications like grossly communicated fractures. Because of the excellent blood supply to the face, small fragments of bones will combine and heal if the associated periosteum is not disturbed. The communicated fracture is managed like a bag of bones and the clinician utilizes closed techniques to establish normal occlusion. In non-displaced favorable fractures, the simplest possible means should be used to reduce and fix fractures. Hence you don't perform open reduction unless absolutely indicated. Fracture repair is also dependent on the soft tissue coverage and vascular supply. Therefore, fractures exposed by significant loss of overlined tissues are created by closed reduction until the soft tissue coverage is established by flaps or grafts. In identialist mandibular fractures, again the vascular supply is compromised. Open reduction requires stripping of periosteum which further inhibits fracture healing. Open reduction with implants carries the risk of damage to developing tooth buds. Therefore, in majority of pediatric mandibular fractures, closed reduction is performed with specialized wiring techniques. Fracture of coronoid is usually simple with little displacement. Then this usually carried out if the occlusion is compromised or the fracture segment impinges on the zygomatic arch. Most condyla fractures are created via closed reduction unless absolutely indicated for open reduction. This topic shall be covered in detail in subsequent lectures. Moving on to the different techniques of closed reduction and indirect skeletal fixation. The fracture is reduced without exposing it and the fixation is also indirect meaning the fracture is stabilized in position by applying devices external to it. The techniques are as follows, direct interdental wiring, eyelet or IV loop, continuous loop wiring, arch bars, cap splints, gunning type splints and biphasic ping fixation. All these techniques may be performed on a dental chair under leukronostasia. Direct interdental wiring or Gilmour's technique. It is a simple and rapid method of jaw immobilization. Here a 15 centimeter long pre-stretched stainless steel wire is passed around each tooth which emerge through the interdental space. The wire is placed around the necks of the teeth and the two ends are twisted and tightened. This is performed on both the arches and the opposite wirings are twisted together. As you can see in the second diagram the opposite wirings are tightened together. This way maxilla mandibular fixation is accomplished. The main disadvantage of this technique is that if one of the wiring breaks or needs a tightening then the entire wiring has to be removed. Extortion of teeth is another disadvantage. eyelets or IV loop is a relatively simpler technique provided there is sufficient number of quality teeth. This is how an eyelet looks like. It wires are made by twisting a 15 centimeter wire around a pin of 3 mm diameter. It has two ends of equal length. The wiring technique is shown in this diagram. These two ends will together pass through interdental space. Each end is then taken out to the buccal region again through the adjacent interdental areas. The loop is then engaged in close fit interdently. The distal end is then turned and passed through the loop which is then twisted with the mesial end and secured. With a full complement of teeth 8 eyelets are placed in the upper jaw and 6 in the lower jaw. Later intermaxillary fixation is performed by passing wires through the opposite loops. This diagram shows a completed eyelet wiring. Several modifications have been made to the eyelet wiring techniques in accordance to case types. Arch bars are indicated in fractures with insufficient dentition, simple dental alveolar fractures or even in fractures with multiple tooth bearing fragments. There are several designs for arch bars. This model is called the Erics Arch Bar. It is basically a stainless steel bendable band with several cleats attached to it. The arch bar is secured to both jaws using wires and while doing this make sure the cleats open gingively and not occlusively. It faces the gingiva. Maxilla mandible fixation is then performed using box shaped wires. Cap splints are indicated in fractures of tooth bearing segments where the teeth are periodically compromised or it is also used in cases where a portion of the body of mandible is missing. A custom made cap splint is fabricated using specialized impression technique. It is then fixed to the mandible and fracture reduction is achieved. Gunding splints are used to reduce favorable and un-splaced fractures of a dentuous mandible. It is an acrylic splint in the form of a modified denture with bite blocks in the posterior region and an open space in the anterior region to facilitate fielding. It is contraindicated in unfavorable or severely displaced fractures. Bifasic pin fixation is a close technique which uses external fixation. Though the fracture is not exposed, a stab incision is made on the skin to fix two screws each on either side of the fracture. As you can see in this diagram, two screws or pins are fixed on either side of the fracture. These pins are locked and they will have an extension out of the skin. The pins are removed after fracture healing. Bifasic pin fixation is used in edentulous fractures where intermaxial fixation is not feasible. It is also used in comminuted fractures where there are requirements of bone grafts. It is contraindicated in evaluated or ghastly contaminated tissues and in certain bone anomalies like osteoporosis and osteosclerosis. With the various close reduction techniques explained, let's look into the advantages and disadvantages of close reduction. It is inexpensive, convenient, conservative and easy not requiring a great operator skill. The disadvantages are that the function might be compromised because of incomplete stability and reduced range of motion. Long duration of intermaxial fixation will also lead to poor oral hygiene, TMG changes, reduced footpeg and weight loss. We have thus discussed the principles of magibular fracture management as well as the closed reduction techniques. The open reduction and fixation shall be discussed in the next lecture. Thank you. Hello and welcome back to OMFS lecture series. In the previous lecture, we had dealt in detail the closed reduction of magibular fractures. Today we shall be discussing about the open reduction and fixation of magibular 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 palasimfacial 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 condyla fracture will necessitate opening of at least one of the condyla fractures. This is done in order to establish the vertical dimension of face. If you do not 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-ecrophied 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 inter-maxillary 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 inter-maxillary 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 inter-maxillary 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. Now going into the various techniques of open reduction and fixation, we shall discuss the various approaches to the fracture site. There are both extraoral 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. Extraoral 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. Subcutaneous 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. The 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 nerves 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. This is how you expose the fracture site. The second extravoryl 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 subcondyla region. This incision will curve behind the angle and is placed at least 3 cm above the submandibular incision. Here also you encounter the pedauted, 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 condyla fractures. The most common and technically easier approach is the intra-oreal approach. For fractures of anterior mandibular, first the incision region is infiltrated with local and aesthetic 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 subperiosteally 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 degloving incision or an anterior vestibular incision to gain access to the fractures at pedasimfasis region. In body, angle and ramus fractures, the incision is made 5 mm from the mucosinjival junction. It extends anteriorly from the first molar region and along the external oblique ridge as high as the mandibular occlusion plane. Extending the incision higher means you are prolapsing the buccal fat pad into the surgical field. The anterior surface of the ramus can be exposed after dissecting through the buccinator and temporalis tendon. A notch retractor and a cocker's clamp can be used to retract in the cornoid 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 inter-maxillary 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 inter-maxillary 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 inter-maxillary fixation. In today's lecture, we shall be discussing about the methods of osteosynthesis with inter-maxillary 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 edentulous 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 incra-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 a 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 commutated 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. Twine Sausage 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 buccal cortical plate is sufficient. As you can see in the second diagram here, here the holes are drilled only on the buccal cortex. Whereas in the first diagram both the cortical plates, the buccal and the lingual cortical plates are drilled for the wiring. This 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 alde 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 force 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 required 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 wire is drilled through the cortex on one side of the fracture through an extra oval 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 subcondyle even in multiple fractures of mandible. Several modifications have also been made to the K-wire 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. Hello everyone welcome back to OMFS lecture series. So far in the management of mandibular fractures we have discussed the basics, principles, closed reduction, surgical approaches and open reduction with inter-maxillary fixation for mandibular fractures. In this lecture we shall have a detailed discussion on open reduction with rigid internal fixation where we shall see the various plating systems used in managing mandibular fractures. There are certain principles of rigid fixation as given by association for the study of internal fixation. The first goal of anatomical reduction of bone fragments imply that occlusion and basal reduction is of equal importance. In closed reduction we aim to achieve only an occlusion reduction. In order to achieve basal reduction we perform open reduction and internal fixation thereby the reduction is complete. Stable fixation and semi-rigid fixation which is also called functionally stable fixation reduces the inter-fragmentary motion. What is inter-fragmentary motion? It is a relative motion between the blades and the bone and also between the bone ends. Inter-fragmentary motion or inter-fragmentary gap will result in osteolysis and poor healing of the fracture. Therefore, open reduction and internal fixation is highly essential to avoid inter-fragmentary gap and provide stabilisation. We know that fracture healing is highly dependent on its soft tissue coverage and blood supply. Therefore, try to preserve maximum vascular supply to the fracture fragment through a traumatic surgery. Early active and pain-free mobilisation is very important and this makes open reduction superior to closed reduction or conventional inter-maxillary fixation. Patients can also take normal diet, speed normally and interact socially. So these set goals are universal principles of surgical fracture management. In the previous lectures, we had discussed techniques of closed reduction and inter-maxillary fixation. We had also seen open reduction methods used in combination with IMF. In this lecture, we shall be discussing in detail the osteosynthesis without inter-maxillary fixation. That is, the bone implant alone is sufficient to provide a stable fixation and there is no requirement of inter-maxillary fixation. The most important osteosynthesis techniques are non-compression mini-plates, compression plates and lag screws. Before going into the technical details of these plates and screws, it is very important to understand the principles and certain terminologies related to internal fixation. Let us see each of these terms one by one. Rigid, non-rigid and functionally stable fixation. Rigid fixation is any form of fixation applied directly to the bones which is strong enough to prevent inter-fragmentary motion across the fracture when actively using skeletal structure. We know inter-fragmentary motion is the relative motion between the plates and the bones. So when a functional load is applied, rigid fixation will prevent this inter-fragmentary motion when the mandible is back to function like mastication. It will not even allow micro movements between the fragments. This is rigid fixation. What is non-rigid fixation? It is any form of bone fixation that is not rigid enough to prevent inter-fragmentary motion when actively using the skeletal structure. So non-rigid fixation is just opposite to rigid fixation. Therefore, it needs an additional support like IMF to stabilize the fragment. So all the techniques we discussed earlier on osteosynthesis with IMF like transorcious wiring, circumferential wiring, k wires, everything falls under the category of non-rigid fixation. The third entity is the functionally stable fixation. Here there is adequate stability to allow function of the skeletal structure even though it doesn't allow a direct bone union. It means the fixation is not as rigid as in rigid fixation but functional load can be applied even without a period of IMF or immobilization. Primary bone healing takes place with rigid fixation whereas secondary bone healing that is with callous formation takes place in functionally stable fixation. Examples for functionally stable fixation is a single lag screw or mini plates. The next set of terms is compression and non-compression. Here you need to understand that compression and non-compression is the principle or the property within the bone implants that we use. Compression is the property of rigid fixation. So what is the purpose of compression? A compression plate creates inter fragmentary compression which in turn produce a large frictional force between the bone fragments. And it is this friction between the fragments that prevent gliding of the metal implant and the bone. This enables rigid fixation. Bending torsion and shear forces associated with mastication are the major factors that disturb the fracture healing. A compression plate can withstand all these forces still stabilizing the fracture without the help of IMF. And osteosynthesis with IMF doesn't have these features and hence fall under non-compression category. Another concept of fixation is load bearing and load sharing osteosynthesis. These terms are self-explanatory. Load bearing fixation is a device that is of sufficient rigidity to bear the entire load applied to the mandible during functional activities. That means it takes all the forces upon itself. It doesn't transmit any force to the mandible. An example of load bearing osteosynthesis is the reconstruction plate used in communitued fractures of mandible or fractures where there is a loss of a portion of mandible. It is used in fractures with bone defect. Whereas a load sharing fixation device is of insufficient stability to bear all the functional load itself. It distributes the load across the fracture. Therefore, the fractured mandible also has to bear a portion of the functional load. Mini plates and lag screws are examples of load sharing osteosynthesis and is used in simple linear fractures of mandible. Another concept of fixation is the locking and non-locking plates used for osteosynthesis. An important thing to consider while plating the bone is to accurately adapt the plate to the bone surface. This is important because if the adaptation is not proper, torsional forces can cause instability of the implant and the fracture. In locking system, the threads on the screw head lock into the congruent threads of the plate and as they are tightened the plate and screw becomes a single unit. That means the screw gets completely locked or the screw head gets completely locked into the plate thus becoming one single unit. The fixation here is thus rigid with high mechanical stability. Screw loosening is unlikely here and an accurate plate adaptation like that in non-locking system is also not needed. Whereas in non-locking system a precise plate adaptation is required and chances of screw loosening is also very high. Having understood the various concepts of fixation, let us now see in detail some of the internal fixation devices. The first among them is the compression plate. Compression plates provide rigid fixation with axial compression between the fractured bone ends. Need for inter-maxillary fixation is obviated and primary bone healing takes place. Even with these desirable features, the indications and uses of compression plates are limited due to its bulkiness in size. It is indicated in minimally oblique fractures or linear fractures with sound butt verses. It means there shouldn't be any bony defect in the mandible while applying compression plate. A precise plate adaptation is absolutely necessary, failure of which may cause overriding of the fracture fragments, spleying of lingual cortex and eventually maliflution. These are the disadvantages of compression plates. There are two types of compression plates. Dynamic compression plate and eccentric dynamic compression plates. Let's see how a dynamic compression plate is designed and how it works. Dynamic compression plate or DCP has in total four holes. Two central holes are called the compression holes and the two terminal holes are called the retention holes. The screws placed in the central holes provide inter-fragmentary compression and the screws at the ends helps in plate retention. The shape of these holes also vary. The central holes are pure shaped or oval shaped and the retention holes are spherical. The inter-fragmentary compression is created through a principle called spherical gliding principle. What is spherical gliding principle? Imagine a hollow cylinder as you can see in this figure. This hollow cylinder has a bend or an angle which gives the cylinder two components, an oblique and a horizontal component. Now imagine you are passing a ball or a sphere through this cylinder. The ball first passes through the inclined or the oblique component and then it has to glide through the bend to enter the horizontal part. The same design applies to the central holes of the compression plate. The screw head which is placed in the oblique part of the central hole glides and settles at the horizontal part as the screw is tightened. As it glides through the bend in the hole it approximates the fracture fragments by pulling it together. While the screw is tightened in the central compartment of the central hole it provides an inter-fragmentary pressure thus compressing the two fragments together and the fracture gets reduced. The retentive screws are then tightened after the central ones. So this is how a dynamic compression plate act by providing inter-fragmentary compression in between the fracture fragments. The compression plates are designed in such a way that it is bulky and cannot be placed at the upper border of the mandible it can only be placed at the lower border. Even though the compression plates provide a rigid fixation the upper border tends to open up during the compression or tightening of the screws. This is because there is always a constant tension at the superior border that tends to pull the fracture fragments apart. Therefore an additional fixation is required to compensate the tension at the superior border. Either a mini plate can be fixed to the upper border or a tension band can be applied. The tension band can be an arch bar that can counteract the opening up of the superior border. So this is the condition when you apply only the compression plate at the inferior border. To avoid opening up of the superior border you either place a mini plate at the upper border or you can place an arch bar to the teeth. Excentric dynamic compression plate is similar to dynamic compression plate with the only difference at the terminal plate holes. The outer holes are positioned oblique to the long axis of the plate. If this is the plate axis the end screws are placed at an angulation. Various modifications have been made for the EDCP with the oblique holes at 45 degree, 75 degree and 90 degrees. The main purpose of this angulation is to resolve the plane at the superior border. This specific design will compress the superior border thus obviating the use of an additional mini plate or a tension band. EDCP is used in fractured idensilus mandible where IMF is not possible. It is also used in idensilus or partially idensilus cases where the height of the mandible is not sufficient enough to accommodate two plates. Excentric dynamic compression plate and Excentric dynamic compression plate. The central compression design is the same for both, spherical gliding principle. EDCP in addition has oblique outer compression holes to compress the upper border therefore tension band is required for DCP and not for EDCP. This is all about compression plate osteosynthesis. The most common, convenient, technically easier, feasible and least complicated osteosynthesis technique is the semi-rigid or functionally stable fixation, the mini plates. Champagne and his co-workers argued that compression plates were unnecessary because there is a natural line of compression existing along the lower border of the mandible. It was observed that physiologically coordinated muscle function produced tension at the upper border, compression at the lower border and torsional or rotational forces anterior to the canine region. Champagne at all determined the ideal osteosynthesis lines also known as Champagne's lines of osteosynthesis where mini plate fixation is most stable. Therefore ideal osteosynthesis line is nothing but the sites where mini plate fixation can be most effectively performed in a mandible. Let us see which are those ideal regions of mini plate fixation. In the body of mandible the ideal position to fix a mini plate is between the upper border and the lower border. To be precise it is placed just below the roots and above the inferior alveolar canal. As you can see in the figure here the lines marked in pink are the lines of osteosynthesis. Behind the foramen the blue plate is fixed in between the teeth roots and the canal. In the angle region Champagne's line is present at the external oblique ridge. Therefore the plate is fixed on to the broad surface of the external oblique ridge as high as possible. In the anterior region two plates are fixed. Some sub-apically that is below the root apices and one plate near the lower border. The two plates are positioned to neutralize the torsional forces or the rotational forces acting at the anterior mandible. Here is the armamentarium for mini plate fixation. This is the bone plating kit with plate benders, this are the plate benders and plate holders. These are the mini plates and the screws used for fixing them. Plates are available in different designs with different number of holes and lengths. Screws also comes in various lengths and head diameters. This is a screw holder with which you carry the screws into the bone and with a screwdriver you tighten it. Dwells are available in different sizes to drill the bone through the plate holes. This photo shows two mini plates fixed at the anterior mandible. A deloving incision is made in the anterior vestibule, mentalism muscle is incised and subperiostal dissection is performed to expose the lower border. The fracture is then reduced in its anatomical position and the temporary IMF is performed to achieve occlusion. The plate is then adapted to the bone contour and fixed in position with the screws. This is how a mini plate fixation is performed. Having discussed about both compression and mini plates, let us compare both the systems. Compression plate is bulky and difficult to use, hence applied extra orally whereas mini plates are smaller, need lesser soft tissue dissection and hence applied intra-orally. Compression plates are difficult to adapt, it causes nerve injury and cannot be applied to the upper border. On the other hand, mini plates can be placed at both the upper and lower borders with fewer complications. Compression plate provides rigid fixation with no interfragmentary motion and mini plates provide functionally stable fixation with little interfragmentary motion under functional loading. That's all about the two important plating systems. Third type of osteosynthesis is the lag screw. Stable unit of two bone fragments can be achieved by means of lag screws. The principle is that the axial tensile stress within the screws while tightening it is converted into a compressive stress acting upon the fracture surface. The special feature of lag screw is that the threads are confined to one half of the shaft. The threads are confined to the lower half of the shaft and the remainder near to the screw head is smooth. This part of the screw is smooth and the lower part is threaded. First a hole is made through both the fracture fragments using a drill bit of 2mm. Then you use something called a screw tap. It is used to make a gliding and a thread hole of required size. The threaded part of the lag screw that is the lower part fits into the thread hole and the upper smooth part fits into the gliding hole. As the screw is being tightened the threaded lower tip engages the lingual cortex. This is the buckle cortex and this is the lingual cortex. So as the screw is tightened the threaded lower tip engages the lingual cortex and pulls it towards the buckle and the two cortices are compressed against each other. This way fracture is reduced and lag screws are used for stabilizing or it is used as a fixation device. Lag screws are ideal for oblique surface fracture which means the length of the fracture surface should be greater than or equal to the mandibular height. Such fractures are considered oblique. And ideal number of lag screws is 3 or more in number to neutralize the functional forces that acts in all directions but two screws are an absolute minimum. Other indications are fractures in the edentulous mandible with concomitant fractures of body and condyle. It is helpful in patients in whom IMF is contraindicated and also in non or mal union fractures. Reconstruction plates as the name suggests is used to reconstruct the lowest part of mandible following a fracture or surgical resection. They are load bearing and provide rigid fixation. It makes up for the bony defect and restore the continuity of the bone. This particular slide has been included only to make you understand which fixation devices fall under rigid fixation and which under semi-rigid fixation. By now you would have understood the different concepts of fixation and the working principles of each devices. Therefore you may use them in combinations to achieve the desired type of fixation. For example a single reconstruction plate or a single 6 hole 2.4 mm compression plate is sufficient to provide rigid fixation whereas for certain other devices you need a combination. Only a combination can provide rigid fixation for example two bone plates. The bone plates can be either two compression plates or two mini plates or it can be one compression plate and one mini plate. So a combination of two bone plates. A combination of two lag screws. One bone plate and one lag screw. And one compression plate and arch bar. These four combinations will give rigid fixation. And reconstruction plate and one 6 hole compression plate will provide rigid fixation. Now coming to semi-rigid fixation. If you place one 2 mm mini plate at the angle region without arch bar then you achieve functionally stable fixation or semi-rigid fixation. Whereas elsewhere in the mandible you need to place one 2 mm mini plate along with an arch bar for semi-rigid fixation. So one lag screw and arch bar and one 4 hole 2.4 mm compression plate without arch bar are examples of semi-rigid fixation. So here one 4 hole compression plate with arch bar will provide rigid fixation whereas the same plate same compression plate without arch bar will provide semi-rigid fixation. Lastly let us have a look at the advantages and disadvantages of open reduction and internal fixation. Advantages are that there is accurate reduction and fixation of the fractures with primary bone healing. There is early return to normal jaw function. The patient can maintain a good oral hygiene and there is a lower risk of major complications. The disadvantages are that the procedure requires surgical exposure under general anesthesia which makes the treatment expensive. Compared to the IMF technique open reduction is difficult and risky. You are leaving a foreign body inside the tissues because you are placing a bone implant. The risk of neurovascular structure and teeth is also more when compared to closed reduction. If required a second surgery also has to be performed to remove the hardware. So these are few advantages and disadvantages of open reduction and internal fixation. That's all about the topic and with this we have completed the management of mandibular fractures. In the next lecture we shall be discussing condylar fractures exclusively. Thank you. Hello and welcome back to OMFS lecture series. Today we shall be discussing condylar fractures under the headings, anatomy of TMJ, mechanism of condylar injuries and classification of condylar fractures. Let's have a quick look at the anatomy of temporal mandibular joint. TMJ basically has two components, a passive component and active component. Passive components are the glenoid fossa which is a part of the temporal bone, condyle which is part of the mandibular and articular eminence, capsules and ligaments and articular disc. These five are the passive components of TMJ of which the glenoid fossa, condyle and articular eminences are made up of bones or heart tissue and the capsules and ligaments and the disc are made up of soft tissue. The active components of temporal mandibular joint are the muscles of mastication, all the muscles of mastication, the temporalis muscle, medial and lateral teregoid and mesater. All these fall under the active components of TMJ. TMJ is formed by the mandibular condyle fitting into the mandibular fossa and the two bones are separated by articular disc. The different capsular and ligament attachments are the fibrous capsule. Fibrous capsule or the joint capsule covers the entire joint. Temporal mandibular or lateral ligament. It extends from the zygomatic process to the lateral aspect of condylar head. Spenomandibular ligament is an accessory ligament that extends from the spinal spinoid to the tip of lingula on the medial aspect of the ramus. Stylomandibular ligament is the fourth ligament which extends from the styloid process to the posterior border of ramus at the angled region. So these four structures have attachments to and around the TMJ and their main function is to control the excessive movement or to guide the direction of the condylar head and articular disc during the movement or functioning of TMJ. In the lecture on basics of management of mandibular fractures, we had seen how elevators and depressors act on a fracture to displace it. Latval tergoid has direct attachment to the anterior part of the neck of the condyle at the tergoid fovea and it can displace the fractured condylar head anteriorly and medially. The condylar head is a semi-cylindroid process which is 15-20 mm in length and 8-10 mm in thickness. The long axis of the condyle is related to the position of the ramus of mandible and not to the skeleton. It is not related to the skeletal axis but it is related to the ramus of the mandible. The angle formed by the two condylar axis varies between 145 degree to 160 degree. This is an axial section of the CT showing cross sections of condyles on both the sides. So it is told that it is found out that the two condyles meet at the foramen magnum at an angle of 145 to 160 degrees. The vascular supply to the TMJ arises anteriorly from the mesotric artery and posteriorly from the branches of superficial temporal and maxillary arteries. All these are the branches of external carotid artery. The nerve supply to the joint is from the auricular temporal nerve with some additional innervation from mesotric nerve and deep temporal nerves. These diagrams depict the anatomical and histological differences between the condylar heads of a child and an adult. As you can observe, the cortical bone thickness at the condylar head in a child is very less when compared to that in an adult. The periosteum of the condyle facing the joint is in its active osteogenic state in a child whereas it has moved to the latent osteogenic state in an adult. The lower neck in a child is broader with thin articular surface. Therefore, an impact at the condyle will confine the fracture within the capsule or it is called intracapsular fracture with hematrosis meaning bleeding and swelling within the joint. This carries a higher risk of progressing into TMJ ankylosis. On the other hand, in an adult, the condylar neck is relatively narrow and the articular surface is thicker. Hence, an impact to the condyle will result in extracapsular fracture with normal vascularity. Injury to the condyle may be caused by a variety of mechanisms. Lindal divided traumatic forces causing condylar injury into three categories. The first is energy imparted on a static individual by a moving object. For example, a blow to the face by a fist or a bat or any other object. The second type of force is that of a moving individual striking a static object such as a child falling and hitting the chin against the pavement. This mechanism is also seen in parade ground fracture wherein a standing soldier collapses hits the chin onto the ground and fractures his condyle for mandible. The third classification is energy developed by a combination of the first two mechanisms. This type of force is typical of that generated during an automobile accident in which the individual is moving forward and the object is moving in the opposite direction. For example, where a person is moving in a car and hitting his chin across the dashboard. There have been many studies into the resistance of mandible. This diagram shows the deformation of bone by an applied force. When a force causes compressive strain at one side, it gets converted into tensile strain at another. It was found that bones fracture at sides of tensile strain because their resistance to compressive force is greater. Studies by Hulkan Hodson showed that isolated mandible is liable to particular pattern of distribution of tensile strain when forces are applied to it. Antidere forces applied to the symphysis mentai, the mental phamin or mandibular body gets converted into strain at condylar necks and the lingual plates on the contralateral side. The areas in red denote the force applied and the areas in blue denote the resultant tensile strain. The subcondylar fracture as you can see in this diagram is usually a result of indirect violence to the mental prominence or the contralateral body of mandible. As you already know the mesater has insertion at the lateral aspect of ramus. The medial teregoid has insertion at the medial aspect of ramus and lateral teregoid is inserted at the teregoid phobia at the anterior neck of condyle. So usually a subcondylar fracture is evident just superior to the insertion of mesater. Therefore a coordinated action of the mesater and the teregoids will displace the condylar head in supido anterior and medial direction. Moving on to classification of condylar injuries. There are basically three types of injuries seen in temporal mandibular joint. They are contusion, dislocation and fracture. Contusion involves soft tissue injuries like that to ligaments, muscles, synovium and may cause formation of inflammatory exudates or hemarthrosis. A tear in meniscus can also result in osteoarthritic changes. Dislocation is a displacement of the condylar head completely out of the glenoid fossa which usually cannot be reduced by the patient. There is one more term associated with it, it is called subluxation. In subluxation patient can reduce the displaced condylar head himself. And fracture can either be intra-capsular that means within the capsule like seen in majority of condylar fractures in children and also extra-capsular or sub-condylar fractures as seen in adults. Such classification systems have been given by various authors. Here we shall be discussing two such systems in detail. The first system was given by Lindahl in the year 1977. He proposed a system that classified condylar fractures based on several factors like based on anatomic location of the fracture, based on the relationship of the condylar segment to the mandibular fragment and based on the relationship between the condylar head and glenoid fossa. Let's see each of them in detail. Based on anatomic location of the fracture, he classified condylar fractures into fractures of the condylar head, condylar neck and sub-condylar fractures. The condylar head is usually defined as the portion of the condyle superior to the narrow constriction of the condylar neck. Fractures of the condylar neck are intra-capsular means it is within the confinement of the fibrous capsule. The next classification is that of condylar neck. The neck is the thin constructed area located immediately below the condylar head. Therefore it is extra-capsular. Any fracture at or below the condylar neck is considered extra-capsular fracture. Sub-condylar fracture. So sub-condyle is the region located below the condylar neck and extends from the deepest point of the sigmoid notch anteriorly to the deepest point along the concave posterior aspect of the ramus. So depending on the location, these fractures are described as high or low sub-condylar fractures. Now based on the relationship of condylar segment to the mandibular fragment, fractures are classified as undisplaced or non-displaced. That means even if there is a fracture, the condylar head doesn't displace itself. So this is undisplaced fracture, deviated. This involves only an angulation of the condylar fragment in relation to the mandibular segment. As you can see in the diagram, there is only a little bit of angulation of the condylar fragment. The fractured ends remain in contact with no separation or overlap. This is deviated fracture. Displacement with medial or lateral overlap. Here the fractured ends of the condylar segment lies either medially or laterally to the displaced of the distal mandibular segment. Medially displaced condylar fragment is more commonly seen. Displacement with anterior or posterior overlap. As you can see in the diagram here, the condylar head is displaced anterior to the mandibular segment or it can be displaced posteriorly also but it is very rare. And the sixth type is no contact. Here there is no contact at all between the condylar fragment and the mandibular distal fragment. So this is the classification of condylar fractures under the category based on the relationship of condylar segment to the mandibular fragment. Based on the relationship between the condylar head and the glenoid fossa, it can be classified as non-displaced, displaced and dislocated fractures. In non-displaced fracture, the condylar head is in normal relation to the glenoid fossa. As you can see here, the relationship between the condylar head and the glenoid fossa remains the same. In displaced fractures, the condylar head remains within the confinement of the fossa but there is alteration in the joint space. The normal anatomy is not being seen here, there is displacement or there is change in the relationship between the condylar head and the glenoid fossa, there is change in the joint space. And in dislocated fractures, the condylar head lies completely outside the fossa. The usual location of dislocation is antedomedial due to the pull of the lateral tigal. So this is how Lindhal has classified condylar fractures based on the anatomic location of fracture, based on relationship of the condylar segment to mandibular fragment and based on the relationship between the condylar head and the glenoid fossa. Another classification of condylar fractures was given by Matt Lennon in the year 1952. His system consists of four divisions, type I fracture or non-displaced fracture. As you can see in the diagram here, the fracture is non-displaced, type II fracture or fracture deviation. This type consists of simple angulation of the fracture segment without overlap or separation. This type includes the green stick fracture which is common in children. Type III fracture or fracture displacement. Here the fracture is characterized by overlap of the proximal and distal fracture segments. The overlap can be anterior, posterior, lateral or medial, but medial displacements are more common. Type IV fracture is fracture dislocation. Here the condylar head is completely outside the glenoid fossa, therefore it is complete extra-capsular fractures. Again the dislocation may be medial or lateral, anterior or posterior. So this is all about classification of condylar fractures. So we have seen in today's lecture the anatomy of TMJ, the mechanism and classification of condylar fractures. In the next lecture we shall be discussing in detail about the management of condylar fractures. Thank you. Hello everyone, welcome back to OMFS lecture series. Coming with condylar fractures, today we shall look into the clinical features, investigations and management of fractures of mandibular condyle. Let's see the clinical features associated with unilateral condyle fracture. There is often swelling and tenderness over the TMJ area of the affected side. There is hemorrhage from ear on the same side which results from laceration of the anterior wall of external auditory mayadis. Here it is important to distinguish bleeding originating in the external auditory canal from the middle ear hemorrhage. In middle ear hemorrhage it indicates a fracture of the pectoral temporal bone and this may be accompanied by cerebrospinal auteura that means escape of cerebrospinal fluid through the ear. It is known as cerebrospinal auteura. You will also find achemosis of the skin just below the mastoid process on the same side. This particular physical sign also occurs with fractures of the base of the skull and it is known as battle sign. If the condyle head is dislocated medially and after all the edema has subsided due to passage of time, a characteristic hollow over the region of the condyle head is observed. So this is characteristic of unilateral condyle fracture. In opening the mandible deviates towards the side of the fracture that means deviates towards the affected side. There is unilateral posterior cross bite. Displacement of the condyle from the fossa or if the fractured condyle or neck is over winding, then it causes shortening of the ramus on the same side and produces gagging of occlusion on the same side molars. There is also limited or painful protrusion or excursion. Excursion means while the mandible is being deviated to the opposite side, it is painful. In bilateral condyle fractures, all the signs and symptoms present in unilateral fractures may be present on both the sides. And overall the mandibular movement is more restricted than in unilateral fractures. If there is a displacement of the condyle from the glenoid fossa or overriding of the fractured bone ends, then an anterior open bite is present. Pain and limitation of opening and restricted protrusion is present in case of bilateral fractures also. Bilateral condyle fractures are frequently associated with fracture of the symphysis and tata symphysis. Also the appearance of an elongated face may be result of bilateral subcondyle fracture. Here is a diagrammatic representation of the characteristic disturbances of occlusion after condyle injury. As you can see in the first diagram, this is a post-chromatic effusion or hemarthrosis. Hemarthrosis means collection of blood within the joint space. So this hemarthrosis may distract the joint surfaces causing a posterior open bite on the affected side or the same side with the deviation of the mandibular midline towards the opposite side. So this is characteristic of a contusional injury or where there is bleeding within the joint space without any definite fracture. The second diagram is that of a unilateral fracture with significant dislocation or displacement. This may result in contraction of the fragments under the action of pterigomacetic sling with ipsilateral premature posterior contact. ipsilateral means on the same side. So when there is action of pterigomacetic sling, it produces a premature posterior contact on the same side and the deviation of mandibular midline to the affected side. So there is premature contact and shift of midline towards the same side. The third diagram is that of bilateral fracture dislocation. Here the fracture condyles are dislocated medially, in this case medially. This will produce a premature posterior contact on both the sides with no deviation. Here there is no shift in midline. But there is premature contact on both the sides with anterior open bite. This is characteristic of bilateral condyler fractures with dislocation. The fourth figure shows bilateral dislocation without fracture. Here the condyles are not fractured but it is dislocated completely. It means the condyler heads are out of glenoid fossa. This is likely to produce an appearance of long face or prognathism. The patient is unable to occlude the posterior teeth. So there is almost complete inability to occlude any teeth and there is appearance of prognathism or pseudo prognathism. So these are the characteristic disturbances of occlusion after condyler injury. Moving on to the investigations associated with condyler injuries. Patient advances in the field of imaging technology have enabled accurate diagnosis and localization of condyler injuries. So you may use conventional radiographic techniques like orthopantamogram, reverse towns view or a transcranial view of TMJ to visualize the injured condyle. You may also use computer tomography and MRI or orthography. MRI or magnetic resonance imaging is usually performed to study the soft tissues associated with the temporal mandibular joint and orthography is mainly used to study the joint space. So these are the investigations associated with condyler injuries. The proper management of the fractured mandibular condyle is one of the most controversial topics in maxillofacial trauma. The commonly accepted goal of treatment is the re-establishment of the pre-operative function of the masticatory system. That means it is important to restore the masticatory function as it was before the injury and this involves re-establishment of the pre-op relationship of the fracture segments, the occlusion and maxillofacial symmetry. So even if you perform a perfect radiographic alignment of the fracture segments, it is not adequate if you are unable to achieve a fully functioning and pain-free joint. These are the general principles associated with management of condyle and fracture. Whichever technique you follow, whether you do it conservatively or surgically, these are the principle goals you need to achieve. Now the treatment is divided into two schools, conservative or non-surgical and surgical approaches. Moving on to the conservative management of condyle fractures. Conservative approaches have been practiced by a majority of surgeons and this technique is utilized for all kind of mandibular condyle fractures except those fractures which are an absolute indication for open re-election. Primary goal of conservative and functional treatment is to facilitate active jaw movement as early as possible and also to restore normal occlusion and neuromuscular pathways. The conservative management of condyle fractures can be as simple as observation and soft diet or it may include variable periods of immobilization followed by intense physiotherapy. But still close supervision is mandatory and at the sign of any occlusion instability, deviation with opening or increasing pain, both clinical and radiographic re-evaluation should be performed. Any of these findings like occlusion instability or pain may indicate the conversion of treatment from conservative to surgical. Immobilization is one of the major components of conservative management of condyle fractures. The period of immobilization is controversial and must be long enough to allow initial union of the fracture segments but short enough to prevent the complications. What are the complications associated with long duration of immobilization? They include muscular atrophy, joint hypermobility and ankylosis. Currently the period of immobilization ranges from 7 to 21 days i.e. up to 3 weeks. This period may be increased or decreased based on concomitant factors such as the age of the patient, level of fracture, degree of displacement or presence of additional fractures. So this is all about conservative management of condyle fractures. The second approach to manage a fractured condyle is surgical or open reduction. Zaid and Kent have proposed a set of both absolute and relative indications for open reduction of the fractured manubular condyle. The absolute indications include displacement of the condyle into the middle cranial fossa, impossibility of obtaining adequate occlusion by closed techniques or conservative techniques, lateral extracapsular dislocation of the condyle, any foreign bodies within the TMJ capsule, mechanical obstruction that impedes the function of the TMJ and also open injuries like penetration, laceration or evulsion to the TMJ. All these conditions require immediate treatment and is an absolute indication. The relative indications include bilateral condyle fractures in an edentulous patient where you cannot fabricate a splint because of severe rich atrophy. Unilateral or bilateral fractures where splinting is again not recommended because of any concomitant medical conditions or when physiotherapy is not possible. Bilateral fractures associated with comminuted mid-facial fractures and also bilateral fractures associated with other ortho-natic problems. So these are the absolute and relative indications mentioned for opening a manubular condyle. But still you need to carefully evaluate the patient on an individual basis and then decide upon the treatment plan. Several surgical approaches to the condyle and the location of the fracture and the degree of displacement decides the selection of approach to access the joint. Subcondyla fractures may be easily accessed via submandu-blur or recromandu-blur incisions. But the danger of these techniques is the possible damage to the marginal mandu-blur nerve. If the fracture is in the intra-capsular or high on the condylar neck then a pre-auricular or end-aural approach is used. It offers better access, more visibility and ease of manipulation. Some surgeons use intra-aural approach to reach the condyle. This approach has the advantage of visualizing the fracture reduction as well as the occlusion simultaneously. But the disadvantage of intra-aural technique is that there is limited access and also it is difficult to place certain fixation devices. Metidectomy again provides a good access and it is considerably aesthetic also because the scar is placed behind the ear fold. Hemi-coronal approach is used when the condylar fracture is associated with concomitant mid-face fractures or frontal bone fractures. In such cases, Hemi-coronal approach can be used which gives good access to the condyle. The vital structure at highest risk of damage during a pre-auricular approach to the condyle is the facial nerve. This diagram shows the relationship of facial nerve and its branches to the condyle and auditory canal. Here is the bifurcation of the main concoff facial nerve. It is at this point that the facial nerve divides into its five peripheral branches. So this bifurcation is approximately 1.5 to 2.8 cm away from the lowest concavity of external auditory canal. This is the external auditory canal and the bifurcation is 1.5 to 2.8 cm away from this position. Bifurcation is again 2.4 to 3.5 cm away from the post-gluenoid tubercle. This is the posterior most tubercle at the glenoid fossa and the bifurcation is approximately 2.4 to 3.5 cm away. Here is the temporal branch of facial nerve which is again 2 cm away from the most anterior concavity of the canal. This is the anterior concavity of the external auditory canal and the temporal nerve or the temporal branch is 0.8 to 3.5 cm away from the anterior most concavity. So it is important to keep these measurements in mind to avoid any damage to the nerve while placing an incision or proceeding with dissection. Here is a brief explanation of the pre-auricular approach. First the skin in front of the tragus of the ear is infiltrated with local anaesthetic solution to ensure hemostasis. Then the incision is outlined at the junction of the facial skin and the helix of the ear. The incision is usually 3 to 4 cm in length and has 2 limbs, an upper curved limb and an inferior vertical limb anterior to the tragus. Incision is made through the skin and subcutaneous tissues towards the depth of temporalis fascia. It is here that you encounter the superficial temporal vessels and it is retracted anteriorly. This is exposure of the temporalis fascia. At this point you can palpate the zygomatic arch and the lateral pole of mandibular condyle. Here is the arch and here is the condyle. So at this point you can palpate it using finger. Then you make an oblique incision on the surface of temporalis fascia. You place an oblique incision which is parallel to the temporal branch of the facial nerve. The incision should be parallel so that it doesn't cut or it doesn't reset the temporal branch. So you place an oblique incision parallel to the temporal branch through the superficial layer of temporalis fascia and this is all done above the arch. As you can see in the diagram this incision and the dissection following incision is all performed above the level of zygomatic arch. You then insert a periostial elevator beneath the superficial layer of temporalis fascia and the temporalis muscle and strip off the periosteum from the lateral aspect of the arch. You insert an elevator through this incision to reach the zygomatic arch and elevate the periosteum of the arch. The dissection is then carried out inferiorly to expose the capsule of the joint. As you can see in the diagram as the dissection proceeds inferiorly the capsule of the joint is visible which is then incised and the fracture is exposed. So this is in general the principle and the procedure of pre-oricular approach to condyne. There are different modifications of pre-oricular incision. Pre-oricular incision is basically placing an incision within the skin crease in front of the tragus. As you can see in this diagram here the dotted lines represent the classic pre-oricular incision. Several authors have given modifications to this incision by exchanging or altering it. For example, alkyt and dramedy modification is the extension of pre-oricular incision anteriorly and superiorly. Few other modifications are inverted hockey stick incision by Blair, vertical angulated incision by Thoma and Dinkman incision. Here is the Popovich incision in which the pre-oricular incision is modified into a question mark shape. You have post-oricular incision as you can see in the diagram here. The dotted violet lines represent post-oricular incision. This is placed behind the ear within the skin crease. You also have end-orial incision. This incision is carried through the skin over the tragal cartilage. It is not placed right in front of the tragus but it is placed within the cartilage of the tragus. In this kind of incision most of the vital structures are in the superficial plane and it gives good access to both the joint and the coronoid process. This is another approach to the condyle which is called the righted echemy or facelift approach. This is an incision that provides the same exposure as the retro mandibular and pre-oricular approach. Basically it is a combination of both the retro mandibular and pre-oricular approach. The advantage of this incision is that it is placed in a more cosmetically acceptable location. So in this figure you can see all the incisions and all the approaches used to reach the condyle that is pre-oricular incision, the end-orial incision, inverted hockey stick incision, post-oricular incision and retro mandibular incision. Here is the hemicoronal or bicaronal incision which is used to gain access to the condyle when it is associated with mid-face or frontal bone fractures. Here the incision is placed in this manner and the dissection is guided out to all the layers of scalp. After gaining a surgical access to the condyle, the fractured fragments are reduced in anatomical position and fixed using any of these methods, transaussious wiring. This is used for sub-condyle fractures. Here the condyle is approached through submandibular incision and holes are drilled in the fragmented segments. The wire is passed across the segments, it is twisted and tightened. In case of a high-condyle fracture, this is a high-condyle fracture where a pre-oricular incision will be better. Here the fragments are drilled obliquely from the lateral aspect of the fracture. That is, you know a mandible has both the lateral and middle aspect. So while performing any procedure on the condyle or head, you take access from the external or the lateral aspect of the mandible. So you drill a hole obliquely here so that you don't injure maxillary artery or other blood vessels in the vicinity. Again transaussious wiring is performed and the fragments secured in place. The next technique is the Kishner wire or K-wire technique in which a vertical passage is first drilled across the two fracture fragments and a K-wire is passed in through it. The wire is then secured using transaussious wires. The third technique is the intramedullary screw which is placed through submandibular incision. It is a rather inaccurate technique and not used commonly these days. In bone pin technique, two pins are inserted on either side of the fracture site and connected by a condyle or head and universal joint. This technique is also no longer in use and if at all practiced is very rare. Bone plating is the most popularly used fixation technique. Bone plates provide both stability and frigidity. It also has added advantage of EC application. This is an example of subcondyle or fracture which is stabilized using a mini plate. But whereas in case of multiple fracture it is difficult to perform this procedure within the surgical field. Therefore in such cases the ramus is osteotomized in this way. The ramus is osteotomized and the fractured fragments are plated outside the surgical field. That is the fragments are treated like autogenous bone grafts. It is treated totally outside. It is then plated to the main segment again using bone plates. So after fixation the drains are placed, the wound is closed and pressure dressing is applied. The postoperative management includes analgesics, anti-inflammatory, soft diet and intense physiotherapy. Moving on to the complications associated with condyle or fractures. There are early and late complications. Complications that occur concurrent or with the treatment of condyle or fractures include the following. Complications of tympanic plate, fracture of the glenoid fossa, with or without displacement of the condyle or segment into the middle cranial fossa. Damage to the cranial nerves 5 and 7 that is the trigeminal and the facial nerves and vascular injuries. These are the early complications of condyle or fractures. Late complications include malocclusion, growth disturbances, temporomandibular joint dysfunction and ankylosis in children. So with this we have completed the topic on condyle or fractures as well as management of mandibular fractures. Thanks for watching. Complications associated with condyle or fractures during the time of trauma or during immediate post-op period include tympanic plate fractures, glenoid fossa fractures, damage to the trigeminal and facial nerves and vascular injuries. The late complications are the complications that arise after the surgical procedures include malocclusion, growth disturbances, TMG dysfunction and ankylosis in children. So this is all about management of fractures of mandible as well as condyle. Thank you.