must rely on blood supply from the periosteum surrounding the bone. if a fracture occurs in a child with mixed dentition different treatment protocols are needed. other fractures of the body, are classified as open or closed. because fractures that involve the teeth, by definition, communicate with the mouth this distinction is largely lost in mandible fractures. condylar, ramus, and coronoid process fractures are generally closed whereas angle, body and parasymphsis fractures are generally open. multiple mandible fractures of a patient in the right condyle (extracapsular/neck/not dislocated), right body (vertically unfavourable) and left coronoid process displacement the degree to which the segments are separated. the larger the separation, the more difficult it is to bring them back together (approximate the segments) favourability for angle and posterior body fractures, when the angle of the fracture line is angled back (more posterior at the top of the jaw and more anterior at the bottom of the jaw) the muscles tend to bring the fracture segments together. this is called favorable. when the angle of the fractures is pointing to the front, it is unfavorable. age of the fracture while mandible fractures have similar complication rates whether treated immediately or days later, older fractures are believed to have higher non-union and infection rates although the data on this makes it difficult to draw firm conclusions. treatment like all fractures, consideration has to be given to other illnesses that might jeopardize the patient, then to reduction and fixation of the fracture itself. except in avulsive type injuries, or those where there might be airway compromise, a several day delay in the treatment of mandible fractures seems to have little impact on the outcome or complication rates. general considerations since mandible fractures are usually the result of blunt force trauma to the head and face, other injuries need to be considered before the mandible fracture. first and foremost is compromise of the airway. while rare, bilateral mandible fractures that are unstable can cause the tongue to fall back and block the airway. fractures such as a symphyseal or bilateral parasymphyseal may lead to mobility of the central portion of the mandible where genioglossus attaches, and allow the tongue to fall backwards and block the airway. in larger fractures, or those from high velocity injuries, soft tissue swelling can block the airway. in addition to the potential for airway compromise, the force delivered to break the jaw can be great enough to either fracture the cervical spine or cause intra-cranial injury (head injury). it is common for both to be assessed with facial fractures. finally, vascular injury can result (with particular attention to the internal carotid and jugular) from high velocity injuries or severely displaced mandible fractures. loss of consciousness combined with aspiration of tooth fragments, blood and possibly dentures mean that the airway may be threatened. reduction reduction refers to approximating the ends of the bones edges that are broken. this is done with either an open technique, where an incision is made, the fracture is found and is physically manipulated into place, or closed technique where no incision is made. the mouth is unique, in that the teeth are well secured to the bone ends but come through epithelium (mucosa). a leg or wrist, for instance, has no such structure to help with a closed reduction. in addition, when the fracture happens to be in a tooth bearing area of the jaws, aligning the teeth well usually results in alignment of the fracture segments. to align the teeth, circumdental wiring is often used where wire strands (typically 24 gauge or 26 gauge) are wrapped around each tooth then attached to a stainless steel arch bar. when the maxillary (top) and mandibular (bottom) teeth are aligned together, this brings the fracture segments into place. higher tech solutions are also available, to help reduce the segments with arch bars using bonding technology. fixation simple fractures are usually treated with closed reduction and indirect skeletal fixation, more commonly referred to as maxillo-mandibular fixation (mmf). the closed reduction is explained above. the indirect skeletal fixation is accomplished by placing an arch bar, secured to the teeth on the maxillary and mandibular dentition, then securing the top and bottom arch bars with wire loops. many alternatives exist to secure the maxillary and mandibular dentition including resin bonded arch bars, ivy loops (small eyelets of wires), orthodontic bands and mmf bone screws where titanium screws with holes in the head of them are screwed into the basal bone of the jaws then secured with wire. closed reduction with direct skeletal fixation follows the same premise as mmf except that wires are passed through the skin and around the bottom jaw in the mandibule and through the piriform rim or zygomatic buttresses of the maxilla then joined to secure the jaws. the option is sometimes used when a patient is edentulous (has no teeth) and rigid internal fixation cannot be used. open reduction with direct skeletal fixation allows the bones to be directly mandibulated through an incision so that the fractured ends meet, then they can be secured together either rigidly (with screws or plates and screws) or non-rigidly (with transosseous wires). there are a multitude of various plate and screw combinations including compression plates, non-compression plates, lag-screws, mini-plates and biodegradable plates. external fixation, which can be used with either open or closed reduction uses a pin system, where long screws are passed through the skin and into either side of a fracture segment (typically 2 pins per side) then secured in place using an external fixator. this is a more common approach when the bone is heavily comminuted (shattered into small pieces, for instance in a bullet wound) and when the bone is infected (osteomyelitis). regardless of the method of fixation, the bone need to remain relatively stable for a period of 3–6 weeks. on average, the bone gains 80% of its strength by 3 weeks and 90% of it by 4 weeks. there is great variation depending on the severity of injury, health of the wound, and age of the patient. maxillomandibular fixation with circumdental wires, archbars and elastics for a condyle fracture rigid internal fixation of parasymphysis fracture of the mandible. white arrow marks fracture, black arrow marks arch bar on lower teeth rigid internal fixation of right condyle fracture with mini-plate on the neck of the condyle. black arrow marks right earlobe, white arrow marks head of the condyle external fixation of left mandible fracture current clinical evidence a 2013 cochrane review assessed clinical studies on surgical (open reduction) and non-surgical (closed reduction) management of mandible fractures that do not involve the condyle. the review found insufficient evidence to recommend the effectiveness of any single intervention. condyle the best treatment for condylar fractures is controversial. there are two main options, namely closed reduction or open reduction and fixation. closed reduction may involve intermaxillary fixation, where the jaws are splinted together in the correct position for a period of weeks. open reduction involves surgical exposure of the fracture site, which can be carried out via incisions within the mouth or incisions outside the mouth over the area of the condyle. open reduction is sometimes combined with use of an endoscope to aid visualization of fracture site. although closed reduction carries a risk of the bone healing out of position, with consequent alteration of the bite or the creation of facial asymmetry, it does not risk temporary damage to the facial nerve or result in any facial scar that accompanies open reduction. a systematic review was unable to find sufficient evidence of the superiority of one method over another in the management of condylar fractures. paediatric condylar fractures are especially problematic, owing to the remaining growth potential and possibility of ankylosis of the joint. early mobilization is often recommended as in the walker protocol. edentulous mandible a broken jaw that has no teeth in it faces two additional issues. first, the lack of teeth makes reduction and fixation using mmf difficult. instead of placing circumdental wires around the teeth, existing dentures can be left in (or gunning splints, a type of temporary denture) and the mandible fixated to the maxilla using skeletal fixation (circummandibular and circumzygomatic wires) or using mmf bone screws. more commonly, open reduction and rigid internal fixation is placed. when the width of the mandible is less than 1 cm, the jaw loses its endosteal blood supply. instead, the blood supply comes largely from the periosteum. open reduction (which normally strips the periosteum during the dissection) can lead to avascular necrosis. in these cases, oral surgeons sometimes opt for external fixation, closed reduction, supraperiosteal dissection or other techniques to maintain the periosteal blood flow. high velocity injuries in high velocity injuries, the soft tissue can be severely damaged far from the bullet wound itself due to hydrostatic shock. because of this the airway must be carefully managed and vessels well examined. because the jaw can be highly comminuted, mmf and rigid internal fixation can be difficult. instead, external fixation is often used,. pathologic fracture fractures where large cysts or tumours are in the area (and weaken the jaw), where there is an area of osteomyelitis or where osteonecrosis exist cause special challenges to fixation and healing. cysts and tumours can limit effective bone to bone contact and osteomyelitis or osteonecrosis compromise blood supply to the bone. in all of the situations, healing will be delayed and sometimes, resection is the only alternative to treatment. prognosis the healing time for a routine mandible fractures is 4–6 weeks whether mmf or rigid internal fixation (rif) is used. for comparable fractures, patients who received mmf will lose more weight and take longer to regain mouth opening, whereas, those who receive rif have higher infection rates. the most common long-term complications are loss of sensation in the mandibular nerve, malocclusion and loss of teeth in the line of fracture. the more complicated the fracture (infection, comminution, displacement) the higher the risk of fracture. condylar fractures have higher rates of malocclusion which in turn are dependent on the degree of displacement and/or dislocation. when the fracture is intracapsular there is a higher rate of late-term osteoarthritis and the potential for ankylosis although the later is a rare complication as long as mobilization is early. pediatric condylar fractures have higher rates of ankylosis and the potential for growth disturbance., rarely, mandibular fracture can lead to frey's syndrome. epidemiology mandible fracture causes vary by the time period and the region studied. in north america, blunt force trauma (a punch) is the leading cause of mandible fracture whereas in india, motor vehicle collisions are now a leading cause. on battle grounds, it is more likely to be high velocity injuries (bullets and shrapnel). prior to the routine use of seat belts, airbags and modern safety measures, motor vehicle collisions were a leading cause of facial trauma. the relationship to blunt force trauma explains why 80% of all mandible fractures occur in males. mandibular fracture is a rare complication of third molar removal, and may occur during the procedure or afterwards. with respect to trauma patients, roughly 10% have some sort of facial fracture, the majority of which come from motor vehicle collisions. when the person is unrestrained in a car, the risk of fracture rises 50% and when an unhelmeted motorcyclist the risk rises 4-fold. history management of mandible fractures has been mentioned as early as 1700 b.c. in the edwin smith papyrus and later by hippocrates in 460 b.c., "displaced but incomplete fractures of the mandible where continuity of the bone is preserved should be reduced by pressing the lingual surface with the fingers...". open reduction was described as early as 1869. since the late 19th century, modern techniques including mmf (see above) have been described with titanium based rigid internal fixation becoming commonplace since the 1970s and biodegradable plates and screws being available since the 1980s.