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  1.  Osteomyelitis of the jaws is osteomyelitis (which is inflammation of the bone marrow, sometimes abbreviated to OM) which occurs in the bones of the jaws (i.e. maxilla or the mandible). Osteomyelitis usually begins in the medullary cavity, involving cancellous bone; then it extends and spreads to cortical bone and eventually to the periosteum.
  2.  Signs and symptoms  The signs and symptoms depend upon the type of OM, and may include:  Pain, which is severe, throbbing and deep seated.  Swelling. External swelling is initially due to inflammatory edema with accompanying erythema (redness), heat and tenderness, and then later may be due to sub- periosteal pus accumulation. Eventually, subperiosteal bone formation may give a firm swelling.  Trismus (difficulty opening the mouth), which may be present in some cases and is caused by edema in the muscles.  Dysphagia (difficulty swallowing), which may be present in some cases and is caused by edema in the muscles.
  3.  Cervical lymphadenitis (swelling of the lymph nodes in the neck).  Aesthesia or paresthesia (altered sensation such as numbness or pins and needles) in the distribution of the mental nerve.  Fever which may be present in the acute phase and is high and intermittent  Malaise (general feeling of being unwell) which may be present in the acute phase  Anorexia (loss of appetite).  Leukocytosis (elevated numbers of white blood cells) which may be present in the acute phase  Elevated erythrocyte sedimentation rate and C reactive protein are sometimes
  4.  An obvious cause in the mouth (usually) such as a decayed tooth.  Teeth that are tender to percussion, which may develop as the condition progresses  Loosening of teeth, which may develop as the condition progresses.  Pus may later be visible, which exudes from around the necks of teeth, from an open socket, or from other sites within the mouth or on the skin over the involved bone.  Fetid odor.
  5.  Pathogenesis  In general, microorganisms may infect bone through one or more of three basic methods: via the bloodstream (haematogeneously) - the most common method -, contiguously from local areas of infection (as in cellulitis), or penetrating trauma, including iatrogenic causes such as joint replacements or internal fixation of fractures or root-filled teeth. Once the bone is infected, leukocytes enter the infected area, and, in their attempt to engulf the infectious organisms, release enzymes that lyse the bone. Pus spreads into the bone's blood vessels, impairing their flow, and areas of devitalized infected bone, known as sequestra, form the basis of a chronic infection.
  6.  Often, the body will try to create new bone around the area of necrosis. The resulting new bone is often called an involucrum. Invasion of bacteria into cancellous bone causes soft tissue inflammation and edema within the closed bony marrow spaces. As with the dental pulp, soft tissue edema that is enclosed by unyielding calcified tissue results in increased tissue hydrostatic pressure that rises above the blood pressure of the feeding arterial vessels. The resulting severe compromise of the blood supply then causes soft tissue necrosis. The failure of microcirculation in cancellous bone is a critical factor in the establishment of osteomyelitis because the involved area becomes ischemic and the cellular component of bone becomes necrotic. Bacteria can then proliferate because normal blood borne defenses do not reach tissue, and the osteomyelitis spreads until it is arrested by medical and surgical therapy.
  7.  The major predisposing factors for osteomyelitis of the jaws are preceding odontogenic infections and fractures of the mandible . Even these two events rarely cause infections of bone unless host defenses are suppressed by such problems as diabetes, alcoholism, intravenous drug abuse, malnutrition, and myeloproliferative diseases (e.g., leukemias, sickle cell disease, or chemotherapy-treated cancer). Although the maxilla can also become involved in osteomyelitis, it does so rarely compared with the mandible. The primary reason for this is that the blood supply to the maxilla is much richer and is derived from several arteries, which form a complex network of feeder vessels. Because the mandible tends to draw its primary blood supply from the inferior alveolar artery and because the dense overlying cortical bone of the mandible limits penetration of periosteal blood vessels, the mandibular cancellous bone is more likely to become ischemic and, therefore, infected.
  8.  Classification  The classification is similar to the classification of OM generally, according to the length of time the inflammation has been present and whether there is suppuration (the formation of pus). Acute osteomyelitis is loosely defined as OM which has been present for less than one month and chronic osteomyelitis is the term used for when the condition lasts for more than one month. Traditionally, the length of time the infection has been present and whether there is suppuration (pus formation) or sclerosis (increased density of bone) is used to arbitrarily classify OM.
  9.  Suppurative osteomyelitis  Acute suppurative osteomyelitis  Chronic suppurative osteomyelitis  Primary (no preceding phase)  Secondary (follows an acute phase)  Non-suppurative osteomyelitis  Diffuse sclerosing  Focal sclerosing (condensing osteitis)  Proliferative periostitis (periostitis ossificans, Garré's sclerosing osteomyelitis)  Osteoradionecrosis
  10. SUPPURATIVE OSTEOMYELITIS( ACUTE AND CHRONIC)  Osteomyelitis is an inflammatory reaction of bone to infection which originates from either a tooth, fracture site, soft tissue wound or surgery site. The dental infection may be from a root canal, a periodontal ligament or an extraction site. Suppurative osteomyelitis can involve all three components of bone: periosteum, cortex, and marrow. Usually there is an underlying predisposing factor like malnutrition, alcoholism, diabetes, leukemia or anemia. Other predisposing factors are those that are characterized by the formation of avascular bone for example, therapeutically irradiated bone, osteopetrosis, and Paget's disease, . Osteomyelitis is more commonly observed in the mandible because of its poor blood supply as compared to the maxilla, and also because the dense mandibular cortical bone is more prone to damage and, therefore, to infection at the time of tooth extraction.
  11.  Acute osteomyelitis is similar to an acute primary abscess in that the onset and course may be so rapid that bone resorption does not occur and, thus, a radiolucency may not be present on a radiograph. Acute suppurative osteomyelitis shows little or no radiographic change because at least 10 to 12 days are required for lost bone to be detectable radiographically. Clinical features include pain, pyrexia, painful lymphadenopathy, leukocytosis, and other signs and symptoms of acute infection.  Later, after approximately two weeks, as the lesion progresses into the chronic stage, enough bone resorption takes place to show radiographic mottling and blurring of bone.
  12.  A sclerosed border called an involucrum forms around the affected area. The involucrum prevents blood supply from reaching the affected part. This results in the formation of pieces of sequestra or necrotic bone surrounded by pus. A fistulous tract may develop by the suppuration perforating the cortical bone and periosteum. The fistulous tract discharges pus onto the overlying skin or mucosa.
  13.  Chronic osteomyelitis usually demonstrates bony destruction in the area of infection. The appearance is one of increased radiolucency, which may be uniform in its pattern, or patchy with a moth-eaten appearance. Areas of radiopacity also may occur within radiolucency. These radiopaque areas represent islands of bone that have not been resorbed and are known as sequestra. In longstanding chronic osteomyelitis, an area of increased radiodensity surrounding the area of radiolucency, called an involucrum, may be present. This is the result of a reaction in which bone production increases as a result of the inflammatory reaction.
  14.  --Diagnosis of osteomyelitis is often based on radiologic results showing a lytic center with a ring of sclerosis. Culture of material taken from a bone biopsy is needed to identify the specific pathogen; alternative sampling methods such as needle puncture or surface swabs
  15. Involucrum A sheath of new bone separated from the sequestra by a zone of radiolucency. sequestrum (radiopaque necrotic bone surrounded by radiolucent suppuration) Wire for fixation
  16. sequestrum radiopaque necrotic bone surrounded by radiolucent suppuration
  17.  --Osteomyelitis is treated medically as well as surgically. Acute osteomyelitis of the jaws is primarily managed by the administration of surgical débridement, removal of causative factors, and appropriate antibiotics. The precipitating event, condition, or both must be carefully managed. If the event is a fracture of the mandible, careful attention must be given to accurate reduction and stable fixation. The antibiotics of choice include clindamycin, penicillins, and fluoroquinolones because of their effectiveness against the flora of odontogenic infections and their good-to-excellent bone penetration. If the patient has a serious acute osteomyelitis, hospitalization may be required for intravenous administration of antibiotics, which can then be followed by home intravenous therapy via a peripherally inserted central catheter or oral therapy.
  18.  Surgical treatment of acute or chronic suppurative osteomyelitis consists primarily of removing obviously nonvital teeth in the area of the infection, any wires or bone plates that may have been used to stabilize a fracture in the area, or any necrotic, loose pieces of bone. Bone specimens are sent for aerobic and anaerobic cultures, sensitivity testing, and histopathologic examination. In addition, corticotomy (removal or perforation of the bony cortex) and excision of necrotic bone (until actively bleeding bone tissue is encountered) may be necessary. For acute osteomyelitis that results from jaw fracture, the surgeon must stabilize the mobile segments of the mandible, usually by open reduction and rigid internal fixation. Immobility of the fracture segments aids in the resolution of
  19.  Chronic osteomyelitis requires not only aggressive antibiotic therapy but also aggressive surgical therapy. Because of the severe compromise in the blood supply to the area of osteomyelitis, the patient is usually admitted to the hospital and given high-dose intravenous antibiotics to control the infection. The surgeon should obtain culture material at the time of surgery so that the selection of an antibiotic can be based on the specific microbiology of the infection.
  20.  Therapy for acute and chronic osteomyelitis, most authorities agree, should ensure that antibiotics are continued for a much longer time than is usual for odontogenic infections. For mild acute osteomyelitis that has responded well, antibiotics should be continued for at least 6 weeks after resolution of symptoms. For severe chronic osteomyelitis that has been difficult to control, antibiotic administration may continue for up to 6 months.  Hyperbaric oxygen therapy has been shown to be a useful adjunct to the treatment of refractory osteomyelitis. Hyperbaric medicine, also known as hyperbaric oxygen therapy (HBOT), is the medical use of oxygen at a level higher than atmospheric pressure. The equipment required consists of a pressure chamber, which may be of rigid or flexible construction, and a means of delivering 100% oxygen. 
  21.  Non-suppurative osteomyelitis  Focal sclerosing osteomyelitis  Condensing osteitis is a periapical inflammatory disease that results from a reaction to periodontal infection. This causes more bone production rather than bone destruction in the area (most common site is near the root apices of premolars and molars). The lesion appears as a radiopacity in the periapical area hence the sclerotic reaction. The sclerotic reaction results from good patient immunity and a low degree of virulence of the offending bacteria. The associated tooth may be carious or contains a large restoration, and is usually associated with a non-vital tooth.
  22.  Etiology  Infection of periapical tissues of a high immunity host by organisms of low virulence which leads to a localized bony reaction to a low grade inflammatory stimulus.  Treatment  The process is usually asymptomatic and benign, in which case the tooth does not require endodontic treatment.  The offending tooth should be tested for vitality of the pulp, if inflamed or necrotic, then endodontic treatment is required, while hopeless teeth should be extracted.
  23.  ---GARRÉS OSTEOMYELITIS (It was first described by the Swiss surgeon Carl Garré.) (Periostitis ossificans, Osteomyelitis with proliferative periostitis) Garrés osteomyelitis or proliferative periostitis is a type of chronic osteomyelitis which is nonsuppurative. It occurs almost exclusively in children and young adults who present symptoms related to a carious tooth. The process arises secondary to a low-grade chronic infection, usually from the apex of a carious mandibular first molar. The infection spreads towards the surface of the bone, resulting in inflammation of the periosteum and deposition of new bone underneath the periosteum. This peripheral formation of reactive bone results in localized periosteal thickening. The inferior border of the mandible below the carious first molar is the most frequent site for the hard nontender expansion of cortical bone. On an occlusal view radiograph, the deposition of new bone produces an "onion-skin" appearance.
  24.  ---Osteoradionecrosis is a possible complication following radiotherapy where an area of bone does not heal from irradiation. Irradiation of bones causes damage to osteocytes and impairs the blood supply. The affected hard tissues become hypovascular (reduced number of blood vessels), hypocellular (reduced number of cells) and hypoxic (low levels of oxygen). Osteoradionecrosis usually occurs in the mandible, and causes chronic pain and surface ulceration. Prevention of osteradionecrosis is part of the reason all teeth of questionable prognosis are removed before the start of a course of radiotherapy
  25.  Treatment of osteoradionecrosis  1-Surgery  This means removing dead or infected tissue from around a wound. Dead, or necrotic, bone may also need to be removed. This is called sequestrectomy. This may include microvascular reconstructive surgery to restore blood flow to the area. Bone grafts may be needed to replace the sections of the jawbone that are removed. Soft tissue grafts can be used to replace muscle and other tissues that have been removed. You may also need dental implants if teeth are removed.
  26.  2-Hyperbaric oxygen therapy  Hyperbaric oxygen therapy involves breathing pure oxygen in a pressurized room. It is done in a special chamber where the pressure inside is higher than the normal pressure of the atmosphere. The higher pressure allows more oxygen to get into your blood, which can help heal damaged and infected tissues.  Hyperbaric oxygen therapy is used in combination with wound care and surgery. The treatment plan often includes 20 treatments before surgery and 10 more treatments after surgery. After you finish radiation therapy, your healthcare team may recommend that you have hyperbaric oxygen therapy before you have any teeth removed.
  27.  FibrinolyticAlveolitis (Dry Socket)  This postoperative complication appears 2–3 days after the extraction. During this period, the blood clot disintegrates and is dislodged, resulting in delayed healing and necrosis of the bone surface of the socket. This disturbance is termed fibrinolytic alveolitis and is characterized by an empty socket, fetid breath odor, a bad taste in the mouth, denuded bone walls, and severe pain that radiates to other areas of the head.  As for the etiology and pathogenesis of dry socket, various factors have been cited, some of which include dense and sclerotic bone surrounding the tooth, infection during or after the extraction, injury of the alveolus, and infiltration anesthesia.
  28.  Treatment. This type of complication is treated by gently irrigating the socket with warm saline solution, and placing gauze impregnated with eugenol, which is replaced approximately every 24 h, until the pain subsides. Also, gauze soaked in zinc- oxide/eugenol maybe used, which remains inside the alveolus for 5 days; alternatively iodoform gauze or enzymes are applied locally.
  29.  Special types of osteomyelitis  TUBERCULOSIS OSTEOMYELITIS  Tuberculosis is a chronic granulomatous disease which may affect any organ, although in man the lung is the major seat of the disease and is the usual portal through which infection reaches other organs. The microorganisms may spread by either the bloodstream or the lymphatics. Oral manifestations of tuberculosis are extremely rare and are usually secondary to primary lesions in other parts of the body. Infection of the socket after tooth extraction can also be the mode of entry into the bone by Mycobacterium tuberculosis. Mandible and maxilla are less commonly affected than long bones and vertebrae. On a radiograph, the appearance of bony lesions is similar to that of chronic suppurative osteomyelitis ("worm- eaten" appearance) with fistulae formation through which small sequestra are exuded. Periostitis ossificans (proliferative periostitis) can also occur and change the contour of bone. Calcification of lymph nodes is a characteristic sign of tuberculosis.
  30.  SYPHILITIC OSTEOMYELITIS  Syphilis is a chronic granulomatous disease which is caused by the spirochete Treponema pallidum. It is a contagious venereal disease which leads to many structural and cutaneous lesions. Acquired syphilis is transmitted by direct contact whereas congenital syphilis is transmitted in utero. In congenital syphilis, the teeth are hypoplastic, that is, the maxillary incisors have screwdriver-shaped crowns with notched incisal edges (Hutchinson's teeth) and the molars have irregular mass of globules instead of well-formed cusps ("mulberry
  31.  Also, a depressed nasal bridge or saddleback nose occurs because of gummatous destruction of the nasal bones. Acquired syphilis, if untreated, has three distinct stages. The primary stage develops after a couple of weeks of exposure and consists of chancres on the lips, tongue, palate, oral mucosa, penis, vagina, cervix or anus. These chancres are contagious on direct contact with them.
  32.  The secondary stage begins 5 to 10 weeks after the occurrence of chancres and consists of diffuse eruptions on skin and mucous membrane. This rash may be accompanied by swollen lymph nodes throughout the body, a sore throat, weight loss, malaise, headache and loss of hair. The secondary stage can also damage the eyes, liver, kidneys and other organs.
  33.  The tertiary-stage lesions may not appear for several years to decades after the onset of the disease. In this stage of osteomyelitis, the bone, skin, mucous membrane, and liver show gummatous destruction which is a soft, gummy tumor that resembles granulation tissue. Paralysis and dementia can also occur. In the oral cavity, the hard palate is frequently involved resulting in its perforation. The gummatous destruction is painless. Syphilitic osteomyelitis of the jaws is difficult to distinguish from chronic suppurative osteomyelitis since their radiographic appearances are similar.
  34.  ACTINOMYCOTIC OSTEOMYELITIS  Like tuberculosis and syphilis, actinomycosis is a chronic granulomatous disease. It can occur anywhere in the body, but two-thirds of all cases occur in the cervicofacial region. The disease is caused by bacteria-like fungus called Actinomyces israeli. These microorganisms occur as normal flora of the oral cavity, and appear to become pathogenic only after entrance through previously seated defects.
  35.  The portal of entry for the microorganisms is either through the socket of an extracted tooth, a traumatized mucous membrane, a periodontal pocket, the pulp of a carious tooth or a fracture. In cervicofacial actinomycosis, the patient exhibits swelling, pain, fever and trismus. The lesion may remain localized in the soft tissues or invade the jaw bones. If the lesion progresses slowly, little suppuration takes place; however, if it breaks down, abscesses are formed that discharge pus containing yellow granules