Lec 5 - Osteomyelitis Lecture Notes PDF

Field of Dentistry Oral Pathology I Lecture : (Osteomyelitis) Dr : (Mohamed Hussein Amer) Date : 6 /11 /2024  Osteomyelitis Osteon = Bone Inflammation of bone and bone marrow due to infection by bacteria Muelinos = Bone marrow...

Field of Dentistry Oral Pathology I Lecture : (Osteomyelitis) Dr : (Mohamed Hussein Amer) Date : 6 /11 /2024  Osteomyelitis Osteon = Bone Inflammation of bone and bone marrow due to infection by bacteria Muelinos = Bone marrow Acute Itis= inflammation Chronic Etiology: Abscess Infected cyst Dry socket Forceful extraction Compound fracture of jaw Maxillofacial injury Radiation Uncontrolled diabetes Malnutrition  1- Suppurative (destructive) →Acute →Chronic 2- Sclerosing (healing or regenerating) Osteomyelitis → Focal →Diffuse 3- Garre’s osteomyelitis (Chronic osteomyelitis with proliferative periostitis)  Predisposing factors Chronic systemic diseases (Diabetes) Decreased immnunity: acquired immunodeficiency, leukemia, prolonged high dose of corticosteroid) Disorders causing decreased vascularity of bone (Paget’s disease, osteopetrosis, sickle cell anemia, irradiation)  Acute suppurative osteomyelitis Causative organisms: → staph aureus (most common) → streptococci and anaerobic bateroids (less common) Clinically: →The patient complains of fever, lymphadenopathy, swelling.  Pathogenesis: Microorganism excit inflammation in medullary bone, resulting in edema and exudation Pus is forced under pressure in medullary bone, resulting in thrombosis of arteries present inside bone (i.e. inferior alveolar artery) Decrease blood supply necrosis Later, pus penetrate the cortex to drain via sinuses in skin or mucosa  Pathogenesis: ⦿SEQUESTRUM fragment of necrotic bone separates from the adjacent vital bone and is spontaneously discharged or remain to cause more infection ⦿ INVOLUCRUM Necrotic bone fragment surrounded by lay down new bone  Acute suppurative osteomyelitis An adult diabetic male patient came to the clinic with a painful soft tissue swelling after extraction of a third molar. The overlying skin is erythematous and warm. He also suffers from fever and lymphadenopathy.  Acute suppurative osteomyelitis Radiographically: Radiographic changes do not appear usually before one or two weeks, as a diffuse ill-defined radiolucency  Acute suppurative osteomyelitis Histological features: ⦿ Necroticbone shows a loss of osteocytes from their lacunae, peripheral resorption and bacterial colonization. ⦿ Theperiphery of the bone and the Haversian canals contain necrotic debris and an acute inflammatory infiltrate [polymorphnuclear leukocytes]  Acute suppurative osteomyelitis U/M: Necrotic bone shows loss of osteocytes leaving empty lacunae, peripheral resorption and surrounding acute inflammatory cell infiltrate also can be seen.  Chronic suppurative osteomyelitis ⦿ This type exists when the defensive response leads to the production of granulation tissue, which subsequently forms dense scar tissue in an attempt to wall off the infected area. ⦿ Radiographically: Mottled (moth-eaten) appearance, of patchy ill-defined radiolucency, with central radiopaque sequestra.  Chronic suppurative osteomyelitis U/M: Chronically inflamed fibrous C.T filling the intertrabecular spaces of bone. Scattered sequestra are present. Focal sclerosing osteomyelitis (Condensing osteitis) Or (Bony scar)  Focal sclerosing osteomyelitis Means focal bone reaction to a low-grade inflammatory stimulus. An area of bone sclerosis associated with the apices of non-vital teeth with large carious lesion (usually lower premolar/molar area). Mostly in children or young adults (