Osteomyelitis Flashcards
Explain what causes osteomyelitis
- Bacteria enter bone canaliculi. This causes necrosis of osteocyte/ bone
- PMNs & other antimicrobials are unable to penetrate into osteocyte canaliculi or lacunae because it’s so small
- Constant re-infection of tissue from infected necrotic bone
- The body responds with bone resorption and the formation of granulation tissue to reach/ destroy the bacteria
List the types of osteomyelitis (5)
- Acute suppurative osteomyelitis
- Chronic suppurative osteomyelitis
- Focal sclerosing osteomyelitis
- Garre’s osteomyelitis
- Medication related osteomyelitis
Explain what acute suppurative osteomyelitis is, and state its causes
Explanation:
• Involves acute inflammation of the bone and bone marrow
• Mainly in mandible
Causes:
• When it occurs orally, it is most commonly due to a periapical abscess
• It may also follow fracture of the bone or surgery
State the histopathological features for acute suppurative osteomyelitis
- Loss of osteocytes from lacunae -> indicates nonviable bone
- Peripheral resorption
- Acute inflammatory cell infiltrate
- Bacterial colonies in marrow spaces
State the clinical and radiographic features of acute suppurative osteomyelitis
Clinical signs: • It is suppurative • Pain • Decreased ROM/ trismus • Dysphagia
Radiographic signs:
• Irregular radiolucencies “moth eaten”, but otherwise hard to see because it is acute
Explain the cause of chronic suppurative osteomyelitis, and state 6 possible sources.
• The primary cause of chronic osteomyelitis is usually microbiologic.
Sources can be: • Odontogenic infection • Post extraction complication • Inadequate removal of necrotic bone • Trauma • Inadequate treatment for fracture • Irradiation to the mandible
List the histological features of chronic suppurative osteomyelitis
- Inflamed connective tissue filling intra- trabecular areas
- Pockets of abscess
- Dense fibrous tissue with inflammatory cells
List the clinical features of chronic suppurative osteomyelitis
- Local pain
- Fever
- Swelling
- Purulent discharge
- Intraoral and skin fistula
- Unhealed soft tissue in the oral cavity
- Neuropalsy in the involved area
- Pathologic fracture
- Trismus
List the radiographic features of chronic suppurative osteomyelitis
- Radiolucent areas
- Bony destruction
- Sequestrum formation (diffuse, irregular radiolucency that eventually becomes radiopaque as bone forms within the chronically inflamed tissue)
Explain the pathogenesis of focal sclerosing osteomyelitis and state the most commonly affected tooth
- Chronic intraosseous bacteria causes an internal layer of chronic inflammatory cell build up
- Most affected tooth is mandibular first molar
For focal sclerosing osteomyelitis, list:
- Histological features
- Clinical features
- Radiographic features
Histopathological features:
• Dense bone with little marrow or connective tissue
• Usually no / minimal inflammation
Clinical signs:
• Asymptomatic, most lesions are discovered on routine radiographic examination
Radiographic signs:
• Radiopaque area in the periapical area of teeth
• Borders may be diffuse or well defined
For Garre’s osteomyelitis, state who it affects and what it is associated with.
Who it affects and what it is associated with:
• Type of chronicosteomyelitis
• Mainly affects children and young adults, which may be due to dental caries
List the histopathological features of Garre’s osteomyelitis
- Trabeculae of bone and osteoid tissue are surrounded by fibrous connective tissue
- Osteoblasts border many trabeculae
- Fibrous tissue has chronic inflammatory infiltrate
- Numerous blood capillaries are discernible
List the clinical and radiographic features of Garre’s osteomyelitis
Clinical features:
• Periosteum is thickened with peripheral reactive bone formation
• Hard swelling of lower jaw with little or no pain
• Facial asymmetry
• It is non- suppurating
• Usually in mandible
Radiographic features:
• Laminated periosteal thickening
Explain the pathogenesis of medication related osteomyelitis (MRONJ), and state the 5 possible theories
General:
• Adverse drug reaction which causes progressive bone destruction in the maxillofacial region
• Due to antiresorptive and antiangiogenic medications
Theories:
1. Inhibition of osteoclastic bone resorption and remodeling:
• Antiresorptive drugs inhibit osteoclast differentiation and function and increase apoptosis, all leading to decreased bone resorption and remodeling
- Inflammation and infection:
• Early studies identified Actinomyces bacteria, in specimens of necrotic bone from patients with ONJ - Inhibition of angiogenesis:
• Osteonecrosis may be due to interruptions in vascular supply - Soft Tissue Toxicity:
• Multiple cell types have exhibited increased apoptosis or decreased proliferation after exposure to bisphosphonate medications in vitro - Immune Dysfunction
