NEET MDS Lessons
Oral Pathology
Infective osteomyelitis
- Tuberculous osteomyelitis
- Syphilitic osteomyelitis
- Actinomycotic osteomyelitis
Tuberculous osteomyelitis
- Non healing sinus tract formation
- Age group affected is around 15 – 40 years.
- Commonly seen in phalanges and dorsal and lumbar vertebrae.
- Usually occurs secondary to tuberculosis of lungs.
- Cases have been reported where mandibular lesions were not associated with pulmonary disease.
- Another common entrance is through a carious tooth via open pulp.
- Usually affects long bones and rare in jaws.
- Results when blood borne bacilli lodge in cancellous bone. Usually in ramus , body of mandible. may mimic parotid swelling or submassetric abscess.
Syphilitic osteomyelitis
- Difficult to distinguish syphilitic osteomyelitis of the jaws from pyogenic osteomyelitis on clinical & radiographic examination.
- Main features are progressive course & failure to improve with usual treatment for pyogenic osteomyelitis.
- Massive sequestration may occur resulting in pathologic fracture.
- If unchecked, eventually causes perforation of the cortex.
Actinomycotic Osteomyelitis
- The organisms thrive in the oral cavity, especially tissues adjacent to mandible.
- May enter the bone through a fresh wound, carious tooth or a periodontal pocket at the gingival margin of erupting tooth.
- Soft or firm tissue masses on skin, which have purplish, dark red, oily areas with occasional zones of fluctuation.
- Spontaneous drainage of serous fluid containing granular material.
- Regional lymph nodes occasionally enlarged.
- Mimics parotitis / parotid tumors
Osteomyelitis
Osteomyelitis is an extensive inflammation of a bone. It involves the cancellous portion, bone marrow, cortex, and periosteum
Conditions that alter HOST IMMUNITY
Leukemia, Severe anemia, Malnutrition, AIDS, IV- drug abuse, Chronic alcoholism, Febrile illnesses, Malignancy, Autoimmune disease, Diabetes mellitus, Arthritis, Agranulocytosis
Conditions that alter vascularity of bone
Osteoporosis, Paget’s disease, Fibrous dysplasia, Bone malignancy, Radiation, Virulence of the organisms
Certain organisms precipitate thrombi formation by virtue of their destructive lysosomal enzymes.
Organisms proliferate in enriched host medium while protected from host immunity.
Etiology
- Odontogenic infections
- Trauma
- Infections of oro facial region
- Infections derived from hematogenous route
- Compound fractures of the jaws.
PATHOGENESIS
DEV . OF INFECTION --> BACTERIAL INVASION --> PUS FORMATION --> SPREAD OF INFECTION --> INCREASED INTRAMEDULLARY PRESSURE , BLOOD FLOW , OSTEOCLASTIC ACTIVITY --> INFLAMMATORY RESPONSES --> INCREASED PERIOSTEAL PRESSURE --> PROCESS BECOMES CHRONIC GRANULATION TISSUE FORMATION --> LYSIS OF BONE --> SEQUESTRUM FORMATION
Classification
Classification based on clinical picture, radiology, and etiology
Suppurative osteomyelitis
I. Acute suppurative osteomyelitis
II. Chronic suppurative osteomyelitis
– Primary chronic suppurative osteomyelitis
– Secondary chronic suppurative osteomyelitis
III. Infantile osteomyelitis
Nonsuppurative osteomyelitis
I. Chronic sclerosing osteomyelitis
– Focal sclerosing osteomyelitis
– Diffuse sclerosing osteomyelitis
II. Garre's sclerosing osteomyelitis
III. Actinomycotic osteomyelitis
IV. Radiation osteomyelitis and necrosis