📖 Oral Pathology
Classification of cysts of the orofacial region
Oral PathologyEpithelial cysts
Developmental odontogenic cysts
Odontogenic keratocyst
Dentigerous cyst (follicular cyst)
Eruption cyst
Lateral periodontal cyst
Gingival cyst of adults
Glandular odontogenic cyst (sialo-odontogenic)
Inflammatory odontogenic cysts
Radicular cyst (apical and lateral)
Residual cyst
Paradental cyst
Non-odontogenic cysts
Nasopalatine cyst
Nasolabial cyst
Non-epithelial cysts (not true cysts)
Solitary bone cyst
Aneurysmal bone cyst
Garre’s Osteomyelitis
Oral PathologyGarre’s Osteomyelitis (Chronic Osteomyelitis with Proliferative Perosteitis)
- Chronic Non Suppurative Sclerosing Osteitis/ Periostitis Ossificans.
- Non suppurative productive disease characterized by a hard swelling.
- Occurs due to low grade infection and irritation
- The infectious agent localizes in or beneath the periosteal covering of the cortex & spreads only slightly into the interior of the bone.
- Occurs primarily in young persons who possess great osteogenic activity of the periosteum.
Clinical Features
- Uncommonly encountered, described in tibia and in the head and neck region, in the mandible.
- Typically involves the posterior mandible & is usually unilateral.
- Patients present with an asymptomatic bony, hard swelling with normal appearing overlying skin and mucosa.
- On occasion slight tenderness may be noted
- pain is most constant feature
- The increase in the mass of bone may be due to mild toxic stimulation of periosteal osteoblasts by attenuated infection.
Radiographic features
- Laminations vary from 1 – 12 in number, radiolucent separations often are present between new bone and original cortex. (“onion skin appearance”)
- Trabeculae parallel to laminations may also be present.
Histologic Features
- Reactive new bone.
- Parallel rows of highly cellular & reactive woven bone in which the individual trabeculae are oriented perpendicular to surface.
- Osteoblasts predominate in this area.
D/D for Garre’s Osteomyelitis
- Ewing's sarcoma
- Caffey’s disease
- Fibrous dysplasia
- Osteosarcoma
Treatment
- Removal of the offending cause.
- Once inflammation resolves, layers of the bone consolidate in 6 – 12 months, as the overlying muscle helps to remodel.
- If no focus of infection evident, biopsy recommended.
Non-epithelial cysts
Oral PathologyNon-epithelial cysts (not true cysts)
Solitary bone cyst
Radiology
The solitary bone cyst appears as a well-defined but non-corticated radiolucency. Typically, it has little effect
on adjacent structures and 'arches' up between the roots of teeth .
The inferior dental canal may not be displaced, but the cortical margins of the canal may be lost where it overlies the lesion. Expansion is rare.
Pathology
The cyst is lined by fibrovascular tissue that often includes haemosiderin and multinucleate giant cells.
Aneurysmal bone cyst
Radiology
The aneurysmal bone cyst typically presents as a fairly well-defined radiolucency. Sometimes it has a multilocular appearance because of the occurrence of internal bony septa and opacification. Marked expansion is a feature.
Pathology
The predominant feature of an aneurysmal bone cyst is the presence of blood-filled spaces of variable size lying in a stroma rich in fibroblasts, multinucleate giant cells and haemosiderin. Deposits of osteoid are also seen
Osteomyelitis
Oral PathologyOsteomyelitis
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