NEET MDS Lessons
Oral Pathology
Acute suppurative osteomyelitis
- Serious sequela of periapical infection.
- Leads to spread of pus through the medullary cavities of bone.
- Depending upon the main site of involvement of bone, can be of two types-
- Acute intramedullary
- Acute subperiosteal
Acute Intramedullary Osteomyelitis
CLINICAL FEATURES:
- Patient experiences dull , continuous pain , indurated swelling forms over the affected region of jaw involving the cheek , febrile.
- When mandible involved, loss of sensation occurs on lower lip on affected side due to involvement of inferior alveolar nerve.
- Teeth become loose later along with tender on percussion
- Pus discharge , trismus , foul smell , regional lymphadenopathy , weakness
RADIOGRAPHIC FEATURES
- Earliest radiographic change is that trabeculae in involved area are thin, of poor density & slightly blurred.
- Subsequently multiple radiolucencies appear which become apparent on radiograph.
- In some cases there is saucer shaped area of destruction with irregular margins.
- Loss of continuity of lamina dura, seen in more than one tooth.
HISTOLOGIC FEATURES:
- Dense infiltration of marrow by polymorphonuclear leukocytes.
- Bone trabeculae in involved site (sequestrum) are devoid of cells in the lacunae.
- separation of considerable portions of devitalized bone.
Acute Subperiosteal Osteomyelitis
CLINICAL FEATURES
- Pain , febrile condition , i/o and e/o swelling , parasthesia
- Bone involvement limited to localized areas of cortex.
- Pus ruptures rapidly through the overlying cortex, tracks along the surface of mandible under the periosteal sheath.
- Elevation of periosteum from cortex is followed eventually by minute cortical sequestration.
General Features
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Caused by mutation in DSPP gene (dentin sialophosphoprotein).
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Teeth appear translucent or opalescent.
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Enamel fractures easily due to poor dentin support.
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Pulp chambers are obliterated or enlarged depending on type.
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Also called Hereditary Opalescent Dentin or Shell Teeth.
Type II DI
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Pulp chambers are normal but rapidly obliterate.
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Associated with progressive hearing loss.
Type III DI
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Pulp chambers are large and shell-like.
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Seen in Brandywine isolate population.
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Lichen Planus:
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Reticular form: Most common type, characterized by Wickham's striae.
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Malignant potential: Atrophic and erosive forms are associated with significant malignant transformation risk.
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Histology: Saw-tooth shaped rete pegs.
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Solar Elastosis: Characterized clinically by "sailor's skin" or "farmer's skin" (due to chronic sun exposure).
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Psoriasis & Hereditary Gingival Fibromatosis: Both show test tube-shaped rete pegs histologically.
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LE Cell Test: LE cells represent rosettes of neutrophils that have phagocytosed other leukocytes (seen in Systemic Lupus Erythematosus).
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Tzanck Cells: Seen in vesiculobullous conditions like Pemphigus, Herpes Simplex, Varicella, Herpes Zoster, and CMV infection.
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Ectodermal Dysplasia: Characterized by truncated, conical teeth and missing teeth (hypodontia).
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Widened Periodontal Ligament Space: Extreme widening seen in Scleroderma and Osteosarcoma.
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Geographic Tongue & Psoriasis: Share a common histological feature: Munro's abscesses (neutrophilic microabscesses).
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Hyperplastic Candidiasis: The only form of candidiasis that is non-scrapable. Often appears as admixed white and red areas, known as speckled leukoplakia or erythroleukoplakia.
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Median Rhomboid Glossitis: Etiology is controversial (developmental vs. fungal); if forced to choose, developmental.
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Gilchrist's Disease: Another name for North American Blastomycosis.
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Mucormycosis: More common in diabetic patients. Has a strong propensity to invade blood vessels.
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Blood: Aneurysmal bone cyst, Vascular lesion, Vessel puncture.
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Air: Traumatic bony cyst (Simple Bone Cyst/Hemorrhagic Bone Cyst), Maxillary sinus.
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Chocolate Colored Fluid: Warthin's Tumor (salivary gland cyst).
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Zone 1 – Normal Dentin:
Healthy tissue; no treatment needed -
Zone 2 – Subtransparent Dentin:
Acid-demineralized, no bacteria, remineralizable; preserve -
Zone 3 – Transparent Dentin:
Softened, no bacterial invasion; remineralizable; preserve -
Zone 4 – Turbid Dentin:
Bacterial invasion; not remineralizable; must be removed -
Zone 5 – Infected Dentin:
Fully decomposed; heavily infected; must be removed
Macroglossia
- Feature: Crenated (scalloped) lateral tongue borders
Lymphangioma of Tongue
- Appearance: Tapioca pudding/Frog's egg
Geographic Tongue
- Associated With: Fissured tongue
- Histopathology: Similar to psoriasis
- Key Feature: Munro's abscesses
Median Rhomboid Glossitis
- Unique Sign: "Kissing lesion" on soft palate due to tongue contact
Hairy Tongue
- Misnomer: Elongated filiform papillae—not actual hair