NEET MDS Lessons
Oral Pathology
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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).
Gemination
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Attempted division of a single tooth germ before calcification.
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Results in two crowns (complete/incomplete) with one root and canal.
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Tooth count remains normal.
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Difficult to differentiate from fusion with a supernumerary tooth.
Twinning
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Complete division of a single tooth germ.
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Results in one normal + one supernumerary tooth.
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Tooth count is more than normal.
Fusion
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Union of two separate tooth germs.
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If before calcification → single large tooth.
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If after calcification → roots fused, crowns may be separate.
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More common in deciduous teeth.
Concrescence
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Union by cementum only.
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Occurs after root formation.
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Common in maxillary molars.
Leukoplakia
- Type: Clinical term
- Histology: Hyperkeratosis ± Dysplasia
Verrucous Carcinoma
- Type: Variant of SCC
- Features:
- Intact basement membrane
- Parakeratin plugging
- Broad "elephant-foot" rete ridges
Adenosquamous Carcinoma
- Features: Mixed adenocarcinoma + SCC
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
| Disease | Serum Marker Changes |
|---|---|
| Paget’s Disease | ↑ Alkaline phosphatase |
| Caffey’s Disease | Fibrous dysplasia; may show ↑ alkaline phosphatase |
| Hyperparathyroidism | ↑ Alkaline phosphatase |
| Osteopetrosis (Marble Bone Disease) | ↑ Acid phosphatase |
| Osteogenesis Imperfecta | Normal calcium & phosphate; ↑ bone fragility due to collagen defect |
| Chondrodysplasia | Normal alkaline phosphatase |
| Odontogenic Myxoma | ↑ Acid phosphatase |
| Thalassemia | Prominent premaxilla; marrow expansion may affect jaw bones |
Exception Alert: Serum alkaline phosphatase is raised in all of the following except: ➡️ Osteogenesis Imperfecta
📝 QUICK MEMORY AIDS
- "Paget's Patients Prefer Tight Dentures" - Paget's disease causes denture tightening
- "Fibrous Faces Feel Funny" - Fibrous dysplasia features (leontiasis, Chinese script, ground glass, hockey stick)
- "Giant Cells Have Three Homes" - Hyperparathyroidism, Cherubism, Central Giant Cell Granuloma
⚡ HIGH-YIELD FACTS
- Chalk-stick fractures: Paget's disease & Osteopetrosis
- Leontiasis ossea: Paget's, Fibrous dysplasia, Cemento-ossifying fibroma
- Chinese script pattern: Fibrous dysplasia & COF
- Ground glass appearance: Fibrous dysplasia & Hyperparathyroidism
- Giant cells + vascular stroma + hemosiderin: Hyperparathyroidism, Cherubism, CGCG
- Triads to remember: Hutchinson's, Melkersson-Rosenthal, Ascher syndrome
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.