NEET MDS Lessons
Oral Pathology
-
Schilling Test: Done to identify the deficiency of either extrinsic (dietary vitamin B12) or intrinsic factor involved in Pernicious Anemia.
-
Fanconi's Syndrome: Associated with Aplastic Anemia.
-
"Safety-Pin" Cells: Characteristic finding in Thalassemia / Erythroblastic Anemia.
-
Radiographic Features of Anemias:
-
"Salt and Pepper" effect (Intraoral Periapical Radiograph): Found in Cooley's Anemia (Thalassemia) and Sickle Cell Anemia.
-
"Hair-on-End" pattern (Skull Radiograph): Found in Thalassemia, Sickle Cell Anemia, Congenital Hemolytic Jaundice, Chronic Iron Deficiency Anemia.
-
-
"Rh Hump" (Erythroblastosis Fetalis): Describes a ring-like defect.
-
Plummer-Vinson Syndrome: Associated with Iron Deficiency Anemia.
-
Chediak-Higashi Syndrome: Giant abnormal PAS positive granules found in peripheral circulating leukocytes are basically altered lysosomes.
-
Philadelphia Chromosome: Translocation of chromosomal material from chromosome 22 to chromosome 9; found in Chronic Myeloid Leukemia (CML).
-
Pulp Polyp (Chronic Hyperplastic Pulpitis):
-
Source of epithelium: Implantation of desquamated cells from saliva or by implantation from oral mucosa due to continuous rubbing.
-
Most common teeth: Deciduous molars and permanent first molars.
-
-
Periapical Granuloma: Always associated with a non-vital tooth.
-
Garre's Osteomyelitis: Another name for Chronic Osteomyelitis with Proliferative Periostitis.
| 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
-
Gingivitis - Immune Cells: Neutrophils are the predominant immune cells present in the first stage of gingivitis.
-
Acute Necrotizing Ulcerative Gingivitis (ANUG): Involved papillae show punched out, crater-like necrotic areas covered by grayish pseudomembrane.
-
Drug-Induced Gingival Enlargement: Never seen in edentulous areas, as there is no plaque in these areas for the drug to interact with.
-
Papillon-Lefèvre Syndrome:
-
Cause: Mutation of the cathepsin C gene located on chromosome 11q14.
-
Result: Impaired chemotaxis and phagocytosis, leading to severe periodontitis and palmar/plantar hyperkeratosis.
-
Streptococcus mutans Mechanism
- Key Substrate: Sucrose
- Metabolic Pathway: Phosphorylation → Glycolysis → Lactic acid
- Enzymes:
- Invertase: Converts sucrose to glucose + fructose
- Glucosyltransferase (GTF): Forms sticky glucans
- Fructosyltransferase (FTF): Produces fructans
Actinomyces naeslundii
- Fimbriated surface → fuzzy texture
- Type 1 fimbriae: Bind tooth surfaces/collagen
- Type 2 fimbriae: Bind galactose/galactosamine (epithelial/bacterial targets)
-
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.
-
Median Rhomboid Glossitis: Etiology is controversial (developmental vs. fungal); if forced to choose, developmental.
-
Gilchrist's Disease: Another name for North American Blastomycosis.
-
Mucormycosis: More common in diabetic patients. Has a strong propensity to invade blood vessels.
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