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)

• Café au Lait Spots:

  • "Coast of California": Associated with Neurofibromatosis (Type 1).

  • "Coast of Maine": Associated with Fibrous Dysplasia.

• Carpet Tack Lesions: Characteristic of Discoid Lupus Erythematosus.

• Cerebriform Tongue: Seen in Pemphigus Vegetans.

• Charcot's Triad: Seen in Multiple Sclerosis, characterized by:

  • Intention tremor

  • Nystagmus

  • Dysarthria

• Chipmunk Facies: Seen in Thalassemia.

• Chvostek's Sign: Indicative of Hypoparathyroidism (facial muscle twitching upon tapping the facial nerve).

• Buffalo Hump: A characteristic clinical sign of Cushing's Syndrome (fat pad on the upper back).

• Rapid drop in plaque pH after sugar
• Critical pH for enamel demineralization: ~5.5
• Caries-prone individuals:
  • Lower plaque pH
  • Higher Lactobacillus counts

Research Highlights

• Stephan: Rapid pH drop post-carbohydrates
• Caries-free pH: ~7.1
• Caries-active pH: ~5.5
• Maxillary anterior teeth: Greater drop than mandibular
• Stratfors: Lower pH ↔ higher Lactobacillus; plaque buffers better than saliva

• Lichen Planus:

  • Reticular form: Most common type, characterized by Wickham's striae.

  • Malignant potential: Atrophic and erosive forms are associated with significant malignant transformation risk.

  • Histology: Saw-tooth shaped rete pegs.

• Solar Elastosis: Characterized clinically by "sailor's skin" or "farmer's skin" (due to chronic sun exposure).

• Psoriasis & Hereditary Gingival Fibromatosis: Both show test tube-shaped rete pegs histologically.

• LE Cell Test: LE cells represent rosettes of neutrophils that have phagocytosed other leukocytes (seen in Systemic Lupus Erythematosus).

• Tzanck Cells: Seen in vesiculobullous conditions like Pemphigus, Herpes Simplex, Varicella, Herpes Zoster, and CMV infection.

• Ectodermal Dysplasia: Characterized by truncated, conical teeth and missing teeth (hypodontia).

• Widened Periodontal Ligament Space: Extreme widening seen in Scleroderma and Osteosarcoma.

• Geographic Tongue & Psoriasis: Share a common histological feature: Munro's abscesses (neutrophilic microabscesses).

1. Nasopalatine cyst is the most common non-odontogenic cyst
2. Globulomaxillary cyst entity is controversial - many consider it a variant of lateral periodontal cyst
3. Median mandibular cyst is extremely rare - always consider other diagnoses first
4. Nasolabial cyst is the only one with no radiographic features
5. All these cysts are developmental in origin

Quick Facts for MCQs:

• Oval + Maxillary midline = Nasopalatine cyst
• Pear-shaped + Between teeth = Globulomaxillary cyst
• Soft tissue swelling + No X-ray changes = Nasolabial cyst
• Mandibular midline + Rare = Median mandibular cyst

MEMORY AIDS

"NASAL" for Nasopalatine Cyst:

• Non-odontogenic (most common)
• Anterior maxilla
• Spacing of centrals
• Above/between central incisors
• Location: incisive canal

"PEAR" for Globulomaxillary:

• Pear-shaped (inverted)
• Enlarges slowly
• Adjacent to lateral incisor & canine
• Root divergence

"SOFT" for Nasolabial:

• Soft tissue cyst
• Obstruction of nose
• Fold involvement (nasolabial)
• Tissue only (no bone involvement)

• Stevens-Johnson Syndrome (SJS):

  • Characterized by ulcers with hemorrhagic crusts.

  • Typically has an acute onset following drug exposure (mainly sulfa group drugs).

• Biopsy for Vesiculobullous Pathology: Should be taken from the margin of the vesicle/bulla, including a significant amount of normal-appearing mucosa, to capture the pathological changes and adjacent healthy tissue for comparison.

• Linea Alba: A white, bilateral line on the buccal mucosa associated with pressure, frictional irritation, or sucking trauma from the facial surface of teeth.

• Morsicatio Buccarum: Chronic irritation seen on the buccal mucosa as a result of suction and glassblowers (chewing habits).

• Riga-Fede Disease: Sublingual ulcerations in infants resulting from chronic mucosal trauma from adjacent primary teeth (often natal/neonatal teeth).