• Pioneer Bacteria: S. mutans are considered pioneer bacteria as they multiply and synthesize extracellular matrix polymers, initiating biofilm formation.

• Caries Progression - Key Bacteria:

  • Initiation of caries: S. mutans.

  • Progression of caries / Dentinal caries: Lactobacillus.

  • Root surface caries: Actinomycetes.

• Body of the Lesion (Enamel Caries): Shows increased prominence of the striae of Retzius.

• Sugar Intake: Frequency of sugar intake is of more importance than the total amount consumed in caries development.

• Actinomycosis (Sulfur Granules):

  • Yellow sulfur granules: Are actually bacterial colonies.

  • Histopathology: Colonies appear "cotton wool" shaped. (Note: "Cotton wool appearance" is seen radiographically in Paget's disease).

• Tuberculosis (TB):

  • Diagnosis (Gold Standard): Presence of acid-fast bacilli in sputum.

  • Staining Method: Ziehl-Neelsen staining method is used to identify acid-fast bacilli.

  • Scrofula: TB of cervical lymph nodes.

  • Lupus Vulgaris: TB of skin.

• Tongue & Gingival Appearance in Systemic Conditions:

  • Strawberry tongue and Raspberry tongue: Seen in stomatitis of Scarlet Fever.

  • Strawberry Gingivitis: Seen in Wegener's Granulomatosis.

Bacterial & Fungal Infections

Syphilis - Congenital

Hutchinson's Triad:

1. Mulberry molars & peg-shaped incisors
2. VIII nerve deafness
3. Interstitial keratitis

Higoumenaki Sign: Thickened sternoclavicular joint

Rhinoscleroma

• Also Called: Hebra nose

Sarcoidosis

• Diagnostic Test: Kveim–Siltzbach
• Histology: Schaumann bodies

Candidiasis

• Id Reaction: Hypersensitivity to Candida antigen
• Chairside Diagnosis: Wet smear in 10% KOH

• SLE → IgG, IgM, IgA deposits at BMZ + superficial lamina propria
• Lichen Planus (Erosive/Atrophic) → Autoimmune T-cell; BMZ involvement
• Cicatricial Pemphigoid → Subepidermal blistering from anti-BMZ antibodies

• Inverted Pear-shaped Radiolucency: Globulomaxillary cyst.

  • Associated teeth need not be non-vital.

  • Klestadts’s cyst: Soft tissue variant of Globulomaxillary cyst.

• Tear Drop-shaped Radiolucency: Lateral Periodontal Cyst.

  • Associated teeth are vital.

• Cluster of Similar Cysts / Cluster of Grapes: Botryoid Odontogenic Cyst.

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