Shape Recognition (Classic Boards Question)

• Heart/Oval Shape → Nasopalatine cyst
• Inverted Pear/Teardrop → Globulomaxillary cyst
• No Radiographic Feature → Nasolabial cyst

Location-Based Diagnosis

• Midline Maxilla (anterior) → Nasopalatine cyst
• Between maxillary lateral incisor & canine → Globulomaxillary cyst
• Midline Mandible → Median mandibular cyst
• Nasolabial fold → Nasolabial cyst

Clinical Correlations

• Spacing between centrals → Nasopalatine cyst
• Root divergence → Globulomaxillary cyst
• Nasal obstruction → Nasolabial cyst
• Usually asymptomatic → Median mandibular cyst

DIFFERENTIAL DIAGNOSIS PEARLS

For Midline Radiolucencies:

1. Nasopalatine cyst - Oval/heart shape, above centrals
2. Median palatine cyst - Posterior to nasopalatine
3. Central giant cell granuloma - More aggressive, may show septations

For Interradicular Radiolucencies:

1. Globulomaxillary cyst - Classic pear shape
2. Lateral periodontal cyst - More cervical location
3. Radicular cyst - Associated with non-vital tooth

• 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).

 Benign Migratory Glossitis

• Also called Erythema migrans, wandering rash, or geographic tongue.

• Associated with fissured tongue.

Fissured Tongue

• Seen in:

  • Melkersson-Rosenthal syndrome

  • Down syndrome

  • Benign migratory glossitis

Melkersson-Rosenthal Syndrome

• Triad:

  • Bell’s palsy

  • Cheilitis granulomatosa (lip/facial swelling)

  • Fissured tongue

Ankyloglossia

• Tongue-tie may cause speech defects.

• Affects articulation of: l, r, t, d, n, th, sh, z

Paget's Disease

• Chief Complaint: Denture tightening (due to arch expansion)
• Fractures: Chalk-stick fractures
• Facial Feature: Leontiasis ossea (lion-like facies)
• Radiology: Cotton wool appearance
• Histology: Jigsaw puzzle pattern
• Clinical: Bone warm to touch (↑ vascularity)
• Laboratory: ↑ Alkaline phosphatase (>250 Bodansky units)
• Other Signs: Osteoporosis circumscripta, platybasia
• Memory Aid: "Paget's Patients Prefer Tight Dentures"

Osteopetrosis

• Radiographic Sign: Rugger Jersey Spine (classic)
• Fractures: Chalk-stick fractures

Fibrous Dysplasia

• Facial Feature: Leontiasis ossea
• Histology: Chinese script pattern
• Radiology:
  • Ground glass appearance
  • Rind sign, orange peel appearance
• Bone Deformity: Hockey stick/Shepherd's crook deformity (femur)
• Key Feature: Lesional bone fused with normal bone (vs COF)
• Memory Aid: "Fibrous Faces Feel Funny"

Cemento-Ossifying Fibroma (COF)

• Histology: Chinese script pattern
• Facial Feature: Leontiasis ossea
• Difference: NOT fused with normal bone (vs Fibrous Dysplasia)

Hyperparathyroidism

• Radiology: Ground glass appearance (brown tumor)
• Histology: Numerous giant cells, vascular stroma, hemosiderin deposits

Cherubism & Central Giant Cell Granuloma

• Histology: Same as hyperparathyroidism (giant cells + vascular stroma + hemosiderin)
• Note: Cherubism previously called "Familial fibrous dysplasia"
• Memory Aid: "Giant Cells Have Three Homes" (Hyperparathyroidism, Cherubism, CGCG)

Juvenile Ossifying Fibroma

• Aggressiveness: More aggressive than Cemento-ossifying fibroma
• Types:
  • Trabecular type: Common in jaws
  • Psammomatoid type: Involves base of skull

• 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

 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)