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Information

Differential Diagnosis of Skull and Spine Disorders

Attenuation (lytic / sclerotic / mixed / ground-glass attenuation), margination (narrow / wide transition zone), and relationship to adjacent teeth determine the radiologic diagnosis of jaw lesions.

Maxillary Hypoplasia!!navigator!!

  1. Down syndrome
  2. Drugs (alcohol, dilantin, valproate)
  3. Apert / Crouzon syndrome
  4. Achondroplasia
  5. Cleft lip / palate

Mandibular Hypoplasia = Micrognathia!!navigator!!

  1. WITH ABNORMAL EARS
    1. Treacher-Collins syndrome
    2. Goldenhar syndrome (hemifacial microsomia) = facioauriculovertebral spectrum (x-rays of vertebrae!)
    3. Langer-Giedion syndrome (IUGR, protruding ears)
  2. ABNORMALITIES OF EARS + OTHER ORGANS
    1. Miller syndrome (severe postaxial hand anomalies)
    2. Velocardiofacial syndrome (hand + cardiac lesions)
    3. Otopalatodigital syndrome - type II (hand abnormalities)
    4. Stickler syndrome (ear anomalies not severe)
    5. Pierre-Robin syndrome (large fleshy ears)
  3. NO EAR ANOMALIES
    1. Pyknodysostosis
  4. OTHERS
    1. Seckel syndrome (bird-headed dwarfism)
    2. Multiple pterygium syndrome
    3. Pena-Shokeir syndrome
    4. Beckwith-Wiedemann syndrome
    5. Arthrogryposis
    6. Skeletal dysplasias
    7. Trisomy 13, 18, 9 (abnormal karyotype in 25%)

Destruction of Temporomandibular Joint!!navigator!!

mnemonic: HIRT

  • Hyperparathyroidism
  • Infection
  • Rheumatoid arthritis
  • Trauma

Mandibular Lesion by Location!!navigator!!

  1. ANTERIOR MANDIBLE
    1. Adenomatoid odontogenic tumor
    2. Periapical cemental dysplasia
    3. Florid cemento-osseous dysplasia
    4. Central giant cell granuloma
    5. Odontoma
  2. POSTERIOR MANDIBLE
    1. Follicular (dentigerous) cyst
    2. Odontogenic keratocyst
    3. Solitary bone cyst
    4. Ameloblastoma
    5. Cementoblastoma
    6. Ossifying fibroma
    7. Ameloblastic carcinoma
    8. Stafne cyst
    9. Metastasis
  3. Nonspecific location
    1. Periapical (radicular) cyst

Odontogenic Lesion Of Impacted 3rd Molar Tooth

  1. Dentigerous cyst (93%)
  2. Odontogenic keratocyst (7%)
  3. Ameloblastoma (0.41%)

Solid Benign Lesion of Jaw!!navigator!!

Primary Odontogenic Tumor of Jaw

  1. Odontoma
  2. Ameloblastoma = Adamantinoma of Jaw
  3. Odontogenic Myxoma
  4. Calcifying Epithelial Odontogenic Tumor
  5. Cementoblastoma
  6. Ameloblastic fibroma
  7. Adenomatoid odontogenic tumor

Primary Nonodontogenic Tumor of Jaw

  1. Ossifying fibroma
  2. Cemento-osseous dysplasia

Prevalence of Solid Benign Mandibular Lesions

  1. Most common
    1. Odontoma
  2. Fairly common
    1. Ameloblastoma
    2. Periapical cemento-osseous dysplasia
    3. Florid cemento-osseous dysplasia
    4. Ossifying fibroma
  3. Less common
    1. Calcifying epithelial odontogenic (Pindborg) tumor
    2. Ameloblastic fibroma
    3. Odontogenic myxoma
    4. Cementoblastoma
  4. Rare
    1. Adenomatoid odontogenic tumor
    2. Juvenile ossifying fibroma
    3. Clear cell odontogenic tumor
    4. Squamous odontogenic tumor
    5. Calcifying odontogenic cyst

Vascular Lesion of Jaw

  1. Central giant cell granuloma
  2. Brown tumor of hyperparathyroidism
  3. Arteriovenous Malformation of jaw

Solid Malignant Lesion of Jaw!!navigator!!

  1. Odontogenic Carcinoma
    = rare aggressive intraosseous lesion
    Histo: poorly differentiated epithelial + clear cells
    • diffuse honeycomb-like radiolucent lesion
    • surrounding cortical destruction
      Prognosis: high rate of recurrence
  2. Ameloblastic Carcinoma
    = malignant ameloblastoma
    • aggressive features of cortical destruction, extraosseous extension, extensive solid components
  3. Sarcoma
    Histo: osteo~, chondro~, fibro~, leiomyosarcoma
    • symmetrically widened periodontal membrane in a single tooth (earliest sign of osteogenic sarcoma of mandible)
  4. Mucoepidermoid Carcinoma
    • typically originate from minor salivary glands of buccal mucosa
  5. Lymphoma / leukemia
  6. Multiple Myeloma
    • may present with chin numbness ← involvement of inferior alveolar nerve

Prevalence of Solid Malignant Mandibular Lesions

  1. MOST COMMON
    1. Squamous cell carcinoma arising from adjacent mucosa
  2. FAIRLY COMMON
    1. Multiple myeloma, plasmacytoma
    2. Lymphoma, leukemia
    3. Metastasis
    4. Mucoepidermoid carcinoma arising from adjacent mucosa
    5. Adenoid cystic carcinoma arising from adjacent mucosa
  3. RARE
    1. Nonodontogenic sarcoma
    2. Odontogenic carcinoma
    3. Odontogenic sarcoma
    4. 4, Odontogenic carcinosarcoma

Sclerotic Lesion of Jaw!!navigator!!

Sclerotic Tooth-Related Jaw Lesion

  1. Cementoblastoma
  2. Cemento-osseous dysplasia
  3. Condensing osteitis
  4. Odontoma
  5. Idiopathic osteosclerosis
  6. Hypercementosis
    = bulbous enlargement of a root
    1. idiopathic
    2. associated with Paget disease

Sclerotic Non–Tooth-Related Jaw lesion

  1. Osteoma
  2. Torus = exostosis
  3. Benign fibro-osseous lesions
    1. Ossifying fibroma: young adult; mandible >maxilla
    2. Monostotic fibrous dysplasia: M <F; younger patient
    • near apex of nonvital tooth
  4. Paget disease involvement of jaw in 20%; maxilla >mandible
    Location: bilateral, symmetric involvement
    • widened alveolar ridges
    • flat palate
    • loosening of teeth
    • hypercementosis
    • may cause destruction of lamina dura
  5. Sclerosing metastasis / multiple myeloma

Jaw Lesion with Ground-glass Attenuation

  1. diffuse
    1. Renal osteodystrophy
    2. Fibrous dysplasia
  2. multifocal
    1. Florid cemento-osseous dysplasia
    2. Multiple ossifying fibromas
    3. Brown tumor of HPT
  3. unifocal jaw lesion with ground-glass attenuation
    1. Ossifying fibroma
      Path: osteoblastic rim
      • narrow zone of transition
    2. Monostotic fibrous dysplasia
      • wide zone of transition
      • longitudinal growth pattern
      • nondisplaced teeth

Periapical Sclerotic Lesion with Periapical Halo

  1. Cementoblastoma
  2. Cemento-osseous dysplasia

Mixed Lytic and Sclerotic Jaw Lesion

  1. Osteoradionecrosis
    Vulnerability: mandible >maxilla buccal >lingual cortex
    • Chin + angle of mandible spared ← muscle insertions
    • area of marked osteosclerosis
    • loss of trabeculation in spongiosa
    • cortical interruptions + fragmentation
    • poorly marginated areas of soft-tissue attenuation + fluid collections + gas attenuation
    • sequestration
  2. Biphosphonate-related osteonecrosis of jaw (BRONJ)
  3. Mandibular osteomyelitis
    Cause: caries, extractions, fracture, osteoradionecrosis
    • cortical interruption
    • sclerotic sequestra in low-attenuation zones
    • periosteal new bone formation
    • areas of gas attenuation
  4. Primary chronic osteomyelitis
    Age peak: childhood and >50 years
    • insidious jaw swelling, normal mucosa, vital teeth
    • absence of fever + leukocytosis
    • poorly marginated lesion with progressive sclerosis
    • scattered osteolysis + bone expansion
    • “onion skin” periosteal reaction

Radiolucent Lesion of Mandible!!navigator!!

Sharply Marginated Radiolucent Lesion of Mandible

  1. AROUND APEX OF TOOTH
    1. Radicular cyst
    2. Cementoma
  2. AROUND UNERUPTED TOOTH
    1. Dentigerous cyst
    2. Ameloblastoma
  3. UNRELATED TO TOOTH
    1. Simple bone cyst
    2. Fong disease
    3. Basal cell nevus syndrome

DDx:

  1. Early cemento-osseous dysplasia
  2. Early ossifying fibroma

Poorly Marginated Radiolucent Lesion of Mandible

  • “floating teeth”: suggestive of primary / secondary malignancy
  • resorption of tooth root: hallmark of benign process
  1. INFECTION
    Cause: mostly dental caries → irreversible pulpitis → periapical cyst → granuloma → abscess
    1. Apical periodontitis
      • thickened periodontal ligament space (earliest sign of the cystic form)
      • contrast-enhancing rim around abscess
    2. Osteomyelitis
      = infection of bone and marrow
      • focal / diffuse radiolucent / radiopaque lesion
  2. RADIOTHERAPY
    1. Osteoradionecrosis
      • scattered sclerotic + lytic lesion
      • enlarged trabecular spaces
      • sequestered bone
  3. MALIGNANT NEOPLASM
    1. Osteosarcoma (⅓ lytic, ⅓ sclerotic, ⅓ mixed)
    2. Local invasion from gingival / buccal neoplasms (more common)
    3. Metastasis from breast, lung, kidney in 1% (in 70% adenocarcinoma)
      location: posterior body and angle ← increased marrow vascularity
  4. OTHER
    1. Eosinophilic granuloma: “floating tooth”
    2. Fibrous dysplasia
    3. Osteocementoma
    4. Ossifying fibroma (very common)

Cystic Lesion of Jaw!!navigator!!

  1. Periapical cyst = Radicular cyst
    • Most common cyst of the jaw
      Cause: periapical inflammatory lesion ← pulpal necrosis in deep carious lesion / deep filling / trauma
      Age: 30–50 years
      Pathogenesis: secondary apical periodontitis → granuloma → abscess → cyst
      Site: intimately associated with apex of nonvital tooth
      • round / pear-shaped unilocular well-defined periapical lucent lesion, usually <1 cm in diameter
      • bordered by thin sclerotic rim of cortical bone
      • ± displacement of adjacent teeth
      • ± mild root resorption
        Cx: root canal therapy, tooth extraction, surgery (creation of mucoperiosteal flap over tooth apex)
        DDx: periapical granuloma, periapical abscess
    • Dentigerous cyst = follicular cyst
      • Most common type of noninflammatory developmental odontogenic cyst
        Path: epithelial-lined cyst from odontogenic epithelium developing around crown of an unerupted tooth
        Histo: fluid collection between follicular epithelium and crown of tooth
        Age: 30–40 years
      • typically painfree
        Location: mandible, maxilla (may expand into maxillary sinus)
        Site: around crown of unerupted tooth (usually 3rd molar)
      • expansile cystic pericoronal lesion containing the crown of an impacted tooth projecting into cystic cavity (PATHOGNOMONIC)
      • roots of tooth often outside lesion
      • well-defined round / ovoid corticated lucent lesion ± mandibular remodeling rather than expansion
        Cx: may degenerate into mural ameloblastoma (rare)
        DDx: unilocular odontogenic keratocyst
    • Odontogenic keratocyst (OKC)
      Origin: dental lamina + other sources of odontogenic epithelium
      Prevalence: 5–15% of all jaw cysts
      Age: 2nd–4th decade
      Associated with: basal cell nevus (Gorlin-Goltz) syndrome if OKC multiple
      Path: daughter cysts + nests of cystic epithelia in vicinity (high rate of recurrence)
      Histo: parakeratinized lining epithelium + “cheesy” material in lumen of lesion
      Location: body + ramus of mandible (most often); may be anywhere in mandible / maxilla
      • unilocular lucent lesion with smooth corticated border
      • often associated with impacted tooth
      • ± undulating borders / multilocular appearance (daughter cysts)
      • ± cortical thinning / erosion, tooth displacement, root resorption
        Prognosis: high recurrence rate after resection
        DDx: indistinguishable from dentigerous cyst (no cortical erosion or expansion) / ameloblastoma
    • Primordial cyst
      arising from follicle of tooth that never developed
      Cause: dental follicle undergoes cystic degeneration
      • well-defined radiolucent nonexpansile lesion
    • Stafne Cyst
      = STATIC BONE CAVITY = LINGUAL SALIVARY GLAND INCLUSION DEFECT
      = well-defined depression in lingual surface of mandible
      Path: cavity filled with fat ± aberrant submandibular gland tissue
      • asymptomatic
        Location: posterior mandible, usually near mandibular angle
        Site: just above inferior border of mandible, anterior to angle of jaw, inferior to mandibular canal, posterior to 3rd molar
      • oval / round / rectangular well-defined radiolucent lesion within cortical defect
      • typically <2 cm
      • border surrounded by an opaque line
      • may extend to buccal cortex
        DDx: arteriovenous malformation
    • Solitary bone cyst
      = TRAUMATIC BONE CYST = SIMPLE BONE CYST = HEMORRHAGIC BONE CYST
      = not a true cyst for lack of epithelial lining
      Pathogenesis: trauma → intramedullary hemorrhage → resorption
      Age: 2nd decade
      • asymptomatic
        Location: marrow space of posterior mandible
      • unilocular sharply marginated lucent defect
      • CHARACTERISTIC scalloped superior margin with fingerlike projections extending between roots of adjacent teeth
      • ± thinning of mandibular cortex ± osseous expansion
        DDx: vascular lesion, central giant cell granuloma, ossifying fibroma
    • Residual cyst
      = any cyst that remains after surgical intervention

Periapical Lucency

  1. Periapical cyst
  2. Periapical cemento-osseous dysplasia
  3. Hyperparathyroidism
  4. Langerhans cell histiocytosis
  5. Odontogenic keratocyst
  6. Leukemia / lymphoma

Prevalence of Cystic Mandibular Lesion of Jaw

  1. Most common
    1. Periapical (radicular) cyst
    2. Follicular (dentigerous) cyst)
  2. Fairly common
    1. Odontogenic keratocyst
    2. Stafne cyst
    3. Solitary bone cyst
  3. Rare
    1. Aneurysmal bone cyst
    2. Calcifying odontogenic cyst
  4. Lesions radiolucent ONLY early in their development
    Periapical inflammatory lesions are entirely radiolucent. So are early ossifying fibromas or early cemento-osseous dysplasia (the latter associated with a vital tooth + intact lamina dura ± central calcifications)
    1. Cemento-osseous dysplasia
    2. Ossifying fibroma (= pure osteoid matrix)

Unilocular Cystic Lesion of Jaw

  1. Radicular cyst: surrounding apex of infected tooth
  2. Dentigerous cyst: adjacent to unerupted tooth

Outline