Mandibular Landmarks

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Mandibular Landmarks

• Professor Nancy Rivaldo
• Monroe Community College

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Mandible

• 1. Mental Ridge
• 2. Mental Foramen
• 3. External Oblique Ridge
• 4. Ramus

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1
2
3
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Cont.

• 5. Lingual Foramen
• 6. Internal Oblique Ridge
• 7. Mandibular Foramen

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External Oblique Ridge

• Continuation of anterior border of ramus--buccal
  aspect
• Radiopaque line typically superimposed over crown
  of 3rd molar

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Internal Oblique Ridge

• Radiographic term
• Radiopaque line that overshadows the roots of
  molar teeth--lingual aspect of mandible
• If internal and external seen together the
  internal is the lower of the two

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Mandibular Canal

• Extends downward and forward from mandibular
  foramen to mental foramen
• Radiolucent band with radiopaque walls

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Mental Foramen

• Oval or round radiolucency
• Near apices of mandibular premolars
• Found between, below or superimposed on roots

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Genial Tubercles

• Located on lingual surface of mandible
• Bony growths which serve as muscle attachments
• Appear as a radiopaque circle

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Lingual Foramen

• Exit point of lingual branches of incisive
  vessels and nerves
• Appears as a radiolucency in middle of radiopaque
  genial tubercles

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Mental Ridge

• Ridge of bone on labial aspect of mandible
• Bilateral below apical area of canine and
  incisors
• Appears as a broad radiopaque band

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Mental Fossa

• Concavity in labial plate of bone
• Mandibular incisor area
• Appears radiolucent

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Mandibular Fossa/Submandibular Fossa

• Area of reduced thickness of bone
• Lingual aspect of mandible
• Radiolucent area below internal oblique ridge

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Shadow of lip

• Seen on anterior radiograph
• Portion of film not covered by lip appears darker
  then rest of film because there is no soft tissue
  attenuation in that area