1. Overall Classification: UNCLASSIFIED//REL TO NATO/ISAF

2.  Radiopacity – light on film  Radiolucency - dark on film

3.  Radiopaque:refers to a light area on the film ◦ Structures that are absorbers of x-rays block the x- rays from reaching the film ◦ The x-rays are attenuated (decreased in intensity) by absorbing structures ◦ Fewer radiation reach the film ◦ Dense structures are strong absorbers

4.  Radiolucent:refers to a dark area on the film ◦ Structures that are less dense are poor absorbers and allow more radiation to reach the film

5.  Enamel  Cementum  Dentin  Bone  Muscle  Fat  Air Restorative and surgical materials have various densities and abilities to absorb. Metallic materials are more dense than enamel, thus appear very white on radiographs

6. NIH

42.  Radiolucent depression between alveolar ridge and mental ridge

65.  Floor of sinus extends to alveolar crest due to missing teeth

67.  Radiopaque  V-shaped

68.  Extends bilaterally away from ANS

69.  Variable size and shape, border  Variable position, due to angulation of x-ray beam

70.  Transmits nasopalatine nerves and vessels  Terminates in incisive foramen  Not always seen

71.  Superimposition of septal cartilage and vomer  Deviated septum

72.  In the nasal fossa  Away from the septum

73.  Median suture  Uniform width

86. Overall Classification: UNCLASSIFIED//REL TO NATO/ISAF