Basics of X- ray Technology, Techniques of projections

=Intra Oral Radiographs=

Periapical
Roots of teeth. Must include root apex and 2mm or more of the bone under it. Good for Periapical treatment planning, RCT, apex location, Seeing Impaction, Periapical Inflammatory Process, Tumors, Cysts etc.

Edge of the film placed at the level of the incisal or occlusal surface, X-Ray beam directed 90 degrees to plane which bisects the angle between the long axis of the tooth and the film.
 * Bisecting Angle Technique

Film placed parallel to long axis of tooth. X-Ray Beam directed at 90 degrees to film.
 * Paralleling Technique

Bitewing
Shows contact points between adjacent teeth, peridontal analysis, caries analysis, height of alveolar bone. Beam directed 90 degrees to buccal surface of teeth.

Occlusal X-Ray
Cross sectional view of Jaw and Teeth. Film placed horizontally in mouth. Beam directed 70 degrees to film. Maybe useful in looking for calcified structures in floor of mouth, eg. Salivary Gland Stones.

=Extra-Oral Radiographs=

Panoramic
Single image of upper and lower Jaw and surrounding tissue. ROutine pre/post surgical evaluation, fractures of mand, max, impacted teeth etc.

Standard Occito-Mental X-Ray, Waters View
Good for Orbits, Max Sinus and Facial Skeleton. Good for seeing Diseases to do with Max Sinus and Facial Fractures. View: Pt with chin on film, beam directed 90 degree to film 2cm above occipat.

PA Projection
Good for Skull Bones (Frontal and Jaw Bones). Good for Frontal Sinus and Facial Fractures. View: Pt with head and nose on film, beam directed 90 degree to film.

Caldwell View
Same as PA just with patient lieing down with face flat on film.

Reverse Townes View
Good for Condyles and TMJ. Good for Condyle fractures and TMJ disorders etc. View: Pt with head and nose on film, beam directed so central beam passes at 25 degree angle upwards in condylar region.

PA of Jaws Clemecic View
Good for Post. Mand., Mand Cysts, Maxfac Defects. View: Pt with head and nose on film, beam directed 90 degree to film 7cm above occipat.

Lateral Skull Projection
Good for ortho analysis and orthognatic surgeon analysis and good to see skull dev from side and lat. proj. of facial skeleton. View: Pt with ear on film, beam directed 90 degree to film passing through malar bone.

Submentovortex Projection
Good for seeing Base of Skull, Facial Skeleton from below, Sphenoid Sinus and Zygomatic Arch Fractures. Pt with head on film neck fully extended, beam directed at 90 degree to film so beam passes through chin and between angles of mandible.