Radiographic examination

Radiographic examinationBuccal object rule (SLOB rule): states that when you take a radiograph of an image and you cast it down on a film, that you superimpose the 3D tooth onto film, and buccal and lingual object will superimpose. When you change the horizontal angulation of the xray, move the buccal object away by that change in angulation.

If you take image of tooth and you move the horizontal angulation mesial or distal the buccal object will move away from that change in angulation. If you take straight on xray of upper bicuspid, and you superimpose buccal over lingual, change angulation, the buccal object moves away from the film. When you have endofiles in there, knowing what angle you took the film will tell you. SLOB rule means same lingual opposite buccal. Move the horizontal angualtion, object stays same on the lingual and is opposite the buccal.

Canine with three roots. Lingual and two buccal. If we rotate, buccal object move away with distal angle.

What we are interested in is what angulation we take so that we know where image is if its buccal or lingual. Pulp chambers and relationship to crown and root, images that tell us how far to drill. Looking for ligament lines because roots are figure 8, and buccal and lingual ligament lines superimpose as double image. When we see double ligament, then buccal and lingual side. Resorption and mineralization where body lays down scar tissue, invaginations on root, and canals that disappear in the xray, indication canal has split off into two. Remember that double ligament lines means two sides of a root.

C shaped canals is continuous, difficult to clean and shape.

Anatomical landmarks because all the upper molars, roots are in the sinus.

When we are looking for pathology on radiograph, two things must occur. Another cardinal principle: lesion must be big enough to break cortical medullary junction that surrounds the root and xray beam must go through that break, mesial or distal. Can have a big abscess but if angulation doesnt break that junction you wont see it. Also need 10-30% of mineral to be leached from the bone to show up. These are cardinal principles of what you can see.

If any tooth in lower anterior has two canals they all have two canals. Cracked teeth. Once it gets to bone, dissolves away from the crack. On the X-ray shows loss around one root. Dens in dente, enamel bud flipped, tooth developed within the other.

Post and core with endo to radiographic apex. If you dont image properly and the direction the root tip turns, upper lateral incisors root end turns distal lingual, that information is important.

Body treating protein on root surface and pulp like it was no longer part of patient, resorption on external surface, internal on the pulp is internal reapportion. Try to take angles, if you can see outline of the pulp through the image, means its external, if you change angulation and image moves away or with the angulation change but doesnt stay centered then its external, if you move angulation and resorption is centered on pulp, then internal resorption.

Tooth thats never had a filling, trauma of some sort causes resorption. This is orthodontic tooth movement, moving too far too fast, ruptured vasculature to the pulp and the body attacks it.

When we see the canal outline through resorption then its on the external surface.

When we see traumatic injuries, over time body will still attack the tooth.

After traumatic injury, recognize that even the one tooth that received the blow, adjacent teeth could also be harmed. Here all three, one resorbed, one became necrotic and the other mineralized.

Radiographic interpretation of fracture root. Vertical for restorative reasons or horizontal from trauma. Buccal and lingual cracks superimpose, looks like double crack.Xray picks up buccal and lingual side giving a double image.

Mobility determines where the fracture was. Closer to coronal makes it more moveable.

Two errors you can make: place the film improperly or angle to the film improperly. 90% of the time its the placement error.

Good quality with gray and white image.