Buccal object rule


The buccal object/SLOB rule is a method used to determine the relative position of two objects in the oral cavity using projectional dental radiography.

Clark's Rule

In 1909, Clark described a radiographic procedure for localizing impacted teeth to determining their relative antero-posterior position. If the two teeth are located in front of one another relative to the x-ray beam, they will appear superimposed on one another on a dental radiograph, but it will be impossible to know which one is in front of the other. To determine which is in front and which is behind, Clark proposed his , as a complicated set of three radiographs, but which can be simplified as follows using just two:

SLOB rule in Dentistry Video Tutorial

The video below shows a 5 minute illustration describing SLOB rule in dentistry
https://www.youtube.com/embed/AzjvFPlZtZg

Buccal Object Rule

In 1952, Richards amended this rule using only 2 radiographs, asserting that the object positioned more buccally will move more relative to the object positioned more palatally or lingually.
As a generalization, but not specifically stated as part of Richards' buccal object rule, the more buccal an object is the more it will move in the second radiograph when repositioning the x-ray source.
At the University of Alabama School of Dentistry, this rule is referred to as the BAMA rule: buccal always moves away.