Buccal Object Rule

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Buccal Object Rule ?X???????? 2011/11/05
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07-31211012755
yukkwa_at_kmu.edu.tw
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Introduction
In 1909, Clark 1 reported a radiographic
procedure for the localization of impacted
teeth. The Buccal Object Rule is a method for
determining the relative location of
objects hidden in the oral region. The rule is
When two different radiographs are made of a
pair of objects, the image of the buccal object
moves, relative to the image of the lingual
object, in the same direction that the X-ray
beam is directed. The initial concepts of the
procedure were reported in 1952 1953 2,
3 since that time the procedure has been
developed to its present state of refinement
usefulness.
1 CLARK C A. A method of ascertaining the
relative position of unerupted teeth by means of
film radiographs. Royal Society of
Medicine Transactions 387-90, 1909-1910. 2
RICHARDS AG. Roentgenographic localization of the
mandibular canal. Journal of Oral Surgery
10325-329, 1952. 3 RICHARDS AG. The Buccal
object rule. Journal of the Tennessee State
Dental Association 33263- 268, 1953.
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Understand buccal object rule
X-ray beam
X-ray beam
Ref. 1
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Assessment of the impacted maxillary canine tooth
position

• Parallax in the horizontal plane
• Parallax in the vertical plane
• A vertex occlusal
• A true PA and lateral skull views
• (two views at right angles)

Impacted maxillary canine teeth occur in about
2 of the population.
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1. Parallax in the horizontal plane
Principle of parallax The apparent displacement
of an object due to different positions of the
observer
Object moves in different direction
SLOB
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Ref. 2
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1. Parallax in the horizontal plane
Ref. 2
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1. Parallax in the horizontal plane
Choice
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(??)
Ref. 2
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1. Parallax in the horizontal plane
Choice
(??)
(??)
Crown
Apex
Ref. 2
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2. Parallax in the vertical plane
Ref. 2
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3. A vertex occlusal
Not recommended due to high radiation dose
Vertex occlusal
Ref. 2
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4. A true PA and lateral skull views (two
views at right angles)
Ref. 2
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Summaries
http//www.unc.edu/jbl/
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Summaries
http//www.unc.edu/jbl/
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Summaries
http//www.unc.edu/jbl/
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Thank you very muchfor your kind attention