(1) Buccal Object Rule X :
~2755 1 Introduction Understand buccal object rule
Assessment of the impacted maxillary canine tooth position 2. Eric Whaites: Essentials of dental radiography & radiology, 3rd edition, p.7, 8, 113, 1. White & Pharoah: Oral radiology: principle & interpretation, 5th edition, Chapter 5, p References: Introduction Conclusions Introduction * Clark [1909, ref. 1] reported a radiographic procedurefor the localization of impacted teeth. * Buccal Object Rule (BOR) is a method for determining the relative location of objects hidden in the oral region. * Initial concepts of the procedure were reported in 1952 & 1953 [refs. 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 3:87-90, [2] RICHARDS AG. Roentgenographic localization of the mandibular canal. Journal of Oral Surgery 10: , 1952. [3] RICHARDS AG. The Buccal object rule. Journal of the Tennessee State Dental Association 33:263- 268, 1953. Understand buccal object rule
Lingual Mesial shift Tube shift technique Buccal object rule Clakes rule (1910) Direct orientation Zygomatic process X-ray beam Buccal Mesial shift Distal shift Zygomatic process mesial (X-ray beam) X-ray beam Ref. 1 Assessment of the impacted maxillary canine tooth position
Parallax in the horizontal plane Parallax in the vertical plane A vertex occlusal A truePA and lateral skull views (two views at right angles) *Impacted maxillary canine teeth occur in about 2% of the population. 1. Parallax in the horizontal plane
Principle of parallax: The apparent displacement of an object due to different positions of the observer Front Right Left Object moves in different direction SameLingual OppositeBuccal SLOB () () Ref. 2 1. Parallax in the horizontal plane
Position 1- centrally oriented Position 2- distal shift Position 1 Position 2 SameLingual (-palatal side) 11 12 Ref. 2 1. Parallax in the horizontal plane
12 22 21 22 21 12 11 Choices (1) SameLingual (2) OppositeBuccal () () Ref. 2 1. Parallax in the horizontal plane
Choices (1) SameLingual (2) OppositeBuccal () () Apex Crown Ref. 2 2. Parallax in the vertical plane
Panorex Upper occlusal Unerupted mesiodens Crown portion (-palatal side) (-labial side) SLOB (1) SameLingual (2) OppositeBuccal Apex portion Ref. 2 3. A vertex occlusal Vertex occlusal Not recommended
due to high radiation dose Vertex occlusal Ref. 2 Mass of head in a different position & different shape
4. A true PA and lateral skull views (two views at right angles) Mass of head in a different position & different shape Similar images PA view Lateral view Similar images Radiodense object Ref. 2 Conclusion (1) Conclusion (2) Conclusion (3) Summaries Knowing : Understand Clakes rule
Assessment of the impacted maxillary canine tooth position ,.(Flying over America!)
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