Bisecting Angle Technique

Bisecting Angle Technique

Write short note on Bisecting Angle Technique.
Answer.

Principle of angle-Bisecting technique

• Angle bisecting technique is based on the simple geometrical principle known as “Cieszynski’s law of isometry” which states that two triangles are said to be equal when they share one complete side and have two equal angles.

“Understanding the role of the bisecting angle technique in dental imaging: Q&A explained”

Steps of bisecting angle technique

• In dental radiography, the above given law is applied as:
  • Film should be positioned close to the lingual surface of teeth, resting on palate or on the floor of mouth.
  • Plane of the film along with the long axis of tooth form an angle with its apex at a point where film is in the contact with the teeth.
  • When the angle is bisected via the imaginary line two congruent angles with a common side are formed.
  • A line which represent the central ray of an X-ray beam complete the third side of two triangles when it is bisected perpendicular to bisecting line.
  • This involves in taking the radiographs in the manner that the long axis of rays is perpendicular to bisector between the long axis of tooth and the long axis of film.
  • Here an 8 inch cone is used with 55 to 65 kVp.

“Importance of studying the bisecting angle technique for better dental outcomes: Questions explained”

Bisecting Angle Technique Advantages

• Primary advantage is that it can be used without film holder when the anatomy of patient not allowed use of holder (like in shallow palate bony growth).
• Positioning is reasonably comfortable, simple and quick.
• Decreased exposure time, as a short (8 inch) PID is used.

Advantages of the bisecting angle technique

• Positioning of film packet is comfortable to the patient.
• In the technique, if angulations are assessed properly,there be no changes in the dimension seen of the tooth which is imaged.
• If angulations are discussed properly, there will be no changes in demission of tooth which is in aged.

“Common challenges in applying the bisecting angle technique effectively: FAQs provided”

Bisecting Angle Technique Disadvantages

• Image distortion: Due to short PID, there is increase in the divergence of X-rays which causes image magnification.
• Angulation problem: It is difficult for the dental radiologist to visualize the imaginary bisector and determine vertical angulation without the use of film holder and aiming the ring. So if there is any error in the vertical angulation, this causes image distortion.

“Factors influencing success with the bisecting angle technique: Q&A”

Disadvantages of the bisecting angle technique

• Unnecessary exposure: As the patient stabilizes the film by their finger, the patient’s hand is unnecessarily exposed to the primary beam of X-ray radiation.
• Incorrect horizontal angulation: This leads to overlapping of the images, while incorrect vertical angulation leads to foreshortening or elongation of the image.
• Periodontal bone levels are poorly represented.
• Shadow of the zygomatic bone frequently overlaps the periapical area of maxillary molars.
• Crown of the teeth are often get distorted so detection of proximal caries is difficult.