How to take dental x-rays with bisecting angle positioning

The video introduces the bisecting angle technique for dental X-rays, noting that while some offices use ring instruments that simplify the process, many rely on the technique itself. The goal is to obtain the correct tooth image length by using the precise vertical tube angle, avoiding errors like elongation and foreshortening.

The bisecting angle is formed by the film placement in the mouth and the long axis of the tooth. To correctly apply this technique, the X-ray beam must be directed to cross the bisected line (an imaginary line exactly bisecting the angle between the film and the tooth's long axis) at a perpendicular angle. Incorrect angles lead to distorted images.

For offices using sensors, which are often bulkier, proper placement is crucial. If the sensor hits the roof of the mouth and pulls out, it can distort the image. The presenter demonstrates how to slightly tip the sensor and adjust the patient's bite to ensure proper seating and reduce distortion, recommending an increased tube angle for better results.

The video illustrates the process for upper primary teeth, showing how to slant the sensor, retract the cheek, and have the patient gently close. The patient’s head should be adjusted so the occlusal plane is horizontal. The X-ray tube's angle should be brought up to match the bisected angle of the sensor and tooth, ensuring the beam is perpendicular to this imaginary line. A purple line on the holder indicates the sensor's front edge for precise cone positioning.

For bite wings, the film must be placed to include the premolar, extending far enough forward in the mouth. If the film cannot be positioned ideally, it might need to be wedged slightly. The patient should not bite hard but gently, with the chin adjusted to simplify angling. The horizontal beam must hit the buccal surface of the premolars at a right angle, determined by observing the arch shape or patient's grin. The cone's front edge must cover the film's front edge to avoid errors.

The video concludes by reiterating that vertical tube angle issues cause elongation and foreshortening, while horizontal angulation causes overlapping. Mastering these techniques, though initially difficult, improves with practice. For more questions, viewers are directed to dentalxrays.info.