stick the table on tube indicator mark so no need to remember before taking because it is s manual
Tube angulations in dental radiography are crucial for obtaining accurate and diagnostic images of teeth and surrounding structures. Here's a summary of tube angulations used in intraoral periapical radiographs for different techniques:
- Bisecting Angle Technique
This method follows the rule of isometry. The central X-ray beam is directed perpendicular to the bisecting angle between the tooth's long axis and the film.
Maxillary Teeth (Approximate Vertical Angulations):
Central Incisors: +40°
Lateral Incisors: +40°
Canines: +45°
Premolars: +30°
Molars: +20°
Mandibular Teeth (Approximate Vertical Angulations):
Incisors: -15°
Canines: -20°
Premolars: -10°
Molars: -5°
- Paralleling Technique
The X-ray beam is directed perpendicular to both the long axis of the tooth and the image receptor.
Vertical angulation is adjusted so the beam is perpendicular to the film, not following specific degree values like the bisecting technique.
Horizontal angulation is aligned perpendicular to the arch and aimed through the interproximal spaces to avoid overlap.
- Occlusal Radiographs
Maxillary: Tube angulation around +60 to +65°
Mandibular: Tube angulation around -55° to -90° depending on the view
Would you like a diagram or a table for easier recall?
Exactly — you're spot on, but let me fine-tune the understanding just a little for clarity:
Bisecting Angle Technique
Yes — Angles are needed.
You must manually set the vertical angulation so the X-ray beam is perpendicular to the imaginary bisector.
These angles vary per tooth (e.g., +40° for maxillary incisors).
Horizontal angulation must also be set to open contacts.
Technique is based on estimation.
Paralleling Technique
Angles are still present, but:
You don’t manually calculate or memorize them.
The beam is simply directed perpendicular to both the film and tooth, which are already aligned using film holders.
Angles happen naturally through proper positioning, not by numerical estimation.
Horizontal angulation is still important to avoid overlapping.
So the key difference:
Bisecting = You actively choose and set angles.
Paralleling = You position everything, and the angles take care of themselves.
Let me know if you want a comparison chart or visual to lock it in!
bisecting angle techinque¶
parallel¶
Point of entry Central ray should
Angulation