Các mốc giải phẫu trên phim cận chóp P1

Summary

The lecture explains how to identify normal anatomical landmarks on periapical dental X-rays, focusing first on the upper teeth and then on selected landmarks in the lower jaw. The central skill is to identify which part of the mouth was imaged, recognize the expected anatomy, and avoid mistaking normal structures or superimpositions for disease.

1. Start by locating the region shown

• A periapical image captures only a limited part of the mouth, unlike a panoramic radiograph.
• Determine whether the film shows upper or lower teeth, and whether it covers incisors, canines, premolars, or molars.
• Tooth size and shape can help:
  • The upper central incisors are generally larger than the upper lateral incisors.
  • The lower incisors are more similar in size to one another.
• The X-ray angle affects which structures are visible and how much they overlap.

2. Landmarks around the upper front teeth

The lecture points out several structures that may appear near the roots of the upper incisors:

• The nasal cavity, including its floor and septum.
• The inferior nasal concha.
• The anterior nasal spine.
• The incisive canal/foramen, associated with the nerve and vessels in the front of the palate.
• The midline palatal suture, which may be more distinct in children and becomes more fused with age.
• Soft-tissue shadows from the nose and lips, which may appear over the teeth on an X-ray.

These structures can overlap the roots, so their appearance should be interpreted in relation to the tooth and the region being imaged. The lecturer also briefly connects the incisive region with local anesthesia, though the captions make the details of that discussion unclear.

3. Recognizing the upper canine and premolar region

• In images near the upper canine and premolars, the boundary between the nasal cavity and the maxillary sinus may form a characteristic Y-shaped radiographic appearance.
• The maxillary sinus can extend above the premolar roots, but its size and position vary between individuals.
• A normal sinus boundary or other anatomical shadow should not automatically be interpreted as inflammation or a lesion.

4. Landmarks around the upper molars

The lecture reviews structures that can appear in radiographs of the upper molars:

• The maxillary sinus, including its floor and internal septa.
• The zygomatic process/cheekbone, which may appear as a prominent radiopaque shape over the molar region.
• Structures associated with the sphenoid and pterygoid region, whose appearance can vary with the projection angle.
• Overlapping structures may look confusing in some images; changing the beam angle can make them appear more distinct.

The lecturer emphasizes that the posterior wall of the maxillary sinus contains an important blood vessel. This is clinically relevant during sinus-lift procedures: the sinus lining is thin and can tear, and injury to a vessel may cause significant bleeding. The exact vessel name is unclear in the auto-generated captions.

5. Landmarks in the lower jaw

• Lower-incisor images do not show the nasal cavity, and the four lower incisors tend to look more alike in size.
• The lecture also introduces landmarks around the chin and lower jaw, including a mental-region prominence and a nearby opening that students are asked to identify.
• A round radiolucent area near the lower premolars may be a normal anatomical opening rather than a periapical lesion. Its position and relationship to the roots help distinguish it from disease.
• Students are encouraged to discuss possible identifications rather than assume every unusual shadow is abnormal.

Practical approach emphasized

1. Identify which teeth and jaw region are shown.
2. Use tooth size and shape as clues to the region.
3. Look for expected nearby structures, such as the nasal cavity, sinus, cheekbone, or chin-region landmarks.
4. Consider how the X-ray angle may create overlap or change the appearance of a structure.
5. Distinguish normal anatomy from pathology before interpreting a shadow as a lesion.
6. Keep clinical implications in mind when relevant, particularly the sinus anatomy involved in sinus-lift surgery.

Speakers and sources

• Lecturer: The video’s lecturer, identified by the channel as Nguyễn Thế Lực.
• Students: Several students are addressed and invited to identify landmarks; no additional speaker is clearly identifiable from the captions.