NEET MDS Lessons
Radiology
Fractures of the Zygomatic Arch
- Structures:�Zygomatic arch, zygomatic bone.
- Best Views:
- Submento-Vertex View:�Provides a clear view of the zygomatic arch and helps assess fractures.
- Waters View:�Useful for visualizing the zygomatic bone and maxillary sinus.
- Reverse Townes View:�Can also be used to visualize the zygomatic arch.
Base of Skull
- Structures:�Base of the skull, cranial fossae.
- Best Views:
- Submento-Vertex View:�Effective for assessing the base of the skull and related fractures.
Maxillary Sinus
- Structures:�Maxillary sinus, zygomatic bone.
- Best Views:
- Waters View:�Excellent for visualizing the maxillary sinus and any associated fractures.
Fractures of Zygoma
- Structures:�Zygomatic bone, zygomatic arch.
- Best Views:
- Waters View:�Good for assessing zygomatic fractures.
- PA View:�Provides a frontal view of the zygomatic bone.
- Reverse Townes View:�Useful for visualizing the zygomatic arch.
Nasal Septum
- Structures:�Nasal septum, nasal cavity.
- Best Views:
- PA View:�Useful for assessing the nasal septum and any associated fractures.
Condylar Neck Fractures
- Structures:�Mandibular condyle, neck of the condyle.
- Best Views:
- Lateral Oblique View (15�):�Good for visualizing condylar neck fractures.
- Transpharyngeal View:�Useful for assessing the condylar region.
Medially Displaced Condylar Fractures
- Structures:�Mandibular condyle.
- Best Views:
- Lateral Oblique View (30�):�Effective for visualizing medially displaced condylar fractures.
Coronoid Process of Mandible
- Structures:�Coronoid process.
- Best Views:
- PA View of Skull:�Can help visualize the coronoid process.
Fractures of Ramus and Body of Mandible
- Structures:�Mandibular ramus, body of the mandible.
- Best Views:
- Lateral Oblique View (15�):�Useful for assessing fractures of the ramus and body of the mandible.
Horizontal Favorable and Unfavorable Fractures of Mandible
- Structures:�Mandible.
- Best Views:
- Lateral Oblique View (30�):�Effective for evaluating horizontal fractures.
Bony Ankylosis of TMJ
- Structures:�Temporomandibular joint.
- Best Views:
- CT Scan:�Provides detailed imaging of bony structures and ankylosis.
Fibrous Ankylosis of TMJ
- Structures:�Temporomandibular joint.
- Best Views:
- CT Scan:�Useful for assessing fibrous ankylosis.
Internal Derangement of the Disk
- Structures:�TMJ disk.
- Best Views:
- MRI:�The best modality for evaluating soft tissue structures, including the TMJ disk.
Disk Perforation
- Structures:�TMJ disk.
- Best Views:
- MRI:�Effective for diagnosing disk perforation.
Arthrography
- Structures:�TMJ.
- Best Views:
- Arthrography:�Can be used to assess the TMJ and visualize the disk and joint space.
Radiographic films used in Dentistry
1.�Intraoral Periapical (IOPA) Film
- Size 0:
- Dimensions: 22 x 35 mm
- For: Small children
- MPD (Maximum Permissible Dose) for whole body: 0.1 Rem in 1 year
- Size 1:
- MPD for gonads/bone marrow: 0.5 Rem in 1 year
- Size 2:
- Dimensions: 24 x 40 mm or 32 x 41 mm
- For: Anterior projections and adults
- MPD for gestation period in relation to the fetus: 5 Rem
- MPD for skin: 0.5 Rem in 1 year
- Radiation Exposure:
- Mean exposure from one IOPA: 300 mR
- Mean exposure from improved dental X-ray techniques: as low as 110 mR
2.�Bitewing Film
- Size 0:
- For: Very small children
- Size 1:
- For: Children
- Size 2:
- For: Adults
3.�Occlusal Film
- Size:
- 3 times larger than size 2 film (57 x 76 mm)
- Used for capturing larger areas of the dental arch.
4.�Screen Film
- Size:
- 8 x 10 inches
- Used for extraoral projections in conjunction with an intensifying screen.
Additional Information
- Erythema Dose: The amount of radiation necessary to produce a noticeable skin reaction, typically 300-400 R.
- ALARA Principle: Stands for "As Low As Reasonably Achievable," emphasizing the importance of minimizing radiation exposure.