Podcast
Questions and Answers
What is the primary purpose of the Submentovertex Projection?
What is the primary purpose of the Submentovertex Projection?
In the Facial Lateral Projection, where is the CR positioned?
In the Facial Lateral Projection, where is the CR positioned?
What is unique about the patient position in the Facial Modified Waters Projection?
What is unique about the patient position in the Facial Modified Waters Projection?
What is the angle formed by the OML and the film in the Facial Modified Waters Projection?
What is the angle formed by the OML and the film in the Facial Modified Waters Projection?
Signup and view all the answers
What is the primary advantage of the AP Axial Reverse Waters Projection?
What is the primary advantage of the AP Axial Reverse Waters Projection?
Signup and view all the answers
What is the main reason for radiographing the paranasal sinuses in an erect position?
What is the main reason for radiographing the paranasal sinuses in an erect position?
Signup and view all the answers
Which projection is best suited to demonstrate the frontal sinuses and anterior ethmoidal sinuses?
Which projection is best suited to demonstrate the frontal sinuses and anterior ethmoidal sinuses?
Signup and view all the answers
What is the purpose of having the patient rest their head on their chin in the Parietoacanthial projection?
What is the purpose of having the patient rest their head on their chin in the Parietoacanthial projection?
Signup and view all the answers
What is the primary advantage of the Parietoacanthial projection?
What is the primary advantage of the Parietoacanthial projection?
Signup and view all the answers
What is demonstrated through the open mouth in the Open-mouth Water's projection?
What is demonstrated through the open mouth in the Open-mouth Water's projection?
Signup and view all the answers
Study Notes
Submentovertex Projection
- Projection of the sphenoid sinuses through the open mouth, demonstrating an axial image
- Central Ray (CR) is perpendicular to the line extending from the sella turcica to the center of the open mouth at 30° caudad to the Mid-Sagittal Plane (MSP)
PNS Submentovertex Projection
- Projection of the sphenoid, ethmoid, and maxillary sinuses, demonstrating a basal image
- CR is perpendicular between the angles of the mandible
Facial Lateral Projection
- Projection of the zygoma, centered to the Mid-Lateral Line (MLT)
- CR is perpendicular to mid-zygoma, midway between the outer canthus and the External Auditory Meatus (EAM)
- Useful for demonstrating depressed fractures of the frontal sinus
Facial Waters Projection
- Projection of the facial bones, demonstrating an axial image
- Best single projection for demonstrating the entire facial bone
- Petrous ridge is projected below the maxillary sinus
- Useful for demonstrating fractures of the orbit and nasal wings
Modified Waters Projection
- Prone position, with the patient's head resting on the chin and nose
- Left Median Line (LML) is perpendicular to the table, and the Occipital Mandibular Line (OML) forms an angle of 55° with the film
- CR is perpendicular to the acanthion
- Demonstrates facial bones with less axial angulation, with petrous ridges projected into the lower half of the maxillary sinuses
- Best demonstrates a more direct view of the orbital rim compared to the Waters projection
Facial Bones AP Axial Reverse Waters Projection
- Supine position
- Inferior Oculo-Mental Line (IOML) is perpendicular to the Image Receptor (IR)
- CR is 30° cephalad, entering the face or slightly below the lips, and exiting 2 inches above the inion
- CR must be parallel to the Mid-Mental Line (MML)
- Demonstrates an axial position of the superior facial bone, similar to the Waters projection, although the structures are magnified
Nasal Lateral (Soft Tissue Lateral) Projection
- CR is perpendicular to ½ inch inferior to the nasion
Paranasal Sinuses
- Large air-filled cavities that should be radiographed in an erect/upright position to demonstrate the presence of air-fluid level and differentiate between shadows caused by fluid and those caused by other pathologic conditions.
- Patient must be in an erect position for at least 5 minutes before examination.
Types of Paranasal Sinuses
- Frontal Sinuses: located in the frontal (cranial) bone.
- Ethmoid Sinuses: located in the ethmoid (cranial) bone.
- Maxillary Sinuses: located in the maxillary (facial) bone.
- Sphenoid Sinuses: located in the sphenoid (cranial) bone.
Projections for Paranasal Sinuses
Lateral Projection
- CR horizontally directed 1 inch posterior to outer canthus.
- Best projection to demonstrate all 4 sinuses.
- Demonstrates the sphenoid sinus, which is of primary importance in this projection.
Caldwell's Method
- CR 15° caudad to nasion.
- Best projection to demonstrate the frontal sinuses and anterior ethmoidal sinuses.
- Petrous ridge is projected into the lower 1/3 of the orbits.
Parietoacanthial Projection (Water's Method)
- Patient's head is resting on the chin.
- MML is perpendicular to IR.
- OML forms an angle of 37° with the plane of the film.
- Tip of the nose is 1/2 inch from the image receptor.
- CR is directed to acanthion.
- Best projection to demonstrate the maxillary sinuses above the petrous ridge.
- Useful for demonstrating the foramen rotundum and the petrous pyramids below the maxillary sinuses.
Parietoacanthial Open-Mouth Projection (Water's Method)
- Demonstrates the sphenoid sinuses through the open mouth.
- The open mouth projection removes the upper teeth from direct superimposition of the sphenoid.
Axial Transoral Projection (Pire Method)
- Head is resting on the nose and chin.
- Patient is instructed to phonate "ah" softly during exposure.
- Useful for demonstrating the sphenoid sinuses.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
This quiz covers different radiography projections used to visualize facial bones and sinuses, including the submentovertex and facial lateral projections. It also includes details on how to position the CR and how to demonstrate specific sinuses and bones.
