Reverse Caldwell and Waters Flashcards
What is the CR for Reverse Caldwell skull
15 degrees cephalad to OML
What needs to be included on Reverse caldwell
Vertex to base of skull with petrous ridges in lower 1/3 of orbits
What is the CR for Facial bone Reverse Caldwell
20-25 degrees cephalad from OML entering nasion
What needs to be included on facial caldwell
Glabella to occlusal plane… petrous ridges will now be just inferior to orbits
Why do we change the angle from 15 to 20 for the facial bones
To better visualize the supraorbital fissures, foramen rotundum and inferior orbital rim
What is the CR for Reverse Caldwell Orbits
30 degrees cephalad to OML entering mid orbit
What needs to be included in reverse caldwell orbit
Petrous ridges well below inferior orbital rim, entirety of orbits included
What is the formula to determine angles for adaptive situations
(original angle/goal angle)-(OML angle)=(adapted angle)
If the patient’s OML is tipped back 10 degrees from the vertical what will be your new CR for an AP Caldwell Skull?
15-10=5 degrees cephalad
If the patient’s OML is tipped back 20 degrees from the vertical what will be your new CR for an AP Caldwell Skull?
15-20=-5
This means 5 degrees caudad will be the new angle as it is a negative
What is the degree difference between the OML and IOML
7 degrees
What is the CR for reverse waters
Parallel to MML
In a Waters projection, what angle does the OML form with the IR
According to Merrills 37 degrees
If a patient’s MML is forming a 30 degree angle with the vertical what will the adapted CR need to be
30 degrees cephalad (parallel to the MML)
If a patient’s OML is perpendicular to the IR what is the new CR for a Waters
53 degrees
How do we know this
OML relationship to the IR needs to be 37 degrees. If goal is 90 degree angle to MML then the remaining angle of the triangle is the new CR needed…. (180-37-90)=53 degrees
