NUCCA X-Ray Analysis
description
Transcript of NUCCA X-Ray Analysis
NUCCA X-Ray Analysis
Analysis Equipment
Cephalometer
Circumscale
Relatoscope
Vertex square
Lateral Film
PURPOSE:
To obtain the S line of the atlas
To tell if the atlas has gone inferior or superior
To determine where to take the Nasium
Lateral Film Analysis
S LinePlace a dot where the posterior arch of atlas meets
the lateral massPlace a second dot about 1/3 down along the length
of the posterior arch of atlas
*Note that because of how the Nasium film is taken, if the S line does not go through the mastoid markers, you must move the line up/down in a parallel fashion so that it does. This way it will be taken at the proper angle.
S-Line
Nasium FilmPURPOSE:
To determine atlas laterality
To determine upper and lower angle to determine the basic type
To determine APL, A/O, C/A, Ang, At, OD, BC, Sp
To calculate the height vector
To determine if C2 spinous rotation is present (torque)
Nasium Film
Atlas Plane Line (APL)Place a dot on the lower border of the posterior arch
where it crosses the lateral masses on each side of atlas
Nasium Film
Central Skull Line (CSL)Mark the squamous
suture on each side of the head
Mark the vertex of the head on each side
The CSL will only be determine using the area between these two points
Nasium Film
CSL ContinuedUse the Cephalometer to match like points on either
side of the head in order to determine the center of the skull
Mark a lower pivot point intersecting the APLMark an upper pivot point at the top of the skull
Nasium FilmCSL Continued
Starting with the lower pivot point, make your way up the skull finding like points with the cephalometer by keeping the lower pivot point in the slot. The line should match up with the two pivot points
Then make your way down with the upper pivot point
Repeat If the line shifts, you have
the wrong pivot points and need to redo
Once you have the best points, mark the CSL with a solid line
Nasium Film
Atlas Laterality (At)To find laterality measure the side of the acute angle
between the CSL and APL
Nasium Film
Head TiltTo find the head
tilt, measure the angle between the true vertical and the CSL
Nasium Film
Condylar CircleMark the outer 1/3 of the surface of the occipital
condylesUsing the circumscale, find the best fit circle = c If it comes out to ½, round down
Nasium FilmAxial Circle
Place a dot (A) on the most lateral aspect of the superior surface of C2 on each side
Also place a dot (B) on the medial aspect of the superior surface of C2 on each side
Connect those dots on each side From the medial dots, place
another dot (C) 3/32’’ down perpendicularly from that line
Use A and C to find the best fit circle for axis = a
If it comes out to ½, round up
A ABB
Condylar and Axial Circles
Nasium Film
Odontoid Center (OD)Mark the center of the Odontoid
Nasium
C2 Body Center (BC) Using the dots on the lateral aspect of the superior
surface of C2, place the center of a protractor on each dot and scribe and arcs above and below
Use a straight edge to connect the two intersections Draw a small line down the center in the middle of the
intersections
Nasium Film
BC ContinuedUse the relatoscope that corresponds to the condylar
circleSquare up atlas so that the horizontal lines of the
relatoscope are parallel to the APL and the lateral masses are boxed in equally
Determine the degrees (if any) the body center line is off from the 0 mark on relatoscope If BC is on the same vertical line as the 0 mark then BC
= At
Nasium Film
C2 Spinous (SP)Mark the inferior bifurcation of C2 spinousUse the relatoscope again to compare position of C2
spinous to atlas like you did with BC The lateral film can help you locate its position if its hard
to see by comparing where it is on the lateral film in relation to the posterior arch of atlas
OD/BC/SP
Nasium FilmFixed Point
Mark the lateral aspects of the zygapophyseal joints of C7
Determine the midpoint
Mark a point (D) between BC and SP if not on same vertical line
Connect the midpoint of C7 to D dot
D
Nasium Film
Lower AngleMeasure the
acute angle between the APL and the fixed point line
Nasium Film
Height Vector ComponentsPLA/BCC/AAng
Height Vector CalculationsPL
Use a true horizontal and move it up/down until it matches up where the APL crosses the ramus of the jaw on the side opposite of laterality and draw a small straight reference line on the side of laterality
Measure how far above or below the APL is compared to that true horizontal
If APL is lower by: 1/16th “ - ¼” 2/16th “ - ¾” 3/16th “ - 1’’
If APL is higher by: 1/16th “ + ¼” 2/16th “ + ¾” 3/16th “ + 1’’
PL
Height Vector Calculations
A/BCCompare the amount of atlas laterality due to atlas
side slip (ss) versus head tilt (ht) If ht ≥ ss, then A/BC = -1/2 ht but only up to amount
of laterality If ht < ss, then A/BC = -1/2 ht If ht = 0 or if it does not contribute to laterality, then
A/BC = 0 If BC > At like in a Type I with a large lower angle,
then A/BC = +1 for the first degree extra
Height Vector Calculations
C/AThis is equal to + (a-c)⁄2
Height Vector Calculations
AngTake the difference of At – lower angleFor contralateral acute angles
+ ¼” for every 1° difference
For ipsilateral acute angles - ¼” for every 1° difference
If the lower angle is less than or equal to atlas laterality, then Ang = 0
Height Vector Calculation Practice
At R2
OD R2
BC R2
SP R2
3c
8a
L6 PL = + 1 ¼A/BC = 0C/A = + 2 ½Ang = + 1_______________ + 4 ¾
+ 4/16th
Height Vector Calculation Practice
At R4 (RS)
OD R4
BC R1
SP R4
3c
10a
L4 PL = + ¾ A/BC = - 1 ½ C/A = + 3 ½Ang = 0_______________ + 2 ¾
+ 2/16th
Height Vector Calculation Practice
At R4 (R4)
OD R4
BC R0
SP R4
3c
5 ½a
L0 PL = 0A/BC = - 2C/A = + 1 ½ Ang = 0_______________ - ½
Vertex Film
PURPOSE:
To determine C1 rotation
To determine anterior/posterior vector
Vertex Film
Mark the anterior and posterior aspect of both lateral masses
Mark the center of the transverse foramen and draw a line connecting the two points
Use the vertex square to box in atlas using the lateral masses to make sure all those points/lines are parallel If the line of the transverse foramen isn’t parallel to the lateral
masses, use the lateral masses
Measure the angle between the true vertical line and the transverse foramen or lateral mass line on the side of laterality If the angle is acute = anterior rotation If the angle is obtuse = posterior rotation Vector = 1” for every 1° anterior or posterior
Vertex