mouth area
reduce the lines so they fit the cropped
picture
select the photo + horizontal line + vertical line and group them
enlarge the group so it takes most of the slide
re-position if needed the horizontal line so it crosses the anterior teeth
make sure the line is above the incisal edges of the anterior teeth
bring the 20mm ruler image to the slide and get your digital caliper
measure on the patient or on the model the distance between the distal (11) to distal (21)
draw 2 lines crossing exactly the position that you used to measure (distals)
position the zero value of the ruler on one of the lines
adjust by distorting the ruler image to the exact measurement lining up to the second line
your ruler is calibrated now
rotate the ruler vertically (use the shift key) and position on the incisal of 3 selected teeth
check the numbers that the line crosses the ruler
transfer the 3 distances by marking the model with your caliper and connect them
draw a parallel line on the gingiva area of your model
do the same procedure for the vertical line, your cross is transferred to the model
DSD - Step 2 - Model Transferring