Cleveland Family Study

16.6.3 Geocalc

To harvest tongue area from the radiograph, a software program called GeoCalc is utilized. During the location of the landmarks on the ceph, the tongue area will have been outlined by the analyst. To harvest these data, the operator simply needs to trace this outline with a digitizing mouse on a SummaGraphics digitizing tablet. The procedures for accomplishing this are listed below.

1. Turn on the PC designated for this task.
2. Open Windows by typing “win” at the C:\ prompt.
3. From Windows, select Exit to DOS option.
4. At the DOS prompt, type “GC98”.
5. At the green start up screen, press Enter.
6. To warm up the program, choose Option 1: Measure Linear Distance.
7. Measure an imaginary line on the tablet.
8. Tape the acetate sheet from the x-ray down to the tablet to prevent movement during analysis.
9. Pick a good starting point, such as the Menton, and place the crosshair sight above it.
10. Choose Option 3 from the GeoCalc main menu.
11. Choose Option 1 to digitize the specimen.
12. Press the yellow button to begin the process.
13. Carefully follow the outline of the tongue area with the mouse, trying to remain on the outside of the line at all times.
14. When you return to the starting point, press the blue button on the mouse.
15. The program will give you a strange message while it is processing the data. Ignore it and be patient.
16. Record tongue area on the acetate.
17. Repeat the procedure two more times.
18. Choose the median score.
19. Continue to next x-ray.