How to construct the Goal Anterior Limit Line

(GALL)

forehead shapes

straight angular round

trichion/superion

glabella

FA point

trichion

superion

FA point

glabella

glabella

FA point

superion

trichion

1 judged -2 mm to FA point of the

forehead

1. Place patient in an upright head position.

2. Select the FA point of the forehead (midway between trichion/superion and glabella).

3. Judge how far the FA point of the upper central incisor is: even with (0), anterior to (+), or posterior to (-) the FA point of the forehead.

19 -7 = 12 x .6 = 7.2mm

1 is -2 mm to FA point of the forehead

FALL GALL

1. On a cephalometric tracing, mark a point (inferion) near the upper central incisor to indicate whether the FA point of the incisor is: even with (0), anterior to (+), or posterior (-) the FA point of the forehead.

2. Draw a line (FALL) from the FA point of the forehead to inferion. Draw a line from superion to glabella.

3. Measure the forehead inclination.

4. Subtract 7 from the forehead inclination.

5. Multiply this number by .6 mm.

6. For every degree greater than 7 , the GALL is .6 mm more anterior than the FALL. For a forehead inclination of 0 or less, the GALL is the same as the FALL.

7. Draw the GALL parallel to the FALL, but not beyond glabella.