1. An ultrasound system comprising: a display configured to form an ultrasound image with respect to a fetus in a body and display the ultrasound image on a screen; a controller configured: to determine a reference position at a position where a first straight line corresponding to a ridge of a nose of the fetus and a second straight line corresponding to a jawbone of the fetus intersect, to generate a figure template comprising a vertex position at the reference position, the first straight line and the second straight line, wherein the first straight line and the second straight line form an angle, to automatically adjust the generated figure template so that a matching energy between the figure template and the ultrasonic image is reduced by changing the angle between the first straight line and the second straight line based on the vertex position, thereby measuring a frontmaxillary facial (FMF) angle between the first straight line and the second straight line when the matching energy is minimized, to superimpose the adjusted figure template on the ultrasound image and display the resulting combination, and when the measured FMF angle is beyond a predetermined angle range, to automatically display an indication indicating a possibility that the fetus is in an abnormal condition.