Y axis is used to analyze:

 # Y axis is used to analyze:

A. Maxillary growth

B. Mandibular growth

C. Both maxillary and mandibular growth

D. To design appliance

The correct answer is B. Mandibular growth.

Y-axis is obtained by joining the sella - gnathion line with the F.H. plane. The mean value is 59 degree with a range of 53 to 66 degree. The angle is larger in Class II Facial patterns than in patient exhibiting Class III pattern. In addition, Y axis indicates the growth pattern of the individual. If the angle is greater than normal, it indicates greater vertical growth of mandible. If the angle is smaller than normal, it indicates greater horizontal growth of mandible.