<prompt> The Y-axis is also known as growth axis becauseIts axis is parallel to patients growth in heightIt is an indicator of the direction of growth patternIt is an indicator of the amount of facial growthIt increases in size as the growth increases  <response>: Y-axisIt is also called as growth-axis angle, measured as the posterior inferior angle on SGnFHP. The Y-axis indicates the degree of downward and forward position of the chin in relation to the upper face. A large Y-axis is indicative of the clockwise rotation of the mandible. Y-axis does not give an indication of the size of the lower jaw but the direction in which it is growing. Mean 59.4, range 5366. 