Axis estimation is how the software calculates the orientation of the tooth to overlay the movement widget over the tooth.
Original: The software overlays the movement widget on the tooth only taking into consideration the location of the tooth along the arch.
Original
Advanced: The software overlays the movement widget on the tooth, estimating the rotation and tilt of the tooth to have the movement widget reflect the angle.
Advanced
Advanced - Vertical Axis Locked: The software overlays the movement widget on the tooth, estimating the rotation of the tooth while keeping the vertical axis straight up and down.
Advanced - Vertical Axis Locked