Fig 5. The volumetric difference of specific soft and hard tissue regions after surgery based on the constructed reference planes.

(A) Cranial base superimposition of preoperative and postoperative CBCT models based on the reference planes (e.g., FHP-P). (B) The 3D landmarks were indicated, forming the horizontal and vertical borders of some specific regions based on the constructed reference planes. (C) The volumetric difference of the soft and hard tissue of various regions after subtracting the preoperative and postoperative images.