Fig. 2.

3D maxilla was separated from the 3D skull. a, The landmarks used to reconstruct the palatal morphology. 1, U1’ in the horizontal plane; 2 and 3, U6L’ and U6R’ in the coronal and horizontal plane; 4, U7L’ and U7R’ in the horizontal plane. b, The boundary of the maxilla. 1, The lowermost horizontal plane was through the U1’, U6L’ and U6R’; 2, the foremost coronal plane was through the U1’; 3, the backmost coronal plane was through the U7L’or U7R’; 4, the uppermost horizontal plane was through the ANS. c, The 3D objects of maxilla. 1, Upwards view; 2, front view; 3, lateral view; 4, the maxilla in the skull