A series of scientific tests conducted in the Orthodontic Department of the Dental Faculty of Paris 5 University has led to the selection of eighteen cephalometric with which main craniofacial anatomical structures (basicranium, maxillary, mandible and teeth)are sketched out

A) The 18 landmarks that must be digitized.

1. Sellion
2. Basion
3. Ricketts Pterygoid Pt Point
4. Nasion
5. Anterior Nasal Spine
6. Posterior Nasal Spine
7. Point A
8. Point B
9. Chin
10. Gonion
11. Articulare
12. Incisal edge of maxillary incisor
13. Apex of maxillary incisor
14. Incisal edge of mandibular incisor
15. Apex of mandibular incisor
16. Occlusal point : projection of the 1st maxillary bicuspid on the occlusal plane
17. Most distal point of the 1st maxillary molar crown
18. Most distal point of the 1st mandibular molar crown

Note : The lines drawn between landmarks do not have any influence on calculations.

B) Three optional points that define Frankfort plane allow us to compute conventional cephalometric values.

1. Porion
2. Orbital
3. Pogonion

The Frankfort plane is not used in superimposition