TABLE 1.

Cephalometric points identified on each lateral cephalograph

Trait	Abbreviation	Description
1. Articulare	Ar	The intersection of the image of the posterior border of the ramus with the external surface of the basicranium
2. Basion	Ba	The anterior margin of the foramen magnum
3. Nasion	N	The intersection of the nasal and frontal bones
4. Posterior nasal spine	PNS	The posterior point of the hard palate
5. Prosthion	Pr	The anterior point of the premaxilla between the upper central incisors
6. Sella	S	The pituitary fossa of the sphenoid bone
7. Gonion	Goa	The external angle of the mandible
8. Menton	Me	The most inferior point on the mandibular symphysis
9. Gnathion	Gn	The lowest, most anterior point on the mandibular symphysis
10. Posterior condylion	PCd	The point tangent to a perpendicular line extending from the S–N plane
11. Infradentale	Id	The anterior point of the tip of the alveolar process of the mandible between the lower central incisors
12. Point D	D	The center of the cross-section of the mandibular symphysis
13. Pogonion	Pog	The most anterior point of the mandibular symphysis
14. Pterygomaxillary fissure	PTMa	Teardrop-shaped area between maxilla and pterygoid process of the sphenoid
15. Center of face	CFa	Posterior-most point of the pterygomaxillary fissure
16. Orbitale	Ora	Inferior-most point of the orbit
17. Porion	Poa	Superior margin of external auditory canal
18. Frankfort horizontal	FHa	Plane defined by right and left porion and left orbitale
19. Facial plane	FP	Line connecting nasion and pogonion
20. Xnnn		Points defined along the endocranial surface of the neurocranium relative to the S–N plane (e.g., X100 is the point at which a line drawn 100° from the S–N plane intersects the endocranium)

All points represent midline structures except where noted.

^aPoints not on midline of the skull.