This document discusses cephalometrics, which uses oriented radiographs to make head measurements. Cephalometrics is used to study craniofacial growth, diagnose orthodontic issues, and plan and evaluate orthodontic treatment. Key measurements taken from cephalometric radiographs and tracings include assessments of the skeletal classification, dental angulation, soft tissues, and airway.

1. Basic Cephalometrics
Mark H. Taylor, D.D.S., F.A.C.D.

2. Cephalometrics is a technique employing
oriented radiographs for the purpose of
making head measurements.
Purpose of Cephalometrics
• Study craniofacial growth
• Diagnosis
• Planning orthodontic treatment
• Evaluation of treated cases

3. 15"15"60"60"
Source PlaneSource Plane
X-ray SourceX-ray Source
Patient in Head
Positioning Device
Patient in Head
Positioning Device
Mid-saggital PlaneMid-saggital Plane
Film PlaneFilm Plane
X-ray Film in
Cassette
X-ray Film in
Cassette
Cephalostat

4. Cephalostat

5. Cephalostat

6. White Black Israeli Chinese Japanese
SNA 82 85 82 82 81
SNB 80 81 78 79 77
ANB 2 4 4 3 4
U1-NA 4 mm, 22 7 mm, 23 5 mm, 24 5 mm, 24 6 mm, 24
L1-NB 4 mm, 25 10 mm, 34 6 mm, 29 6 mm, 27 8 mm, 31
U1-L1 131 119 124 126 120
GoGn-SN 32 32 35 32 34
L1-MnPl 93 100 93 93 96
L1-FH 62 51 57 57 57
Y axis 61 63 61 61 62
from Proffit,Contemporary Orthodontics, 1992
Cephalometric Values for
Selected Groups

7. What Are We Trying to
Accomplish?
• Find out skeletal classification
– anteroposterior
– vertical
• Find out angulation of incisors
• Consider soft tissue
– facial profile
– airway considerations

8. What Are We Trying to
Accomplish? (In other words)
• Is the patient Class I, II, III skeletal?
• Does the patient have a skeletal open bite
growth pattern, or a deep bite growth
pattern, or a normal growth pattern?
• Are the maxillary/mandibular incisors
proclined, retroclined or normal?
• Is the facial profile protrusive, retrusive, or
straight; can the patient breathe normally?

9. Structures to be Traced

10. Sella
Porion
Gonion
PNS
Menton Gnathion
Pogonion
B Point
A Point
ANS
Orbitale
Nasion
Articulare
Standard Cephalometric
Landmarks

11. Radiographic Landmarks

12. SN Plane
Frankfort Plane
Palatal Plane
Occlusal Plane
Mandibular Plane
Frequently Used Planes

13. 8282
Antero-posterior maxillary assessment
Skeletal Assessment
SNA

14. 8080
Antero-posterior mandibular assessment
Skeletal Assessment
SNB

15. 22
Antero-posterior bimaxillary assessment
Skeletal Assessment
ANB

16. -1 mm-1 mm
BO anterior toBO anterior to
AOAO
Skeletal Assessment
Wits (AO-BO)

17. 6666
Skeletal Assessment
Y Axis

18. 5959
Vertical Skeletal Assessment
Skeletal Assessment
Y Axis (to Frankfort Horizontal)

19. 3232
Vertical Skeletal Assessment
Skeletal Assessment
NS(SN plane)-GoGn

20. 104104
Incisor Angulation Assessment
Dental Assessment
U1-NS (Max 1 - SN)

21. 2222
Dental Assessment
Max 1 - NA (degrees)

22. 4 mm4 mm
Dental Assessment
Max 1 - NA (mm)

23. 9595
Incisor Angulation Assessment
Dental Assessment
L1-GoGn (Man 1 - GoGn)

24. 2525
Dental Assessment
Man 1 - NB (degrees)

25. 4 mm4 mm
Dental Assessment
Man 1 - NB (mm)

26. 2 mm +/- 22 mm +/- 2
Dental Assessment
APog - Man 1

27. 130130
Inter-Incisor Angulation Assessment
Dental Assessment
U1-L1 (Max 1 - Man 1)

28. -2 mm-2 mm
CHANGES WITH AGE!
Soft Tissue Assessment
E Plane

29. >4 mm.>4 mm.
Soft Tissue Assessment

30. Composite Cephalometric
Tracing

31. Children with airway obstruction, when
compared to normal controls, show:
Nasorespiratory Considerations
• Increased total and lower face heights
• More retrognathic mandibles
• Steeper (increased) mandibular plane
angles
• Spontaneous improvement after
reestablishment of normal respiration

32. Cases