cephalometric analysis for orthognathic surgery

CEPHALOMETRIC ANALYSIS FOR ORTHOGNATHIC SURGERY

Dr. Mohd Ullah KhanDept of Othodontics & Dentofacial OrthopedicsCIDS

CONTENTS

INTRODUCTION CHARACTERISTICS LANDMARKS CHARLES.J.BURSTONE ANALYSIS CONCLUSION REFERENCES

INTRODUCTION

Developed in University of connecticut

The successful t/t of orthognathic surgical pt is dependent of careful diagnosis.

This system describes H and V position of facial bones Size of bone—linear measurement Shape ----angular measurements

CHARACTERISTICS

1. The chosen landmarks and measurements can be altered by various surgical procedures.

2. The comprehensive appraisal includes all of the facial bones and a cranial base reference.

3. Measurements can be readily transferred to a study cast for mock surgery.

4. Critical facial skeletal components are examined.5. For variations in age and sex standards are available.6. Computerized systematic approach to measurement can be

used.

LANDMARKS

Sella (S)

CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

Nasion (N) –

CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

9Articulare (Ar)

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

10 Pterygomaxillary fissure (PTM)

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

11

Subspinale (A) –

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

12 Pogonion (Pog)

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

13Supramentale (B)-

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

14 Anterior nasal spine (ANS) –

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

15Menton (Me) –

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

16

Gnathion (Gn)

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

17 Posterior Nasal Spine (PNS)

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

18 Mandibular plane (MP) –

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

19 Nasal Floor (NF)

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

20 Gonion (Go)

7HP

Horizontal plane

CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

Hard tissue analysis Cranial base Horizontal profile Vertical height - dental & skeletal Maxilla & mandible Dental

Cranial base

1. Ar-N (||HP)

2. Ar-Ptm (||

HP)

Ar-PTM

Ar-N

Ar-N(||HP)(in mm) (F) 50 +3(M) 52.8 + 4.1

Ar-Ptm(||HP)(in mm) (F) 32.8 +1.9(M) 37.1 + 2.8

Ar-PTM is measured to determine horizontal distance b/w post aspect of maxilla and mand.. Greater the distance bt Ar-ptm mandible placed post to maxilla

HORIZONTAL PROFILE

1.N-A-Pog(Angle)2. N-A(|| HP)3. N-B(|| HP)4. N-Pog(|| HP)

CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

26

N-A-Pog (F)2.6° + 5.1° (M)3.9° + 6.4°

N

A

Pog

• Degree of skeletal convexity.

.

N-A(||HP) (in mm)(F) -2 + 3.7(M) 0 + 3.7

.

N-B(||HP) (in mm) (F) -6.9 + 4.3 (M) -5.3 + 6.7

..

N-Pog(||HP) (in mm)(F) -6.5 + 5.1(M) -4.3 + 8.5

VERTICAL HEIGHT - SKELETAL

Vertical Skeletal &

Dental

Anterior

N-ANS ANS-Gn

posterior

PNS-N MP-HP

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

31

HP

ANS

NN-ANS ( in mm) (F) 50 + 2.4 (M) 54.7 + 3.2

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

32

HP

Gn

ANS

ANS-Gn (in mm) (F) 61.3 + 3.3 (M) 68.6 + 3.8

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

33

HP

PNS

N PNS-N (F) 50.6 + 2.2 (M) 53.9 + 1.7

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

34

HP NMP-HP angle (F) 24.2° + 5° (M) 23.0° + 5.9°

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

35 VERTICAL HEIGHT - DENTAL

Vertical dental

dysplasia

Ant

U1-NF L1-MP

post

U6-NF L6-MP

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

36

HP N U1-NF (in mm) (F) 27.5 + 1.7 (M) 30.5 + 2.1

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

37

HP N l1-MP (in mm) (F) 40.8 + 1.8 (M) 45.0 + 2.1

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

38

HP N U6-NF (in mm) (F) 23.0 + 1.3 (M) 26.2 + 2.0

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

39

HP N L6-MP (in mm) (F) 32.1 + 1.9 (M)35.8 + 2.6

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

40 MAXILLA & MANDIBLE

PNS-ANS (||HP) Ar-Go Go-Pog B-Pog (||MP) Ar-Go-Gn (°)

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

41

HP N PNS-ANS(in mm) (F)52.6 + 3.5 (M)57.7 + 2.5

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

42

Ar-Go (in mm) (F) 46.8 + 2.5 (M) 52.0 + 4.2

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

43

B-Pog (in mm) (F) 7.2 + 1.9 (M) 8.9 + 1.7

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

44

Ar-Go-Gn (in °) (F) 122°+ 6.9° (M) 119.1° + 6.5°

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

45 DENTAL

OP-HP (angle) A-B(||0P) U1-NF (angle) L1-MP (angle)

OP-HP angle

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

47

HP NOP-HP angle (F) 7.1 + 2.5 (M) 6.2 + 5.1

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

48

HP N A-B(||0P) (in mm) (F) -0.4 + 2.5 (M) -1.1 + 2

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

49

HP NU1-NF angle (F) 112° + 5.3 (M) 111° + 4.7

May 1, 2023CHARLES J BURSTONE,J ORAL SURGERY...VOL 36,APRIL 1978

50

HP N L1-MP angle (F) 95.9° + 9.7 (M) 95.9° + 5.2

SOFT TISSUE Landmarks used for the analysis

GLABELLA

GLABELLA

COLUMELLA POINT

COLUMELLA POINT

SUBNASALE

LABRALE SUPERIUS

STOMION SUPERIUS

LABRALE INFERIUS

STOMION INFERIUS

SOFT TISSUE POGONION

SOFT TISSUE MENTON

CERVICAL POINT

SOFT TISSUE GNATHION

Horizontal analysis of the soft tissue profile

Facial Form Angle of convexity G to Sn and Sn to Pog Mean Value is 12 degree with a

standard deviation of 4 degree

So to define the anterior posterior position of the jaws two soft tissue measures are taken.

Sn point to G perp : 6 +/- 3 mm

Pog’ point to G perp : 0 +/- 4 mmm

Lower cervicofacial angle Formed by the

intersection of Sn – Gn’ and Gn’ – C lines.

Mean Value is 100 degree with a SD of 7 degree.

.

1. Height of the mid third of the face/ height of the lower third ( A / B)

Height of the lower third of the face increases in : a) Maxillary vertical over growth b) Class 3 patients with vertical height increase c) Skeletal open bites Height of the lower third of the face decreases in : a) Maxillary Vertical undergrowth b) Mandibular retrusion with deep bite c) Vertical undergrowth of the chin

Nasolabial Angle

Formed by the intersection of lines Cl-Sn and Sn-Ls.

Mean Value is 102 degree with a standard deviation of 8 degree.

A-P Lip PositionLine drawn from Subnasale to soft tissue Pog to Ls 3mm

Line drawn from Subnasale to soft tissue Pog to Li 2mm

Labiomental sulcus

Sulcus perp to Li-Pog

4 mm normal

MAXILLARY INCISORS EXPOSURE

2mm is desirable.

INTERLABIAL GAP

Lightly touching to approximately 2mm apart.

CONCLUSION

• A simplified and relevant ceph analysis has been developed that is applicable to planning tt for pt requiring orthognathic surgeries.

• This analysis evaluates both hard tissue and soft tissue with both vertical as well as horizontal aspects of the face.

• If a prime pbjective of orthognathic surgery is facial improvement, soft tissue analysis becomes paramount in treatment planning

REFERENCES