treatment planning in orthognathic surgery.

1. Orthognathic surgerydecisionmaking,
treatmentplanningand timing of surgery
Presented by
Dr. Cathrine Diana PG III

2. 1.Introduction to craniofacial deformities
a. Various treatment options
2. Introduction to orthognathic surgery
a. History
b.Timing of surgery
A. Indication
B. Basic therapeutic goals
C. Soft tissue limitation
3. Data collection
4. diagnosis/problem list
5. cephalometric analysis
6. Treatment plan
7. prediction tracing
8. Model surgery
9. virtual treatment planning
10. Predictable Soft tissue changes

3. • Leo Tolstoysaidthat , “i Am convinced that nothing
has so marked influence on the directionof a man’s
mind as his appearance…

4. Introduction
• genetic factors
• environmental factors
Pre-natal
• genetic factors
• environmental
factors
Post-natal

5. • All these factors give rise to the following types of changes in
craniofacial skeleton for which the patient seeks correction
Combination
Transverse
defect
Antero-
posterior
defect
Vertical
defect

6. Various treatment options
1. Growth modification by dentofacial orthopedics:
1.
• to alter the growth pattern by changing the
relationships of the jaws
• In growing age
2.
• Accurate diagnosis
• Appropriate direction and amount of force
3.
• Prolonged treatment time
• Patient non- compliance
• Expensive
• Variable stability

7. Camouflage by orthodontic
• mild skeletal discrepancy
• Accepted soft tissue profile
• satisfactory occlusion at the expense of facial aesthetics.

8. Envelope of discrepancy
• Maxilla Mandible
3 5 25
2
5
15
5101
2
4
6
10
7 12 15
2
5
15
2510
4
6
10
Orthognathic surgery
Growth modulation
Orthodontic treatment

9. Orthognathic surgery
• the art and science of diagnosis, treatment planning and execution of
treatment by combining orthodontics and oral and maxillofacial surgery to
correct musculoskeletal, dento-osseous and soft tissue deformities of the
jaws and associated structures.

10. • Dr. Harold Hargis coined the term orthognathic surgery
• Hullihen is regarded as the first surgeon to describe a mandibular
orthognathic surgical procedure. In 1849, he reported an anterior
subapical osteotomy.
• Jaboulay and Berard (1898), Kostecka (1931) performed operations on
condylar neck and upper part of ramus by closed blind approach.
• Surgical treatment for mandibular prognathism started in early 19th
century.

11. • In 1959, Trauner and obwegeser introduced sagittal split osteotomy as the
beginning of a new era of orthognathic surgery.
• American surgeons modify the technique for maxillary surgery that has
been developed in Europe
• Epker, bell and wolford developed lefort-1 maxillary downward fracture
,so that we can keep the maxilla stable in all 3 planes of spaces
• By 1980 progress has reached such an extent to reposition either or both
the jaws to move chin in all 3 planes of spaces. Rigid internal fixation made
it possible for comfort and better immobilization was achieved

12. Timing
After growth completion – only treatment
option
Delay in mandibular prognathism
Rarely done before adolescent growth spurt

13. Indication
• Impaired mastication
• TMJ pain and dysfunction
• Psychological effects
• When dentofacial orthopaedics can no longer prevent severe jaw
discrepancy.
• When skeletal discrepancy is too severe to be corrected by orthodontics
alone to give a satisfactory dental occlusion and facial aesthetics.
• Internally motivated patient

14. Basic therapeutic goals
function
aesthetics
• macro
• mini
• micro
stability
• Minimal
treatment
time

15. Basic therapeutic goals

16. Soft tissue limitations
• Pressure on teeth by lips ,cheek, tongue -STABILITY.
• Periodontal attachment apparatus -ORAL HEALTH.
• Temporo-mandibular muscular and connective tissue attachments-
FUNCTION.
• Soft tissue integuments of face primarily determine AESTHETICS.

17. Data collection
• Patient concerns or chief complaints
• Clinical examination
• Radiographic imaging and analysis
• Dental model analysis

18. Patient interview
• Chief complaint of patient
• Patient concern and motivation
• Time and cost of surgery and treatment on the whole.
Co -decision
maker
Problem list
Risk –
benefits
Alternate
treatments
Patient
expecttion
and reality

19. History taking
• Medical history
• Dental and orthodontic history
• Diagnostic factors and risk factor:
• Congenital or developmental deformity
• Acquired deformity
• TMJ dysfunction
• Infection, psychological impairment, bone and soft tissue pathoses
• Bleeding dyscrasias, compromised vascularity
• Allergies, respiratory problem, poor patient compliance, neuromuscular
imbalance.
• Habits – mouth breating, thumb sucking, tongue thrusting

20. Patient preparation
• The patient should sit upright in a straight-backed chair with the examiner
seated directly opposite at eye level.
• The Frankfort horizontal plane should be parallel to the floor.
• mandibular condyles should be seated in glenoid fossae with the teeth
lightly touching.
• Evaluate centric occlusion and centric relation.
• Patient’s lips should be relaxed and not forced together

21. Frontal facial evaluation
The distance from glabella to subnasale and subnasale to menton
should be approximately in a 1:1 ratio, providing that the upper tip
length is normal.

22. • Forehead, eyes, orbits and nose are
evaluated for symmetry, size and
deformity.
• Symmetry of canthi
• Eyelids – ptosis, entropion, ectropion
• Sclera, ocular imbalance
• Scleral show – mid facial defieciency
• ICD -32 ± 3 mm and 35 ± 3 mm blacks
• IPD65 ± 3 mm.
• The intercanthal distance, alar base width
and palpebral fissure width should all be
equal.
Frontal facial evaluation

23. Width of nasal dorsum should be one half
the intercanthal distance and width of the
nasal lobules should be 2/3rd the
intercanthal distance.
• A vertical line through the medial canthus
and perpendicular to the pupillary plane
should fall on the alar bases ± 2 mm
• Cheek prominence
• 8 – 12 mm laterally and 10 – 20 mm
inferior to lateral canthus
•Ears -Upper 1/3rds just above the canthal
level.
Frontal facial evaluation

24. Lips
• Width of lips equal to interpupillary distance
• If asymmetry exists
- Cleft lip
- Facial nerve dysfunction
- Dental skeletal deformity
• Lip incompetence is common in children
• What looks like incompetent lips in childhood or early adolescence is
merely a reflection of incomplete soft tissue growth
• Females : Upper lip - till 14 yrs, Lower lip - continues to grow up to the age
of 16
• Males : growth of both upper & lower lip continues till late teens
• The length of the upper lip should be 1/3rd the length of the lower facial
third, almost 22 ±2 mm in males and 20 ±2mm in females

25. A normal upper tooth – to lip relationship
exposes 2.5 ± 1.5 mm of incisal edge to
lips.
The facial midline, nasal midline, lip
midline dental midline all should be in line
and face should be reasonably symmetric,
vertical and transversely.
During smiling the vermilion of the upper
lip should fall at the cervicogingival
margin with no more than 1 to 2 mm of
exposed gingival.
Lips

26. Profile view
• Fore head Slopes anteriorly
• Accentuated at supra orbital rim
• Frontal bossing
• Supra orbital hypoplasia
• The distance form glabella to subnasale and
from subnasale to soft tissue menton should
be in a 1:1 ratio if the upper lip length is
normal.
• Lateral orbital rims – 8 to12 mm behind the
anterior projection of globe. Globe is 0-2 mm
anterior to IO rim
• A line perpendicular to Frankfort horizontal
and tangent to the globe should fall on the
infraorbital soft tissues ± 2 mm.

27. • Alar base has to be supported by skeletal
nasal bone.
• Nasal bridge – 5 – 8 mm ant to globes
• Nasal tip ( prn ) – subnasale : subnasale –
alar base crease = 2:1
• If values of 1: 1 – maxillary defeciency
• Naso labial angle – 90 to 110 degrees
• The length of the upper lip should be 1/3rd
the length of lower facial height (third). Lower
lip stomion to soft tissue menton should be
twice the vertical dimension of the upper lip if
the upper lip is normal in length
Profile view

28. Clinical facial examination - Profile view
• Mandibular area
With the maxilla in normal AP
position and the upper lip normal
thickness, ideal chin projection is 3
± 3 mm posterior to a line through
subnasale that is perpendicular to
a clinical Frankfort horizontal.

29. Labiomental fold
• The labiomental sulcus should form a
shallow S curve, with the upper and lower
portions similarly shaped. The
prominence of the chin should be slightly
less than the prominence of the lower lip.
– Neck – chin angle – 110
– Throat length– 50 mm
• skin laxity, cervical facial lipomatosis, high
mandibular plane angle are conditions –
obscure the definition

30. TMJ Examination
•The range of movements
• Deviation from normal
movements
• Any pain during movement
• The joint sounds.

31. Intra-oral examination
• Periodontal health (pre-existing periodontal disease exacerbated with
orthodontic treatment) along with H/O smoking, excess alcohol
consumption, bruxism etc. check adequacy of attached gingiva, especially
in mandibular anterior region. Correct these problems if present.
• Tooth size discrepancy
• Occlusal relationship (class I, II, III)

32. Dentition
• Vertical
– Overbite
– Plane of occlusion
– Curve of spee
• Transverse :
Posterior Cross bite – max.
deficiency

33. Horizontal
• Anatomical variation
• Crowding / spacing
• Overjet
• Missing, decayed, retained primary teeth
• Impacted teeth

34. Soft tissues
• General periodontal condition
• Tongue size, position and activity
• Mentalis muscle activity
• Finger or thumb sucking

35. Evaluation Of nose
• H/O nasal trauma, nasal airway obstruction, allergies, sinus problems,
mouth vs. nasal breathing and previous surgeries
• Examination of internal and external nasal structures.

36. Photographs
• To keep a record of the clinical
findings. Photographs are
taken at different angles:
• Frontal view – at rest and
smiling
• Profile view
• Oblique View
• Occlusion/bite
• Canting

37. Pre-surgical orthodontics
The basic presurgical orthodontic goals are as follows:
• Align and position teeth over basal bone
• Avoid excessive intrusion or extrusion of teeth
• Decompensate teeth
• Avoid unstable expansion of the dental arches
• Avoid class II and class III mechanics (unless required for dental
decompensation correction in the arches)
• Perform stable and predictable orthodontics
Treatment includes: inter-proximal reduction of teeth (slenderizing teeth),
space creation, extractions, altering axial and mesio-distal inclination on
incisors, protraction and retraction of teeth, distalization of posterior teeth
and various inter-arch mechanics.

38. • Positioned Long axis of max. CI 22 ° and labial surface is 4 mm anterior to
the NA line
• Positioned maxilla and normal occlusal plane angle.
• Positioned Long axis of mand. CI 20 ° and labial surface is 4 mm anterior
to the NB line
• Satisfy arch length requirements
• Pre-surgical phase takes 24 – 30 months.

39. Radiographs
Lateral Cephalograms: taken with jaws in CR, teeth slightly touching and lips
relaxed. If bite is closed, second lateral ceph is taken with condyles still in CR
but jaws open till lips just begin to separate. Head position such that FH is
parallel to the floor. Intensifying screens may be used for proper visualization
of hard and soft tissues.

40. • P-A Cephalograms: taken to asymmetries. Head is kept 5 degrees down
from clinical FH plane.
• OPG and IOPAs: taken to assess tooth alignment, root angulation, pathosis
and nerve/canal position assessment
• Other radiographs like TMJ tomograms, water’s view, CT, MRI may be
taken if required (Eg. CT may be done in cleft cases to determine the
amount of bone in the cleft)

41. Dental study models
• Arch length analysis
• Tooth size analysis
• Incisor angulation
• Arch width analysis
• Curve of Spee/ wilson
• Cuspid-molar relation
• Tooth arch symmetry

42. Diagnosis and treatment planning
• Keep in mind: treatment of patient not photograph/radiograph
Developing diagnostic list
• Functional problems
• Aesthetic problems
• Dental problems
• The jaws relation and facial proportion including the nose and the
ears.
• Periodontal condition.
• Speech pattern.
• Psychological condition.

43. Cephalometric analysis
• The cephalometric analysis helpful in diagnosing the problem, helps in
treatment planning and also allows clinician to evaluate changes after
surgery.
• These analyses primarily designed to evaluate the position of the teeth
with the existing skeletal pattern.
• HARD TISSUE ANALYSIS - COGS, STEINERS, WITS APPRAISAL, SCHWARZ
ANALYSIS
• SOFT TISSUE ANALYSIS -COGS, HOLDAWAY
• PA CEPH ANALYSIS FOR SYMMETRY – gurmmons analysis

44. COGS analysis
HORIZONTAL PLANE (HP), which is
a surrogate Frankfort plane,
constructed by drawing a line 7 o
from the line S to N.
• Ar- PTM :
– The relationship of maxilla to
the cranial base

45. Horizontal skeletal profile
• N-A –Pg (Angle): gives an
indication of the overall facial
convexity. A positive (+) angle of
convexity denotes a convex face;
a negative (-) angle denotes a
concave face.

46. Vertical skeletal and dental
• Middle third facial height : Distance
from N to ANS
• Posterior maxillary height : PNS-N
• Lower third facial height :
ANS – GN
• Divergence of mandible posteriorly :
M.P-H.P angle(clockwise or counter
- clockwise rotations of the maxilla
and mandible)

47. • U1 to NF: Anterior maxillary
dental height
• L1 to MP: Anterior mandibular
dental height
These two measurements define
how far the incisors have erupted
in relation to NF and MP
respectively.
• Max. molar to NF : Posterior
maxillary dental height
• Mand. Molar to MP: Post
mandibular dental height

48. Max-mand. Relation
• ANS-PNS: This measurement along with the
N-ANS and PNS– N gives a quantitative
description of the maxilla in the skull
complex.
• Ar - Go : Length of Mandibular ramus
• Go - Pg : Length of Mandibular body
• Ar - Go - Gn Angle : Gonial angle that
represents the relationship between ramal
plane and MP. Vertical /Horizontal growth
• B - Pg : Distance from B point to line
perpendicular to MP through Pg describes
chin prominence.

49. Dental
• OP- upper HP:
• AB – OP:
• U1 to NF angle & L1 to MP angle:
These angulations determine the
procumbency or recumbency of
the incisors.

50. Steiner’s analysis
S.N
o
Measurement Mean
1. SNA 820
2. SNB 800
3. ANB 20
4. SND 760
5. M.P to SN 320
6. U1 to N-A 4mm
7. U1 to N-A (angle) 220
8. L1 to N-B 4mm
9. L1 to N-B (angle) 250
10. Interincisal angle 1300
11. Occ. Plane to S-N (angle) 140

51. Wits appraisal
• AO is 2mm ahead of BO - skeletal class I

52. Holdaway’s soft tissue analysis
Measurement Mean
Facial angle 90-920
Upper lip curvature 1.5-4mm (2.5)
Skeletal convexity
at point A
-2 to +2
H-line angle 7-150
Nose tip to H-line Upto 12mm
Upper sulcus depth 3-7mm
Upper lip thickness 15mm
Upper lip strain Same as ULS
Lower lip to H-line 0mm -1to +2mm
Lower sulcus depth 5mm
Soft tissue to chin
thickness
10-12mm

53. Cogs soft tissue analysis

54. The first horizontal plane
connects the medial aspects of
the zygomaticofrontal sutures.
The second horizontal plane
connects the center of the
zygomatic arches.
The third horizontal plane
connects the jugal processes.
A fourth horizontal plane runs
through the menton and is
parallel to the first plane
Grummons article JCO 1987
Gurmmon’s analysis

55. MSR-J maxillary width
MSR-Ag mandibular width
MSR-NC width of NC
Nasal septum
deviation
MSR-Co Asymmetry in condyle
MSR-Me Mandibular symmetry
LINEAR ASYMMETRY
MAXILLARY MANDIBULAR COMPONENTS

56. Limitations of cephalometric analysis
1)Growth pattern not taken into consideration
2)Mean values are based on different population
3)Two dimensional representation of three dimensional object
4)Form and functions not taken into consideration

57. Prediction tracing (surgical treatment
objective /STO)
• Establish pre-surgical orthodontic goals
• Develop accurate surgical objective that will achieve the best functional
and esthetic results
• Create a facial profile objective that can be used as a visual aid in
consultation with patient and family members.

58. Prediction tracing (surgical treatment
objective /STO)
• Only maxillary surgery – vertical position
• Only mandibular surgery
• Double- jaw surgery
1. Vertical position of maxillary incisor
2. A-P position of maxillary incisor
3. Occlusal plane angulation

59. Computerized Chephalometry
• First, Profile Image & Lateral
Cephalogram of the patient should be
taken in Natural Head Position.
• An image of lateral cephalogram is
scanned into pt’s file or direct digital
cephalogram is entered.
• An “electronic tracing” is then
produced by using digitization pad to
enter points.
• Pt’s Profile Image is then entered into
file.

60. Computerized Chephalometry
• Digital tracing is then “sized” to fit &
coordinate with the facial image, using
profile as the overlay reference.
• The small boxes on teeth & jaws seen
at this point respresent treatment
“handles” by which teeth & osseous
segments can be moved in simulation
of treatment changes.

61. Analytic model surgery
Facebow transfer and mounting Reference line marking

62. Analytic model surgery
1. Isolated mandibular surgery
2. Isolated maxillary surgery
3. Segmental maxillary surgery
4. Combined – doublejaw surgery

63. Post-surgical orthodontics
• Post surgical should start within 4-8 weeks. detailing of
occlusion requiring 4-6 months
• GOALS: posterior cross bite correction, extrusion for leveling
and setting, detailing occlusion, root paralleling.

64. Virtual surgical planning
• performed on a virtual model composed of
a three-dimensional (3D) scan of the
maxillofacial skeleton and a 3D scan of the
dental arch
• Standard CT with 1mm cut and dental
model
• Super impositio n of Soft tissue profile
• key anatomical land marks like ANS,
Point A,B pog, were marked
Virtual surgery starts
by setting the maxillary position followed by
mandible
• occlusal splints can be fabricated using
CAD/CAM technique.

65. The two major soft- ware systems for 3D virtual planning are SimPlant &
Dolphin 3D
Virtual planning appears to be an accurate and reproducible method
for orthognathic treatment planning as difference of maximum 2 mm

66. Soft tissue changes
• Nasal tip elevation-1mm for 6mm superior movement of U1
• Nasiolabial angle decreases 1-4 degree per 1mm advancement
• Low angle cases-maxillary superior reposition if 10 mm then forward auto
rotation -3mm
• High angle cases-maxillary superior reposition if 10 mm then forward auto
rotation -6.5mm
• The type of soft tissue manipulation employed, in particular the use of the
alar base cinch suture and V-Y closure techniques, were important factors in
determining the response of the upper lip to the surgery. The maxillary soft
tissues moved forward 90% of the hard tissue change and showed 20%
shortening of the upper lip, with the changes in the nasolabial angle
British Journal of Oral and Maxillofacial Surgery Volume 30, Issue 5, October 1992,

68. • For the impaction group,
(1) the upper lip closely followed the movement of the maxillary central
incisor in the horizontal plane
(2) the mandibular soft tissue followed the skeletal mandibular autorotation
on an approximately 1:1 basis, (3) the lower border of the upper lip moved
superiorly approximately 40 percent of the vertical maxillary change, and
(4) there was a superior vertical change in all of the maxillary soft-tissue.
• For the advancement group,
(1) a progressive increase in the horizontal soft-tissue movement from the tip
of the nose to the free end of the upper lip was observed and
(2) vertical change in the soft-tissue and horizontal movement of the
mandibular soft tissue was unpredictable

69. Surgery first approach
• Recently popularized
• To eliminate pre- operative orthodontic phase
• Need proper case selection - only anterio-posterior discrepancy
• The segment movement is based on lower lip and chin contour, height of
the lower facial region, and the consonance of the smile arc,
• Duration of treatment upto 12 months

70. Hierarchy of stability
Head & Face Medicine 2007, 3:21

71. summary
• Proper patient selection and treatment planning are necessary
• Radiographs are adjuvant to clinical diagnosis
• Priority has to be given for Patient expectations
• Basic therapeutic goals taken into consideration
• soft tissues are the limiting factors

72. • REFERENCES
• Peterson’s principles of oral and maxillofacial surgery (volume 2)
• Oral and maxillofacial surgery: raymond J Fonseca (volume 2: orthognathic surgery)
• Text book of oral and maxillofacial surgery - Kruger
• Essentials of orthognathic surgery: Johan P. Reyneke
• Orthodontic cephalometry: Athanasiou
• Dentofacial deformities-Epker Fish
• A systematic review on soft-to-hard tissue ratios in orthognathic surgery part I: Maxillary
repositioning osteotomy JOURNAL OF CRANIOMAXILLOFACIAL SURGERY 2012.
• Current Status of Surgical Planning for Orthognathic Surgery: Traditional Methods versus 3D
Surgical Planning Jeffrey A. Hammoudeh, MD, DDS, Lori K. Howell, MD, Shadi Boutros, MD,
DDS, Michelle A. Scott, DDS, MS, and Mark M. Urata, MD, DDS Plast Reconstr Surg Glob
Open. 2015 Feb; 3(2): e307
• Virtual planning in orthognathic surgery. Int. J. Oral Maxillofac. Surg. 2014; 43: 957–965.
• Computer-aided planning in orthognathic surgery—systematic review. Int. J. Oral Maxillofac.
Surg. 2015; 44: 329–342
• PLANNING OF ORTHOGNATHIC SURGERY – ‘A NEW ERA. Prof Dr K C Gupta , Dr Rajbir Kaur
Randhawa , Dr Rashi Yadav, Prof Dr S M Agrawal, Prof Dr P G Makhija, Dr Anurag Bhargav, Dr
Madhur Navlani NJDSR,Vol.1, January, 2012

73. • Soft tissue changes associated with double jaw surgery Alan C. Jensen, DDS, MS,
Peter M. Sinclair, DDS, MSD, Larry M. Wolford, DDS (AM J ORTHOD DENTOFAC
1992;101:266-75
• An evaluation of soft-tissue changes resulting from Le Fort I maxillary surgery
Stephen Mansour, D.M.D., Charles Burstone, D.D.S., M.S, Harry Legan, D.D.S.
American Journal of Orthodontics Volume 84, Issue 1, July 1983, Pages 37-47
• A three dimensional analysis of soft and hard tissue changes following bimaxillary
orthognathic surgery in skeletal III patients A.M. McCance, FDSRCPS, MSc,
MOrthRCS J.P. Moss, FDSRCS, PhD, MOrthRCS, W.R. Fright, PhD, D.R. James,
FRCS, FDSRCS, A.D. Linney, PhD. British Journal of Oral and Maxillofacial Surgery
Volume 30, Issue 5, October 1992, Pages 305-312

74. Thank you…