Description of orthognatic surgery Le Fort 1, bilateral sagittal split osteotomy and genioplasty

1. Orthognathic surgery
A visual aid of what happen.
slideshare.net/sylvainchamberland
©Sylvain Chamberland

2. Le Fort 1 Osteotomy
Zygomatic
Piriform rim
buttress
Infraorbital nerve
• Osteotomy half way
between apices of the
teeth and infraorbital
nerve
Courtesy Dr Carl Bouchard
©Sylvain Chamberland

3. Le Fort 1 Osteotomy
Parasagittal cuts
• Down fracture of the maxilla
viewed from above
! The maxilla has been
separated down from the 1 4
2
skull
3
! Ostetomy cuts are done each
side of the mid palatal suture
and distal to the canine
©Sylvain Chamberland Courtesy Dr Martin Gaboury Distal to canine cuts

4. Segmentation of the maxilla
Parasagittal cuts
• When transversal expansion is
needed, the maxilla is segmented
! Islet 1, 2, 3 are the 3 segmented
part of the maxilla 4
1 2
! Islet 4 is the midpalatal suture
3
! Blood flow is maintained by
soft tissue from the palate and
soft palate
©Sylvain Chamberland Courtesy Dr Martin Gaboury
Distal to canine cuts

5. Le Fort 1 Osteotomy
Sinus floor Cortocospongious
bone
• Autogenous corticospongious
bone grafting
! Donor site are either the malar
bone or the mandibular ramus.
Iliac crest can be used.
! Demineralized allogenic bone
particles fills the interstice
©Sylvain Chamberland
Allogenic bone particles Courtesy Dr Martin Gaboury

6. Positionning the maxilla
• The surgical splint is fixed
to the maxilla
• The lower jaw is attached
to the upper jaw by the
intermediary splint to
guide the maxilla to its
new position
Intermediary splint Surgical splint
©Sylvain Chamberland Courtesy Dr Martin Gaboury

7. Rigid fixation
• Osteotomy sites filled with bone
from the slice removed at the
symphysis
• Rigid fixation to the
piriform rim
& zygomatic buttress
©Dr Sylvain Chamberland
DL 130312
Courtesy Dr Carl Bouchard

8. Bilateral sagittal split
osteotomy
• Osteotomy cut
vertically extending
down near the 1st molar
and horizontally
extending posteriorly to
the ramus
• 3 bicortical screws on
each side
©Dr Sylvain Chamberland
Courtesy Dr Carl Bouchard

9. Genioplasty
• Pre-bended 6 mm
monocortical plate
• 2 lateral cortical plates to
avoid rotation of the distal
segment and improve bone
contact
Mental nerve
©Dr Sylvain Chamberland Courtesy Dr Carl Bouchard

10. Genioplasty
• Wire fixation for genioplasty
! This avoid having any fixation in the resorptive
zone
! The twisted part of the wires will be embed by
bone apposition
• Note the amount of advancement
obtained
©Dr Sylvain Chamberland Courtesy Dr Dany Morais

11. Why I don't like rigid fixation
for a genioplasty
Lu.Mo.010710 Lu.Mo.130212
Apposition zone Screw Embed
Screw in the
resorptive zone
Screw
Poor contact between distal prominent
Note bone formation over superior
& proximal segment portion of fixation device and
resorption in area of inferior
portion of fixation device
©Dr Sylvain Chamberland

12. • Lack of bone contact between distal and proxmial
segment
• Horizontal rotation of distal segment to the right
• Notch on the left side of the chin
This surgery was NOT
©Dr Sylvain Chamberland
performed in Quebec

13. Why do I prefer
osteosynthesis?
Apposition
zone
R: Remodeling
A: Apposition Courtesy Dr Dany Morais
Resorptive
Note complete coverage of fixation
zone
wires by bone and smooth labial Resorptive zone
Improved contact between proximal and cortical bone of anterior manbible
distal segment
De.Le060608 De.Le130410
©Dr Sylvain Chamberland
Precious D., Armstrong J., Morais D., Anatomic placement of fixation device in genioplasty, OOO 1992,; 73-2-8

14. Why I don't like posterior
openbite after orthognathic
surgery?
Pressure Condyle resorb
• Lack of posterior occlusion
may increase pressure at the
condyle and cause
non-physiologic remodeling
or condylar resorption
Screwed Setting Jam-packed Slight progressive
occlusion retrusion The bite open
©Dr Sylvain Chamberland