©Sylvain Chamberland

Orthognathic surgeryA visual aid of what happen.

slideshare.net/sylvainchamberland

©Sylvain Chamberland

Le Fort 1 Osteotomy

• Osteotomy half way between apices of the teeth and infraorbital nerve

Courtesy Dr Carl Bouchard

Piriform rimZygomatic buttress

Infraorbital nerve

©Sylvain ChamberlandDistal to canine cuts

Le Fort 1 Osteotomy

• Down fracture of the maxilla viewed from above

! The maxilla has been separated down from the skull

! Ostetomy cuts are done each side of the mid palatal suture and distal to the canine

Courtesy Dr Martin Gaboury

1 2

3

4

Parasagittal cuts

©Sylvain Chamberland

Segmentation of the maxilla

• When transversal expansion is needed, the maxilla is segmented

! Islet 1, 2, 3 are the 3 segmented part of the maxilla

! Islet 4 is the midpalatal suture

! Blood flow is maintained by soft tissue from the palate and soft palate

Courtesy Dr Martin Gaboury

1 2

3

4

Parasagittal cuts

Distal to canine cuts

©Sylvain Chamberland

Le Fort 1 Osteotomy

• 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

Courtesy Dr Martin Gaboury

Sinus floor Cortocospongious bone

Allogenic bone particles

©Sylvain Chamberland

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

Courtesy Dr Martin Gaboury

Surgical splintIntermediary splint

©Dr Sylvain Chamberland

Rigid fixation

• Osteotomy sites filled with bone from the slice removed at the symphysis

• Rigid fixation to the piriform rim & zygomatic buttress

Courtesy Dr Carl Bouchard

DL 130312

©Dr Sylvain Chamberland

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

Courtesy Dr Carl Bouchard

©Dr Sylvain Chamberland

Genioplasty

• Pre-bended 6 mm monocortical plate

• 2 lateral cortical plates to avoid rotation of the distal segment and improve bone contact

Courtesy Dr Carl Bouchard

Mental nerve

©Dr Sylvain Chamberland

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

Courtesy Dr Dany Morais

©Dr Sylvain Chamberland

Why I don't like rigid fixation for a genioplasty

Poor contact between distal & proximal segment

Screw EmbedLu.Mo.010710 Lu.Mo.130212

Note bone formation over superior portion of fixation device and resorption in area of inferior

portion of fixation device

Screw in the resorptive zone

Apposition zone

Screw prominent

©Dr Sylvain Chamberland

• 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 performed in Quebec

©Dr Sylvain Chamberland

Courtesy Dr Dany Morais

Why do I prefer osteosynthesis?

Resorptive zone

R: RemodelingA: Apposition

De.Le060608 De.Le130410

Resorptive zone

Apposition zone

Improved contact between proximal and distal segment

Precious D., Armstrong J., Morais D., Anatomic placement of fixation device in genioplasty, OOO 1992,; 73-2-8

Note complete coverage of fixation wires by bone and smooth labial

cortical bone of anterior manbible

©Dr Sylvain Chamberland

Why I don't like posterior openbite after orthognathic

surgery?

• Lack of posterior occlusion may increase pressure at the condyle and cause non-physiologic remodeling or condylar resorption

Jam-packedScrewed Setting occlusion

Pressure

The bite openSlight progressive

retrusion

Condyle resorb