Orthoghantic surgery Flashcards
Orthognathic surgery - definition
Surgery aimed at correcting dentofacial deformity
Dentofacial deformity: definition
Deviation from “normal” facial proportions and dental relationships severe enough to be handicapping to the patient
Handicap may be due to
-Aesthetics
-Jaw function
Jaw function
Eating
Speech
Indications for orthognathic surgery ?
- severe skeletal discrepancy
- severe dento-alveolar problem too extreme to correct with orthodontics alone
- Unsuitable for growth modification or orthodontic camouflage
Sagittal indications?
Severe class II skeletal malocclusions Severe class III skeletal malocclusions
Vertical indications?
Severely increased traumatic overbite
Extreme AOB
Transverse indications?
Asymmetry
Types of Maxillary procedures
Segmental procedures Le Fort I Le Fort II Le Fort III Surgically assisted rapid palatal expansion (SARPE)
Le Fort 1 procedure
Most common procedure
Horseshoe incision of buccal mucosa and bone
Maxilla freed and attached only by palatal vessels and soft tissues
Maxilla can be moved:
Upwards – bone removed
Downwards – bone graft
Forwards
Le Fort 2 procedure
More extensive than Le Fort I
For mid-face advancement
Le Fort 3 procedure
Commonly used for treatment of craniofacial anomalies
Access usually requires raising of a bicoronal flap
SARPE what does it stand for?
Surgically assisted rapid palatal expansion (SARPE)
Surgically assisted rapid palatal expansion (SARPE) procedure
An attempt to correct transverse inefficiency without segmental surgery
Corticotomies and rapid palatal expansion
RPE activated immediately
Mandibular procedures
Segmental procedures Ramus procedures Body osteotomy Genioplasty Post-condylar graft
Remus procedure
Vertical subsigmoid osteotomy
- For mandibular prognathism
- Bone cut from sigmoid notch to lower border
Saggital split osteotomy
- To advance or retrude mandible
- Bone cut extends obliquely from above lingula, across retromolar region and vertically down buccal plate to lower border
Body ostiotomy
Rarely used
May be useful if natural space anterior to mental foramen
Otherwise extraction required
Genioplasty proceedure
Chin tip moved
Limited only by bony contact and muscle attachments
Can avoid more complex procedures
Post condylar graft
Used in growing children with severe mandibular retrognathism
Insertion of cartilage behind condylar head
Can get condylar fossa remodelling
However may require multipal interventions
May still require orthognathic surgery
Bimaxillary surgery procedure
Surgery required in both maxilla and mandible
Skeletal discrepancy may be too severe for single arch treatment
Aesthetic balance
Distraction osteogenesis procedure
Increasingly used to treat congenital craniofacial abnormalities
Attempt to overcome limitations on movement by soft tissues
Bone sectioned
Incremental traction applied to bone ends
Tension in callus
Bone formation stimulated in direction of traction
Treatment sequence
Extractions Pre-surgery orthodontics Reassessment and definitive surgical planning Surgery Post-surgery orthodontics
What do we need to achieve with pre surgery ortho?
Level and align Co-ordinate arches Decompensate Specific space creation Majority of movement before osteotomy More accurate planning of surgery More predictable surgery
What does the surgey involve?
Hospital procedure Bony plates in maxilla Plates or screws in mandible Wafer inserted Inter-maxillary elastics
What are the surgical factors for relapse?
Size of movement required >5mm in maxilla >8mm in mandible Condylar head distraction from glenoid fossa during surgery Inadequate fixation
