Genioplasty in Brief

3,185 views

Published on

Genioplasty overview

Published in: Health & Medicine
1 Comment
10 Likes
Statistics
Notes
No Downloads
Views
Total views
3,185
On SlideShare
0
From Embeds
0
Number of Embeds
2
Actions
Shares
0
Downloads
257
Comments
1
Likes
10
Embeds 0
No embeds

No notes for slide

Genioplasty in Brief

  1. 1. DR MOHAMMED HANEEF
  2. 2.  Introduction and History  Pre-operative evaluation and facial analysis  Implant materials and sizing  Implantation technique  Complications
  3. 3. Introduction  Multiple factors contribute to the aesthetically pleasing face ○ Skin  Texture  Color  Thickness ○ Soft tissue  Composition, location ○ Bony contours  Size, shape, location, and symmetry ○ Cultural norms
  4. 4. CLASSIFICATION OF CHIN DEFORMITIES  Class I macrogenia a. Horizontal b. Vertical c. Combination of both  Class II microgenia a. Horizontal b. Vertical c. Combination of both  Class III combined a. horizontal macrogenia with vertical microgenia b. horizontal microgenia with vertical macrogenia
  5. 5.  Class IV assymmetric chin a. Short anterior facial height b. Normal anterior facial height c. Long anterior facial height  Class V Witch’s chin(soft tissue ptosis)  Class VI pseudomacrogenia  Class VII pseudomicrogenia
  6. 6. PREOPERATIVE EVALUATION  Lip position, shape  Depth of labio mental fold  Soft tissue around chin  Mentalis muscle activity  Cephalometric evaluation downs analysis steiners analysis tweeds analysis
  7. 7. SOFT TISSUE EVALUATION  Gonzalez – Uloa & Steven’s analysis  A line is dropped from the soft tissue Nasion perpendicular to frankfort horizontal plane  This line is called zero meridean  Ideally Soft tissue pogonian of the chin should be at or just posterior to the zero meridean
  8. 8. HISTORY OF GENIAL PROCEDURES  Hofer in 1942 described horizontal sliding osteotomy  Trauner & Obwegesser in 1957 horizontal sliding osteotomy with intraoral incision  Reichenbach in 1965 wedge osteotomy & vertical shortening of chin
  9. 9. Advanced sliding genioplasty
  10. 10. Chin Augmentation  Often an adjunct to rhinoplasty  Particularly important in creating an aesthetic profile
  11. 11. Horizontal osteotomy with advancement  Incision half way the depth of vestibule and extended to canine region bilaterally.  Periosteum left intact on the inferior border  Line of osteotomy should be 5 mm below canine root & 10 to 15 mm above the inferior border & 5 mm below the lowest mental foramen
  12. 12.  Fragment stabilized by  unicortical or bicortical wires  bone plates  prebent chin plates  lag screws
  13. 13. HORIZONTAL OSTEOTOMY WITH REDUCTION  Prefabricated chin fixation plate or H shaped plate is used  When the chin is set back postero lingual area has a palpable step defect.  To prevent this postero lingual area is contoured  Labio mental fold is enhanced by contouring the anterior superior edge.
  14. 14. Vertical increase of the chin
  15. 15. Vertical decrease of the chin
  16. 16. DOUBLE SLIDING HORIZONTAL OSTEOTOMY  In very deficient chin  Creation of a stepped intermediate wafer of bone between the inferior fragment and mandible  This segment is advanced to produce bony contact between upper and lower fragments
  17. 17. Correction of assymmetry of chin  Done in unilateral condylar hyper or hypoplasia where the chin is deviated.  Done for the lateral movement of the chin  Also known as propeller osteotomy  First osteotomy is performed parallel to the inter pupillary line  Second osteotomy is performed parallel to the lower border of the chin
  18. 18. Altering the width of the chin  Altering the posterior dimension  Before the chin is mobilised fix a 4 hole straight plate at the labial cortex of the chin  Midline osteotomy is performed both buccal and lingual cortex  Chin widened using bone plate as a hinge  To narrow the chin triangular midline ostectomy is performed.
  19. 19. Altering the anterior dimension  For narrowing the anterior dimension of chin a midline ostectomy is performed at the centre and this part is removed  Lateral segments are moved medially  For widening the anterior dimension of chin osteotomy is performed in the centre of the chin fragment  After increasing the width bone graft is placed between the segments
  20. 20. Augmentation using implants  Autologous  Calvarial bone  Metals  Corrosive  High rate of bone erosion  Polymers – most commonly used
  21. 21.  Polymers – carbon chain based molecules with crosslinking  Dimethylsiloxanes ○ Silicone based ○ Silastic  Polyamide ○ Supramid  Polyethylene (polyester fiber) ○ Mersilene (Polyethylene terephthalate) ○ Dacron ○ Medpor (porous polyethylene)  Expanded polytetrafluoroethylene (PTFE) ○ Gore-Tex ○ Avanta  PTFE ○ Teflon ○ Proplast I and II  Polymethylmethacrylate (PMMA) Silicone chin implants
  22. 22.  Composite polymer implants  Hard Tissue Replacement (HTR) ○ PMMA + polyhydroxyethylmethacrylate and calcium hydroxide  Hydrophilic outer layer for osseointegration  Silastic implant with Dacron backing ○ Increase interface soft tissue ingrowth
  23. 23. Complications  Wound dehiscense  Prolonged neurosensory disturbances  Avascular necrosis of mobilised segments  Hemorrhage causing lingual hematoma  Chin ptosis  Bony resorption under alloplasts  Devitalisation of teeth  Mandibular fracture  Mucogingival problems
  24. 24. References  Fonseca vol2 orthognathic surgery  Johan P Reyneke – Essentials of orthognathic surgery

×