Orthognathic Surgery And Osteotomy Procedures

Orthognathic Surgery And Osteotomy Procedures Important Notes

1. Indications Of Sagittal Split Osteotomy:

• Mandibular prognathism
• Mandibular retrognathia
• Bimaxillary protrusion
• Skeletal open bite
• Mandibular excess

2. Classification Of Osteotomy Procedures:

1. Mandibular Body Osteotomies
   • Mandibular body osteotomies
     • Anterior body
     • posterior body
     • Midsymphysis
   • Segmental Subapical
     • Anterior
     •  Posterior Total
   • Genioplasties
     • Augmentation
     • Reduction
     • Straightening
     • Lengthening
2. Mandibular ramus osteotomies
   •  Sub condylar
   •  Bisagittal split
3.  Maxillary osteotomy procedures
   • Segmental
     • Single Tooth
     • Interdental
     • Anterior
     • Posterior
   •  Total
     • Superior repositioning
     • Inferior repositioning
     • Advancement of maxilla
     • Leveling of maxilla

Read And Learn More: Oral and Maxillofacial Surgery Question and Answers

3. Types Of Genitoplasty:

• Augmentation genioplasty
• Reduction genioplasty
• Straightening genioplasty
• Lengthening genioplasty

4. Treatment For Mandibular Prognathism:

• Sagittal split osteotomy with mandibular setback Oblique sub condylar osteotomy

5. Bilateral Sagittal Split Osteotomy:

• First described by Trauner and Obwegesser
• Modified by Dalpont, Hunsuck, and Epker It is the most popular and versatile procedure
• Performed on mandibular ramus and body
• The osteotomy splits the ramus and the posterior body of the mandible sagitally
• This allows either setbacks or advancement

6. Various Malocclusion And Their Treatment Options;

Orthognathic Surgery And Osteotomy Procedures Long Essays

Question 1. Pre-operative planning in orthognathic surgery.
Answer:

Assessment Of Patient:

• Includes:
  • Patient’s chief complaint
  • Patient’s expectations
  • Medical status of the patient
• Patient’s Examination:
  • Hard & soft tissues examination
  • TMJ evaluation
• Measurement Of Facial Proportions:
  • Dividing facial contour in 3 horizontal planes & comparing them
  • Dividing facial contour in 3 vertical planes & comparinging them
  • Facial profile examination
• Radiographic Examination:
  • Conventional radiography: For assessing any pathology
  • Cepholometric analysis
  • Hard & soft tissue landmarks are marked & jaw & face
  • contour is analysed
  • Special radiography done
  • Facial photography: For maintaining records
  • For computer-aided analysis
  • For treatment planning
  • For comparing pre- & post-operative appearance
• Model Surgery:
  • Involves the construction of occlusal models
  • Predict any occlusal problems
  • Modify orthognathic movements
• Treatment Planning:
  • All data is collected
  • Analysis is done
  • Review all orthodontic & surgical options
  • Decision made on whether surgical or orthodontic treatment is required

Phases Of Treatment:

1.  Pre orthodontic preparatory phase
   • Treatment of periodontics & restorative problems
2. Pre-surgical orthodontics
   • Orthodontically aligning of teeth
3. Surgical phase
   • Model surgery done
   • Fabrication of splint
   • Osteosynthesis done
4. Post-surgical phase
   • 4–8 weeks after surgery
   • Closing of spaces present
   • Removal of orthodontic brackets
   • Applying retainers
5. Prosthodontics phase
   1.  Placement of implants
   2. Periodontal management
   3. Esthetic restoration

Orthognathic Surgery And Osteotomy Procedures Short Essays

Question 1. Bilateral sagittal split osteotomy.
Answer:

Bilateral Sagittal Split Osteotomy

Described by Obwegeser & Trauner

Procedure Of Bilateral Sagittal Split:

• Bite block inserted on opposite side
• Incision made on lateral ascept of anterior border of the ramus
• Extend the incision into the vestibular depth
• Soft tissue dissection done
• Soft tissues are reflected
• Medial bone cut is done through lingual cortex
• Cut extended upto second molar region bite block is removed
• Separate the segments with the help of osteotome
• Accordingly, advancement or setback is done
• Fix the fragment

Question 2. Anterior maxillary osteotomy.
Answer:

Anterior Segmental Osteotomies:

• Indications:
  • Pre-maxillary protusion
  • Deep bite
  • Anterior open bite

1. Wassmund Procedure:

• Blood supply is from palatal mucoperiosteum Vertical incision given in the premolar region
• A small vertical incision given in the midline to expose the anterior nasal spine
• Premolars are extracted
• Buccal bone cuts are made
• The palatal cortical plate is cut vertically
• · Detach the nasal septum
• Mobilize the segment
• Reposition it to the desired position
• Fix it
• Closure of wound

2. Wunderer’s Procedure:

•  Blood supply is from buccal mucoperiosteum
• Horizontal incision is given across the palate
• Vertical incisions made in buccolabial sulcus
• A small vertical incision given in the midline to expose the anterior nasal spine
• Extract the premolars
• Buccal bone cuts given
• Detach nasal septum
• Mobilize palatal bone cut
• Mobilize anterior segment
• Fix & sutured it

Question 3. Mandibular hypertrophy.
Answer:

Features Of Mandibular Hypertrophy:

1. Extraoral features:
   • Concave profile
   • Anterior facial divergent
   • Prominent chin
2. Intraoral features:
   • Class 2 malocclusion
   • Lingually tilted lower incisors
   • Anterior cross bite
   • Narrow upper arch
   • Wide lower arch
   • Posterior crossbite
   • Crowded upper teeth
   • Spacing present in lower teeth

Treatment Of Mandibular Hypertrophy:

• Chin cup therapy to restrict maxillary growth
• In nongrowers
• Surgical mandibular setback which is followed after split osteotomy

Question 4. Genioplasty.
Answer:

Genioplasty

Used as an adjunctive

Types Of Genioplasty:

1. Augmentation Genioplasty:
   • Deglove inferior border of the symphysis
   • Periosteal releasing incision given
   • Horizontal osteotomy cut given at the apices of canine
   • Segment is mobilized
   • Removal of bony interferences
   • Check for the facial contour
   • Fix the superior body
2. Reduction Genioplasty:
   • Horizontal osteotomy cuts are given
   • Setback the fragment
   • Excise the bony interference
   • Fix the fragment
3.  Straightening Genioplasty:
   • Horizontal osteotomy cut are given
   • Shift segment laterally
4.  Lengthening Genioplasty:
   • Horizontal osteotomy cut are given
   • Segment is shifted inferiorly
   • Bone graft is sandwiched between the fragments.

Question 5. Cephalometry
Answer:

1. Introduced by Broadbent in USA & Hofrath in Germany in 1931
2. Describes analysis & measurements made on the cephalometric analysis

Types Of Cephalometry:

1. Lateral cephalogram
2. Frontal cephalogram

Uses Of Cephalometry:

• For diagnosis
• To study dental & soft tissue structures
• For the classification of skeletal & dental abnormalities
• Assess facial type
• For treatment planning
• For presuming results
• For predicting growth-related changes
• For research work

Question 6. Treatment for mandibular prognathism.
Answer:

Treatment For Mandibular Prognathism

• Sagittal split osteotomy with mandibular setback
• Oblique sub condylar osteotomy
  • Described by Obwegeser & Trauner

Procedure Of Treatment For Mandibular Prognathism:

• Bite block inserted on the opposite side
• Incision made on the lateral aspect of the anterior border of the ramus
• Extend the incision into the vestibular depth
• Soft tissue dissection done
• Soft tissue reflected
• Medial bone cut done in second molar region
• The bite block is removed
• Separate the segments with the help of osteotome
• Setback is done
• Fix the fragment

Orthognathic Surgery And Osteotomy Procedures Short Question And Answers

Question 1. Shift cone technique.
Answer:

Shift Cone Technique

Shift Cone Technique is an object localization technique

Technique Of Shift Cone:

• A standard radiograph is taken
• The tube is shifted either mesially or distally
• Second radiography is taken
• If an object appears on the same side, then it is located lingually
• If the object appears on the opposite side in the radiograph, then it is located buccally
• Also called same lingual opposite buccal [Slob Technique]

Question 2. Indications of sagittal split osteotomy.
Answer:

Indications Of Sagittal Split Osteotomy

• Mandibular prognathism
• Mandibular retrognathia
• Bimaxillary protrusion
• Skeletal open bite
• Mandibular excess

Question 3. Classification of Osteotomy procedures.
Or
Mandibular orthognathic producers.
Answer:

1. Mandibular Body Osteotomies:
   • Mandibular body osteotomies:
     • Anterior body
     • posterior body
     • Midsymphysis
   • Segmental Subapical:
     • Anterior
     • Posterior
     • Total
   • Genioplasties:
     • Augmentation
     • Reduction
     • Straightening
     • Lengthening
2.  Mandibular Ramus Osteotomies:
   1. Sub condylar
   2. Bisagittal split
3. Maxillary Osteotomy Procedures:
   • Segmental:
     
     • Single Tooth
     • Interdental
     • Anterior
     • Posterior

• • Total:
    • Anterior
    • Posterior
    • Superior repositioning
    • Inferior repositioning
    • Advancement of maxilla
    • Levelling of maxilla

Question 4. Define orthographic surgery.
Answer:

Orthographic Surgery

1. Orthognathic surgery is the art and science of diagnosis treatment planning & execution of treatment by combining orthodontics & oral & maxillofacial surgery to correct musculoskeletal endosseous & soft tissue deformities of the jaws & associated structures.
2. In severe skeletal deformities, orthodontic along may compromise stability & esthetics & surgery alone may compromise function & stability.

Ortho gnathic Surgery And Osteotomy Procedures Viva Voce

1. Genitoplasty is done to correct the deformities of the chin without altering the denture-bearing part
2. Anterior maxillary osteotomy is combined with an anterior subapical mandibular osteotomy to correct bimaxillary protrusion
3. In reduction genioplasty, the symphysis part of the mandible is reduced so that chin will attain a straight profile
4. Lefort I osteotomy are commonly performed procedure for the treatment of maxillary retrognathia
5. Apertognathia is a condition in which there is open bite deformity
6. During genitoplasty there are chances of injuring mental nerve