Orthognathic Surgery Flashcards

1
Q

What is orthographic surgery?

A

Surgery to correct the irregularities in the jaw bones and re-position either one or both of the jaws so that the patient bites together in a better position.

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2
Q

What are the fundamentals of orthographic surgery?

A
  1. Team approach- MDT
  2. History- find out how the deformity happened, what they don’t like about it.
  3. Careful clinical examination
  4. Special Investigations
  5. Prediction planning.
  6. Stable surgical techniques
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3
Q

Who might be involved in the MDT for orthographic surgery?

A

Orthodontist
Maxillofacial surgeon
Paediatric dentist
GDP
Psychologist
Speech and language therapist
Dietician
Technician
Restorative dentist

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4
Q

Why is a psychologist required prior to orthognathic surgery?

A

Understand the motivation for surgery- is there an underlying psychological disorder? Body dysmorphia?

Post-surgical depression

Psychological adaptation to a new face

What is the patient’s mental state? Anxious? Depressed?

Previous or current mental health conditions.

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5
Q

What does the technician do with regards to orthognathic surgery?

A

Provide occlusal wafer to guide surgery

Building 3D skull models

Digital predictions of final occlusion

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6
Q

What is the role of the orthodontist in orthognathic surgery?

A

Early recognition of dento-facial abnormalities

Orthodontic preparation of the dentition before and after surgery.

Follow up.

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7
Q

What is the role of the surgeons in orthognathic surgery?

A

Surgically move the jaws into the right position.

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8
Q

What aspects of the history are important to find out from someone when considering them for orthognathic surgery?

A

Does anyone else in your family have jaws like this?

If it is not genetic then think about what else it could be
- Condylar hyperplasia
- Cysts
- Acromegaly
- Trauma

Determine the motivation of the surgery and what they don’t like about their jaws.

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9
Q

What aspects of the E/O examination would you want to check?

A

Look from the front- is the face symmetrical? Look at vertical symmetry and horizontal symmetry.

Lip and nose morphology- upper lip and lower lip should touch- oral seal.

A-P relationship- relationship of the maxilla and the mandible to the anterior cranial base and also to each other.

Skeletal relationship- Class I, II or III

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10
Q

What aspects of the I/O examination would you want to investigate?

A

General dental examination

Smile line
Crowded/spaced/misaligned in the upper and lower dentition
Incisor classification
Canine classification
Molar classification
Overbite
Overjet
Inclination of upper and lower incisors
Centre line discrepancy

Tongue size, mobility, speech pattern.

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11
Q

What special investigations might you opt to do?

A

Radiographs- OPT, PA, lateral ceph
CBCT- tells us the shape of the mandible and the maxilla in 3D

Study models

Clinical photographs

Stereophotogrametry- 3D photographs, use an intra-oral scanner for this.

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12
Q

What are study models used for in orthognathic surgery?

A

Study occlusion
Orthodontic analysis
Orthognathic surgery planning
Occlusal safer for surgery
Assess surgical changes
Assess long term stability/relapse

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13
Q

What diagnosis might someone have that might be helped with surgery?

A

Maxilla
- Retrognathic
- Prognathoc
- Vertical excess
- Vertical deficiency
- Narrow or wide maxilla

Mandible
- Retrognathic
- Prognathic

Chin
- Progenia
- Retrogenia

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14
Q

What options can you give to the patient?

A

Orthodontics alone

Orthodontics and surgery

Surgery alone

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15
Q

What would the orthodontics and surgery combination involve?

A

Pre-surgical orthodontics- decompensated the incisors, align the teeth, co-ordinate the arches.

Surgery to correct the jaw position.

Post-surgery orthodontics for fine tuning.

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16
Q

What type of surgery might be needed to correct the position of the maxilla?

A

Le Fort I osteotomy
- Disarticulate the maxilla from the base of the skull and move it to pre-planned position using the surgical wafer and fix in place with plates and screws.
- Can move the maxilla forwards, downwards and upwards but not backwards because of the pterygoid plate.

Anterior maxillary osteotomy- this surgery is to move the maxilla backwards.

17
Q

What surgical techniques might be employed for the mandible?

A

Sagittal split mandibular osteotomy- this is advancement surgery.
- Separate the ramus from the body of the mandible- movie the body of the mandible in any direction that you want.
- Then fix in place with plates and screws.

Sagittal split osteotomy- set the mandible back.
VSSO- set the mandible back

18
Q

What surgery might you employ for the chin?

A

Genioplasty- Advancement, set back, rotation, reduction.