ORTHODONTIC AND ORTHOGNATHIC

SURGERY

BY DR. FITRI OCTAVIANTIDEPARTMENT OF ORTHODONTICS USIM

• Definition

• Indication and contraindications

• Advantages and disadvantages

• Criteria for orthognathic surgery

• Steps in orthognathic surgery

• Risk and complication of orthognathic surgery

WHAT DO YOU NEED TO KNOW?

• Orthognathic surgery is the surgical correction of abnormalities of the mandible, maxilla, or both

• The underlying abnormality may be present at birth or may become evident as the patient grows and develops or may be the result of traumatic injuries

DEFINITION

• Orthognathic surgery is concerned with the correction of dento-facial deformity

• In majority of cases a combined surgical and orthodontic approach is required to achieve an optimum result

DEFINITION

• Orthognathic surgery is necessary for those cases with a skeletal discrepancy outside the limits of orthodontic treatment either because of their severity or a lack of growth

• Usually performed when growth is virtually complete.

WHO NEEDS ORTHOGNATHIC SURGERY?

• To achieve an occlusion which has good function, aesthetics and stability

• To enable the achievements of optimal facial aesthetic

• To provide the best means of intraoperative intermaxillary fixation

• To provide for the attachment of post-operative intermaxillary elastics

THE ROLE OF ORTHODONTIST

1. Dentofacial problems too severe for orthodontics alone

2. Non-growing adults

3. Children with cranial-facial syndromes and severe dentofacial abnormalities, distraction osteogenesis may be considered.

INDICATIONS

4. Cases where there are specific documented signs of dysfunction.

• These may include conditions involving airway dysfunction such as sleep apnea, temporomandibular joint disorders, psychosocial disorders and or speech impairments

INDICATIONS

1. Severe anteroposterior discrepancies (class II/ class III malocclusions)

2. Vertical discrepancies (open bite/ deep overbite)

3. Transverse discrepancies

4. Skeletal asymmetry

EXAMPLES OF INDICATIONS

• Growing patients

• Mild malocclusion

• Patient with body dismorphic syndrome

• Medical problems

CONTRAINDICATIONS

• Aesthetic • 75% - 80% of patients seeks aesthetic improvement

• Psychological• About 90% of patients who undergo orthognathic surgery report

satisfaction with the outcome and over 80% say they would recommend such treatment to others and would undergo it again

• Functional • Able to speak and eat normally

ADVANTAGES

• Surgical risk

• Relapse

• Unsatisfied with results

• Motivated patients

• Availability of surgeons + orthodontist

• Cost

DISADVANTAGES

1. Anteroposterior discrepancies

2. Vertical discrepancies

3. Transverse discrepancies

4. Asymmetries

CRITERIA FOR ORTHOGNATHIC SURGERY

(THE AMERICAN ASSOCIATION OF ORAL AND MAXILLOFACIAL SURGEONS, 2008)

• Maxillary/mandibular incisor relationship: overjet of 5mm or more, or a 0 to a negative value (norm 2mm).

• Maxillary/mandibular anteroposterior molar relationship discrepancy of 4mm or more (norm 0 to 1mm).

1. ANTEROPOSTERIOR DISCREPANCIES

• Open bite

• No vertical overlap of anterior teeth.

• Unilateral or bilateral posterior open bite greater than 2mm

• Deep overbite with impingement or irritation of buccal or lingual soft tissues of the opposing arch.

• Supra eruption of a dentoalveolar segment due to lack of occlusion.

2. VERTICAL DISCREPANCIES

• Presence of a transverse skeletal discrepancy which is two or more standard deviations from published norms.

• Total bilateral maxillary palatal cusp to mandibular fossa discrepancy of 4mm or greater, or a unilateral discrepancy of 3mm or greater, given normal axial inclination of the posterior teeth.

3. TRANSVERSE DISCREPANCIES

• Anteroposterior, transverse or lateral asymmetries greater than 3mm with concomitant occlusal asymmetry.

4. ASYMMETRIES

2. Pre-surgical orthodontics

1. Diagnosis and treatment planning

3. Orthognathic surgery

4. Post-surgical orthodontics

STEPS IN ORTHOGNATHIC SURGERY

• A team approach is essential -orthodontist and surgeon to produce a coordinated treatment plan (joint clinic)

• Establish whether they are concerned with their skeletal pattern, the position of their teeth or a combination of two

1. DIAGNOSIS AND TREATMENT PLANNING

• The patient should be made fully aware of the various treatment options, the advantages, disadvantages and short and long term complications of each of possible treatment

Bring the teeth to a more normal position over their respective skeletal bases

AIMS:

• Alignment

• Decompensation

• Arch coordination

• Creation of space for interdental osteotomy cuts

• Falitation of the placement of temporary intermaxillary fixation during surgery.

2. PRESURGICAL ORTHODONTICS

Lateral chephalogram and intra-oralphotograph bebore and after presurgical surgery for management Class III malocclusion.Increase in reverse overjet during decompensation.

Space created for interdental cuts distal to the maxillary canines.The reserve tip of canines produced intentionally to move the canine

root away from osteotomy site.

• At the end of presurgical phase, heavy rectangular stainless steel archwires are placed (0.019 x 0.025 SS)

• Metal hooks are crimped directly into the archwire

Metal hooks are crimped directly into the archwire

• Prior to surgery records should be taken so that final surgical plan can be confirmed

• This include study models, photographs

and lateral cephalogram

• The models should be mounted on a semi adjustable articulator

3. THE SURGICAL PHASE OF TREATMENT

• Acrylic intermediate and or final interocclusal wafers are also constructed from the models

Type of surgical procedure:

• Bilateral sagittal split mandibular osteotomy

• Vertical subsigmoid osteotomy

• Mandibular distraction

• Le fort I maxillary

• Le fort II maxillary

• Le fort III maxillary

• Segmental osteotomy

• Genioplasty

Range of surgical movement:- Maxilla can be moved forwards, upwards and

downwards- Mandibula can be moved forwards and backwards- Chin can be moved forwards, backwards, upwards

and downwards

•Bilateral sagittal split mandibular osteotomy

•Vertical subsigmoid osteotomy

• Mandibular distraction

• Le fort I maxillary

• Le fort II maxillary

• Le fort III maxillary

• Segmental osteotomy

• Genioplasty

• 1-7 days post operatively, light intermaxillary elastics may need to be placed to detail the occlusion

• In the arch where most vertical movement is required, a more flexible archwire may be used such as rectangular nickel titanium

• In the opposing arch where vertical movement is not required, a stiffer rectangular steel wire can remain in place

4. POSTSURGICAL ORTHODONTIC

• The postsurgical orthodontic usually last 3 – 6 months depending on the degree of presurgical orthodontic already carried out

• At completion of treatment the fixed appliances are removed and retainers are fitted

Postsurgical stage, with light vertical elastics to maintain the vertical position of the teeth

Maxillary archwire .017x.025 beta-TiMandibular archwire 0.16 SS

2. Intra operative

1. Preoperative (orthodontic complications)

3. Postoperative

RISK AND COMPLICATIONS

• Decalcification of enamel

• Gingival recession

• Alveolar bone loss

• Root resorption

1. Preoperative (orthodontic complications)

• Damage to the neurovascular bundle during mandibular osteotomy leading to parasthesia, this occurs in 32% of patients and can be disturbing for 3% of patients

• Loss of blood supply to part of maxilla

• Hemorrhage

2. Intraoperative

• Failure of bone to split cleanly

• Failure to relocate the osteotomised fragments into their correct preplanned position

• Damage to the teeth adjacent to osteotomy site

• Fatality

• Failure of the osteotomy to undergo bony union

• The bone plate perforates through mucosa with chronic infection

• Relapse towards the preoperative position

3. Postoperative

• Stability after surgical repositioning of the jaws varies a great deal, depending on the direction of movement, type of fixation used and the surgical technique that was employed

• Superior repositioning of the maxilla is the most stable procedure and closely followed by mandibular advancement in patient with normal or decreased anterior face height

HIERARCHY OF STABILITY

Problem: horizontal deficiency and vertical chin excessSurgical procedure: vertical reduction with vertical advancement of the chin

Problem: Class II mandibular deficiencySurgical procedure: sagittal split osteotomy with advancement

Problem: Excess vertical maxillary growthSurgical prosedure: Le fort I osteotomy with maxillary impaction

Problem: Class III with mandibular excessSurgical procedure: sagittal split osteotomy with setback

Problem: Class III maxillary deficiencySurgical procedure: Le fort I osteotomy with maxillary advancement

Problem: Class III maxillary deficiency mandibular excessSurgical treatment: - Le Fort I osteotomy of maxillary advancement - sagittal split osteotomy of mandibular with setback

Problem: Facial asymmetrySurgical procedure: - Differential Le fort I of maxilla - sagittal split rotation of mandible - differential genioplasty

CONCLUSION- SO DO YOU KNOW, NOW??

• Definition

• Indication and contraindications

• Advantages and disadvantages

• Criteria for orthognathic surgery

• Steps in orthognathic surgery

• Risk and complication of orthognathic surgery