orthognathic surgery by almuzian

Surgical Orthodontics, Corrective Jaw Surgery or Orthognathic Surgery

Definition

The correction of the functional and aesthetic consequences of severe

dentofacial deformity through a combination of orthodontic, surgical and

possibly restorative dentistry

Aims

A satisfied patient.

Improve facial aesthetics

Improve dental aesthetics

A functional, balanced and stable occlusion

History

Trauner and Obwegeser introduced the sagittal split ramus osteotomy in

1959.

In 1960s development by Bell, Epker and Wolford of the LeFort I

technique.

In the 1990s, rigid internal fixation greatly improved the surgical result

and increase patient comfortibility

Mohammed Almuzian, University of Glasgow 1

Prevalence

IN UK according to O’Brien 2009, the prevalence of jaw’s surgery is as

follow:

1. Gender and age distribution

Mean age 22y

More female

2. Malocclusion

45% class 2

43% class 3

12% AOB

3. Type of surgery

66% bimax

24% mand surgery only

10% max surgery only

4. Continuation & duration of treatment

28% overall didn't complete treatment

Mean duration of treatment 45months


Timing and sequencing of surgical treatment

A. Usually all operations should be delayed until the completion of

growth

B. Early treatment

Indications

1. P sychosocial considerations

2. Mandible problems

Early mandibular advancement for sever mandibular retrognathia can be

done since most of postsurgical growth is expressed vertically, there is no

reason to delay mandibular advancement after sexual maturity

Rib grafts in craniofacial microsomia cases

Class II due to condylar ankylosis

Facial asymmetry to avoid compensatory mal-development of the maxilla

3. Maxilla problems

In general, maxillary advancement should be delayed until after the

adolescent growth spurt unless there are preponderant psychological

considerations. In this case, subsequent growth of the mandible is likely to

result in reestablishment of the abnormal relationships, and the patient and

parents should be cautioned about the possible need for a second stage of

surgical treatment later

No early surgery for vertical excess because vertical growth continues


General Indications of Orthognathic treatment

The cases that can be corrected by OS include:

Severe CI 3

Severe CI 2

Long face syndrome/AOB

Facial asymmetries

Chin abnormalities

Craniofacial anomalies e.g. CLP

However the indications of OS are:

1. Facial aesthetics

Pre-treatment assessment of orthognathic patients found that less than

50% patients were unhappy with their pre-treatment facial aesthetics

(Cunningham et al 1996).

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 (Cunningham et al

1996).

Hunt et al 2001 in systematic review, he concluded that orthognathic

patient experience psychological benefits as a result of orthognathic


surgery including improved self-esteem, body and facial image, and social

adjustment.

Sammaan in HK in 2010 found that the quality of life improved didn't

effected before surgery but only immediately after surgery. While the oral

health impact had been dropped in the decompensation phase and then

improved after surgery.

2. Dental aesthetics which cannot be addressed orthodontically

In a study of pre-treatment orthognathic patients, 72% were unhappy with

their teeth (Cunningham et al. 1996).

In non-growing patients when growth modification is not applicable

When too severe for orthodontics alone

When orthodontic treatment alone might cause determinately effect on the

facial and occlusal aesthetic as well as PD compromization

Presence of complete compensation

Presence of sever crowding that might use the whole extraction space

leaving nothing for more compensation by orthodontic means.

Sever vertical or transverse problem

3. Masticatory function

Speech problem like lisping in AOB


Anterior open bites with chewing problems

NB: Evidence suggests that there is a change in the bite force experienced

by many post-operative patients. Work by Hunt and Cunningham (1997)

found that when mandibular advancement was undertaken for reduced

patients face height, the bite forces reduced in the post-surgical phase.

Conversely, in long face patients who underwent bimaxillary surgery the

bite force increased.

4. Airway In a few centres in the UK and in North America, orthognathic

surgery may be performed to increase the airway in patients with

obstructive sleep apnoea.

5. TMD This is an area of controversy. The evidence suggests we should

warn all patients that they have a 20% risk (approximately) of developing

TMD post-op but for those who have TMD pre-op, a percentage may

improve, other will stay the same or a small number may worsen.

6. Periodontal indications: especially in deep OB when it is traumatic and

cannot be addressed by conventional orthodontics. Complete overbites may

suffer trauma to the palatal or labial gingivae.

7. Prosthetic indications like a case of sever attrition in which the

prosthetic restorations are impossible without increasing the VH by

surgery.


Contraindications &/or limitations

Growing patient

Minor cases

Medical condition

Psychologically unstable patient

Parameters indicators or Yardsticks for orthognathic surgery

1. For class II

Proffit 1992

OJ 10mm

ANB > 9°

Pog posterior to N perpendicular 18mm

Mandibular length less than 70 mm

Anterior facial height more than 125mm

Squire et al., 2006:

Positive overjet greater than 8mm,

A transverse discrepancy greater than 3mm were not considered to be

orthodontically treatable


2. For class III

1. Squire et al., 2006:

A negative overjet of -4mm or greater,

A transverse discrepancy greater than 3mm were not considered to be

orthodontically treatable

2. Stellzig-Eisenhauer et al (2002)

Wits analysis value of –12.2 ± 4.3 mm while camouflage indicated when

Wits value is less than -4.6 ± 1.7 mm.

3. Kerr et al 1992

ANB = -4°;

maxillary mandibular ratio = 0.84 ,

lower incisor inclination (LI/MP = 83°)

Soft tissue profile (Holdaway angle = 3.5°)(soft tissue nasion-soft tissue

pogonion labrale superius). Interestingly, vertical dimension had little

influence on treatment decision.

The management protocol for facial deformity

1. History

2. Clinical examination

3. Psychological assessment


4. Investigations

5. Clinical and radiographical examination.

6. Initial diagnosis

7. Initial Treatment plan

8. Presurgical orthodontics

9. Final treatment plan

10. Surgery

11. Postsurgical orthodontics

12. When appropriate, restorative dentistry, psychological intervention or

support and speech therapy will be required.

In details

History and patient assessment

1. Age and sex - influences amount of growth remaining

2. Race - influences profile considerations

3. PDH: To identify the cause (family trait, congenital deformity, or

trauma in infancy or adolescence)

4. CC: To know the main CC in order of priority


5. MH: medical disorders, which require specific attention include:

Haemophilia or similar clotting disorders which require pre-and

intraoperative correction

Rheumatic or congenital heart valve lesions

Acromegaly patients may be a cardiomyopathy risk

Obstructive sleep apnoea should warrant a sleep study and specific

assessment.

Antibiotic or analgesic idiosyncrasy or allergy

Psychological assessment

Ideally all patients should be assessed by a psychologist to establish their

motives and to determine whether their goals are realistic.

A few patients have great difficulty in adapting to significant changes in

their facial appearance. This is more a problem in older individuals.

Also, a period of psychological adjustment following facial surgery must

be expected. In part, this is related to the use of steroids and Steroid

withdrawal, causes mood instability at 3 to 6 weeks post-surgery.

A. Body Dysmorphic Disorder

Patients who request treatment of a non-existent or very minor facial

deformity.


BDD was diagnosed in 7.5% of patients attending for orthodontic

treatment and 2.5% of the general population (Hepburn and Cunningham,

2006).

Three criteria must be fulfilled for a diagnosis of BDD to be made

(American Psychiatric Association, DSM-IV, 1994):

1. Preoccupation with an imagined defect in appearance. If a slight

physical anomaly is present, the person's concern is markedly excessive.

2. The preoccupation causes clinically significant distress or impairment

in social, occupational, or other important areas of functioning.

3. Presence of another mental disorder (anorexia nervosa)

Treatment of BDD should ideally involve counseling and behavior

therapy or pharmacological treatment. Surgery should only be considered if

there is a defect to correct and there is appropriate psychological support

(Cunningham and Feinmann, 1998).

B. Ethnic Dysphoria

It is an uncommon BDD variant.

Dentofacial aesthetic norms vary between ethnic groups and when

planning surgical changes special consideration should be given as to

whether they are racially appropriate.


Some ethnic patients, influenced by popular Caucasian features, may

demand changes which are either unsuitable or unattainable.

C. Gender dysphoria

It is an uncommon BDD variant in which the patient, usually a male,

wishes to change gender.

Where this is stated, or when the patient is referred from a psychiatric unit

specialising in gender reorientation, the aim of the treatment is obvious.

However, occasionally the demand for a less prominent mandible or more

prominent malar bones in an otherwise satisfactory face can be difficult to

understand unless seen as part of this problem.

Again, psychiatric assessment of the patient is essential.

Patient motivation types and reaction to orthognathic Treatment

Internal motivation are more likely to have satisfactory treatment

outcomes

External motivation poor outcomes

Patient with unachievable expectation like BDD has higher dissatisfaction

Patients with congenital deformities are at greater risk of experiencing

psychosocial problems.

Individuals with acquired deformities tend to be more critical and express

greater dissatisfaction compared to those with developmental problems

who have never had an image of normality


The Psychopathology of Facial Deformity and Orthognathic Surgery

1. Social Aspects of Facial Deformity

Social reaction: Those who are blessed with an attractive face are

frequently perceived as being more friendly, sensitive and successful

Personality: Certain facial stereotypes are inappropriately portrayed as

being associated with particular characteristics, for example a Class III

malocclusion may be perceived as aggressive or a marked Class II as weak

or stupid.

2. The Psychological Assessment

The following standardised approach is essential to avoid overlooking

problem areas and should be done on a one-to-one basis and not in a large

multidisciplinary clinic,

A. In addition to patients in whom the clinician intuitively feels

concerns, those to be considered for referral include patients with:

A history of previous cosmetic surgery.

Minimal facial deformity.

Expectations that clearly exceed surgical feasibility.

An obsessional concern with certain features.

B. There are 8 questions which should be asked:

1. What is the main complaint?


2. How does their dentofacial deformity interfere with their life?

3. How long has he/she been concerned about their face? Why is

he/she seeking treatment now?

4. What does the patient expect from treatment?

5. What is the main source of motivation?

6. Does the patient have family support?

7. Has the patient previously sought treatment elsewhere?

8. Has the patient received any medical treatment that may be of

importance from psychological point of view ?

In details

1. What is the main complaint? Those who offer vague non-specific

complaints such as “I just don't like my face” tend to make poor surgical

patients compared with those who are clear about their complaint — “I

think my chin sticks out and is not symmetrical”.

2. How does their dentofacial deformity interfere with their life? A patient

who can function in a normal way at work, socialise with friends and has

developed a reasonable body image despite the facial deformity is likely to

be satisfied following treatment. Those who have become reclusive as a


result of their concerns must be investigated further, especially where the

extent of the deformity does not justify this abnormal behaviour pattern.

3. How long has he/she been concerned about their face? Why is he/she

seeking treatment now? Patients should always be asked how long they

have had these concerns. Those who have become concerned only recently

should again be assessed by a psychologist/psychiatrist as their worries

may have been triggered by a recent life event such as redundancy, divorce,

or bereavement.

4. What does the patient expect from treatment? It is helpful to ask “How

do you think this treatment will affect your life?” Those patients who want

to look better and feel more self-confident are classified as expecting

primary gain from treatment and tend to be good surgical patients. Patients

requiring psychological assessment prior to agreeing to treatment include

those who:

a) Are concerned with secondary gain such as promotion, a better job or

new partner

b) Do not have any idea what they expect from treatment

c) Are not able to verbalise their answers to these questions.

5. What is the main source of motivation? Externally motivated patients

may require a change in their environment rather than orthognathic

treatment. They require careful psychological assessment and counselling


prior to consideration for treatment. Patients who are internally motivated

usually make better candidates for orthognathic intervention.

6. Does the patient have family support? Obviously patients should not be

refused treatment if they have little family or social support. However, in

this situation, the orthognathic team may need to offer more support than

usual, particularly in the immediate pre-and postoperative periods when

patients are at their most vulnerable.

7. Has the patient previously sought treatment elsewhere? Patients who

embark upon numerous consultations (or “doctor shopping”) often do so

because they are dissatisfied with a previous rejection or a treatment plan

which does not meet their unrealistic expectations. Other patients may

already have undergone previous operations for dentofacial complaints.

Such a history should be investigated fully, prior to agreeing to further

intervention .

8. Has the patient received any medical treatment that may be of

importance? This is to determine whether the patient has undergone any

previous psychiatric treatment. The general medical history may also

include conditions that make orthog-nathic treatment difficult or

impossible, such as haemophilia, severe thallasaemia, acromegaly or

osteoclast dysfunction bone dysplasias.


C. Dissatisfaction with Treatment

Dissatisfaction may manifest itself in a number of ways including

1. Obsessional behaviour,

2. Depression

3. Even frank psychosis

4. Seeking additional surgical procedures,

5. Physical aggression.

6. Litigation

There are a number of causes of postoperative dissatisfaction

1. Patients who experience pain and numbness

2. Steroid withdrawal

3. Poor results

4. Unfavourable interpersonal relationship

Most forms of post-surgical dissatisfaction can be avoided by

1. Careful presurgical patient assessment

2. Realistic explanations of the procedure in terms of pain, swelling,

speech, eating and time off work.

3. Informed consent, the possibility of the most common and important

complications,


Investigations

BOS guidelines regarding the minimum record for Orthognathic cases

1. Lateral Cephalograms

An immediate post-operative lateral cephalogram should not be taken

routinely. Only take in concern cases, where the post-surgical maxilla

position is in question and a quick return to theatre is likely.

The request for a lateral cephalogram taken at 1-3 weeks post-surgery

should be under the direction of the orthodontist. Any surgical wafer used

should be removed prior to this x-ray exposure and it should be carried out

on the same cephalostat as previously used. The teeth should be in

occlusion with much of the post-op swelling subsided. This view will

record a true and meaningful post-op position of the jaws prior to

significant postsurgery orthodontic mechanics, such as intermaxillary

elastic traction, commencing. In units using IMF for 4-6 weeks, the taking

of this film should be delayed until its release.

A pre-debond lateral cephalogramis conditional upon the post-surgical

orthodontic phase exceeding 6 months. This view will record the final post-

op position of the jaws at the completion of post-surgical orthodontics. For

patients with shorter periods (<6 months) of post-surgical orthodontics, the

‘1-3 week post-op’ cephalogram should suffice.

At 1-year post-surgery, a significant number of patients may have only

recently completed their post-surgical orthodontic treatment.


2-years post-orthodontic debond i.e. a minimum of 1 year out of retention,

to assess the final outcome and any relapse associated with surgical

orthodontics.

2. OPT

At the end of the pre-surgical orthodontic phase, there is no need for an

OPT if 8s previously extracted as a result of the pre-treatment OPT.

If 8s haven’t been extracted and are to be removed at the time of surgery,

then obtain new OPT.

The immediate post-op OPT is the responsibility of the surgeon.

3. Study Models

The pre-surgical planning models are working models. It is not necessary

to keep these “mock-surgery” models long-term.

4. Clinical Measurements

It should be written record.

5. Altered Sensation

A baseline recording of any altered facial/intra-oral sensation present

prior to starting treatment is good practice.

A simple recording can be indicated on the proforma with further details

and drawing (if applicable) made in the patient’s clinical notes. Subjective

testing is sufficient with an additional note made as to whether the altered

sensation is of concern to the patient.

The validated methods to assess the altered sensation was published in

1998 by Ylikontiola, it include:

I. Light touch (LT),


II. Two-point discrimination (2-P),

III. Tactile discrimination

IV. Thermal stimuli (TH),

V. Sensibility testing of the mandibular teeth by a vitality scanner


6. Patient Questionnaires

Psychological-based questionnaire may also be available.

Clinical examination

Patient Evaluation involves:

i) Clinical examination. EOE and IOE

Extraoral examination includes

CFA read CFA notes by Almuzian

TMJ: Although there is no evidence of malocclusion or jaw deformity

causing temporomandibular joint symptoms, it is important to record any

abnormalities present in patients considering surgery. The examination of

the joint should include observation of the path of opening and closure of

the mandible, noting any clicking sounds whilst palpating the joints.

Intraoral Examination

1. Teeth present, unerupted, impacted, carious, over erupted or

periodontally involved.

2. Dental and base relationships

3. Dental centre line.


4. Crossbite & associated displacement it is also important to note

whether the segments have attempted to compensate for the discrepancy by

tipping of the dentition

5. Overbite

6. Overjet from the most prominent incisor should also be recorded.

7. Arch form and the coordination of upper and lower arches.

8. The upper and lower incisor inclinations and in particular,

compensatory changes due to the jaw disproportion, e.g. retroclined lower

incisors and proclined upper incisors in a prognathous mandible.

9. Crowding or spacing and TSD.

10. Tilting and rotation.

11. COS

12. Occlusal plane canting.

13. Tongue size and mobility, and the speech pattern

14. Enlarged tonsils may jeopardise the patency of the airway. Adenoids

are rarely a problem as they have usually regressed in size during early

adolescence. However, remember that the micrognathic mandible will

create an intubation problem for the anaesthetist


15. Cleft cases require careful analysis of the cleft site and bony defects

that will require grafting. Velopharyngeal competence should be examined

by endoscopy and speech recorded by a speech therapist.

ii) Radiographic examination

OPT

Used to diagnose:

The shape and relative size of each half of the mandible, including the

condyles, in two dimensions.

The presence of any pathological condition such as impacted unerupted

teeth, caries, periodontal disease, apical granulomas or cysts.

The trabeculation pattern of the bone, especially at the lingula, which

when visible is an indication of adequate thickness of the ascending ramus

and ease with which the ramus can be split.

For symmetry analysis, tracing of the normal side of the radiograph

has been superimposed on the abnormal side using the occlusal plane

as a guide. The discrepancy of the mandibular borders can be seen

readily


Lateral Cephalometric

To provide precise details of the relationships of the parts of the

dentofacial complex as part of the diagnosis.

To plan tooth angulation movements and osteotomy cuts and movements

prior to treatment commencement.

Analysis of soft tissue and airway spaces

To provide baseline data against which later treatment response can be

measured

The tracing of lateral ceph

The soft tissue profile including glabella, nasion, nasal tip, upper lip,

lower lip and the soft tissue chin.

The inner outline of the sella turcica, the anterior aspect of the nasal bones

together with the frontonasal suture and the outline of the lower bony

margin of the orbit.

The maxillary outline, upper incisors and upper first molar.

The mandibular outline with the mandibular incisors and first molar and

articulare.

In general, where bilateral landmarks present two images, the average of

the two should be drawn. The exceptions to this are those cases where there

is an obvious asymmetry of the mandible, which has resulted in two

distinct lower borders to the mandible. From the point of view of


measurement, it is normal practice to take the lower border which conforms

to the normal side of the face, as assessed clinically.


The total anterior face height (TAFH) is the sum of the upper anterior face

height (UAFH), measured from nasion to the maxillary plane, and the

lower anterior face height (LAFH), maxillary plane to menton. The lower

anterior face height is usually 55+2% of the total anterior face height.

Posterior face height is similarly measured from sella to gonion using the

maxillary plane to divide the upper posterior face height (UPFH) from the


lower posterior face height (LPFH). The lower posterior face height being

approximately 43 +2% of the total posterior face height

The angle of the maxillary to the mandibular plane (MxP/MP) is normally

27+4. This angle is important because as with the posterior face height

measurement, it reflects the surgically important pterygomasseteric sling

length (muscle, fascia and ligaments). For instance, a patient with a high

angle, i.e. greater than 35, tends to have a relatively short posterior face

height and therefore posterior musculo-ligamentous height. Any attempt to

stretch this posterior connective tissue by rotating the anterior body of the

mandible upwards, in an anticlockwise direction, around a fulcrum

produced by the posterior molar occlusion, is doomed to failure and will

lead to early surgical relapse.

If the SN/MxP value is outside this range then Eastman correction cannot

be applied and alternate analyses of the anteroposterior skeletal pattern

should be employed like Wits or McNamara analysis.

Posterior-anterior radiograph

A poster anterior view of the skull helps to reveal facial bone asymmetry.

Long cone periapical films are essential for assessing the space between

teeth when segmental surgery is required.

A maxillary occlusal radiograph defines the bone defect in cleft cases.


Major deformity is best visualised with a 3-dimensional CT scan.

Chest radiograph: If the patient elects to have surgery, a preoperative chest

radiograph is required by some surgeons but is only justified where a

costschondral graft is to be harvested.

iii) Analysis of study models

iv) Psychological examination where appropriate.

Special investigations and assessment

Surgery prediction methods

1. Manual Cephalometric Prediction

A. Overlay Method Tracing

B. Template Method

2. Computer Prediction

E.g. CASSOS

3. Cast Prediction (Model Surgery)

Soft tissue prediction

Upton et al (1997) found that chin; upper lip and lower lip are predictable

in 80%, 80% and 50% respectively. The soft tissue changes depend on:

A. Type of surgery

B. Soft tissue composition and thickness


C. Presence of dead space between ST and teeth

D. Racial and individual variations,

Error in perdition

1. Errors in carrying out ‘’surgically’’ the planned movements i.e. our

inability to move the teeth and bones to the exactly intended positions.

Overall, 80% of the results fell within 2 mm of the prediction and 43%

within 1 mm.

2. Errors in the equipment, materials and software used in the prediction

process. Again there are again two major sources of error:

I. The usual digitising errors e.g. point identification, posing errors etc.

PS: Cunningham 2004 compare OPAL and hand prediction and found that

hand type is better in bimax and similar in mand surgery alone. The main

problem of OPAL is in the region of lip (Eckhardt, 2004 #41). Smith and

Proffit 2004 found dentofacial planner the best as computer stimulation

II. Prediction of the soft tissue changes for a given hard tissue movement

What are the risks of showing computer simulations to patients? Bell

1997

1. No significant difference in the level of satisfaction

2. Reduce the anxiety about the surgical experience

3. Increase the concern about the possibility of surgical problems,


4. Better method of informed consent to treatment

Presurgical orthodontics

Appliance

The use of ceramic brackets in orthognathic cases due to their potential

for fracture.

A 022” slot should be used to allow the use of full thick wires.

It is worthwhile considering the variations in bracket tip and torque

required in specific cases. In an ideal occlusion, the crown of the lower

incisor lies labial to the apex for ideal tooth inclination.

A. In Class II cases where proclined lower incisor require decompensation,

the use of MBT brackets with the 6 degree of additional lingual crown

torque can aid the mechanics.

B. Conversely, Super-torque TM brackets, with additional palatal root

torque to the upper incisors, can be useful in correcting severely retroclined

incisors in Class II division 2 cases.

C. In class III the use of low torqued upper incisors and inverted torqued

LLB.

Mesio-distal tooth angulation (tip) becomes important when considering

the preparation of a case for segmental surgery as it is important to

facilitate the surgery (see below) by ensuring the roots adjacent to the


osteotomy site are either parallel or slightly divergent. Where the

osteotomy cuts are to be made distal to the canines, the use of the canine

bracket of the opposite side ensures that the tip incorporated into the

bracket keeps the apices forward and out of the way of the surgical cuts.

Segmental surgery requires the added facility of a double tube on the

mandibular molars and/or a triple.

The use of TPA to control arch width if segmental levelling is used in

AOB case, since intrusion of incisors can cause buccal flaring of the

posterior teeth.

TAD can be used for better decompensation aims.

The role of orthodontic component of orthognathic treatment

1. Relieve crowding

2. Alignment

3. Complete or partial levelling of the curve of Spee

4. Space closure or sometimes relocalisation prior to restorative

procedures

5. Correction of dental centreline discrepancy ( within each arch but not

necessarily relative to each other)

6. Transverse arch coordination for post-surgical occlusion(Q helix, RME,

SARPE, or Segmental Le Fort osteotomy)


7. Creation of optimal buccal segment inclinations to ensure good stability

and function of the final occlusion and as much as possible that all teeth

have an opposing tooth contact at the end of treatment

8. Dentoalveolar decompensation of incisors. Decompensation helps in

allowing maximum jaw movement during surgery which enables the

achievements of optimal facial aesthetic.

9. Provide enough room for segmental osteotomies

10. The orthodontic appliance serve to provide the best means of

intraoperative intermaxillary fixation & to provide for the attachment of

post-operative intermaxillary elastics

Leveling of the curves of Spee in the mandible

The decision as to whether to fully level the arches is very much dependent

on the patient's facial height, chin prominence and the upper lip/incisor

relationship.

1. If the goal is to maintain face height when the mandible is advanced,

pre-surgical full levelling is required. Levelling the Curve of Spee without

space will procline the lower incisors, and reduce the potential for

mandibular advancement. If the intention is to maintain anteroposterior

arch length, then premolar extractions will be required, especially if there is

any crowding present

2. If the goal is to decrease face height when the mandible is advanced,


pre-surgical incisor intrusion by orthodontic applianceis required;

If intrusion is difficult orthodontically, a segmented arch levelling is

indicated in the pre-surgical orthodontics and addressed finally by

subapical osteotomies.

Other prefer to deal with levelling similar to average face height then

reduced the skeletal problem surgically as bi-maxillary approach.

3. if the goal is to increase face height , which often is the case in

mandibular deficiency patients, pre-surgical intrusion of the lower incisors

would be a serious error and maintaining or leaving a curve of Spee is

indicated.

Maintaining the curve of Spee in low angle cases

1. Prior to surgery, the teeth are aligned and the anteroposterior position

of the incisors is established, but a curve of Spee is left in all the archwires,

including the surgical stabilizing wire. This means the surgical splint will

be thicker in the premolar region than anteriorly or posteriorly.

2. At surgery, normal overjet and overbite are created, and the space

between the premolar teeth is corrected post-surgically by extruding these

teeth with flat archwires. (three point landing)

3. This occurs rapidly, typically within the first 8 weeks after orthodontic

treatment resumes, because there are no occlusal contacts to oppose the

tooth movement and due to postsurgical increase in the metabolic changes.


4. The alternatives to use an auxiliary wire to assist in pre-surgical

levelling. An auxiliary levelling wire 17*25 SS passed over the main AW

from auxillary molar tube and it can be tied over a continuous reverse

curve base archwire to increase its action.

5. In cases with a severe lateral open bites which are too large to close by

orthodontic extrusion of the premolars and canines. Many operators

consider 2 mm of extrusion from each arch as the absolute maximum that

can be achieved and remain stable without rebound. Beyond this, levelling

should be achieved through surgery, usually through a set-down of the

lower labial segment with an anterior mandibuloplasty. Where there is a

reverse Curve of Spee in the upper arch, as in some Class II division 2

cases, it may be necessary to undertake segmental surgery to both the upper

and lower labial segments.

Advantages of partial levelling

1. The absence of premolar contact postoperatively speeds levelling of the

occlusal plane

2. The posterior rotation of the mandible at surgery may lead to an overall

increase in face height in appropriate cases

Disadvantages of partial levelling

1. Patients prefer a shorter postoperative treatment period.

2. The extrusion of the posterior teeth with preoperative levelling is likely

to be very similar to the postoperative extrusion, so the face is likely to


finish at a very similar face height. Certainly, intrusion of lower incisors is

not beneficial in low face height cases, but studies suggest that such

intrusion is very modest with most mechanics used to level the occlusal

plane and may not be significantly different in the preoperative or

postoperative situations.

Levelling of the curves of Spee in the maxilla

It depends on

Aetiology of AOB,

Facial height,

Amount of autorotation required,

Incisor show

Surgical technique used

The steepness of the COS

1. In a patient with open bite, severe vertical discrepancies within the

maxillary arch are an indication for multiple segment surgery. When this is

planned, the upper arch should not be levelled conventionally.

2. The presurgical orthodontics should accentuate the open bite through

intrusion of the labial segments and extrusion of the buccal segments. In

this way maximal surgical correction can be achieved and any postsurgical

incisor change will ensure closure of the anterior open bite


3. Leveling should be done only within each segment, and the segments

are levelled at surgery.

4. This can be achieved by three segmental archwires, two running in the

buccal segments from premolar to molar on each side together with a third

segment for the canine and incisors. This approach tends to produce a lack

of control of the tooth positions and therefore a continuous arch is

preferred, from molar to molar but with an anterior step for the canines and

incisors.

5. In the latter case, the surgeon will cut the archwire across the

osteotomy site at the time of surgery. Although the segments are

immobilised using rigid internal fixation, it is essential to provide

additional fixation at the occlusal level. This can be done with

A prefabricated continuous archwire bent to the planned postoperative

segment’s position.

However, insertion of this wire intra-operatively can be extremely time-

consuming. It is preferable to use a rigid prefabricated horseshoe shaped

1.0 mm steel supplemental arch wire, engaged passively into double or

triple tubes on the molars and secured by ligatures to the three archwire

segments. Ultimately, the sectional arches can be replaced with a

continuous archwire once the patient has recovered.

Also wafer splint can help in this case


6. If a one-piece osteotomy is planned and pre-surgical orthodontic

levelling is required, but extrusion of anterior teeth before surgery must be

avoided then TAD can be used to vertically stabilize the anterior segments.

Dentoalveolar decompensation of incisors

The extraction and mechanics for decompensation is opposite to

conventional orthodontic camouflage. But all should be done with

minimum dental health side effect. Presurgical preparation

(decompensation) objectives are:

Corrects the axial inclinations to maximise jaw movement.

For best dental aesthetic

For better function

For stability point of view

To compensate for future relapse

Periodontal health

In skeletal Class III cases,

Lower arch

A. Extraction or non-extraction

It depends on:

1. Degree of skeletal movement required as well as the target OJ


2. Curve of Spee

3. LMA. It is better to avoid extraction in obtuse LMA

4. Degree of the existing compensation

5. Thickness of labial alveolar plate, so care to avoid destroying the

periodontal attachment, producing a dehiscence of the gingival margin.

Sometimes, periodontal grafting should be considered.

6. Degree of crowding. Severely crowded cases may need extractions to

provide the space for arch alignment. The extractions of choice are the

lower second premolars, assuming all teeth to be of good prognosis.

B. Appliance

1. Use +ve torque LLS as well as increased tip incorporated into the

canine bracket.

2. Invert the lower incisor bracket to get positive labial crown torque

3. “Laceback” avoided in lower but not upper.

Upper arch

A. Extraction or non-extraction

1. Degree of skeletal movement required as well as the target OJ

2. Curve of Spee

3. Degree of the existing compensation


4. Thickness of labial alveolar plate, so care to avoid destroying the

periodontal attachment, producing a dehiscence of the gingival margin.

5. Degree of crowding. The upper incisors generally need to be retracted

with upper first premolars removal. In very mildly crowded cases, some

would prefer to move the upper arch distally using anchorage-reinforcing

devices on non-extraction base.

6. Differential impaction with rotation of maxillary occlusal plane.

B. Appliance

1. In maxillary brackets, laceback ligatures should be

employed and the canine brackets are swapped.

2. Low torque prescription in the maxillary incisor brackets

unless the posterior maxilla is impacted posteriorly by a

greater amount than the anterior segment, then the

presurgical preparation may intentionally leave the upper

incisors slightly proclined.

3. Class 2 traction is frequently required in these class 3 cases

and vice versa.

4. Additional active labial crown torque should on occasion be employed

to assist soft tissue recoil which means that the upper lip will apply a

palatally force after maxillary advancement which might cause some

relapse.


In skeletal Class II cases

Exactly opposite to the above.

Transverse arch co-ordination

Methods of maxillary arch expansion relate to four factors:

1. The amount of discrepancy

2. The inclination of the buccal segments

3. Bone thickness buccally

4. The proposed surgical procedure. (i.e. single jaw, segmental)

Technique of arch coordination

1. Accept a bilateral posterior crossbite in some instances but may

complicate the achievement of a satisfactorily stable occlusion in the post-

operative period

2. Widening or narrowing of the full-sized archwires with buccal or

lingual root torque respectively (dental expansion or constriction)

3. A quadhelix tends to tip teeth and the hanging down of the palatal

cusps interferes with a good stable intercuspal and functional occlusion.

4. RME (e.g.: a rapid expansion splint) are less appropriate in an adult

with a closed mid-palatal suture.


5. Surgically –Assisted Rapid Maxillary Expansion (SARPE): Advantages

and disadvantages:

No periodontal hazard like Lefort I two piece maxilla to expand the UA.

Simpler orthodontic preparation - no need to create spaces for segmental

osteotomy cuts

Less extractions required

Asymmetric expansion possible ( unilateral lateral corticotomy)

Better at canine expansion than molar expansion

6. Segmental Le Fort osteotomy

Segmental-midline- Le Fort surgery (Bailey et al 1997) must be very

carefully carried out to avoid periodontal damage between the upper central

incisors and some clinicians advocate the creation of a median diastema as

part of the orthodontic preparation if the constriction is required.

The surgery must be mimicked on models and an orthodontic archwire

and wafers made to the planned new archform to be created during the

surgery.

The new archwire should ideally be inserted during the operation and the

chance of the wafers not fitting well is increased.


Advantages and disadvantages

No additional operation or two phase operation like SARPE

Better for molar expansion

Better stability

More complicated and lengthy Le Fort procedure

More complicated orthodontics to create and then resolve spaces for

interdental cuts

Pd damage.

Monitoring Arch Coordination

1. For Class II problems, testing of arch co-ordination in the

transverse dimension can be achieved by simple forward

posturing of the mandible.

2. In Class III corrections the use of

An acrylic template of the occlusal surfaces of the

lower arch is invaluable. The template can be prepared

by taking an alginate impression of the aligned lower

arch and pouring cold cure acrylic resin into the

occlusal portion of the impression. At successive

visits, the template of the lower arch can then be

occluded with the upper arch to check compatibility and avoid the need for

repeated study models.


Another method is by using the lower AW as a guide which should fit

passively along the central fossae of upper teeth and touch the cingulum of

upper incisors.

Using study model

Using digital study model

The Definitive Treatment Plan

A. The key to successful surgery is to place the maxilla and the

decompensated maxillary incisors in the optimum anteroposterior,

transverse and vertical position in relation to the upper lip and face (PIP).

The mandible is then placed in a Class I incisor relationship to the maxilla.

B. The movements of the maxilla based on the clinical prediction of the

incisor position, can then be repeated on a digital image or tracing of the

patient's lateral cephalometric radiograph.

C. The clinician can use software package or hand tracing. When planning

using hand tracing it is important to trace all the teeth in order to avoid

missing potential premature contacts

The maxilla

1. The incisor exposure with the lips parted at rest — will decide the

vertical movement of the maxilla. Aesthetic exposure may vary from 1 to 4

mm. This is inversely proportional to the upper lip length which ranges

from 18-24 mms.


2. Excessive or unaesthetic incisor exposure is corrected with appropriate

maxillary impaction. But where the upper lip is unduly short, the patient

can show a greater amount of incisor.

3. Rarely the patient has marked dento-alveolar hypoplasia and shows

little or no incisor with a normal lip length. This is corrected with an

inferior movement of the maxilla.

4. Horizontally, the maxilla advance until best stable and biologically

acceptable position achieved in relation to zero meridian

5. Horizontal movement similar to the vertical maxillary movements will

affect the incisor exposure. Advancing the maxilla will lead to greater

incisor exposure which will need to be adjusted for when considering the

vertical move. V-Y closure of the lip can be used to compensate for the

increased incisor show after maxillary advancement.

6. Coronal occlusal cants and midline rotations must also be corrected

7. Moving the maxilla will also affect the nose. Vertical impaction widens

the alar base and forward movements will elevate the nasal tip. Depending

upon the initial appearance these changes may or not be desirable. If not,

then a record should be made to provide a “cinch suture” across the lateral

alar cartilages or to reduce the anterior nasal spine at the time of surgery

NB:


The inherent inaccuracy of the planning and surgical technique and the

eye's inability to perceive small anatomical changes, determine that units of

horizontal advancement should be no less than 3 mm. This also facilitates

planning as a 3 mm minor advancement; a 6 mm intermediate; and a 9 mm

major move. Cleft cases usually require 9 mm or more.

Similarly vertical moves of 2 mm for minor; 4 mm intermediate and 6

mm for major impactions are appropriate for all cases. These three

categories also simplify the decision making process.

The mandible

1. Having planned where the maxilla is to be placed, the final step is to

place the mandible in a Class I incisor relationship. This is built into the

final wafer.

2. If the definitive occlusion is not immediately possible because of the

need for further orthodontics or restorative treatment, the wafer maintains

the jaw relationship until orthodontics or restorative treatment can be

commenced.

3. The mandible will require

Autorotation, Any changes in the vertical and horizontal position of the

maxilla will necessitate a change in the vertical and AP position of the

mandible. This is mediated naturally through neuromuscular feedback

mechanisms and the mandibular elevator muscles.


Antero-posterior, Forward movement of the mandible to establish a Class

I incisor relationship in Class II cases, will also increase lower face height

in deep overbite specially when advancing the mandible without levelling

the curve of Spee. The vertical facial height will increase and the everted

lip will unroll and upright. If this change is desirable, the consequent lateral

open bites need to be closed with postsurgical orthodontics to a stable

position. If too severe for orthodontic closure, then surgery must

incorporate a levelling of the occlusal plane with an anterior subapical

osteotomies. On the other hand, mandibular setbacks will evert the lip.

Occasionally this may correct the occlusion but reduce the chin prominence

which will require a paradoxical advancement.

Vertical, no anti-clockwise stretching allowed bec of relapse. The only

vertical movement is autorotation. Some evidences showed that the

tolerable degree of anti-clockwise stretching is between 5-8 degree.

Rotational or rarely transverse movements. These are required in

asymmetry cases, for example hemimandibular elongation where the need

is arch coordination especially with an adequate maxillary intercanine

width.

Revision of the plan after autorotation

1. Assessment of the lower incisor position of the autorotated mandible is

also important in determining if further adjustment of the maxillary

position is required in order to establish a positive overbite.


2. With an anterior open bite autorotation leads to initial buccal segment

contact. Closure of the residual anterior open bite by (anticlockwise)

rotation of the mandible around this posterior pivot will lead to an

elongation of the pterygo-masseteric sling and relapse. In such cases it is

necessary to impact the posterior part of the maxilla differentially to that of

the anterior maxilla. The extent of the differential impaction can be

ascertained from the tracing.

3. With impactions for vertical maxillary excess, any minor incisor

discrepancy on simple autorotation can be overcome by forward or

backward adjusted movement of the maxilla. A significant discrepancy will

require a bimaxillary procedure to ensure the incisor Class I relationship

without compromising the upper lip incisor relationship.

Chin Position

Both anteroposterior and vertical movements of the mandible will affect

the position of the chin. It is important that the chin be carefully assessed to

avoid further surgery.

The immediate pre-surgical phase of treatment

1) Final records: Immediately prior to surgery records should be taken so

that final surgical plan can be confirmed. This include study models,

photographs and lateral cephalogram with OPT or even CBCT


2) Model surgery: The models should be mounted on a semi adjustable

articulator. So the precise surgical movement can be performed on the

models. Acrylic intermediate and or final interocclusal wafers are also

constructed from the models

3) Final AW: Final rigid wire with hook is important to stabilize the wafer

and to allow the use of elastic later on.

4) Patient preparation:

Patient consent

Instruction about the post-surgical complication

postoperative regimens for feeding and oral hygiene

5) Preoperative Investigations like full blood count

6) Blood transfusion: With the increased concern about cross-infection,

autologous blood is now being used in some centres for elective surgery.

Model surgery and wafer splint for orthognathic patient

Cast Prediction (Model Surgery)

Model surgery is the dental cast version of cephalometric prediction of

surgical results.

It can be done before the orthodontic preparation but wax setting of

crowded teeth might needed .


The primary goal of model surgery is to functionally and spatially

simulate the patient's jaws and dental structures as accurately as possible to

allow accurate simulation of the intended surgery.

The secondary goal is to construct the surgical wafers.

Procedure of cast prediction (Model Surgery)

1. The selection of articulator is the first step in preparation for effective

model surgery. it includes:

a. Plain line or simple hinge articulator used in case of:

Maxillary advancement with no height change of the Maxilla i.e.: no

impaction / no down graft.

Mandibular as a single jaw procedure.

Segmental surgery with no height change.

b. Semi-adjustable articulator

Maxillary osteotomies with height changes i.e.: impaction or downgraft.

Bi-Maxillary procedures.

Segmental or multi-part maxillary osteotomies.

Cases of facial asymmetry.


Semi-adjustable articulator (Dentatus).

2. Face Bow Selection.

The function of the face bow recording is to mount the maxillary cast on

the articulator to reproduce the anatomical position of the maxilla in its

relation to the base of the skull. There are many types including:

a. The auricular face bow


b. Condylar face bow

c. Condylar face bow with spirit

bubble

3. The maxillary dental cast is mounted on a semi adjustable articulator

with the aid of a facebow transfer from the patient.

4. Next, the mandibular dental cast is mounted with the aid of a bite

registration taken with the patient's jaws in the retruded contact position, or

centric relation.

5. Several measurement should be done first, This be accomplished by

drawing several vertical reference lines and two horizontal reference lines

on. The distance between the facial surface of the maxillary incisors and

the articulator pin is recorded.


6. Model simulation of anticipated surgical movement (that has been

determined by cephalometric prediction tracing and/or clinical data)

performed next.

7. The sequence of movements are:

The maxillary cast is repositioned first according to the measurements

from the prediction tracing.

Once the maxillary cast has been fixed in the new position on the

articulator,

The first stage or the intermediate occlusal wafer splint is generated

The mandibular cast then is repositioned to oppose the maxillary cast,

simulating the final position of the jaws at surgery. This final position

generates the final occlusal wafer splint for use at surgery and during the

period of jaw rehabilitation following surgery.

It is easier for the surgeon to use a second identical set of dental casts

mounted in a hinge-type articulator for the final splint because the occlusal

surfaces of the first set of casts can be damaged in construction of the

intermediate occlusal wafer splint.

Then the measurement is compared to what had been planned before.

Technical advises

It is essential to use recent models for wafer fabrication;

Impressions must be taken at least two weeks after any final adjustment of

the orthodontic stabilizing arch wire.


Proffit and White advised that the thinnest practical wafers had 1 to 2 mm

If the maxilla must be segmented at surgery, a combined or two-stage

splint can be constructed. This technique involves construction of the

final splint first (on a hinge articulator) followed by fabrication of the

combined splint

The uses of the surgical wafer

1. To translate the planned surgery to the reality in the theatre

2. Splint the segmented arch

3. Intermediate and final splinting in bimaxillary surgery

4. Maintain the maxillomandibular relationship in overcorrected position

if these are planned. They enable a positive occlusion in an

overcorrected position which is not dictated by the intercuspal

position. e.g. class 2 cases can be set up edge-to-edge and class 3

cases to a slightly increased overjet

5. For postoperative rehabilitation or Post-Operative Proprioceptive

Guidance. After rigid fixation of the mandible, the wafer may be

wired to the maxilla, or less frequently to the mandible, to provide

post-operative proprioceptive guidance for up to two weeks. The

wafer will help the patient to occlude into the planned position with

or without the help of elastics by overriding the patient’s pre-

operative proprioceptive drive. This also improves the arch

relationship for any final orthodontic refinement of the occlusion.


Materials and Types of Occlusal Wafers for Orthognathic Surgery

1. Self-cured

2. Heat-cured methyl methacrylate

3. Cast in silver or cobalt chromium alloy for difficult cleft palate

cases.

4. A palatal wire may be added for reinforcement in case of

segemental osteotomies.

Causes of error in model surgery,

1. It is essential that the angle between the occlusal plane and the

Frankfort horizontal for the patient is the same as the angle between the

occlusal plane and the upper member of the articulator on the maxillary

model. If this is incorrect, the result of the model surgery is erroneous.

2. The other source of error is the difference in the patient’s mandibular

position when supine and upright; the mandible tends to be positioned

more posteriorly when the patient is lying down. Therefore, less maxillary

advancement would be achieved than predicted on the articulator and the

mandible has been overcorrected (more setback) to compensate for

maxillary under-advancement. BAMBER et al recommended recording the

centric relationship in the supine conscious position when planning

bimaxillary osteotomies.

3. Under general anaesthesia, the muscles of mastication are relaxed and

the mandible would not serve as a fixed reference plane for maxillary

surgery


4. The other possible source of errors in planning orthognathic surgery is

the inaccuracy in registering and transferring the true hinge axis of the

condyle to the articulator specially when the condyle are in different level

which may incorporate a pseudo-cant.

5. The last cause of error is the main cause of this inaccuracy is that they

are not designed to record facial asymmetry accurately.

Several factors can increase the accuracy and good fit of wafers

1. Leave heavy wires passive for one visit before taking the impression

2. Either take the impression with rubber compound or if using alginate

ensure that it does not lift from the tray

Choosing a larger tray and therefore thicker sections of alginate

Use a tray adhesive

Block undercut by wax

Remove the impression by pushing on the alginate not by pulling on the

tray

3. Insure the facebow is accurately located

4. Construct any intermediate wafer in a different colour acrylic to avoid

confusion at operation


Alternative method of model surgery

1. 3 D model surgery

2. Digital model surgery

3. In facial asymmetry the use of orthognathic articulator is preferable

Surgical procedures and treatment possibilities

Envelope of Surgery

Once the amount of anteroposterior movement required for correction

exceeds 1cm consideration should be given to operating on both jaws

Set back of the maxilla is possible by 5-6 mm but very difficult.

Care must be taken not to compromise the blood supply by over stretching

the tissues

Maxillary Surgery

A. Total maxillary osteotomy:

1- Le Fort I. The surgical cut goes through the wall of the maxillary

sinuses, the lateral nasal walls and the nasal septum at the level just

superior to the apices of the maxillary teeth. It is not indicated in maxillary

set back bec of the negative effect on the profile and bec of the anatomical

restriction as well as telescoping of the maxilla in the sinus. If down

grafting of the maxilla is performed, it is better to combine it with mand

relieving surgery


2- Le Fort II. It is a pyramidal osteotomy, it differs from Le Fort I that it

passes anteriorly toward the orbit. It is used mainly with CLP.

3- Le Fort III. It is used for the correction of symmetrical mid-face

recession affecting zygomatico-maxillary and orbital regions.

4- Le Fort II modified Kufner

The nasal bridge is not involved, but the surgical cuts runs Anterior to the

lacrimal apparatus and laterally to the zygoma.

It is indicated when the nasal bridge and projection are both good, but the

infra orbital region and the dentoalveolus are retruded, with mild

zygomatic flattening.

5- High level Le Fort II

The cuts along the orbital floor may be extended laterally to include

increasing areas of the inferior orbital rim and malar body, full extension

will turn the procedure to sub cranial Le Fort III.

B. Segmental alveolar maxillary osteotomy:

1. Anterior segmental osteotomy. Mobilize the anterior segment of the

maxilla and allows the reposition in an upward, downward and a rotational

manner.

2. Posterior segmental osteotomy (The Posterior Dentoalveolar Segmental

Osteotomy of Schuchardt)


3. Anterior and posterior segmental osteotomy.

C. Maxillary osteotomies for transverse problems

1. LeFort I down fracture surgery with parasagittal osteotomies

LeFort I downfracture surgery used for treatment of Maxillary transverse

problems. It consist of parasagittal

osteotomies in the floor of the nose

or floor of the sinus that are

connected by a transverse cut

anteriorly. A midline extension runs

forward between the roots of the

central incisors.

If constriction is desired, bone is removed at the parasagittal osteotomies

according to presurgical planning.

In expansion, either bone harvested in the downfracture or bank bone is

used to fill the void created by lateral movement of the posterior segments.

2. LeFort I down fracture surgery with midsagittal osteotomies

3. Surgically-assisted palatal expansion, using bone cuts to reduce the

resistance without totally freeing the maxillary segments, followed by rapid

expansion of the jackscrew, is another possible treatment approach for

adult patients with skeletal maxillary constriction.


Soft tissue effects of Le Fort I advancement

1. Nasal tip is advanced by one sixth of the maxillary advancement

(Henderson et al 1984).

2. AP advancement of the lip 60-80% and the tip of nose 20%

3. NLA decreased.

4. Upper lip flattens.

5. Vermilion exposure increased.

6. Increase in the width of the alar base

7. Tip of nose move superiorly

8. Lower lip rolled and advanced

In case of maxillary impaction, the following should be noted

It is important to shorten the nasal septum or free its base so that the

septum is not bent when the maxilla is elevated.

The inferior turbinate can be partially resected if needed to allow the

intrusion, although this procedure rarely is necessary.

The overall facial height is shortened as the mandible responds by

rotating upward and forward. Further surgery to correct the anteroposterior

position of the mandible may or may not be necessary after this rotation,

depending on functional and esthetic concerns


Excellent stability of the vertical position of the maxilla is observed post-

surgically, but long-term, some continued vertical growth of the maxilla

may occur.

In contrast, In case of maxilla moved downward, the following should

be noted:

It tends to relapse back up post-surgically, so that 20% or more of the

vertical change often is lost even when rigid fixation is used.

Both the use of more rigid graft materials (like synthetic hydroxylapatite)

and simultaneous osteotomy of the mandibular ramus have been reported to

improve the stability of downward movement of the maxilla, but this

remains one of the more problematic movements

Mandibular Surgery

Bilateral Sagittal Split Osteotomy (BSSO)

Indication1- Mandibular advancement(less than 10 -12 mm).

2- Mandibular set back (less than 7-8 mm).

3- Correction of asymmetry (Minor).

4- It is not recommended in patients with an anterior open bite without

considering a simultaneous maxillary operation to reduce the posterior

facial height.


NB:

Patient should warn of parasthesia with mandibular advancement

About 20% - 25% will have some degree of long term altered sensation

In case of mandibular setback, Airway should be assessed

Vertical Subsegmoid Osteotomy (VSO)

Indication:

1. Large mandibular set back

2. Restricted mouth opening

3. When splat might occurs bec of thin ramus

(Yoshioka 2008) compared intraoral vertical ramus osteotomy (IVRO)

versus sagittal split ramus osteotomy (SSRO) and found similar outcome in

relation to condylar position and stability one year postoperatively.

Advantages

1. Less risk of damage to the ID nerve. Permanent paraesthesia is thought

to be approximately 5% for the VSSO versus 25% for the BSSO

2. This procedure requires less time than the sagittal split osteotomy

Disadvantages

1. Intermaxillary fixation is required because access for rigid fixation is

not possible

2. Reduce ramus length and height


Inverted L osteotomy

Indications

1. Big advancement where the mandibular rami are deficient both

vertically and horizontally.

2. Big set back.

3. Big asymmetry.

Body osteotomy

The objective is to remove a pre-planned segment of mandibular body

allowing the anterior segment of the jaw to be set back.


Lower labial segemental osteotomy (Subabical ostectomy)

Indications:

1- An exaggerated curve of Spee.

2- Correction of bimaxillary protrusion.

Anterior mandibuloplasty

It combines lower labial segment surgery with simultaneous genioplasty,

all the cuts being continuous.


Genioplasty in Orthognathic Treatment

A. Reduction genioplasty:

1- Vertical reduction genioplaty.

2- Horizontal reduction genioplasty.

B. Augmentation genioplasty:

1- Vertical augmentation.

2- Horizontal augmentation. (sliding or double sliding genioplasty)

Technique

By free a wedge-shaped portion of the symphysis and inferior border that

remains pedicle on the genioglossus and geniohyoid muscles.

This segment can be advanced to augment chin contour, shifted sideways

to correct asymmetry, or downgrafted to increase lower face height.

By splitting the segment vertically, the distal aspects of the wedge can be

flared or compressed.


If narrowing of the anterior portion is needed, bone is removed in that

area.

When reduction is desired in the distance from the incisal edge to the

inferior aspect of the symphysis, a wedge of bone can be removed above

the chin

Genioplasty as an adjunct to non-extraction orthodontic treatment

1. Prominence of the lower incisors relative to the chin traditionally has

been treated orthodontically, by retracting the incisors to establish proper

tooth-chin balance, But when the lower incisors are retracted, the upper

incisors also must be retracted.

2. For some patients, this creates the risk of an unesthetic flattening of the

lips and can make a large nose appear even more prominent.

3. For such patients, a lower border osteotomy to augment the chin

provides an alternative to premolar extraction and retraction of prominent

lower incisors


4. In theory, advancing the chin decreases lip pressure against the lower

incisors and makes them more stable in an advanced position. Although

case reports suggest that this may be correct, it has not been established

scientifically

Integration of Orthognathic and Other Surgery

1. Rhinoplasty

It can correct the nasal prominence and elevation of the nasal bridge that

often accompanies severe Class II malocclusion. If the jaw asymmetry

exists, there is about a 30% chance that the nose also is affected, so it is

important to evaluate the nose carefully in asymmetry patients.

It is better for the patient to have both procedures done as part of the same

operation,

Simultaneous mandibular advancement and rhinoplasty usually can be

accomplished, but it is more difficult to combine maxillary surgery and

rhinoplasty, and still more difficult to combine nasal and two-jaw surgery.

A second-stage rhinoplasty, typically done 12 to 16 weeks after the jaw

surgery, often is the best plan for patients with major asymmetry


Examination of the nose

A detailed examination of the internal and external aspects of the nose is

performed. Anterior rhinoscopy to detail mucosal, caudal septal and

turbinate deformities is supplemented with an endoscopic evaluation of the

posterior nasal cavity and middle meatal areas to exclude infective or

obstructive sinonasal disease.

The internal nasal valve area which is bounded by the upper lateral

cartilage, inferior turbinate, nasal septum

and nasal floor is specifically examined

and any high septal deformity noted. This

is the narrowest part of the nasal airway

and significant internal nasal valve collapse

can be examined by Cottle's test in which

the airway improves when the cheek

adjacent to the mid third of the nose is

pulled laterally.


The importance of the balance of the nose to other aspects of the face is

important. Assessment of this relationship should form the initial part of

the external examination process.

The patient's ethnic characteristics must also be considered. Facial and

nasal asymmetries are documented and detailed to the patient.

2. Tongue Reduction

Indications: The enlarged tongue is an uncommon cause of anterior open

bite and osteotomy failure. If it appears to be large and the incisor teeth are

proclined and separated, surgical reduction is indicated and can be carried

out prior to orthodontics or with segmental osteotomies.

Where there is any doubt, the patient should be informed that it may be

necessary sometime after the dental alignment or osteotomy, and the case is

carefully followed up at 3-monthly intervals to prevent any gross relapse.

This will take the form of recurrent proclination and separation of the

incisors. Once this is obvious, reduction should be carried out and any

dental relapse can be corrected orthodontically.

3. Collagen and Botox

Collagen injections treat the same facial wrinkles that BOTOX®

Cosmetic does, including frown lines, crow's feet and forehead creases.

Collagen injections can also be used to compensate for fat loss in facial

tissues, lip augmentation, and to fill in acne scars or dark under eye circles.

While bovine collagen injections like Zyderm and Zyplast are still used

today, patients are required to undergo a skin test prior to treatment to


ensure against allergic reactions. By comparison, human collagen

injections like CosmoDerm and CosmoPlast can cost more, but they are

proven non-allergenic treatments.

Botox injections don't technically qualify as a dermal filler because their

treatments use the botulinum toxin type A, a neuromuscular blocking toxin,

rather than a filler substance. The botulinum toxin relaxes tense facial

muscles so that the appearance of wrinkles and fine lines is temporarily

eliminated. Botox is FDA approved for the treatment of wrinkles and poses

the risk of a few minor side effects like temporary bruising. Overall, Botox

and collagen injections are considered safe procedures for the majority of

patients

Distraction Osteogenesis

Inducing a callus of bone by osteotomy or corticotomy followed by

distraction of proximal and distal ends resulting in increase of bone length .

Following an appropriately designed osteotomy, carefully controlled

tensile forces are gradually applied to the callus increasing the regenerative

immature bone laid down between the cut ends.

Over time, the bone remodels into mature bone and the surrounding soft

tissues adapt to their new content and length.

Indication

1. Correction of sever congenital craniofacial defects


Micrognathia (up to 24mm elongation reported)

Correction of mid face retrusion

Craniofacial abnormalities, e.g. Crouzons; hemifacial microsomia;

2. Maxillary hypoplasias due to previous cleft palate surgery; to allow

slow and gradual soft tissue adaptation to the new bone position.

3. Palatal and mandibular expansion;

4. Dentoalveolar hypoplasia for implant insertion;

5. Tumour/trauma reconstruction;

6. TMJ ankylosis.

Advantages

1. Used at an earlier age

2. Improves soft tissue functional matrix

3. Less relapse

4. Reduces need for bone grafts

5. Some claim that distraction produces less disturbance of speech with

reduced incidence of VPI.

6. Can achieve movement in 3 plane of space


Disadvantages

1. Movement limited by distraction device

2. Infection

3. 2 operations required: one to place, one to remove

4. Damages to

Teeth by screws, pins and bone cuts

Nerves by direct injury and traction injury

Skin scarring by transcutaneous pins if it is used

Tmj

Types of Distractors1. Internal Distractors

Are partially buried

give excellent control over vectors,

require adequate bone

patient with good manual dexterity to turn the

2. Extra-Oral Distractors

Are easier to activate,

give less control over the vectors of distraction,


do not control the posterior maxilla well,

require a frame that is a disadvantage

Types of Extra-Oral Distractors LeFort I Distraction

LeFort II Distraction

LeFort III (Kufner) Distraction

Techniques1. Corticotomy or osteotomy

2. 7 day latency period, until intact vascular supply established

3. Prolonged, progressive and gradual distraction, correct rate and rhythm

of distraction which should be 1mm/day:

below 0.5mm / day-- premature union

above 1.5mm / day- non-union

4. Consolidation period of 8-10 weeks

5. Digital simulated distraction can also be carried out for the more

complicated cases prior to surgery with STL models.


6. The control of the distraction vector of movement can be achieved

using three dimension distractor or with the aid of intermaxillary elastic to

counteract any unwanted movement.

Fixation for orthognathic surgeryFixation of the jaws following an osteotomy plays a very important role in

promoting the union of the repositioned segments. Any movement of the

osteotomised segment can impair healing, which may result in a fibrous

union, non-union or mal-union.

Types of fixationFixation methods can be classified as external, internal fixation (rigid or

non-rigid transosseous wire fixation) and supportive IMF.

a. Extra-osseous fixation.

1. Occlusal wafers.

2. Fixed orthodontic appliances with supplementary arch wires and tubes.

3. Cast metal splints. Cast metal splints have become less popular because

of the clinical and laboratory complexity and are usually confined to the

unstable components of a cleft case.

4. Arch bars either prefabricated flexible or cast cobalt chromium.

Prefabricated Flexible (Erich — Dentaurum, Pforzheim, FRG) is made of

semi-rigid stainless steel. It can be easily contoured to the arch form and


ligated with stainless steel wires passed around the arch bar and the necks

of the adjacent teeth or it can be bonded directly to the tooth surface using

acid etch technique. Cleats for intermaxillary fixation are also an integral

part of the design.

Advantages

These are useful where orthodontic treatment has not been used.

No technical assistance since it can be easily adapted into the desired

shape, can be placed before the operation, occlusion can always be checked

and at the end of the fixation period the arch bars can easily be removed

without an anaesthetic.

Disadvantages

An adequate number of suitable teeth are required to get rigid and reliable

fixation.

They may not be suitable in osteotomies where there are many crowns

and bridges.

5. Eyelet wires. temporary intermaxillary fixation (IMF) is very important

to secure the mobilised segments of the maxilla and the mandible whilst

applying the internal fixation plates and screws.

6. Intra-oral intermaxillary fixation (Temporary IMF)


Temporary IMF is required at operation to achieve and hold the correct

occlusion during osseous fixation. There are several methods available:

1. Fixed orthodontic appliances with occlusal wafers

2. Arch bars

3. Cortical screws and intermaxillary fixation

7.

b. Intra-osseous fixation.

1. Rigid internal fixation (RIF): RIF is the most common method of

fixation. It includes:

i. Mini-plates (titanium or absorbable plates)

Adapted to the lateral surface of the jaw bone and secured with

monocortical screws (titanium or absorbable screws)

The introduction of L-and Y-shape plates should eliminate apical damage

when screwing into the maxillary alveolar segment.

ii. Bicortical screws (positional screws) (titanium or absorbable screws)

It passes through both the lateral and medial cortices.

A bicortical screw (also known as positional screw) is a fully threaded

screw that binds both the lateral cortex of the distal segment and the medial

cortex of the proximal segment during a bilateral sagittal split osteotomy

(BSSO).


This method of fixation does not place any compression on the bony

contact between the proximal and distal segments as the screw is tightened;

the screw engages both the lateral and medial cortex, while maintaining the

distance between the two cortices.

It is recommended that, for a BSSO to achieve maximum stability, three

screws are used and placed in a triangular pattern. Sometimes a

percutaneous approach is advised using a trocar to achieve the

perpendicular placement of the screws.

It has been suggested that the use of bi-cortical screw fixation in

mandibular advancement procedures can lead to condylar resorption;

torque may be applied to the mandibular condyle through lateral

displacement of the proximal fragment as the screws are tightened.

However, studies by Hoppenreijs et al (1998) and Hwang et al (2000) have

found that there is no significant difference in the incidence of post-

operative condylar resorption following BSSO fixation with transosseous

wiring, positional screws or mini-plate fixation.

NB: In a recent Cochrane review, it was concluded that there is no

statistically significant difference in post-operative discomfort, level of

patient dissatisfaction, plate exposure or infection for plate and screw

fixation using either titanium or resorbable materials in orthognathic

surgery (Federowicz et al. 2009). Despite this finding, however, resorbable

plates are not widely used in the UK because of the concerns outlined.


Disadvantages of RIFExpense

Technique sensitive

Damage to vital structures if placed in an incorrect site e.g. mental nerve,

infraorbital nerve

10-15% of plates require removal

Inflammation of overlying soft tissue which may result in soft tissue

dehiscence.

Bulk - plates can sometimes be felt beneath oral mucosa

2. Transosseous wiring

Before the technique of direct rigid fixation with mini-plates was

introduced, transosseous wiring was the traditional method of immobilising

bony segments (together with supporting intermaxillary fixation IMF).

In the mandible, 0.5mm soft stainless steel wire is passed through the

medial and lateral cortices at either the upper or lower border during a

BSSO procedure.

In the maxilla, 0.35mm wire is used because of the thinner nature of the

maxillary cortical bone.

In cases where bimaxillary osteotomy is carried out, skeletal suspension

wires are added from sites with denser cortical bone such as the piriform

rim in the maxilla, and circummandibular wires in the mandible.


c. Hybrid type: Cortical screws and intermaxillary fixation: Where there

has been no recent orthodontic treatment, a cortical screw placed in the

buccal alveolus in each quadrant or some form of arch bar is essential for

intraoperative fixation of wafer.

Rigid internal fixation (as compared to intermaxillary fixation)

Advantages1. Elimination of six weeks of IMF, so no need for time in intensive care

2. Early mandibular opening is possible.

3. Earlier return to a good diet

4. Better OH.

5. A very early revelation of any significant malposition of a jaw enables

an early return to the operating theatre before fibrosis starts. With rigid

fixation the question arises very soon after operation and not six weeks

later on release of IMF.

6. Generally better final bony stability (e.g. Blomqvist et al 1997 and

Forsell et al 1992)

Resorbable screws and plates

These screws are made from polylactide

with or without a percentage of polyglycide.


Ferretti and Reyneke (2002), compare them with normal RIF screw and

found no difference in the post-operative stability.

It mainly used to overcome the disadvantages of metal fixation include

unacceptable palpability, exposure intraorally, passive migration, and

distortion of future magnetic resonance images (MRI) and computed

tomograms (CT). Titanium particulate matter may be shed into the adjacent

tissues and has also been found in regional lymph nodes. The ideal

bioresorbable material should not only support the bony fragments during

healing but also resorb fully once healing is completed. The resulting

metabolites should not cause any local or systemic disorders. LactoSorb is

a copolymer of poly-l-lactic and polyglycolic acid, in a ratio of 82:18%.

The copolymer is structured to provide adequate strength for 6–8 weeks

and to allow a resorption time of 9–15 months. It is metabolised in the

citric acid cycle and eventually excreted by the lungs as carbon dioxide and

water. No difference in the degree of relapse between the use of

bioabsirbable and metallic screw after BSSO (Mattew and Ayoub 2003)

Medication for Orthognathic cases

Preoperatively Immediate

postop

Up to 3 days

Amoxicillin 1G

intravenously at

500 mg

intravenously

orally 500 mg 8-

hourly for the


induction 3 hours traditional 3

days

Metronidazole 1g rectal

suppository at

induction

1g rectal

suppository

3 hours

400 mg orally

12-hourly for 2-

3 days

Clindamycin 300 mg

intravenously at

induction

150 mg iv. 3

hours

300 mg 6-

hourly orally for

2-3 days.

Dexamethasone for

swelling

8 mg is given

intravenously

with the

anaesthetic

induction agents

8 mg is given

i.v. or i.m. 12-

hourly on

postoperative

day 1

4-5 mg 12-

hourly on day 2

non-steroidal anti-

inflammatory

analgesic,

A rectal

administration

such as

flurbiprofen 150

mg 12-hourly, is

also useful to

avoid

continuous

non-steroidal

anti-

inflammatory

analgesic,


opiate analgesia.

Morphine for Pain 1 mg/ml by a Patient Controlled

Administration “pump” system.

long-acting local

analgesic 0.5%

(5 mg/ml)

bupivacaine

hydrochloride

with adrenaline

(1:200 000)

antiemetic such as

metoclopromide

10 mg with morphine

Postoperative Care

First day

1. A nasopharyngeal tube is left in situ overnight, with strict instructions

to staff to suck out the nasopharynx every 30 minutes with a fine catheter

passed through the tube to minimize vomiting.

2. Oxygen (40%) in air is usually administered by face mask at

approximately 5 litres/min.

Then later after complete recovery:


3. Airway and chest clinically and if not clear, radiographically. All

patients benefit from chest physiotherapy.

4. Note the urinary output and ensure the patient's bladder has been

emptied, especially as transient retention may follow narcotic analgesics.

5. Fluid balance, i.e. blood and fluid replacement should approximate to

blood and fluid loss.

6. Nutrition. During the first 24 hours continue the Hartmann's solution, 2

litres i.v., but try 100 ml/h water by mouth, then tea or orange juice, etc. as

soon as the patient can tolerate feeding, using a syringe and quill, feeding

cup or straw. If this is not possible use a fine-bore (Clinifeed — Roussel,

UK) nasogastric tube which should be passed preoperatively to permit

feeding until the patient can accept fluid and calories by mouth.

7. Occlusion and elastic fixation if used.

8. Cutaneous sensation and facial motor function.

9. Oral hygiene with Chlorhexidine 0.2% solution is commenced.

Second Postoperative Day

Repeat the above but change from intravenous to an oral or nasogastric

regimen, increasing the feed to a full diet.

Follow-Up

1. The occlusion may be checked weekly or fortnightly.


2. It is reassuring for the surgeon to assist maximal intercuspation with the

final wafer and elastics.

3. Soluble sutures should be left or removed when they are accessible and

are a source of irritation.

4. Patients require reassurance that impaired labial or infraorbital

sensation will return to normal within 6 months and that excess soft tissue

will also remodel and disappear over this period.

Immediate Postoperative Feeding

1. 0-24 Hours Post-Operation: Intravenous Fluids compound sodium

lactate (Hartmann's) solution is given to balance vomited fluid, gastric

aspirate, urinary output and metabolic needs. The volume will be 2 to 3

litres depending on the patient's weight and the ambient temperature. The

patient should also be encouraged to drink a little.

2. After 24 Hours

If the patient is well, and the surgical procedure allows, trials of oral fluid

should be commenced using a feeding cup, straw or a large bore syringe

and quill. Most orthognathic cases can cope,

if oral intake is proving difficult, enteral feeding should be commenced

using a fine bore nasogastric feeding tube. Supplemental intravenous fluids

are often needed


3. After 48 Hours Patients who have commenced nasogastric feeding

should continue to receive this until the optimum oral intake has been

established. Patients who have tolerated oral fluids from the start can

progress to a full diet. In many cases of bimaxillary surgery involving the

lower labial sulcus with impaired mental sensation, adequate oral feeding

may not be possible for up to 7 days and need special attention.

4. On Discharge the patient should have a comprehensive assessment and

education regarding food preparation, food fortification and the use of

dietary supplements.

General Guidelines for Patients

Aim for weight maintenance.

Aim to include as much variety in the diet as possible

Liquids are more filling than solids, so more will be needed to prevent

weight loss.

Liquidised foods must be thin and smooth enough to pass through a straw

or quill.

Foods are often more palatable if liquidised separately to preserve

individuals flavours and colours.

Milk is a useful source of protein and calories, and can be fortified further

by adding dried milk powder; 3-4 tablespoons of any dried milk powder to

1 pint of full cream milk.


Vitamin C is an important nutrient for wound healing; a glass of pure

orange juice or blackcurrant drink should be taken daily.

This diet also requires a dedicated oral hygiene regime with a child's soft

tooth brush and a chlorhexidine mouth wash after meals to control plaque.

Problems of orthognathic surgery treatment

A. Orthodontic

1. decalcification,

2. breakage of tooth in debonding,

3. attrition with ceramic bracket,

4. root resorption,

5. alveolar bone loss,

6. pulpitis,

7. pulp obliteration,

8. gingivitis,

9. failed treatment,

10. stopped treatment,

11. relapse

B. Surgical


A. Intraoperative

1. Damage to the neurovascular bundle

2. Hemorrhage

3. Failure to relocate the osteotomised fragments

4. Damage to the teeth

5. Death

Postoperatively

1. Immediate surgical complication including

a. Swelling,

Oedema is reducible with pre-and postoperative dexamethasone and

antibiotic cover.

Contrary to some popular practice vacuum drains can dramatically reduce

the swelling arising from mandibular osteotomies, and the minivacuum

drain is equally valuable for infraorbital haematomas following dissection

through a subciliary incision.

The same applies to the iliac crest donor site. Where possible leave drains

for at least 24 hours after they cease to function.

Where there is gross postoperative swelling and pain, the presence of a

haematoma is more likely than oedema alone. Treatment should be the


release of the haematoma, especially if expanding, as it may be the

presenting feature of a persistent arterial bleed, which needs to be identified

and arrested.

b. Bleeding Problems

Minor Haemorrhage

Even with previously healthy patients not receiving any medication which

would predispose to excess bleeding, intraoperative blood loss is

significantly reduced by the administration of an antifibrinolytic agent such

as tranexamic acid 25 mg/kg orally or 0.5-1 g by slow intravenous injection

pre-and postoperatively.

Tearing the periosteum on the medial aspect of the ascending ramus

whilst exposing it for a sagittal split may produce a troublesome bleed,

which can be controlled with a hot wet tonsil swab and pressure for 3

minutes.

Damage to the facial vessels through the base of the subperiosteal pouch

prepared for the mandibular buccal cortex cut responds to the same

pressure and patience.

Rarely the maxillary, tonsillar or lingual arteries may be damaged, giving

rise to prolonged serous haemorrhage. Again, packing firstly with a swab,

and secondly with a large piece of oxidised cellulose (Surgicel) should be

sufficient, assisted by 0.5-1 g t.d.s. tranexamic acid (Cyclokapron, Kabi)

given intravenously.


If vigorous bleeding persists the external carotid may need to be tied off,

Persistent Haemorrhage

Failure to control bleeding despite efficient conservative measures may be

due to the following.

i) A patent damaged artery, either the maxillary or tonsillar that require

identification and ligation. Do not delay ligation of the external carotid if

significant bleeding persists despite local ligation, packing and

antifibrinolytic therapy for more than 30 minutes. This should allow time

for investigation.

ii) A rare manifestation of a latent coagulation defect or defibrination. In

both cases there is an evident lack of clot formation on the drapes and the

wound oozes “watery blood”.

Secondary Haemorrhage

The patient may suddenly bleed profusely postoperatively in the ward, or

even at home. The common causes are a partially divided large vein or

untied artery in the depths of a mandibular osteotomy wound. Occasionally

an undetected coagulopathy such as von Willebrand's is the underlying

problem, especially when the bleeding is repeated. The management must

commence with pressure applied to the bleeding site with swabs, and rapid

transfer to theatre for exploration and haemostasis, as described. As with

all severe haemorrhage up to 10 mg intravenous morphine should be given

immediately by slow intravenous injection as a sedative analgesic, together


with tranexamic acid 0.5-1 g intravenously to help conserve clotting factors

and clot in favour of haemostasis.

Gastric Haemorrhage

The chance of stress-induced gastric erosion is small, even after prolonged

orthognathic surgery. However, the combination of a patient with a history

of peptic ulceration, a stressful surgical procedure, anti-inflammatory

steroids and analgesics can produce a gastric bleed. Abdominal discomfort,

tachycardia, true melaena and/or haematemesis and a fall in haemoglobin

(a late sign) should alert one to this possibility. Initial treatment should

include intravenous fluid support and administration of a proton-pump

inhibitor (omeprazole), first as an intravenous bolus dose (40 mg), then as

an intravenous infusion for 72 hours. Early endoscopy should be

considered after consultation with a gastroenterologist so that the bleeding

point can be injected or banded. The aim of drug treatment is to raise

gastric pH to above 4, thereby stabilising any clots that may have formed at

the bleeding site. This is the reasoning behind the use of proton pump

inhibitors over H2 receptor blockers such as ranitidine, which have a lesser

effect on pH. With vulnerable patients a regular prophylactic proton pump

inhibitor, such as omeprazole or lansoprazole, should be administered as

well as eliminating both steroids and non-steroidal antiinflammatory

analgesic drugs from the intraoperative and postoperative regimen.

c. The Airway


After an uneventful operation, the airway should be maintained with a

nasopharyngeal tube, which is sucked out throughout the postoperative 12-

18 hours at 30-minute intervals. Unless the nurse ensures that the fine

suction catheter passes beyond the end of the nasopharyngeal airway tube,

the end will gradually become blocked with blood clot and will become an

efficient airway obstruction the same can occur with a tracheostomy tube.

Some anaesthetists leave an endotracheal tube in situ which with modern

closed suction units can be kept unobstructed with minimum effort and

nursing intervention. A facemask with 40% oxygen at a flow rate of

approximately 5 litres/min ensures adequate tissue perfusion.

Nasal obstruction with blood clot and mucous crusting can be prevented

by steam inhalations containing Friar's Balsam or some similar aromatic

vapour.

Occasionally an asthmatic patient develops acute bronchospasm and

airway obstruction despite the dexamethasone cover. This may be resolved

by a salbutamol nebuliser; 2.5-5 mg of salbutamol in a pre-prepared

solution via a nebuliser mask on 8 litres oxygen per minute repeated as

required

Emergency Airway Procedures. Acute upper airway obstruction is more

likely to follow trauma then operative procedures. In the non-intubated

patient, obstruction secondary to haemorrhage into the neck tissues may

prevent the clinician from inserting an endotracheal tube through the cords


to establish airway patency. In such cases needle cricothryroidotomy and

surgical cricothyroidotomy may be used to maintain ventilation and

oxygenation whilst formal endotracheal intubation is attempted.

Needle cricothyroidotomy and jet insufflation can provide supplemental

oxygenation for around 20-30 minutes, the time constraint being carbon

dioxide retention, as only minimal expiration is possible through the

obstructed airway via this method. This relatively simple technique buys

time to perform more definitive airway procedures by a clinician skilled in

difficult and emergency situations.

Surgical cricothyroidotomy involves the insertion of a small endotracheal

tube or tracheostomy tube through the cricothyroid membrane. Using this

method the patient can be successfully oxygenated and ventilated with a

bag valve system with supplemental oxygen until intubation or retrograde

intubation is achieved.

d. Soreness,

e. Difficulty eating,

f. Bruising,

g. Mild post-operative depression.

h. Pneumothorax

Occasionally, despite every care on removing a rib graft, there is a breach

in the pleura and the patient develops a pneumothorax. The presenting


signs are breathlessness and tachypnoea with absent breath-sounds over the

area. The typical radiographic appearance where the visceral pleura is

breached. The most convenient, comfortable and cosmetically pleasing site

for drainage is in the fourth or fifth intercostal space in the mid-axillary

line.

i. Vomiting Postoperative

Vomiting in patients with intermaxillary fixation was a well-recognised

problem. Predisposing factors are blood escaping intraoperatively and

postoperatively into the stomach, where partial digestion together with bile

reflux creates an irritant stagnant mixture. An additional factor is the

emetic effect of opiate analgesics. Prevention

Avoid intermaxillary fixation by using internal rigid fixation.

ii) A 12-16FG nasogastric tube passed at the time of the anaesthetic

induction enables postoperative aspiration of gastric contents. The tube is

attached to a bile bag to create a closed collecting system for any

spontaneous reflux. As the patient is monitored throughout the

postoperative night the stomach should be aspirated hourly and the fluid

loss noted. Initially flushing the tube with 20 ml water before aspiration

prevents the end becoming clogged with clot.

The administration of an antiemetic, e.g. metoclopromide 10 mg

intravenously at the end of the operation, and with any required opiate

analgesics, reduces drug-induced emesis (up to a maximum of 30 mg/24


hours). Metoclopromide 10 mg intravenously should also be given at any

other time if vomiting is anticipated.

j. Iliac Crest Problems

The removal of bone from the iliac crest for orthognathic purposes is

becoming less popular. However, the inverted L osteotomy may require a

substantial amount of corticocancellous bone to correct a very small

mandible. Postoperative pain is the most frequent complication and can be

reduced by drainage and analgesics. Some surgeons leave a fine cannula

for infusion of a long acting local analgesic such as bupivacaine (Marcain).

It is difficult to be certain if this is of significant value. If a large graft has

been removed near the anterior superior iliac spine, this may fracture with

sudden movement once the patient is mobilised.

k. Urinary retention

Catheterisation Catheterisation is necessary for prolonged surgical

procedures, especially where large quantities of fluid have been infused.

This is uncommon with orthognathic cases except where there has been

unexpected major blood loss. Another occasional indication is the patient,

usually male, who has postoperative urinary retention. This may be due to

opioid-induced sphincter spasm, diffidence in using a urinal, or a

combination of both, leading to gross distension.

l. Deep Vein Thrombosis


This is a rare event in orthognathic patients, usually occurring

unexpectedly in young women.

As a precaution, all women should cease taking oestrogen containing

contraceptive pills 4 weeks prior to surgery.

If this has been overlooked, subcutaneous low molecular weight heparin

prophylaxis should be considered,

Both high and low risk patients benefit from elasticated thromboembolic-

deterrent stockings being worn during the operation.

Any complaint of postoperative calf tenderness must be taken seriously,

lower limb Doppler ultrasonography should be carried out and if this is

positive (or not possible) the patient is anticoagulated to prevent extension

of the thrombus and embolism.

m.

2. Late complications:

a. Failure of bony union

b. infection of the surgical plates 10%,

c. Permanent damage to nerve, 20-25% risk of permenant altered

sensation with BSSO.

d. Soft tissue problem:

increase alar width and fullness of upper lip with maxillary impaction


double chin with mandibular set backs

lip sag following augmentation genioplasty

e. Fixation Problems

Infection may occur around screws and plates. Miniature plates are an

essential part of the osteotomy and surprisingly in the maxilla rarely get

infected. If drainage and a course of antibiotics do not suppress the

infection, the plate and screws have to be removed. Similarly, uninfected

bone plates may become palpable subcutaneously or submucosally and also

require removal.

Incorrectly placed screws and plates may displace the bony parts. This

occurs more commonly in the third molar area with the sagittal split

operation, but is also with Le Fort I procedures where maxillary

displacement can distort the nasal septum.

Less commonly plates break. Whenever displacement or loss of control

takes place, the patient should be taken back to theatre for correction.

If the condyle is pushed to the back of the fossa when temporary

intermaxillary fixation is put on to facilitate the insertion of the bicortical

screws or buccal plate, on its release, with the patient conscious and

upright, the condyles will tend to recoil downwards and forwards. This is

favourable for the Class 2 Division I mandibular advancement but gives a

postoperative prognathous malocclusion with the Class 3 setback. To avoid

these artefacts (a) the model surgery should be based on a conscious supine


centric relation squash bite and (b) the ascending ramus proximal fragment

should be displaced backwards for Class 2 advancements but pulled

forwards prior to fixation with the Class 3 mandibular setback. Such

problems were less likely to happen with a loose interosseous wire loop at

the osteotomy site and prolonged intermaxillary fixation for 6 weeks. This

enabled the ascending ramus proximal fragment to achieve an optimum

condylemeniscus-fossa relationship by functional adjustment brought about

by swallowing and speech.

Disturbed muscular proprioception and intracapsular oedema may also

give a transient deranged postoperative occlusion when using rigid fixation.

In these cases, light elastics for 7 days will help to restore the occlusion to

the planned relationship. The final occlussal wafer is often left in situ even

where there is no occlussal problem. This is very uncomfortable for the

patient and there is no evidence that it helps. However, if after this elastic

“proprioceptive regimen” there still appears to be marked displacement and

malocclusion — re-operate.

f. condylar resorption specially in high angle class II, specially on

patients who has:

Posteriorly inclined condyles.

Deliberately increased maxillary-mandibular plane angle.

Reduced posterior face height.


As this may result in an increased risk of progressive condylar resorption

following surgery, with subsequent relapse of the malocclusion (Hwang et

al., 2004).

g. Relapse

It arises from inadequate planning or inappropriate surgical technique. The

latter may be roughly divided into two overlapping groups:

1. Operative Structural Causes of Relapse

Inadequate separation of the proximal mandibular bone and the medial

pterygoid muscle from the buccal plate when doing a sagittal split. A finger

firmly inserted to the depth of the split is used to remove the restraining

periosteum and muscle fibres, which hold the two cortices together at the

lower border.

Inadequate bone removal from the posterior wall of the antrum or

separation of the pterygoid plates in a Le Fort I impaction can also create

problems.

The untrimmed nasal septum will create a buckling effect and either

displace the maxilla and disturb the occlusion, or displace the nose and

produce an asymmetric tip deformity, and obstruct the airway. Late

correction will require a rhinoplasty.

2. Postoperative Functional Causes of Relapse


The most notorious is the recurrent anterior open bite following attempted

correction with a mandibular osteotomy. This will occur in patients with a

high mandibular-maxillary plane angle where the low posterior facial

height reflects a short pterygomasseteric sling. This is stretched as the

mandible is rotated around the fulcrum created by the occluding molar

crowns when the anterior teeth are brought into occlusion to close the gap.

The inelastic ligaments and the return of postoperative muscular tone may

even produce a relapse despite internal fixation. This is avoided by a

posterior maxillary impaction equivalent to the anterior open bite to be

corrected.

Postoperative tooth movement can be favourable, especially with the

spontaneous or assisted closure of lateral open bites. However,

unfavourable tooth movements may arise.

Repositioned lower incisors are proclined by a large or “anteriorly

postured” tongue.

Upper incisors are proclined by the lower lip after a maxillary

segmental pushback procedures is carried out on a marked Class II,

Division 1 patient without a mandibular forward correction to an edge to

edge relationship.

Continued eruption (occlusal drift) of the lower incisors will follow an

anterior segmental setdown unless they are placed in a stabilising contact

with the cingula or incisive edges of the opposing teeth.


Expansion of the maxillary premolar and molar segments may tilt those

teeth buccally. Subsequent palatal drift will produce intercuspal contact on

closure with the creation of an anterior open bite. Major expansion of the

palate should be done surgically with a midline osteotomy to avoid dental

relapse.

Occasionally lower lip sag may follow a bone graft procedure to

increase the chin depth by augmentation, or a mandibular forward

movement with a genioplasty. It is difficult to be sure whether it is due to

inadequate freeing of the periosteal pouch and overlying soft tissues, or

failure to re-attach the mentalis high enough on the anterior mandibular

surface, or abnormal muscle activity. The lip sag should be avoided by the

creation of a large loose periosteal pouch to accommodate the enlarged

chin, carefully suturing the divided mentalis to the deep muscle fibres on

the alveolar surface, and the application of a firm pressure dressing

overlying the labiomantal groove. Once formed it can be eliminated in

some cases by vigorous exercising of the lower lip, i.e. the lip is actively

stretched upwards over the incisor edges. If this fails, it will be necessary to

deglove and reposition the soft tissues upwards using heavy polyglycollate

(Vicryl) sutures to elevate the soft tissues of the chin.

h. Idiopathic periapical and internal resorption may occur in teeth adjacent

to an osteotomy cut, even without untoward bur contact. The cause is

unknown but may be due to a vascular response to the adjacent surgery.


i. Orthodontic depression of lower incisors in adults, before surgery, may

cause proclination with alveolar dehiscence and gingival recession.

Furthermore, the proclined incisors may then upright spontaneously once

fixation is removed.

j. Tooth damage may occur with the bone cuts of segmental osteotomies,

either apically or laterally. Avoid the former by marking the estimated

apical site with a shallow bur hole prior to the section. Lateral root damage

arises when burs are used interdentally. Only the buccal and lingual

(palatal) bone should be cut with a bur and the actual division should be

made with a fine osteotome or saw. Although root damage often appears to

be self-limiting and most teeth survive, occasionally the exposed dentine

undergoes progressive resorption. An attempt may be made to preserve the

tooth by root canal therapy with calcium hydroxide. However, should root

loss progress, extraction and an implant or bridge will be required to

salvage the situation. Segmental cuts in the older patient with incipient

periodontal disease may also create intractable bony pockets unless

anticipated. The cuts must be done carefully with a fine osteotome after

prior periodontal therapy followed by postoperative oral hygiene

instruction.

k. Nerve Damage

i) It is important to warn the patient preoperatively of impaired sensation

that may arise in the mental or mylohyoid nerve distribution of the lower

lip and chin following a sagittal split or anterior segmental operation, and


in the infraorbital area following a maxillary osteotomy. The former

usually recovers in 2-6 months, although some patients have a permanent

deficit, which is less noticeable if the operation is otherwise successful.

When the inferior dental nerve is exposed and torn during the sagittal split,

it may be possible to hold the separated ends together with a 6/0 Prolene

suture prior to fixation.

ii) Facial nerve damage with weakness can be localised following external

incisions for a subsigmoid (subcondylar) osteotomy but will involve a

wider distribution of the facial nerve if it is damaged near its main trunk.

This can occur with a sagittal split pushback or an intraoral subsigmoid

(subcondylar) operation. The cause is probably traumatic instrumentation.

They prognosis is usually very good, with gradual recovery over 6-8

weeks.

iii) The lingual nerve is rarely damaged during an osteotomy. However,

persistent impaired lingual sensation after 6 weeks requires open

exploration and repair. This is most easily done by removing the overlying

sublingual salivary gland.

iv) A rare disturbance is nasal vasomotor hyperfunction, which may occur

after a Le Fort I osteotomy. The patient develops continuous rhinorrhoea,

which look like but not a cerebrospinal fluid leak. The cause is uncertain

and may be either loss of sympathetic vasomotor control or damage to the

sphenopalatine ganglion with enhanced stimulation. There is no

satisfactory treatment.


l. Emotional and Psychiatric Problems

Agitation can arise both from intolerance of intermaxillary fixation or

simply nasal airway obstruction. Both can now be avoided.

Unanticipated anxiety of an alien environment, especially the intensive

care unit,

Emotionally unstable individuals, especially those who have a history of

body dysmorphic disorder, may also become aggressive.

Postsurgical orthodontic

The aims of postsurgical orthodontics are:

1. Final tooth positioning

2. Root paralleling

3. Vertical movements of buccal segments with inter-arch elastics. In the

arch where most vertical movement is required, a more flexible archwire

may be used such as rectangular nickel titanium or rectangular braided

steel wire. In the opposing arch where vertical movement is not required, a

stiffer rectangular steel wire can remain in place


4. In cases of segmental surgery, where canine brackets have been

reversed preoperatively, it is necessary to re-bond the canine brackets,

placing brackets of the correct side in order to produce a normal canine

angulation.

5. Retention

Orthognathic Surgery

The aetiology of relapse

1. Dental relapse

2. Incorrect osteotomies with improper seating of the condyles,

3. Skeletal relapse due to bone remodelling

4. The soft tissue and muscles,

5. Remaining growth

Stability depends on

1. Surgical technique employed

2. Direction of movement

3. Magnitude of movement

4. Type of fixation used.

5. Adaptive capacity of muscle fibres


6. Buccal interdigitation

A hierarchy of stability (Proffit 1996, 2007)

A. Superior repositioning of the maxilla and mandibular advancement is

the most stable procedure

B. Forward movement of the maxilla is reasonable stable with or without

RIF

C. Mandibular setback is not stable, if the ramus is pushed to a more

vertical inclination when the chin is moved back, the mandibular

musculature tends to return the ramus to its original inclination when

function resumes and carries the chin forward again. The principal

circumstance in which neuromuscular adaptation does not occur is when

the pterygomandibular sling is stretched during mandibular osteotomy


D. Downward movement of maxilla is also problematic (relapse 20%) due

to forces from occlusion, three approaches has been suggested to improve

stability of maxillary downward movement:

Placement of heavy fixation bars from the zygomatic arch to maxillary

posterior teeth,

Interposition of synthetic hydroxyapatite graft

Use of simultaneous ramus osteotomy to minimize stretching of the

elevator muscles

E. Transverse widening of the maxilla is the least stable procedure, due to

stretches of the palatal mucosa and its elastic rebound is a major cause of

relapse

A different pattern of stability is evident after twelve months once surgical

healing is complete.

1. Mandibular advancement is associated with some decrease in length,;

2. Maxillary superior positioning will relapse by > 2-mm in a 35% of

patients;

3. Significant changes occur in jaw positions after bimaxillary surgery,

but these are not necessarily reflected in changes of overjet or overbite bec

the dentoalveolar adaptation prevents an increase in overjet in more than

half these patients


4. Class III correction are more stable in the long-term than class II.

As a general role, late relapse >lyr post op in 2.5-8% of patients,

Advantages of surgery fist Eliminate cuspal interference during expansion

Faster movement

Better teeth movement in the new ST environment

Repair imperfect surgery

Less impact on aesthetic during decompensation

Quick facial changes

Other Dental Treatment associated with orthognathic casesFour special points should be considered when orthognathic surgery is

involved:

1. Incision lines contract somewhat as they heal, and when incisions are

placed in the vestibule, this can stress the gingival attachment, leading to

stripping or recession of the gingiva. This is most likely to be a problem in

the lower anterior area in relation to the incision for a genioplasty .Gingival

grafting should be completed before genioplasty if the attached gingiva is

inadequate.

2. If the surgeon will use rigid fixation (bone screws) placed in the third

molar area, it is desirable to have the teeth removed far enough in advance

of the orthognathic procedure to allow good bone healing (minimum 6

months). If the wisdom is extracted at the time of surgery and the screw


passed through the extraction socket, there will be high chance of weak

fixation and infection around the screw.

3. Orthognathic surgery has no influence on TMD. If joint surgery will be

required, usually it is better to defer this until after orthognathic surgery

because the joint surgery is more predictable after the new joint positions

and occlusal relationships have been established.

4. Definitive restorative and prosthetic treatment is the last step in the

treatment sequence

Facial deformity and the proposed treatment orthodontically and

surgically

Mandibular Prognathism

Presurgical orthodontics will be required to

correct arch size discrepancy,

overcrowding

to decompensate the incisors.

Surgery:

sagittal split osteotomy,

oblique subcondylar (subsigmoid) osteotomy

a) extraoral,

b) intraoral (buccal approach),


c) intraoral (medial approach).

Mandibular Asymmetry (Unilateral)

Presurgical orthodontics will be required to

Insufficient maxillary intercanine width to accommodate the lower arch is

common which need an expansion.

with large discrepancies surgical expansion of the maxilla may be the

treatment of choice or distraction osteogenesis with a bone borne expansion

appliance.

Surgery:

Asymmetry, with or without prognathism, can be corrected by a bilateral

ramus osteotomy, such as the sagittal split, which shortens the affected side

and allows rotation at the contralateral angle.

Recurrent growth creates a difficult decision and will require a careful

high condylar shave preserving the meniscus.

Hemimandibular Hyperplasia

Early

High condylar shaving

subsigmoid osteotomy with osteoplasty of the body of the mandible


Late

The most economical correction is simply reducing the lower border

convexity. This improves the facial appearance and corrects the obliquity

of the mouth,

bimaxillary procedure elevating the maxilla with a Le Fort I osteotomy

and the mandible must then be adjusted to this horizontal occlusal plane,

either by a sagittal split or subcondylar osteotomy as well as the convex

lower border will still need to be trimmed.

Condylar Hypoplasia

Features:

1. Deviation of the chin to the affected side

2. The condyle is usually short, flattened or deformed.

3. An exaggerated antegonial notch is present on the affected side.

4. Deficiency in ramus height gives rise to a secondary canting in

maxillary growth that is tilted downwards towards the normal side.

5. Joint ankylosis

6. Greater asymmetry

Treatment


Moderate degrees

Moderate degrees of hypoplasia may be treated like an asymmetrical

hyperplasia, with a bilateral sagittal split osteotomy. This will lengthen the

affected side and provide a rotation adjustment on the normal side.

However, the maxillary occlusal plane has to be levelled first. In

adolescence this can be achieved orthodontically after the mandibular

surgery by creating a lateral open bite intraoperatively with a unilateral

thickened occlusal wafer or splint.

A large unilateral deficiency,

The downward and forward mandibular reconstruction can only be

achieved with an inverted L osteotomy and interpositional bone graft or

distraction osteogenesis . Again, the maxillary occlusal plane will also

require correction. If the patient is an adult, a Le Fort I osteotomy will be

necessary to level the transverse occlusal tilt

Mandibular Retrognathism or Hypoplasia

Treatment

Decompensation of the incisors and a forward osteotomy of the mandible

to an overcorrected edge to edge incisor relationship, giving a three-point

contact occlusion, i.e. incisors and distal molars, followed by orthodontic

closure of the lateral open bites.


Separate orthodontic levelling of the canine and incisors, and the buccal

segments. This will be followed by a lower anterior mandibulotomy

setdown carried out at the same time as the mandibular lengthening

procedure. This has the advantage of maintaining the lower facial height.

Mandibular Incisor Proclination

the first premolars can be extracted and the canine-incisor segment

brought backwards with a Kole subapical (labial segmental) osteotomy.

If the tongue looks large, reduce it with the osteotomy. If there is any

doubt, warn the patient that should incisor proclination relapse occur,

tongue reduction may be necessary

Maxillary Hypoplasia

Orthodontically: expansion of the intercanine is important

The treatment of choice is a Le Fort I osteotomy with a forward

movement

the Kufner modification of the Le Fort III osteotomy produces an

advancement of the malar bones and infra-orbital margins

Nasomaxillary Hypoplasia

Le Fort II osteotomy


Malar Hypoplasia

the Kufner modification of the Le Fort III osteotomy

The Kufner osteotomy followed by distraction osteogenesis.

The alternative solution is a Le Fort I advancement with simultaneous

alloplastic malar onlays.

Maxillary Protrusion

Anterior segmental osteotomy (Wassmund/Wunderer). The canine-incisor

segment is set back after extraction of the first premolars. A midline split is

necessary to maintain a natural dentoalveolar arch.

Le Fort I setback, very difficult and limited.

Bimaxillary surgery

Traditional techniques

B. Initial bony cuts are completed bilaterally for mandibular sagittal-split

osteotomy, delaying the separation of the tooth-bearing segment of the

jaws from the proximal condylar segment.

C. The wounds arc packed with moist gauze

D. Then the leFort I osteotomy completed.


E. With an intermediate occlusal splint (or the combined two-stage splint)

the maxilla and the mandible are wired temporally by IMF and the maxilla

is repositioned and stabilized with RIF.

F. Then, At this point, the IMF is released.

G. Then Sagittal-split osteotomies are completed bilaterally in the

mandible with osteotomes.

H. The tooth-bearing segment of the mandible is repositioned, with the

final occlusal splint used as a guide. With the patient's teeth again held

firmly together, a temporary IMF is performed

I. Then the mandibular osteotomy sites are stabilized and fixed with RIF,

then IMF released.

Alternative techniques

A. Buckle, Tucker, and Fredette have suggested another sequence for two-

jaw surgry.

B. The mandibular BSSO to be completed before LeFort 1 .

C. RIF with position or large screws provides stable, repositioned

mandible.

D. The intermediate splint in this instance uses the intact maxilla as the

guide.

E. With the mandible held in the new position with RIF, the final occlusal

splint properly repositions the maxilla after leFort I osteotomy.

F. The advantages are minimizes the chance of displacement of maxillary

segments once they have been repositioned specially when there is a


difficulty in stabilizing the maxilla after LeFort I osteotomy such as in

repeat Le Fort I osteotomy or with a multi-segmented maxilla.

The Deep Overbite

With a poor profile, consisting of a retrognathic mandible, increased

lower facial height and the lower lip trapped behind the upper incisors ,

treatment comprises orthodontic decompensation of the incisors followed

by a combination of a lower anterior dentoalveolar setdown and a sagittal

split osteotomy to bring the whole mandible forward to an overcorrected

edge to edge incisor relationship.

3 point landing BSSO

Secondary surgical correction for CLP patient

Important Factors to be considered

1. The amount of tissue in the original embryological defect: early cleft

closure cause more growth retardation

2. Preservation of tissue: Also important is the preservation of tissue,

tissue removal should be avoided whenever possible.

3. The nature and quality of the primary surgery: different surgical

technique result in different outcomes.


Specific Problems in Cleft Patients

1. Sever Class III skeletal problem in all direction with malar hypoplasia.

2. Anterior open bites are common

3. Posterior cross bites are common

4. Dental development may also be delayed in both arches but is most

evident in the cleft segment and may compromise the presurgical

orthodontics.

5. The repaired alveolar cleft is a potential site for fracture at the time of

the down-fracture.

6. If the maxillary alveolus has not been reconstructed, alignment of the

alveolus can be incorporated into the orthognathic procedure. However it

complicates the planning of the surgery and increases the potential

morbidity. Segmental osteotomies are less stable than one-piece maxillary

osteotomies.

7. Previous surgery produces scarring of the labial and buccal vestibule,

the palate and behind the maxillary tuberosities. This presents problems

with the surgical incisions, mobilisation and postoperative closure of the

surgical wound.

8. A pharyngeal flap may make advancement of the maxilla difficult and

will need to be divided. The patient has to be informed well in advance


about the possibility of VPI and speech problem that might developed after

the surgery.

Treatment Planning for CLP

The basic facial and orthognathic evaluation is the same as the non-cleft

case with important refinements.

1. Lip-incisor relationship. As in the non-cleft case, the lip to maxillary

incisor relationship is extremely important. The major surgical moves are

predominantly in the maxilla and with a tight, previously scarred upper lip,

small skeletal moves have a pronounced effect on the incisor exposure.

Surgical and orthodontic changes in incisor angulation will have a similar

effect.

2. Asymmetries. Both dental and skeletal asymmetries are dominant

features, often with compensatory asymmetries in the mandible. This

should be considered

3. Pharyngeal obstruction can be caused by hypertrophied adenoidal tissue

or pharyngeal flaps. Nasal airway obstruction may arise from a deviated

nasal septum narrowing of the nares, hypertrophied turbinates, nasal polyps

and posterior choanal constriction from sub-periosteal bone and

asymmetrical vomer flaps. The management of these problems is an

essential part of the orthognathic procedure. Paradoxically the adenoid

mass may contribute to velopharyngeal function and its removal may

precipitate velopharyngeal inadequacy.


4. Preoperative speech assessment and counselling.

5. However, infection, bone and soft tissue necrosis, delayed healing, loss

of teeth and relapse all occur with greater frequency due to multiple

previous surgeries.

The Choice of Operation for CLP

Maxillary Hypoplasia

1. LeFort I osteotomy either one piece or two pieces maxilla for

transverse maxillary widening.

2. High LeFort I level osteotomy.

3. The modified LeFort II and Kufner LeFort III osteotomy

4. SARPE

5. Rhinoplasty may be necessary.

6. Mismanagement of the soft tissues during closure of the labial

vestibular incision may cause shortening and thinning of the upper lip. The

V-Y closure of a maxillary vestibule incision may increase the vermilion

show in patients with a thin upper lip.

7. Maxillary advancement widens the alar base, increases the projection

and elevation of the nasal tip and the width of the nares. Various surgical

manoeuvres can be used to prevent these unwelcome side effects. These

include an alar base cinch suture, recontouring the bony piriform aperture


either by trimming and/or asymmetric bone grafting and alar base

resections.

Mid Face Distraction Osteogenesis

Indications:

With gross maxillary hypoplasia and a severe degree of scarring, the

degree of advancement may be beyond the expected limits of stability of a

conventional osteotomy. Distraction of the maxilla is preferable to a

surgical compromise such as a mandibular setback.

If the deformity is complex particularly in the upper mid face then a

higher level osteotomy with distraction often gives a better result than a

modified LeFort I with masking onlay bone grafts or modified LeFort II

and LeFort III osteotomies that are difficult to perform and can give

unsightly steps particularly over the radix of the nose.

Mandibular setback (BSSO, VSO)

Mandibular set back indicated in case of:

1. Mandibular prognathisism


2. When there is a maxillary surgical limitations such as severe palatal

scarring, borderline velopharyngeal insufficiency or a tight inferiorly based

pharyngoplasty flap.

3. During maxillary advancement and inferior positioning, the anterior

maxilla is differentially positioned more inferiorly. This will produce a

posterior open bite deformity unless a mandibular ramus procedure is

undertaken simultaneously. Differential down grafting of the anterior

maxilla also results in a counter clockwise rotation of the mandible which

may make the chin retrogenic. This can be corrected by a simultaneous

augmentation genioplasty.

Airway Considerations for CLP during surgery

1. The surgeon can do the following whilst the maxilla is down fractured

Contouring of the inner aspects of the nose

Asymmetries in the piriform region

The mucosa of the nostril floor can be repaired

Septoplasty may be indicated

Partial or complete inferior turbinectomies

Antral and nasal polyps can be removed


2. Pharyngeal flaps raise additional concerns for the anaesthetist and

surgeon which may make intubation difficult and restrict the nasal airway,

so submental intubation might be indicated

Postoperative considerations for CLP

1. Speech therapy: The soft palate mechanism in non-cleft patients has

considerable reserve capacity and can adapt to an increase in length. The

repaired cleft soft palate does not have this capacity to adapt especially

after major advances. The patient with borderline velopharyngeal

incompetence preoperatively is likely to develop worsening of their speech

postoperatively.

2. Relapse: As a prophylactic measure, extraoral elastic traction using a

face mask can be used in patients who are considered particularly at risk of

relapse either due to scarring or who have had large surgical moves

anteriorly and inferiorly.

3. Stability: The factors that increase stability include:

High quality orthodontic preparation.

Avoiding segmental procedures

Overcorrection where possible.

Compromise position must be planned and if necessary with

incorporatation of a mandibular setback.


Alveolar bone grafting.

Bone grafting for inferior repositioning of the maxilla.

Internal rigid fixation for all moves.

Feeding and Postoperative Nutritional Support

Malnutrition is a well-recognised problem in hospitals, with 40%-50% of

all patients found to be malnourished on admission and 70%-80% on

discharge.

Consequences of malnutrition for the postoperative patient include

decreased wound healing, decreased immune function and increased

infection risk which can lead to unnecessary morbidity.

Optimum Daily Requirements, Men and women average 2000-3000 kcal.

0.8 g protein/kg; 2-3 litres fluid.


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