Maxillo-facial Trauma - Minia

Maxillo-facial Trauma

Edentulous mandibular fractures: there is special challenge in treating these fractures:

i. Alveolar resorption is four times greater in the mandible than in the maxilla.

ii. Inferior alveolar vascular supply to the bone is greatly compromised.

iii. Too little cancellous bone for repair (osteoblastic endosteum).

iv. Normal healing potential is retarded.

v. Open reduction amounts to stripping of periosteum, which impairs osteogenesis, as

there is greater dependence on periosteal supply in atrophic mandible.

However, small bone discrepancies (nonanatomic alignment by closed reduction) are

usually of no consequences by maturation of the bone.

3

6

Bone awl for gunning splint fixation

Circumpalatal wiring procedure for fitting the Gunning splint to the maxillary edentulous ridge

Gunning splint

Length of MMF:

• adults 4 -6 weeks.

• children 1- 3 weeks.

• elderly patients 6-8 weeks.

external pin fixation: Indications for external pin fixation:

1.Comminuted fracture.

2.Continuity defects. (gun shot injury)

3.Pathological fractures.

4.Infected fractures. (osteomeylitis)

5.Bone grafting procedure

6.Atrophic edentulous mandible.

MANDIBULAR FRACTURES IN CHILDREN

Incidence of facial fracture is less than 2% prior to 5th year of life. However, mandibular fractures in children are most common. Total percentage of facial fractures is less in children, because of the following:

1. Sheltered atmosphere, protection given to children.

2. Decreased facial mass and proportion.

3. Soft consistency of bone.


4. Pliable cancellous bone has got greater proportion with thin buccal and lingual plates.

5. Taut periosteum offers protective mechanism against fracture and its displacement.


The factors to the child’s advantage are as follows:

a. Faster healing and early bony union. Excellent osteogenic and remodeling capacity.

b. The ability for adaptation as the deciduous teeth are shed and permanent teeth erupt.


Clinical symptoms are same as those of fractures of the lower jaw in the adult. Pain, swelling, malocclusion are the leading symptoms. Abnormal mobility, step deformity in the dental arch will be seen. The radiographic examination is usually difficult in unco-operative child.


Conservative Therapy

In crack fractures or greenstick fractures

with no malocclusion, there is no need for

fixation. Patient is advised to take lot of

fluids and soft food for 10 to 14 days.


Conservative Treatment with Splints

Lateral compression splints: These are prepared and fixed to the mandibular body with circummandibular wiring (for the children with complete deciduous dentition or with mixed dentition).

Labio-lingual splint

Bone awl for splint fixation

Open reduction • In open reduction, as the name implies, the fracture site is

exposed, allowing direct visualization and confirmation of the

procedure. This is typically accompanied by the direct application of a

fixation device at the fracture site

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Open reduction and direct skeletal fixation:

• indications • 1. Displaced unfavorable fractures. • 2. Multiple fractures. • 3. Associated midface fractures. • 4. Associated condylar fractures. • 5. When IMF is contraindicated or not possible.

– Medically compromised patients • Gastrointestinal diseases • Seizure disorders • Compromised pulmonary health • Mental retardation • Nutritional disturbances

• Contraindications for Open Reduction:

• 1. GA or a more prolonged procedure is not advisable.

• 2. Severe comminution with loss of soft tissue.

• 3. Gross infection at the fracture site.

• 4. Patient refusing open reduction.

Surgical Approach Intraoral Approach—Symphysis and Parasymphysis Region

Termed as anterior, vestibular approach or ‘degloving incision’. The lower lip is everted and an incision is created at the

depth of the vestibule in the mucosa with a scalpel or electrocautery. Incision is curvilinear and extends anteriorly into

the lip. The mentalis muscle will be visible and the fibers are divided in an oblique fashion, leaving a margin of the

muscle attached to the bone for closure. The periosteum is divided and a subperiosteal dissection is done to identify the

mental nerves. Reduction and bone plate fixation is done. Closure is completed in layers. A pressure dressing is secured

to the area to prevent hematoma formation and maintain the position of the mentalis muscle.

• Surgical approaches for mandibular fractures

(extraoral)

Retro-mandibular Submandibular

Pre-auricular

Extraoral Submandibular Risdon’s Incision

• This incision is used to access the mandibular ramus,

• angle and posterior body. Patient is prepared and draped in routine surgical manner.

• Important landmarks—the corner of the mouth and the eye globe must be visible.

• Head of the patient is turne sideways. • The incision is marked 2 cm below

the inferior border of the mandible • to avoid damage to the marginal

mandibular branch of the facial nerve.

• Ideally the incision is placed in a relaxed skin tension line (the Langer‘s lines)

Means of direct fixation

1- Non-rigid fixation

2- Semi-rigid fixation

3- Rigid fixation

I- Non rigid fixation:

Wire osteosynthesis:

Transosseous Wiring (Intraosseous Wiring) Direct wiring across the fracture line is an age old and effective method of

fixation of jaw bone fractures. Trans-osseous wiring can be done through

intraoral or extra-oral approach. In principle, holes are drilled in the bony

fragments on either side of the fracture line, after which a length of 26 gauge

stainless steel wire is passed through the holes and across the fracture.

The plates available are—4 hole, 6 hole, 8 to 16

hole plates, in addition to 4 to 6 hole plates with an intermediate bar

segment. The plates have a thickness of 0.9 mm. The minimum

diameter of the hole is 2.1 mm with a bevel of 30 degree.

Self-tapping conical screws are available in lengths of 5 to 15 mm.

The screw thread has a diameter of 2 mm, one turn of the screw

corresponds to 1 mm penetration into the bone. The diameter of

the screw head is 2.8 mm, the counter sinking of the head

corresponding to the 30º beveled drill hole in the plate. The drill

which is used to prepare hole in the bone has a diameter of 1.6 mm

and so is 0.4 mm smaller than the screws used. The difference of 0.4

diameter ensures firm anchorage of the self-tapping screws

II- semi-rigid fixation: single Mini-plates

II- rigid fixation: • Definition: fixation that holds the bone

fragments together with absolute stability so that no motion can occur between

them;

•Types: 1.1- Plating and screw system:

a)Compression plate (bicortical screws)

b) Tow Mini-plates

c)Reconstructive plate

2.Screws system:

Lag screw

Plating and screw system: Compression plate (bicortical screws)

The adapted bone plate should lie passively on the contour of the external cortex, without any gap between the plate and the bone. The plate is adjusted in such a way that minimum two screws can be fixed on either side of the fracture line.

reconstruction plate for mandible

Lag

screw

for most angle fractures, superior border plate fixation with a minimum of four

screws placed across the fracture line provides adequate stability of the fracture. The patient can be

placed in MMF for 1-3 weeks, although that is not always necessary. Plates used range from 1.7-2.0

mm with monocortical screws that range in length (depending on the thickness of the cortical plate

and the positioning of the plate) from 5-7 mm.

Other treatment options include inferior border plate and lag screw across the fracture line. If the

fracture is nondisplaced, MMF for 3-6 weeks, or even observation and a nonchew diet, represent

viable options for treatment. With comminuted fractures of the angle, treatment options include

external pin fixation, reconstruction plate and/or MMF.

• Advantages of internal fixation • i. Rigid or stable fixation.

• ii. Obviates the need for immobilization of the mandible.

• iii. Early return to home and work.

• iv. Soft diet can be taken.

• v. Maintenance of oral hygiene.

• vi. Useful in mentally challenged, physically handicapped

• patients.

• vii. Maintenance of airway in multiple fractures.


Open Reduction

Open reduction is not usually necessary. But, in

multiple displaced fractures especially, at the angle

and parasymphysis region, open reduction may be

needed. Intraosseous wiring or bone plating should

be done at the lower border of the mandible

without damaging the developing teeth buds

Resorbable Plate activation and contouring for pediatric fractures

Resorbable plate fixation

Condylar fracture

General nature of injury:

1-Contusion,effusion and haemo-arthrosis

predispose to ankylosis.

2-Dislocation

3-Fracture of the condyle itself

Condylar fracture Classification of condylar fractures :

A- according to the fracture level: 1)Condylar head (intra-capsular)

2)Condylar neck.

3)Subcondylar.

Undisplaced Deviated Displaced

Classification:

B- according to relationship of condylar

segment to ramous:

C- according to relationship of condylar segment to fossa:

The lateral pterygoid muscle is inserted into the medial fossa on the anterior aspect of the condyle. Therefore, in condylar fractures, the head is displaced anteriorly and medially and may also undergo lateral rotation due to the spasm of the muscle.

No

displacement Displacement Dislocation

Diagnosis

clinical Signs & symptoms:

1)Pain and tenderness.

2)Failure to palpate the condylar head

3)Swelling and hematoma.

4)Bleeding from external auditory meatus.

5)Limitation of mandibular movement.

6)disturbances of occlusion

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Computed tomography Computed tomography is the most sensitive and specific of the imaging techniques. The facial bones can be visualized as slices through the skeletal in either the axial, coronal or sagittal planes. Images can be reconstructed into a 3-dimensional view, to give a better sense of the displacement of various fragments. 3D reconstruction, however, can mask smaller fractures owing to volume averaging, scatter artifact and surrounding structures simply blocking the view of underlying areas. Research has shown that panoramic radiography is similar to computed tomography in its diagnostic accuracy for mandible fractures and both are more accurate than plain film radiograph. The indications to use CT for mandible fracture vary by region, but it does not seem to add to diagnosis or treatment planning except for comminuted or avulsive type fractures,although, there is better clinician agreement on the location and absence of fractures with CT compared to panoramic radiography.

64 Coronal CT view

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Treatment: Two main schools of treatment have been evolved:

1.Conservative.

2.Surgical.

Conservative.

I- Closed reduction:

• Done through immobilization of the jaws.

• The length of time of fixation according to :

– age of the patient

–Type of fracture.

II- Open reduction:

Absolute indications:

a) Fracture dislocation into middle cranial fossa.

b) Foreign body within the joint capsule

c) Extracapsular dislocation of the condylar head.

d) Bilateral condylar fractures with loss of facial height

II- Open reduction:

Relative indications: 1) Bilateral condylar fracture with comminuted midface

fracture in which RIF of the midface is not possible.

2) In fracture dislocation to restore the position of the

mensicus.

Complications of fractured mandible and condyle:

1. Delayed and non union:

i. Poor reduction and immobilization

ii. Infection.

iii.Tooth with exposed root or root fracture in the fracture line.

iv.Deficient blood supply.

v. Metabolic deficiency.

2. Infection.

3. Malunion.

4. Ankylosis. (age, site and type of fracture, duration of immobilization and damage of meniscus)

5. Nerve injury

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Maxillo-facial Trauma - Minia