Mandibular trauma

Mandibular Fractures

Presented by Dr. Mohammed haneef

HISTORY ANATOMY INTRODUCTION CLASSIFICATION EXAMINATION AND DIAGNOSIS TREATMENT CONDYLAR FRACTURES

Contents:

• The pre-Christian era

The first description of mandibular fractures dates to the 17th Century BC in the ‘Edwin Smith papyrus’,

The Egyptians’ attitude to mandibular fractures was rather pessimistic:

“If thou examinest a man having a fracture in his mandible,

thou shouldst place thy hand upon it...and find that fracture

crepitating under thy fingers, thou shouldst say concerning

him: One having a fracture in his mandible, over which a

wound has been inflicted, thou will a fever gain from it. An

ailment not to be treated. Death usually followed, presumably

caused by infection”.• Hippocrates – direct reapproximation of # segments with the use of circum

dental wires • 1180, Textbook written in Salerno, Italy – importance of establishing a

proper occlusion.• 1492, the book Cyrurgia by Guglielmo Salicetti – first mention of the use

of maxillomandibular fixation in treatment of mandibular #.

History:

R. Mukerji et al. / British Journal of Oral and Maxillofacial Surgery 44 (2006) 222–228

History• 1887, Gilmer reintroduced MMF in United States.• Buck & Kinlock- first to do ORIF using wires.• 1888 Schede- First to use stainless steel plate & screws.• 1960, Luhr- first to use Vitallium compression plate• 1970, Spiessl through AO/ASIF introduced principles of

rigid internal fixation.• 1970, Michelet- introduced small bendable, non

compression plates- these were further modified by Champy.

• 1987 – M.S. Leonard first to report use of lag screws• Late 1990s – introduction of use of bioresorbable plates

Anatomy:

Area of weakness

• Junction of Alveolar bone & Basal mandibular bone.• Symphysis.• Teeth • Foramen• Angle• Condyle

Muscle Action• Mylohyoid, Geniohyoid,

Genioglossus & Anterior belly of omohyoid – postero-medial & inferior displacement of # fracture fragment.

• Pterygomassetric sling – Supero-medial & anterior displacement of fractured lesser fragment.

• Lateral Pterygoid muscle- Antero-medial displacement of fractured condyle.

• Temporalis – postero-superior displacement of fractured coronoid process.

• Zones of compression and tension within the mandible are determined by the muscles inserting and the forces exerted by these muscles.

• Smaller arrows show direction of muscular forces

• Larger arrows show the load placed during function.

• This gives a zone of compression along the lower border and a zone of compression along the superior border

• Neutral axis about the level of the canal.

Factors influencing displacement of fracture

• Degree of force

• Resistance to the force offered by the facial bones

• Direction of force

• Point of application of force

• Cross-sectional area of the agent or object struck

• Attached muscles

# SYMPHYSIS AND PARASYMPHYSIS:-

Mylohyoid constitues a diaphragm b/w hyoid bone & mylohyoid ridge

on inner aspect of mandible

• Mylohyoid & geniohyoid -- stabilizing force symphysis transverse #

• Oblique # in this region tends to overlaps -- genio & mylohyoid

diaphragm

Bucket handle displacement

• B/L # of parasymphysis results

from force which disrupts the

periosteum.

• displaced posteriorly under the

influence of genioglossus /

geniohyoid muscle

• Often removes attachment of

tongue & allows

TONGUE FALL BACK

ANGLE # :- • medial pterygoid stronger component

• Vertical direction # favors the unopposed action of the medial

pterygoid muscle,, post fragment pulled lingually

• Horizontal direction # line favors the unopposed action of masseter and medial pterygoid muscle,, post fragment displaced upwards

15

Nerves• The inferior dental nerve is frequently damaged in #

of body and angle • The fibrous sheath provides considerable support for

contained vessels and nerves which accounts for surprisingly low incidence of permanent nerve damage after #

• Condyle may impact with such force against the temporal bone and # which results in facial nerve damage within follapian canal [Goin. 1980].

• Injury to facial nerve due to external trauma.

• Angle 110-140*• Angle decreases with growth- changes in condylar

process ,shape and size

Age Changes

Blood vessels

• Vascular damage to inferior dental artery and vein • A large sublingual haematoma may result from

rupture of dorsal lingual veins medial to an angle.• Hemorrhage from torn periosteum.• The facial vessels are vulnerable to direct trauma

where they cross the lower border of the mandible at anteroinferior margin of Masseter muscle.

• A tubular long bone, which is bent into a blunt V-shape.• Mandible is strongest anteriorly in midline with

progressively less strength towards condyle .• dentition• Muscle attachments.• Mandible is one of the strongest bones, the energy

required to # it being of the order of 44.6 –74.4 Kg / M(425Lb) approximately 350- 400 kg (800-900lb), which is about same as zygoma and about ½ that of frontal bone

[Swearingen 1965, Hodgson 1967, Nahum 1975a, Luce et al 1979]

Introduction:

Mandible is embryologically a membrane bent bone although, resembles physically long bone it has two articular cartilages with two

nutrient arteries.

FRACTURE :Definition :

Fracture is defined as sudden violent solution in the continuity of the bone which may be complete or incomplete resulted from direct or indirect causes.Mandibular fractures :

Fractures of the mandible are common in patients, who sustain facial trauma. SEX :

Most mandibular fractures are seen to occur in male patients. Ratio is approximately 4.5 : 1AGE :

35 % of mandibular fractures occur between the ages of 20 to 30 years.

Subodh et al, Clinical Study An Epidemiological Study on Pattern and Incidence of Mandibular Fractures, Hindawi Publishing Corporation Plastic Surgery International, Volume 2012, Article ID 834364,7pages

AETIOLOGY OF MANDIBULAR FRACTURES• 1.Vehicular accidents • 2.Altercation,assaults,interpersonnel violence

• 3.Fall • 4.Sporting accidents • 5.Industrial mishaps or work accidents • 6.Pathological fractures or miscellaneous

Number of fractures per mandible.

The number of mandibular fractures per patient ranged from 1.5 to 1.8.

1. Unilateral , single - 53%2. Bilateral , double - 37%3. Multiple fractures - 10%

Fifty percent have more than one fracture.Subodh et al, Clinical Study An Epidemiological Study on Pattern and Incidence of Mandibular Fractures, Hindawi Publishing Corporation Plastic Surgery International, Volume 2012, Article ID 834364,7pages

Classification of mandibular fractures :

I. General classificationII. Anatomical locationsIII. Relation of the fracture to site of injury IV. CompletenessV. Depending on the mechanismVI. Number of fragmentVII. Involvement of the integumentVIII.The shape or area of the fractureIX. According to the direction of fracture and favourability for the

treatmentX. According to presence or absence of teethXI. AO classification – relevant to internal fixation

1. Kruger's general classification

• Simple or Closed Fracture

• Compound or Open

• Comminuted

• Complicated or complex

• Impacted

• Greenstick fracture

• Pathological

Simple fracture Compound Fracture

Comminuted fracture

Impacted fracture

Greenstick fracture

Classification:

2. Rowe & Killey classification• Fractures not involving basal bone

• Fractures involving basal bone of the mandible. Subdivided into following: Single Unilateral Double unilateral Bilateral Multiple

3. Dingman & Natvig classification• Midline • Parasymphyseal• Symphysis • Body • Angle • Ramus • Condylar process• Coronoid process• Alveolar process

4. Kruger & Schilli classificationI. Relation to the external environment

• Simple Or closed

• Compound or openII. Types of fracture

• Incomplete

• Greenstick

• Complete

• ComminutedIII. Dentition of the jaw with reference to the use of splint

• Sufficiently dentulous patient

• Edentulous or insufficiently dentulous patient

• Primary and Mixed dentition IV. Localization

• Fractures of the symphysis region between canines

• Fractures of the canine region

• Fractures of the body of the mandible

• Fractures of the angle

• Fractures of the mandibular ramus

• Fractures of the coronoid process

• Fractures of the condyle

5. Kazanjian classification

Class – III : Patient is edentulolus

Class – I : teeth are present on both sides of the fracture line

Class – II : Teeth are present on only one side of fracture line

6. According to direction of the fracture and favorability for treatment ( Fry et al)

Horizontally favorable

Horizontally unfavorable

Vertically favorable

Vertically unfavorable

7. Relation of the fracture to the site of injury

• Direct fracture • Indirect fracture

8. AO Classification(relevant to internal fixation): 1) F: Number of fracture or fragments 2) L: Location (site) of fracture 3) O: Status of occlusion 4) S: Soft tissue involvement 5) A: Associated fractures of facial skeleton

9. Grades of severity: I-V

Grade I and II are closed fractures

Grade III and IV are open fractures

Grade V open fracture with a bony defect (gunshot)

10. AO-analogue classification system of mandibular fractures• Each compartment is classified independently, describing the

degree of displacement and the presence of multifragmentation or osseous defects.

• Each fracture is classified:

- type A, nondisplaced fractures

- type B, displaced fractures

- type C, multifragmentary/defect fractures

• Each fracture is divided into 3 groups,

specific to the mandibular unit.

Int.J.Oral Maxillofac.Surg.2008;37:1080-1088

Vertical unit

Horizontal unit

Central horizontal unit

• Direct violence• Indirect violence• Excessive muscular contraction.• Pathological fractures• Iatrogenic

• R.T.A’s

• Falls

• Fights

• Sport Injuries

• Industrial mishaps

Etiology:

History

Clinical Examination

Radiological Examination

Panoramic radiograph

Lateral oblique Radiograph

Posteroanterior Radiograph

Occlusal view

reverse towne’s view

CT scan

Diagnosis of Mandibular fracture:

History• Focussed questioning should reveal following:

• Mechanism of injury• Previous facial fracture• H/O TMJ disorders• Preinjury occlusion

Clinical examination

Examination of pt with # of mandible takes place in 3 stages:

A. Immediate assessment and treatment of any condition constituting a threat to life.

B.  General clinical examination of pt.

C.  Local examination of mandibular #.

• Change in occlusion

• Anesthesia, Paresthesia or Dysesthesia of lower lip

• Abnormal mandibular movements

• Change in facial contour and mandibular arch form

• Laceration, Hematoma and Ecchymosis

• Loose teeth and crepitation on palpation

Clinical Examination

Clinical examination

Test for sensation

Signs and symptoms• Tenderness +ve• Occlusion changes - # teeth

- # alveolar process - # mandible at any location

- # condyle

• Anterior open bite - B/L condylar #

• Posterior open bite - parasymphysis #

• Unilateral open bite - # ipsilateral angle - # parasymphysis

• Posterior cross bite - midline symphysis #- condylar #

Radiological examination

Ideally need 2 radiographic views of the fracture that are

oriented 90’ from one another to properly work up

fractures

• Single view can lead to misdiagnosis and

• complications with treatment

• Most informative • Shows entire mandible and

direction of fracture (horizontal favorable, unfavorable)

Disadvantages:• – Patient must sit up up-right• – Difficult to determine buccal/lingual bone and• medial condylar displacement• – Some detail is lost/blurred in the symphysis, TMJ

and dentoalveolar regions

Posteroanterior (pa) radiograph: Shows displacement of fractures in the ramus, angle, body, and

symphysis region

Disadvantage: • Cannot visualize the condylar region

Lateral oblique • Used to visualize ramus, angle, and

body fractures

Disadvantage: • Limited visualization of the condylar

region, symphysis, and body anterior to the premolar

Occlusal radiograph• Used to visualize fractures in the body in regards to medial or

lateral displacement

Used to visualize symphyseal fractures for anterior and posterior displacement

Computed tomography ct:Excellent for showing

intracapsular condyle fractures

axial and coronal views,

3-D reconstructions

Disadvantage:• – Expensive• – Larger dose of radiation

exposure compared to plain film

• – Difficult to evaluate direction of fracture from individual slices (reformatting to 3-D overcomes this)

1. The patient’s general physical status should be carefully evaluated and monitored prior to any consideration of treating mandibular fracture.

2. Diagnosis and treatment of mandibular fractures should be approached methodically not with an “emergency-type” mentality

3. Dental injuries should be evaluated and treated concurrently with treatment of mandibular fractures

4. Re-establishment of occlusion is the primary goal in the treatment of mandibular fracture.

5. With multiple facial fracture mandibular fracture should be treated first.

6. Intermaxillary fixation time should vary according to the type, location, number severity of the mandibular fracture as well as the patient’s age and health.

7. Prophylactic antibiotics should be used for compound fractures.

General principles in the treatment of mandibular fracture

Basic principles for Rx of Fracture

Reduction• Closed

• Direct interdental wiring Indirect interdental wiring (eyelet or Ivy loop)

• Continuous or multiple loop wiring

• Arch bars• Cap splints• 'Gunning-type' splints• Pin fixation

Open Transosseous

wiring (osteosynthesis)

Plating Intramedullary

pinning Titanium mesh Circumferential

straps Bone clamps Bone staples Bone screws

Fixation Direct Indirect

Immobilization• Methods of immobilization

• (a) Osteosynthesis without intermaxillary fixation• (i) Non-compression small plates• (ii) Compression plates• (iii) Mini-plates• (iv) Lag screws

• (b) Intermaxillary fixation• (i) Bonded brackets• (ii) Dental wiring

• Direct• Eyelet

• (iii) Arch bars• (iv) Cap splints• (v) MMF screws

• (c) Intermaxillary fixation with osteosynthesis• (i) Transosseous wiring• (ii) Circumferential wiring• (iii) External pin fixation• (iv) Bone clamps• (v) Transfixation with Kirschner wires

1. Non-displaced favorable fractures

2. Grossly comminuted fractures

3. Fractures exposed by significant loss of overlying soft tissue.

4. Mandibular fractures in children with developing dentition

5. Coronoid process fracture

6. Condylar fractures

Indication for Closed Reduction of Fractures

ADVANTAGES & DISADVANTAGES OF CLOSED REDUCTION

Advantages• Inexpensive • Only stainless steel wire

needed • Convenient• Gives occlusion• Conservative • O.T not required• Generally easy ,no great

operator skill needed

Disadvantages • Cannot obtain absolute

stability • Difficulty nutrition • Oral hygiene impossible• Long period of IMF• Changes in TMJ cartilage• Weight loss • Decrease range of motion of

mandible • Risk of wounds to operator

CLOSED REDUCTION

• HISTORY • William Saliceto(1210-1277) Tied the teeth (MMF)• Thomas Gilmer(1849-1931) Reveiwed the tech,

introduced Arch Bars in 1907.• Barton bandage by JOHN BARTON

• Lingual-Labial occlusal splint. • Vaccum formed acrylic splint

• Royal Berkshire Haio Frame

Direct interdental wiring

• Gilmer's wiring• simple & rapid method of

immobilization jaw • first aid method • temporary immobilization

of # fragment

Disadvantage

- complete removal of wires

- extrusion of teeth

IV LOOP METHOD

IVY-LOOP METHOD• quick and easy way of

obtaining maxillo-mandibular fashion.

• 24 gauge wire• simple and effective for

reduction and immobilization of #

WILLIAM’S MODIFICATION

Clove hitch• Incase of single tooth

Button Wiring

• Leonard (1977) considers that eyelet wires have several drawbacks.

• He described the use of titanium buttons of 8mm diameter,

inclusive of a 1mm rim, and 2mm deep.

Col. Stout wiring

Risdon’s wiring

Arch bars

• For temporary fragment stabilization in emergency cases before definitive treatment

• As a tension band in combination with rigid internal fixation • For long-term fixation in conservative treatment • For fixation of avulsed teeth and alveolar crest fractures

• Different types of Arch bar• Winters • Jelenkos• Dautrys Arch bar• Berns titinium arch bars• Burmachs arch bar• Custom made

Screws • Screws are quick to place• Reduce the chance of needlestick injury from wires• Can be used with heavily restored teeth• Can be placed and removed rapidly• Well tolerated by patient• Allow oral hygiene to be easily maintained

Pre drilled Drill free

• When drilling the screw holes, saline irrigation assists bone debris removal and cooling of tissues.

• There is a risk of the drill damaging the roots of adjacent teeth, especially in inexperienced hands

•  Cannot be used

• No irrigation required

 • Less chance of damage

to adjacent teeth

 • Drill free screws may

be used in comminuted fractures

Cap Splints :

• Indications Advanced periodontal

disease #s of tooth bearing

segments & condylar neck Portion of body of

mandible missing

• Impression technique• Fitting the splint• Reduction of fracture

Biphasic pin fixation

• Closed technique uses external fixation (Morris appliance & Roger anderson appliance) for management of communited mandibular #.

• screws placed - two on either side of the fracture through stab incisions & holes drilled in the mandible.

• Once external pins are in position,

the fracture segments are manipulated to

achieve reduction.

• Then the pins are locked in reduced position by applying of an acrylic mix that is placed over the ends of the pins that are protruding out of the skin.

• The acrylic is allowed to harden while mandible is held in reduced position.

• Steinmann pins or Kirshner wires can also be used as external pins

Indications• Edentulous fractures• If IMF is not feasible• Comminuted fractures• Bone graft

requirements• With a head frame

Contraindications• Irradiated tissues• Grossly contaminated

tissue• Osteoporosis• Osteosclerosis• Atrophy

Advantages

• Control of the edentulous

fragments without

involving the fracture lines.

• under LA.

• avoidance of the need for

surgery at the fracture site,

• minimum operative time

• Simple surgical technique.

Disadvantages

• Conspicuous

uncomfortable

• uncooperative or cerebrally

irritated patient.

• Difficulty with washing

and shaving

• scars caused- pinholes

• risk of infection.

Acrylic splints take the form of

modified dentures with bite block in place of molar teeth &

space in the incisor area to facilitate feeding

Used in edentulous jaw fractures

Gunning splints

INDICATION

• - unilateral / bilateral # edentulous mandible

CONTRAINDICATIONS

• - unfavorable displaced #s lying out side

denture bearing areas

• - severe posterior displacement of #s of the

anterior part of mandible

• Preparation of cast/ mock surgery

• Preparation of acrylic block in centric

relation

• Acrylic bite block in molar region

• Space in anterior region

• Stainless steel hooks in molar region

Fabrication

Immobilization

Maxilla -Peralveolar wiring

- Circum zygomatic wiring

- With help of bone screws

Mandible - Circum mandibular wiring

Followed by IMF

Early General supervision Infection control Pain control Oral hygiene maintenance Feeding

Post operative care

Late

Testing union & removal of fixation

Jaw physiotherapy

Houpert’s procedure The operator should drill transfixion holes (in a vestibulo‐lingual direction) with a tiny round burr in the crown of the deciduous teeth away from the pulp and a safe distance from the occlusal surface. A 0.2‐mm stainless steel wire impregnated in silver nitrate is introduced through the holes. Depending on the number of teeth used, either bimaxillary or monomaxillary fixation can be applied. Each hole should be filled with amalgam. A variation of this technique (Ginestet) allows placing an eyelet through each hole to fix both a vestibular and a lingual/palatal hard, 0.5‐mm stainless steel wire, with the possibility of a double splint device both in the vestibular and at the lingual/palatal aspect of the dental arcade.

1. Displaced unfavorable fracture through angle of the mandible

2. Displaced unfavorable fractures of the body or pasymphyseal region

3. Multiple fractures of the facial bones

4. Midface fractures and displaced Bilateral condyler fractures

5. Fractures of the edentulous mandible with severe displacement of fragments

6. Edentulous maxilla opposing a mandibular fracture

7. Delay of treatment and interposition of soft tissue between noncontacting displaced fracture fragments.

8. Malunion

9. Special systemic conditions contraindicating intermaxillaryfixation

Indications for open Reduction

Contraindications

• G.A / more prolonged procedure is not

advisable

• Gross infections at the # site

• Sever comminution with loss of soft

tissue

• Patients with difficult to control

seizures

Surgical approaches to the mandible

• Intraoral symphysis and

parasymphysis

Intraoral body, angle and ramus –

Transbuccal approach

Degloving incision

Extraoral approaches

Submental Submandibular Retromandibular

Transalveolar / upper border wiringSir Williams Kelsey Fry • To control the posterior fragment• Use – vertically and horizontally unfavorable #• Horizontal mattress wiring

Transosseous / lower border wiring

Hayton Williams 1958 • # fragments expose extraorally• posterior fragment hole higher level then anterior

fragment• both wires passes simultaneously through same hole

1973 Obwegeser :- • Combined direct and figure of ‘8’ wiring with single stand

of wire

Transosseous or lower border wiring

Bone plate osteosynthesis

• Non compression plate with monocortical screw

• Compression plates with bicortical screw

- DCP - EDCP

• Bio degradable plates and screws

• Three dimensional plates

• Titanium miniplates

Principle of compression plate osteosynthesis

• The holes for the screws should be prepared at the far ends of the plate holes.

• When tightening the screws the fracture ends are approximated by the effect of the spherically shaped holes

Journal of Cranio-Maxillofacial Surgery 2008; 36: e251 - e259

Compression plates

• Axial compression b/w fractured bone ends• Rigid fixation with intra-fragmentry compression• Bone ends correctly opposed and maintained • IMF is not needed post operatively • Primary bone healing occurs by direct osteoblastic activity

within #• AO/ASIF dynamic compression plates

Compression plate approach Eccentric dynamic compression plate

DCP EDCP

• The plate design is based on a screw

head that, when tightened, slides

down an inclined plane within the

plate.

• Screw behaves as compression

screw or the static screw

• Compression is not achieved at the

upper border so tension band is

required

• The EDCP is similar to the DCP in that the

inner holes are designed to produce

compression across the fracture site

• Two oblique outer eccentric compression

holes aligned at an angle oblique to the

long axis of the plate. The activation of

these outer holes produces a rotational

movement of the fracture segments with

the inner screws acting as the axis of

rotation

• Brings compression at the upper border so

tension band is not required

Mini plate Osteosynthesis :- 1973 MICHELET1975 CHAMPY MODIFIED

- Under physiological strain, forces of tension along the alveolar border & forces of compression along the lower border of the mandible. - With in the body of the mandible these forces produce, predominantly, moments of flexion – angle strong & weak in PM region. - with in the symphysis – torsional moments - Champy et al analysed these moments using a mathematical model of the mandible – ideal line of osteosynthesis.# symphysis 2 plates# angle 1 plateMonocortical screws 2 mm diameter and 5 to 10 mm length Plate 2cm long, 0.9mm thick and 6mm wide

Advantages of monocortical miniplate osteosynthesis over bicortical compression plates.

Monocortical • Requires minimal

dissection.• Less technique

sensitive• Less chances of

complications

Bicortical

• Extra oral approach• Nerve injury• Difficult to adapt

Compression plate Miniplates • Bicortical plates

• Bulky and difficult to use

• Applied extraorally

• Cannot be used at the upper border of the mandible

• Provides rigid fixation • No interfragmentary

movement allowed

• Monocortical plates

• Easy to use • Applied intraorally, small

incision , less soft tissue dissection , less likely to be palpable

• Can be used without any associated complication

• Provides functionally stable fixation

• Little interfragmentary movement present, torsional movement seen under functional loading

Champy’s line of osteosynthesis

Locking vs Standard mini plates

3-D plate ostesynthesisDental Research Journal /Mar 2012 /Vol 9 / Issue 2

• Titanium 3-D plating system was developed by Farmand to meet the requirements of semi-rigid fixation with lesser complications.

• The 3-D miniplate is a misnomer as the plates are not three dimensional, but hold the fracture fragments rigidly by resisting the forces in three dimensions, namely, shearing, bending, and torsional forces.

• The basic concept of 3-D fixation as explained by Farmand

is that a geometrically closed quadrangular plate secured with bone screws creates stability in three dimensions. The stability is gained over a defined surface area and is achieved by its configuration and not by its thickness or length.

• The large free areas between the plate arms and minimal dissection permit good blood supply to the bone.

• The newly introduced 3-D plating system provides definite advantages over the conventional miniplates.

• The 3-D plating system uses fewer plates and screws as compared to the conventional miniplates, to stabilize the bone fragments. Thus, it uses lesser foreign material, and reduces the operation time and overall cost of the treatment

• The 3-D plating system has a compact design and is • easy to use. The 1.0-mm-thick 3-D plate is as stable • as the much thicker 2.0 mm miniplate. This offers • better bending stability and more resistance to out-ofplane

movement or torque.

Three dimensional plate

Advantages: -• Improved handling characteristics, • Increased stability,• Shorter surgical time,• Preservation of bony

perfusion,• Decreased bone necrosis,• Increased bony healing and regeneration.

Bioabsorbable PlatesBioresorbable materials used for rigid fixation • Polydioxanone• Polyglycolic acid• Polylactic acid

Strength inadequate to provide clinically acceptable rigid fixation.

• Use of poly-L-lactide in 69 fractures by Kim et al• 12% complication• 8% infection• No malunion

Plastic and Reconstructive Surgery, vol 110, july 2002, 25-31

Bioresorbable plates & screws[Robert M. Laughlin JOMS 2007;65:89-96]

Advantages:• Provides the proper strength

when necessary and then harmlessly degrades over time.

• No need for an additional removal operation.

• Reduce the total treatment & rehabilitation time of the patient.

• No bending pliers are necessary.

Lag screwCompress fracture fragments without the use of bone plate

Two sound bony cortices are required -- Shares the loads with the bone

Uses: • absolute rigid fixation• Less hardware • More cost effective• Rigid method of internal fixation • Insertion -quicker and easier• Reduction more accurate

Lag screwsPlaced indirection that is perpendicular

to the line of fracture to prevent overriding

& displacement during

tightening of the screws.

INDICATIONS

• #s in edentulous parts

• Concomittant #s of body & condyle

• IMF contraindicated

• Saggital/oblique fractures

• Non/mal union

Lag Screw fixation.

Lag Screw technique

107

Anchor lag screw vs conventional lag screw

Journal of oral biology and craniofacial research 3 (2013) 15e19

Loosening of screw, damage to bone, mobility of fragments, incidence of pain, infection presence

Reconstruction plates

• For communited mandibular fractures• Decreased post op morbidity• Stabilization of entire communited complex• Defect fractures can be treated• 2.0 mm plate with bicortical screw used in conjuction with lag

screws or miniplates

Advantages of open reduction. • Accurate reduction &

fixation of fractures by direct visualization.

• Better bone healing.• Early return to normal

jaw function.• Normal nutrition, no

weight loss.• Patient can maintain

oral hygiene.• Early return to work.

Disadvantages of open reduction.• Requires surgical

exposure.• Requires general

anesthesia.• Expensive.• Compared to IMF

technique is difficult and risky.

• Foreign body is left in the tissues.

• Scarring.

Protocol for treatment of mandibular fractures(Philip L. Maloney,J Oral Maxillofac Surg,59:879-884, 2001)

• Simple fractures of the condylar process and ramus - closed reduction. MMF for 48 to72 hours - training elastics and close observation

• No MMF is required for coronoid fractures; archbars and training elastics are used only if a malocclusion is present.

• Simple or compound fractures with a time delay from injury to immobilization of < 72 hours are treated by a closed reduction (CR) or, if indicated, open reduction with rigid fixation (ORIF).

• Compound fractures - delay from injury to immobilization of >72 hours - MMF and IV antibiotics .

• If the closed reduction is adequate, the patient is continued on oral antibiotics for an additional 10 to 14days and maintained in MMF and on a blenderized diet for 5 to 6 weeks from the time of closed reduction.

• If not, ORIF is performed, and MMF is maintained for 10 to 14 additional days.

• Edentulous patients are treated with rigid fixation, no MMF, and a blenderized diet for 4 to 5 weeks.

• Teeth in the line of fracture are judged individually.

The goal of AO/ASIF is rigid internal fixation with

primary bone healing, under functional loading

Basic principals

• Reduction of bony fragments

• Stable fixation of the fragments

• Preservation of the adjacent blood supply

• Early functional mobilization

Bone healing • Histomorphologic changes during fracture healing

Post fracture time Histology

Immediate Extravasation of blood

24 hrs Aseptic inflamm – clot

48 hrs Org of clot

4 days Intramemb bone formation

Subperiosteal bone formatn

5 to 10 days Hyaline cartilage

Fibrocartilage + calcification

30 days until of Trabecular bone formation

healing

Cortical bone formation

General principles in the treatment of mandibular fractures

• Patient’s general physical status

• Methodical approach -not “emergency-type” mentality.

• Dental injuries - evaluated & treated concurrently

with T/t of mandibular fractures.

• Re-establishment of occlusion -primary goal

• With multiple facial fractures, mandibular fractures

should be treated first.

• IMF time should vary • Type• Location• Number • Severity of mandibular fractures

• As well as the patient’s age & health

the method used for reduction & immobilization.• Prophylactic antibiotics should be used for compound

fractures.• Nutritional needs should be closely monitored

postoperatively.

Young adult with Fracture of the angle receiving Early treatment in which Tooth removed from fracture line

3 weeks

Guide for time of immobilization

(a) Tooth retained in fracture line: add 1 week(b) Fracture at the symphysis: add 1 week(c) Age 40 years and over: add 1 or 2 weeks(d) Children and adolescents: subtract 1 week

IF

Teeth in the line of fracture• Potential impediment to healing

• Fracture is compound

• Tooth maybe damaged structurally subsequently become

necrotic

• Pre existing pathology – apical granuloma

Teeth in line of fracture Indications for

removalAbsolute • Longitudinal #• Dislocation/subluxation of

tooth• Periapical Infection• Infection of the fracture line• Acute pericoronitis

Relative• Functionless tooth• Advanced caries• Periodontal disease• Doubtful teeth• Untreated # > 3

days

Management of teeth retained in fracture line

• Intra-oral periapical radiograph

• Systemic antibiotic therapy

• Splinting of tooth if mobile

• Endodontic therapy if pulp exposed

• Immediate extraction if fracture becomes infected

• Follow-up for 1 yr with endodontic therapy if there is

demonstrable loss of vitality.

Fracture healing

• With RIF the strain on the bone is reduced

• Bone heals by direct approximation

• Gap healing – minimal callus

• healing – satisfactory immobilisation

• Inflammatory stage• Cartilagenous stage• Bony callous stage• Remodelling

ComplicationsComplications during primary treatment

Misapplied fixation

Infection

Nerve damage

Displaced teeth and foreign bodies

Pulpitis

Gingival and periodontal complications

Drug reactions

Late complications

Malunion

Delayed union

Non-union

Derangement of the temporomandibular joint

Late problems with transosseous wires and plates

Sequestration of bone

Trismus

Scars

Management of Infections

Intra oral ORIF

Management of TMJ complications

Thank you