MANDIBULAR FRACTURES

Contents.

Introduction.

Surgical anatomy

History.

Epidemiology.

Classification systems

Clinical features and diagnosis

Radiographic features

Conclusion.

References.

Introduction.

Maxillofacial injuries.

Mandibular fractures –

prominence of mandible

Occlusion

Management.

Surgical anatomy

Strongest facial bone

Parabola shaped bone

Angle of curvature is 110-140°

Mandible is the 2nd bone to ossify

Energy of 44.6-74.4 kg/m required to fracture the

mandible.

Weak areas of mandible

Junction between alveolar bone & basal mandibularbone.

Symphysis region - junction of two individual bones.

Parasymphyseal region - lateral to the mentalprominence, incisive fossa and mental foramen.

Junction of the ramus and the body are fracturedcommonly.

Presence of impacted tooth, canine with long roots.

Age changes of mandible.

Mental foramena.

child – near inferior border.

old age – near alveolar ridge.

Ramus angle.

child & old – obtuse

Alveolar ridge

Blood supply

Safe distance in mandible.

Average thickness of

Cortex in symphysis &

parasymphisis

region is 2.5 mm

Average thickness of

Cortex in premolar &

Body region is 3.5 mm

Distance between I.A.

Canal & cortex

At bicuspid - 4.0 mm

Molar region - 5.9 mm

Anteriorly distance

Between adjacent

Root apices is 3.7 mm

Posteriorly distance

Between adjacent

Root apices is 6.3 mm

Champy’s principles

Forces of mastication produce

tensional forces on upper border &

forces of compression on lower

border.

Champy put forward the lines

where plates & screws have to be

placed - “ideal osteosynthesis

lines”

It corresponds to course of a line of

tension at base of the alveolar

process.

Only in symphysis region, 2 plates

are placed to neutralize torsional

forces.

Blood supply.

• Helps in the healing of

fractured bone.

• Endosteal blood supply via

inferior dental artery & veins.

• Peripheral blood supply -

Periosteum

Nerve supply.

• Inferior alveolar nerve

• Damage - angle & body #

• Anesthesia or parasthesia of

the nerve

• Recovery / regeneration - 3 to

12 months

History. Egyptian Papyrus (1650 BC) –

Examination, diagnosis & treatment.

Hippocrates – Approximation of # segments.

Salerno, Italy (1180) – Proper occlusion.

1492, the book Cyrurgia by Guglielmo Salicetti – use of IMF.

John Barton - Barton Bandage

1860 GILMER GILMERS WIRING & FULL ARCH BARS

1900 MAHE PLATING KIT SIMILAR TO MODERN

SYSTEMS

1920 F. RISDON RISDONS WIRING

1961 LUHR DYNAMIC COMPRESSION PLATES

1970 BRONS & BOERING LAG SCREWS

1973 MICHELET MINIPLATES FOR MAND

OSTEOSYNTHESIS

1978 CHAMPY MINIPLATE OSTEOSYNTHESIS

PRINCIPALS

Epidemiology.

Etiology:

Age.

Sex

Site

CAR ACCIDENTS

ASSAULTS

BIKE ACCIDENTS

Classification

General

Anatomical

Completeness

Mechanism of injury

Number of fragments

Shape of fracture

Direction & favorability of treatment

Presence or absence of teeth

AO classification.

Kruger's Classification

SIMPLE ( CLOSED) Linear fracture lines which do not communicate

with the exterior

COMPOUND

( OPEN)

The fracture is communicating intraorally or

extraorally.

COMMUNITED Shattering of bone into multiple pieces

COMPLEX

COMPLICATED

They is adjunct injury to the adjacent nerves or

major blood vessels , joints.

IMPACTED One fragment is firmly driven within the other fragment and

clinical movement not appreciated

GREENSTICK Only one cortex broken. Common in children

PATHOLOGICAL Spontaneous fracture as a result of normal muscle contraction or

trauma due to increased weakness of underlying bone .

Impacted fracture

Dingman & Natvig classification

Symphysis fracture

Canine region fracture

Body of the mandible fracture

Angle fracture

Ramus fracture

Coronoid fracture

Condylar fracture

Dentoalveolar fracture

Direction & favorability of treatment

Horizontally Favourable

Fracture line runs

downward & forward so

upward displacement

avoided

HorizontallyUnfavourable

Fracture line runs Down

Wards and Back Wardsso

upward Displacement

Unrestricted

VERTICALLY FAVORABLE VERTICALLY UNFAVORABLE

FRACTURE LINE RUNS FROM THE

OUTER BUCCAL PLATE OBLIQUELY

BACKWARDS AND LINGUALLY , MEDIAL

MOVEMENT RESTRICTED

FRACTURE LINE RUNS FROM THE

INNER LINGUAL PLATE OBLIQUELY

BACKWARDS AND BUCCALLY , MEDIAL

MOVEMENT UNRESTRICTED

Presence or absence of teeth

Kazanjian V.H. & Converse J.M.

CLASS 1 TEETH ON BOTH

SIDES OF FRACTURE LINE

MONOMAXILLARY

CLASS II TEETH ONLY ON ONE SIDE

OF THE FRACTURE LINE

INTERMAXILLARY

FIXATION

CLASS III EDENTULOUS PATIENT OPEN REDUCTION

/ PROSTHESIS

AO Classification

F NO. OF FRACTURE OR FRAGMENTS

L LOCATION OF THE FRACTURE

O STATUS OF OCCLUSION

S SOFT TISSUE INVOLVEMENT

A ASSOCIATED FRACTURES

F: NO. OF FRACTURES

F0 Incomplete fractures

F1 Single fractures

F2 Multiple fractures

F3 Comminuted fractures

F4 Fracture with bone defect

L: Location of fracture

L1 Pre-canine

L2 Canine

L3 Post-canine

L4 Angle

L5 Supra-angular

L6 Condyle

L7 Coronoid

L8 Alveolar process

O: Status of occlusion

O 0 No malocclusion

O 1 Malocclusion

O 2 Edentulous mandible

A: Associated fracture

A 0 None

A 1 Dentoalveolar fracture

A 2 Nasal bone fracture

A 3 Zygoma fracture

A 4 Lefort I

A 5 Lefort II

A 6 Lefort III

Clinical examination.

History

Mechanism of injury

Extraoral / Intraoral

Clinical features.

• Extensive edema

• Tenderness.

• step deformity

• bone crepitus

• Facial asymmetry

Deviation of jaw Restriction of mouth

opening

Extensive soft tissue and bony defect

Collapsed arch and

Interfragmentary mobility

Open bite due bilateral poster

Gagging of occlusion

Open bite and cross bite due to

Unilateral gagging of occlusion

Occlusal step with

Unilateral cross bite

Mandibular fracture has to be differentiated from extensive

Soft tissue injury and dentoalveolar trauma

UNILATERAL CROSS BITE UNILATERAL OPEN BITE

Multiple fragmentation

With complete loss of occlusion

Sublingual

hematoma

Unfavorable fracture line

Causing displacement

Displacement of fracture

Direction and intensity of the traumatic force.

Site of fracture.

Direction of fracture line.

Muscle pull exerted on fractured fragments.

Presence or absence of teeth.

Extent of soft tissue wound.

Radiographic features

OPG

PA View

PNS View

Lateral oblique Radiograph

Occlusal view

CT scan.

- Commonly used.

- Entire mandible is visualized.

OPG view

PA view.

Medial / lateral

displacement.

Indicated for

Visualizing Medial

Displacement

Of Condylar Neck

The 4th & 5th

MacGregor Line

coincides with Mandible

PNS view

Because of distortion in

Symphysis Region in

an OPG , an Occlusal

View is indicated in

Symphysial fractures

Also shows Vertical

Favorability of Body

Fractures

Occlusal view

CT scan.

Condylar fracture.

Cervical spine injury.

Management of mandibular fractures.

To be continued…..

References.

Oral & maxillofacial trauma- Fonseca,vol 1

Maxillofacial Injuries- Rowe & Williams

Textbook of oral & maxillofacial surgery by Peter Ward

Booth.

Textbook of oral & maxillofacial surgery by Neelima

malik.

Killeys - fractures of the mandible