mandibular fractures and management

1. MANDIBULAR FRACTURES
SOYEBO O.A

2. OUTLINE
• INTRODUCTION
• CLASSIFICATION
• AETIOLOGY
• EPIDEMIOLOGY
• SIGNS & SYMPTOMS
• INVESTIGATION
• MANAGEMENT

3. INTRODUCTION
• Fracture of the mandible occurs more frequently than that of any other
facial skeleton.
• It is the one serious facial bone injury that the average practicing dental
surgeon may expect to encounter, albeit on rare occasions, at his surgery.
• It is also a facial fracture which he may have the misfortune to cause as a
complication of tooth extraction.
• Broadly divided into:
1. Fractures with no gross communition of the bone and without significant
loss of hard and soft tissues
2. Fractures with gross communition of the bone and with extensive loss of
both hard and soft tissues.

4. ANATOMY
• Lower jaw bone
• U shaped body
• 2 vertically directed rami
• Condylar process
• Coronoid process
• Oblique line
• Mental foramen

5. INTERNAL ANATOMY
•
•
•
•
•
Mandibular foramen
Lingula
Pterygoid fovea
Mylohyoid line
Fossae
• Submandibular
• Sublingual
• Digastric
• Mental spines
• Genioglossus
• Geniohyoid

6. MUSCULATURE:
jaw elevators
• Masseter muscle: from
zygoma to angle and
ramus
• Temporalis muscle: from
infratemporal fossa to
coronoid and ramus.
• Medial pterygoid muscle:
medial pterygoid plate and
pyramidal process into the
lower mandible.

7. MUSCULATURE:
jaw depressors
• Lateral pterygoid muscle:
lateral pterygoid plate to
condylar neck and TMJ
capsule
• Mylohyoid muscle:
Mylohyoid line to body of
hyoid
• Digastric muscle: mastoid
notch to digastric fossa
• Geniohyoid muscle: inferior
genial tubercle to anterior
hyoid bone

8. INNERVATION
• CN3; mandibular nerve
through the foramen ovale
• Inferior alveolar nerve
through the mandibular
foramen
• Inferior dental plexus
• Mental nerve through the
mental foramen.

9. BLOOD SUPPLY
• Internal maxillary artery
• Inferior alveolar artery
• Mental artery

10. CLASSIFICATION OF FRACTURES
• Type of fracture
• Site of fracture
• Cause of fracture

11. TYPE OF FRACTURE
• Simple
• Includes a closed linear fractures of the condyle, coronoid, ramus and
edentulous body of the mandible.
• Compound
• Fractures of tooth bearing portions of the mandible, into d mouth via the
periodontal membrane and at times through the overlying skin.
• Communited
• Usually compound fractures characterized by fragmentation of bone
• Pathological
• Results from an already weakened mandible by pathological conditions.

12. COMPOUND
SIMPLE
COMMUNITED

13. SITE OF FRACTURE
• Dentoalveolar
• Condyle
• Coronoid
• Ramus
• Angle
• Body (molar and
premolar areas)
• Parasymphysis
• Symphysis

14. SITE OF FRACTURE
A- CONDYLAR
B- CORONOID
C-RAMUS
D- ANGLE
E- BODY(MOLAR
PREMOLAR AREAS
F- PARASYMPHYSIS
G- SYMPHYSIS
H-DENTO-ALVEOLAR

15. CAUSE OF FRACTURE
• Direct violence
• Indirect violence
• Excessive muscular contraction
• Fracture of the coronoid process because of sudden reflex contracture of the
temporalis muscle.

16. PATTERN OF FRACTURE
• Unilateral fracture
• Bilateral fracture
• Multiple fracture
• Communited fracture

17. AETIOLOGY
• Road traffic accidents
• Interpersonal violence
• Contact sports
• Industrial trauma
• Falls

18. EPIDEMIOLOGY
• The mandible is one of the most commonly fractured bones of the
face and this is directly related to its prominent and exposed position.
• Oikarinen and Lindqvist (1975) studied 729 patients with multiple
injuries sustained in RTA. The most common facial fractures were in
the mandible.
•
•
•
•
Mandible (61%)
Maxilla (46%)
Zygoma(27%)
Nasal Bone (19%)

19. • Studies have shown that the incidence of mandible fractures are
influenced by various etiological factors e.g.
•
•
•
•
Geography
Social trends
Road traffic legislations
Seasons

20. • Site of Fracture: Oikarinen and Malmstrom (1969) analyzed 600
mandible fractures. On analysis the following results were obtained:
•
•
•
•
•
•
•
Body of mandible (33.6%)
Sub- condylar area(33.4%)
Angle (17.4%)
Dentoalveolar (6.7%)
Ramus (5.4%)
Symphyseal 2.9%
Coronoid 1.3%

21. • Even though the body of the mandible has the highest incidence
when it comes to mandibular fracture, the condyle remains the
commonest site for mandibular fracture

22. SIGNS AND SYMPTOMS
• GENERAL
• SPECIFIC

23. GENERAL SIGNS AND SYMPTOMS
• Swelling
• Pain
• Drooling
• Tenderness
• Bony discontinuity
• Lacerations
• Limitation in mouth opening
• Ecchymosis
• Fractured, subluxed, luxated
teeth.
• Bleeding from the mouth.

24. SPECIFIC SIGNS AND SYMPTOMS
• DENTOALVEOLAR FRACTURES
•
•
•
•
•
Lip bruises and laceration
Step deformity
Bony discontinuity
Fracture, luxation or subluxation of teeth
Laceration of the gingivae
• FRACTURE OF THE BODY
•
•
•
•
•
•
Swelling
pain
Tenderness
Step deformity
Anaesthesia or paraesthesia of the lip
Intra oral hemorrhage
• SYMPHYSEAL/PARASYMPHYSEAL FRACTURES
•
•
•
•
Tenderness
Sublingual haematoma
Loss of tongue control
soft tissue injury to the chin and lower lip

25. • FRACTURE OF THE RAMUS
•
•
•
•
Swelling
Ecchymosis
Pain
Trismus
• FRACTURE OF THE ANGLE
•
•
•
•
•
•
•
Swelling
Posterior gag
Deranged occlusion
Anaesthesia or paraesthesia of lower lip
Haematoma
Step deformity behind the last molar tooth
Tenderness

26. • CORONOID FRACTURE
•
•
•
•
Tenderness over the anterior part of the tragus
Haematoma
Painful limitation of movement
Protrusion of mandible may be present.
• SYMPHYSEAL/PARASYMPHESEAL FRACTURES
•
•
•
•
•
•
Tenderness
pain
Step deformity
Sublingual haematoma
Loss of tongue control
May have soft tissue injury to the chin and lower lip

27. • CONDYLAR FRACTURE (unilateral/bilateral and
Intracapsular/extracapsular)
• Unilateral condylar fractures
•
•
•
•
•
•
•
•
Swelling over the TMJ
Hemorrhage from ear on the affected side
Battle’s sign
Locked mandible
Hollow over the condylar region after edema has subsided
rarely, Paraesthesia of lower lip
Deviation to the affected side upon opening
Painful limitation of movement

28. • Bilateral condylar fractures
•
•
•
•
Same as above
Limitation in mouth opening
Restricted mandibular movement
Anterior open bite

29. INVESTIGATION
• Treatment plan for mandibular fractures is very dependent on precise
radiological diagnosis
• RADIOGRAPHS
• Essential radiographs
• Extra-oral radiographs
• Intra-oral radiographs
• Desirable radiographs

30. Essential Extra-oral Radiographs
• Oblique lateral radiographs
(left and right)
• Fracture of body proximal to
canine region
• Fractures of angle, ramus and
condylar region

31. • Posterior-anterior view
• Shows displacement of
fractures in the ramus, angle,
body
• Rotated posterior-anterior
view
• Fractures between Symphysis
and canine region

32. • Reverse Towne’s view
• Ideal for showing
lateral or medial
condylar displacement

33. Essential Intra-oral Radiographs
• Periapical radiographs:
• Association of tooth to line of fracture
• Existing pathology related to tooth in line of fracture
• Fracture of tooth in line of mandibular fracture
• Occlusal radiographs:
• Association of root of tooth to line of fracture

34. Desirable Radiographs
• Panoramic tomography
• represents the best single
overall view of the mandible
especially the condyles
• Standard linear tomography
• Computed tomography (CT)

35. MANAGEMENT
• Airway
•
•
•
•
•
•
•
•
•
•
•
Tongue falling back
Blood clots
Fractured teeth segments
Broken fillings
Dentures
Hemorrhage
Soft tissue lacerations
Support of bone fragments
Pain control
Infection control e.g. compound fractures
Food and Fluid

36. DEFINITIVE TREATMENT
• Reduction
• Restoration of a functional alignment of the bone fragments
• Use of occlusion
1. Open reduction
2. Closed reduction
• Immobilization
• To allow bone healing
• Through fixation of fracture line
1. Rigid
2. Non-rigid

37. BONE HEALING
• Bone healing is altered by types of fixation and mobility of the
fracture site in relation to function
• Primary bone healing
• Secondary bone healing

38. Bone Healing
• Primary bone healing:
• No fracture callus forms
• Heals by a process of
1. Haversian remodeling directly across the fracture site if no gap exists
(Contact healing), or
2. Deposition of lamellar bone if small gaps exist (Gap healing)
• Requires absolute rigid fixation with minimal gaps

39. Bone Healing
Contact Healing
Gap Healing

40. Bone Healing
• Secondary bone healing:
• Bony callus forms across fracture site to aid in stability and immobilization
• Occurs when there is mobility around the fracture site

41. Bone Healing
• Secondary bone healing involves the formation of a sub
periosteal hematoma, granulation tissue, then a thin
layer of bone forms by membranous ossification.
Hyaline cartilage is deposited, replaced by woven bone
and remodels into mature lamellar bone

42. Bone Healing

43. TEETH IN LINE OF FRACTURE
• Teeth in line of fracture are a potential impediment to healing for the
following reasons
1. The fracture is compound into the mouth via the opened periodontal
membrane
2. The tooth may be damaged structurally or loose its blood supply as a
result of the trauma so that the pulp subsequently becomes necrotic
3. The tooth may be affected by some pre-existing pathological process
• Indications for removal
• Absolute
• Relative

44. Absolute indications
• Longitudinal fracture involving the root
• Dislocation or subluxation of tooth from socket
• Presence of periapical infection
• Infected fracture line
• Acute pericoronitis

45. Relative indications
• Functionless tooth which would eventually be removed electively
• Advanced caries
• Advanced periodontal disease
• Teeth involved in untreated fractures presenting more than 3days
after injury

46. Management of teeth retained in fracture
line
• Good quality intra-oral periapical radiograph
• Appropriate antibiotic therapy
• Splinting of tooth if mobile
• Endodontic therapy if pulp is exposed
• Immediate extraction if fracture becomes infected

47. IMMOBILIZATION
• The period of stable fixation required to ensure full restoration of
function varies according to:
1. Site of fracture
2. Presence of retained teeth in the line of fracture
3. Age of the patient
4. Presence or absence of infection

48. • A simple guide to time of immobilization for fractures of the tooth
bearing area of the mandible is as follows:
Young adult
with
Fracture of angle
Receiving
Early treatment
In which
Tooth removed from fracture line
3 weeks

49. • If:
a) Tooth retained in fracture line: add 1 week
b) Fracture at Symphysis: add 1 week
c) Age 40yrs and above: add 1 or 2 weeks
d) Children and adolescent: subtract 1 week

50. METHODS OF IMMOBILIZATION
• Osteosynthesis without intermaxillary fixation
1.
2.
3.
4.
Non-compression small plates
Compression plates
Mini plates
Lag screws

51. • Intermaxillary fixation
1. Bonded brackets
2. Dental wiring
1. Direct
2. Eyelet
3. Arch bars
4. Cap splints

52. • Intermaxillary fixation with Osteosynthesis
1.
2.
3.
4.
5.
Trans osseous wiring
Circumferential wiring
External pin fixation
Bone clamps
Transfixation with kirschner wires

53. CLOSED REDUCTION
• Fracture reduction that involves techniques of not opening the skin or
mucosa covering the fracture site
• Fracture site heals by secondary bone healing
• This is also a form of non-rigid fixation

54. • “If the principle of using the simplest method to achieve optimal
results is to be followed, the use of closed reduction for mandibular
fractures should be widely used” Peterson’s Principle of Oral and Maxillofacial Surgery 2nd
edition
• INDICATIONS
1. Nondisplaced favorable fractures
2. Mandibular fractures in children with developing dentition
3. Condylar fractures

55. • CONTRAINDICATIONS:
1. Alcoholics
2. Seizure disorder
3. Mental retardation
4. Nutritional concerns
5. Respiratory diseases (COPD)
• Unfavorable fractures

56. • ADVANTAGES
1. Low cost
2. Short procedure time
3. Can be done in clinical setting with local anesthesia or sedation
4. Easy procedure

57. • DISADVANTAGES
1. Not absolute stability (secondary bone healing)
2. Oral hygiene difficult
3. Possible TMJ sequelae
a) Muscular atrophy/stiffness
b) Decrease range of motion

58. • TECHNIQUES:
1. Arch bars – Erich arch bars
2. Ivy loops
3. Essig Wire
4. Intermaxillary fixation screws
5. Splints
6. Bridal wires

60. OPEN REDUCTION
• Implies the opening of skin or mucosa to visualize the fracture and
reduction of the fracture
Can be used for manipulation of fracture only
Can be used for the non-rigid and rigid fixation of the fracture
• INDICATIONS
Unfavorable/unstable mandibular fractures
Fractures of an edentulous mandible fracture with severe
displacement
Delayed treatment with interposition of soft tissue that prevents
closed reduction techniques to re-approximate the fragments

61. Open reduction/rigid fixation

62. Open reduction/ non rigid

63. SPECIAL CONSIDERATIONS
• Edentulous mandible
• Mandible in children

64. Mandibular Fractures in children
• Mandible is resilient at this period
• Line between cortex and medulla is less well defined
• High ratio of bone to teeth substance
• Factors to consider in treating fractures in children
• Interference with growth potential
• Fixation in deciduous/mixed dentition
• Unerupted teeth

65. Fracture of Edentulous mandible
• Influencing factors:
1. Decreased inferior alveolar artery (centrifugal) blood flow
2. Dependent on periosteal (centripetal) blood flow
3. Medical conditions that delay healing
4. Decreased ability to heal with age
5. Altered physical characteristics following tooth loss

66. • Methods of immobilization:
• Direct Osteosynthesis
1. Bone plates
2. Transosseous wiring
3. Circumferential wiring
• Indirect skeletal fixation
1. Pin fixation
2. Bone clamps
• Intermaxillary fixation using gunning type splints
1. Used alone
2. Combined with other techniques

67. COMPLICATIONS
• Misapplied fixation
• Infection
• TMJ ankylosis
• Nerve damage
• Displaced teeth
• Gingival and periodontal complications

68. • Malunion
• Delayed union/Non union
• Inadequate immobilization, fracture alignment
• Interposition of soft tissue or foreign body
• Incorrect technique
• Limitation in mouth opening
• Scar formation

69. CONCLUSION
• An adequate knowledge of the diagnosis and management of various
types of mandibular fracture is needed so as to provide the desired
treatment in order to prevent unfavorable and adverse complications.