1. Mandible Fractures

2. Innervation CNV3, the mandibular n., through the foramen ovale
Inferior alveolar n. through the mandibular foramen
Inferior dental plexus
Mental n. through the mental foramen

3. Arterial Supply Endosteal blood supply Inferior alveolar artery
Mental artery
Periosteal blood supply (old age)

4. Musculature: Jaw Elevators
Masseter: Arises from zygoma and inserts into the angle and ramus
Temporalis: Arises from the infratemporal fossa and inserts onto the coronoid and ramus
Medial pterygoid: Arises from medial pterygoid plate and pyramidal process and inserts into lower mandible

5. Musculature: Jaw Depressors
Lateral pterygoid: lateral pterygoid plate to condylar neck and TMJ capsule
Mylohyoid: mylohyoid line to body of hyoid
Digastric: mastoid notch to the digastric fossa
Geniohyoid: inferior genial tubercle to anterior hyoid bone

7. Condylar neck is the weakest point of the mandibble

8. Epidemiology Mandible most common after nasal fractures
Mandible : Zygoma : Maxilla 6:2:1
Ellis 4711 facial fractures, 45% with mandible fractures
Assault>MVA>Fall>Sports

9. Most prevalent age range: 16-30 year old
Males > females; 3 to 1
Most prevalent age range: year old
Concomitant injuries are common
Must rule out spinal injuries
Dental injuries are commonly associated with other facial fractures

10. Epidemiology Sites of weakness Third molar (esp. impacted)
Socket of canine tooth
Condylar neck

11. Epidemiology Boole et al ( 5196 fractures) Young military men
Angle 35%, Symphysis 20%, Body 12%, Condylar 9%, Subcondylar 4%, Ramus 4%, Alveolar 3%, Coronoid 1%
70% 1 fracture, 30% 2 fractures, .2% more than 2
Facial lacerations 30%, other facial fracture 16%, C-spine 0.8%

12. Classifications of Fractures
Simple or closed fracture
Compound or open fracture
Comminuted fracture
Greenstick fracture
Pathologic fracture
Favorable vs Unfavorable fracture

13. Classifications of Fractures
. According to the severity of the injury
Simple fracture: In which the soft tissue, that may be damaged, but there is no open wound communicating the fracture fragment with the outside.
Compound fracture: In which there is an open wound with direct communication of the fragments with the out­ side.(all body # are compound because are open in PDL)

14. According to the type of fracture
Green stick fracture: There is incomplete discontinuity of the bone occurs in children.
Complex fracture: In which the fracture occurs in more than one bone.
Comminuted fracture: In which the bone is fractured into many fragments.
Pathological #

15. Unilateral fracture: Usually single, but occasional more than one fracture line may be present in one side.
Bilateral fracture: Usually occur from combination of direct and indirect force, e.g. angle and opposite condylar fracture.
Multiple fracture: Also occurs from the direct indirect force combination, e.g. symphyseal and bilateral condylar fracture(parade fracture)

16. According to the cause
Direct force: A direct blow to the mandible is the most common cause of mandibular fracture.
Indirect force: Fracture may occur from a blow applied at a distance from the fracture site, e.g. a blow to the symphysis may cause subcondylar fracture.
Excessive muscular contraction: This may cause fracture as with electric shock therapy, (Coronoid #)

17. Anatomic Region Classification
Condylar process
Coronoid
Ramus
Angle
Body
Symphysis or Parasymphysis
Alveolar process

18. According to the direction of the fracture line
The fracture line may be horizontal or vertical, each may be favorable or unfavorable.

19. In Angle area Masseter, Medial and Lateral Pterygoid, and Temporalis tend to draw fractures medial and superior
Medial Pterygoid is the stronger component
This is affected by the vertical or horizontal direction fracture line

20. Favorable vs. Unfavorable
Unfavorable Fractures where the muscles tend to draw fragments apart
Most angle fractures are horizontally unfavorable
Most parasymphyseal fractures are vertically unfavorable
Symphyseal # are favorable why?

21. Favorable/Unfavorable Fractures (Horizontal)

22. Favorable/Unfavorable Fractures (Vertical)

25. Evaluation Stabilization via ATLS protocol Part of secondary survey
Blow to face favors parasymphyseal fracture and contralateral angle fracture
Fall to chin (bilateral condylar fractures)

26. Evaluation Previous occlusion (Class I-III) ( photos)
Psychiatric, seizure disorders
Previous facial trauma
Other injuries (c-spine, intra-abdominal, likely prolonged intubation)

27. Evaluation Common symptoms of mandibular fracture
Pain: Especially with motion,
Tenderness: Palpation over the fracture site reveals tenderness.
Disability: The patient is unable to open the mouth normally.
Swelling: Swelling early after injury is due to escape of blood at the fracture site.

28. Evaluation
Discoloration: The overlying tissue become red, bluish or purplish as a result of hemorrhage or haematoma for­mation.
Deformity: Displacement of the fractured fragment may be suggested by asymmetry of the face and deformity.
Abnormal mobility: The mandible will move in an abnormal way.

29. Evaluation
Crepitation: The patient may note a greeting, cracking or griding sound during movement as the fragments move in contact with each other.
Salivation: Pain and tenderness stimulate salivary secretion. Drooling of saliva from the mouth is increased by the inability to swallow the excessive saliva.
Bad odor: The patient may have offensive breath due to putrefaction of blood clots and mucous.

30. Extensive comminution or bilateral fracture of the symphyseal region may result in sever respiratory difficulties due to the posterior displacement of the fractured fragments

32. Physical Exam Signs Of Mandibular Fracture Step defects \occlusion
Palpable step\ the inferior border
Tenderness to palpation
Malocclusion

33. Physical Exam Trismus (35 mm or less) Altered sensation of V3 Crepitus
Unnatural mobility
Ecchymosis in floor of mouth (pathognomonic)
Mucosal lacerations

34. Physical Exam
Anesthesia of lower lip is “pathognomonic” of a fracture distal to the mandibular foramen (degree displacement)
The converse is not true: not all fractures distal to the mandibular foramen have mental n. anesthesia

35. Physical Exam Dental Exam Lost, fractured, or unstable teeth
Dental Health
Relation to fracture
Quantity

36. Facial lacerations

37. Inspection Sublingual ecchymosis Step defects, ridge
discontinuity, malocclusion

38. Malocclusion
Step defects in the occlusion

39. Mucosal laceration
Step defects in the occlusion

40. PALPATION “Step” Defect Unnatural mobility Crepitus Bony segments
Subcutaneous emphysema
Mobility

41. Condylar Injuries Contusion -Damage to the joint soft tissues leads to
Synovial effusion, haemarthrosis
-Symptoms are pain, limitation of mouth openning and tenderness over the joint
- Accurate Dx need MRI
- ttt soft diet, analgesics

42. Dislocation
Displacement of the condyle from the glenoid foosa(see TMJ topics)
Fracture

43. Condylar Fracture Classification A. Intracpsular fracture
I According to the extend of the fracture line
A. Intracpsular fracture
Fracture through the condylar head generally intracpsular.
B. Extracapsular fracture
Fracture line extends through the neck of the condyle.
C. Subcondylar fracture;
The fracture line runs from the sigmoid notch, downwards and posteriorly to the posterior border of the ramus

44. II. According to the position of the condylar fragment
A. Undisplaced fracture
The fracture is complete but the fragments remain in their anatomical positions.
B. Displaced fracture
The condylar head is displaced, medially and anteriorly but remains within the limits of the glenoid fossa
C. Dislocated fracture
The condylar head is expelled from the fossa and out of the limits of the temporomandibular joint.

45. Physical Exam Unilateral fractures of Condyle
Decreased translational movement, and
functional height of condyle ,lead to
Deviation of chin toward the fractured side,
open bite on the opposite side of fracture
Bilateral fractures of condyle
- Anterior open bite
- Gaging of posterior teeth

46. Picture of open bites

48. Radiographic Exam
x-ray (image areas of concern with 2 films at 90o to one another: eg. peri-apicals & 90o occlusal )
gaps
overlap
lost teeth
displaced teeth
foreign bodies
chest x-ray to locate missing pieces

49. Radiographic Exam Radiographs:
Panoral tomogram: the best single overall view of the mandible (if not available R\L oblique lateral é rotated PA)
PA mandible: to show medial or lateral displacement of fractured body\ angle. not suitable for TMJ
Reverse townes projection: for TMJ #

50. Radiographic Exam intra-oral
- Periapicals to show position& condition of teeth involved in # line
- Occlosal views\ midline # with minimal displacement

51. CT scan
Not as diagnostic as plain films for non displaced fractures of mandible.
Most useful for coronoid and condylar fractures, associated midface fractures
-3D CT very useful for condylar #

52. Fractures of mandibular symphysis and left condyle.

53. Pathologic fracture associated with
large radicular cyst (lateral-oblique view).

54. Mandibular fracture at angle on right
side (PA view).Note the displacement

55. Mandibular fracture: this is the same case but
here the fracture is not so obvious. It is actually
at the right mandibular angle. Two views at right
angles are suggested when looking for fractures.

56. Fracture of left mandibular condyle with
medial displacement of condylar head
(Reverse Towne’s projection).

57. Alveolar fracture
combined with
fracture through
symphysis:
Standard
occlusal
projection.

58. 90° Occlusal