The document discusses the anatomy and biomechanics of the mandible and summarizes various aspects of mandibular fractures including classification, clinical features, and radiographic evaluation. It notes that the mandible is the most commonly fractured facial bone due to its prominent position and exposure to trauma. Key anatomical sites that are weak areas prone to fracture are the angle, body, symphysis, and condyle regions. Clinical examination involves inspection for swelling, deformity, and intraoral findings while radiographs like OPG, PA view, and CT are useful for evaluation and classification of fractures.

1. Dr. Ashish Panda
Dept. Of Oral & Maxillofacial Surgery
Mandibular fracture

2. Mandible:
 Mandible is the largest, heaviest and strongest
bone of the face.
 A solid movable mandible allows normal chewing,
swallowing and speech.
 Parabola shaped bone
 Angle of curvature is 110-140 degree
 Mandible is the 2nd bone to ossify
 It composed of dense cortical bone encloses
medullary bone.

3. Blood supply:

4. Muscle
attachment

5. Nerve supply:

6. Age changes of mandible
 Mental foramina : child-near inferior border
old age –near alveolar ridge

7. Incidence:
 Incidence of injury & the fracture being the most
common of all facial bones [61%] by virtue of its
position and prominence followed by maxilla
[46%], zygoma [27%] & nasal bone [19.5%].
 Experimental cadaveric studies have shown that
mandibular fracture are twice as common as the
maxillary and four times higher force is required
for # of mandible vs. Maxilla.
Oikarinen VJ, Lindqvist C. The frequency of facial bone fractures in
patients with multiple injuries sustained in traffic accidents. Proc Finn
Dent Soc. 1975 Apr;71(2):53-7. PMID: 1078517.

8. Weak areas of mandible:
 Junction of ramus and body (angle of the
mandible) are fractured commonly.
 Symphysis region- junction of two individual
bones.
 Junction between alveolar bone and basal
mandibular bone
 Parasymphyseal region – lateral to the mental
prominence , incisive fossa and mental foramen.
 Presence of impacted tooth,canine with long roots
further weakens the mandible.

9.  The 'weakest' region of the mandible that
fractures in one site only is the angle region and
of the mandible that fractures in more than one
site is the condyle region.
 The 'weakest' site of the dentulous mandible is
the condyle region and of the edentulous
mandible the molar region.
 The two main factors that determine the 'weak'
sites of the mandible have been discussed. The
one is the site of application, direction and
severity of the forces and impacts and the other
the inherent weakness of the condyle and angle-
molar regions.

10. Factors influencing displacement of mandibular
fracture
 1. Direction and intensity of the traumatic force.
 2. Site of fracture.
 3. Direction of the fracture line.
 4. Muscle pull exerted on the fractured
fragments.
 5. Presence or absence of teeth.
 6. Extent of soft tissue wounds.

11. Direction and intensity of the traumatic force
• It is important in that direct trauma at one site causes an in direct force on the
contralateral side thus leading to subsequent injury at both the ends.
• Lowest tolerable frontal impact-425lb
• 800-900lb: force required for b/l subcondylar and symphysis#

12. Site of fracture.
Symphysis fracture
 If the fracture line passes from the labial to the
lingual surface in a straight line.
 The fractures is fairly stable to the inflence of the
muscle which are attached to the genial tubercle.

13. Body fracture of mandible:
 Fracture line is unfavourable that is running from
the alveolar margin downward and backward
towards the inferior border.
 Vertical displacement of the posterior fragment is
not s pronounced due to action of elevator group
of muscle.

14. Canine Region Fracture
 Common site of fracture, partly due to the length of the
canine root weakening the bone and also due to the
maximum convexity of the curvature at this site.
 If the bilateral fracture line in this region runs obliquely
forward and medially from the inner to outer cortical
plate, then due to the pull of geniohyoid and
genioglossus and anterior belly of the digastric muscles,
the entire anterior section of the mandible is displaced
posteriorly and this leads to tongue fall and airway
obstruction

15. Fractures of edentulous mandible:
 Extreme alveolar atrophy in the molar region of
edentulous mandible , are prone to fracture.
 Bilateral fractures of body of edentulous mandible
can occur near posterior attachment of mylohyoid
diphragm.
 Mylohyoid muscle level appears higher in this
situation due to extreme atrophy and loss of vertical
height of body of mandible.
 So downward and backward angulations seen due
to influence of diagestric and mylohyoid muscles.
 This extreme displacement called “ bucket handle ’’
 It can cause respiratory distress in elderly patint.

16. Possible mechanism of producing ‘bucket handle’ type of
fracture of atrophic edentulous mandible.
The fracture is seen in the resorbed body of the mandible in
front of the posterior attachment of the mylohyoid muscle

17. Classification of mandibular
fracture
 Dictionary classification
 Kruger’s classification
 Anatomical location ( Row & Killey , Dingman and
Natwig )
 Kazanjian’s classification
 AO classification
 According to direction and favorability of muscle

18. Dictionary classification(Dorlands)
 Simple/closed
 Compound/open
 Communited
 Greenstick
 Pathologic
 Multiple
 Impacted
 Atrophic
 Indirect
 Complicated/complex

19. Dingman and Natvig classification
 A. Symphysis fracture
 B. Canine region fracture.
 C. Body of the mandible
between canine and angle.
 D. Angle region
 E. Ramus region
 F. Coronoid region.
 G. Condylar fractures.
 H. Dentoalveolar region.

20. Mandibular fracture classification
 (A) Simple fracture,
 (B) Greenstick fracture.
 (C) Compound comminuted fracture
 (D) Compound fracture
 (E) Simple comminuted fracture

21.  Relation of fracture to the site of injury :-
-Direct fracture
-Indirect fracture
 Completeness: -
-complete
-incomplete
 Depending on the mechanism:-
-avulsion fracture
-bending fracture
-burst fracture
-contrecoup fracture
-torsional fracture

22.  Number of fragments:-
-single
-multiple
-communited
 Involvement of integument:-
-closed or open fracture
- grade of severity I to V
 Shape or area of the fracture :-
-transverse
-oblique
-butterfly
-oblique surfaced

23. Mandibular fracture
 According to direction of fracture and favorability for
treatment :-
 i) Horizontally favorable fracture
 ii)Horizontally unfavorable fracture

24.  A) Vertically favorable line of fracture through the
right angle of the mandible
 (B) Vertically unfavorable line of fracture through
the right angle of the mandible

25. Rowe and Killey’s classification (Anatomical
Location)
 A. Fractures not involving the basal bone-are
termed as dentoalveolar fractures.
 B. Fractures involving the basal bone of the
mandible.
 Subdivided into following:
 i. Single unilateral
 ii. Double unilateral
 iii. Bilateral
 iv. Multiple

26. Kruger’s general classification:
 Simple or closed :The linear fracture, which does not
have communication with the exterior or the interior.
 Compound or open: This fracture has communication
with the external environment through skin or with the
internal environment through mucosa or periodontal
membrane
 Comminuted: A fracture in which the bone is
splintered or crushed into multiple pieces.

29. AO Classification (Relevant to Internal Fixation).
 1. F: Number of fracture or fragments
 2. L: Location (site) of the fracture
 3. O: Status of occlusion
 4. S: Soft tissue involvement
 5. A: Associated fractures of the facial skeleton
 Such a classification is helpful in terms of:
 Patient selection and treatment planning
 Evaluation of therapeutic results
 Comparison of different treatment methods
 Information and communication

30.  1. F : Number of fracture
 F0 : Incomplete fracture
 F1 : Single fracture
 F2 : Multiple fracture
 F3 : Comminuted fracture
 F4 : Fracture with a bone defect
•2. Categories of localization (site) L1-L8
•L1 : Precanine
•L2 : Canine
•L3 : Postcanine
•L4 : Angle
•L5 : Supra-angular
•L6 : Condyle
•L7 : Coronoid
•L8 : Alveolar process

31.  3. Category of occlusion—O0-O2
 O0 : No malocclusion
 O1 : Malocclusion
 O2 : Nonexistent occlusion—edentulous mandible
 4. Categories of soft tissue involvement—S0–S4
 The risk of infection and healing depends on the
condition of the soft tissues surrounding the fracture.
 S0 : Closed
 S1 : Open intraorally
 S2 : Open extraorally
 S3 : Open intra- and extraorally
 S4 : Soft tissue defect

32.  5. Categories of associated fractures A0-A6
 A0 : None
 A1 : Fracture and/or loss of tooth
 A2 : Nasal bone
 A3 : Zygoma
 A4 : LeFort I
 A5 : LeFort II
 A6 : LeFort III
 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)

33. Kazanjian and Converse classification:
 Class I: When the teeth are present on both sides of
the fracture line.
 Class II: When the teeth are present only on one side
of the fracture line.
 Class III: When both the fragments on each side of
the fracture line are edentulous.

34. Shetty et al.
 • Fracture type (F):
(a) Incomplete (b) Simple (c) Comminuted (d) Bone defect
 • Location of fracture (L):
(a) Left from midline (L1) to con- dylar head (L8) (b) Right from midline
(R1) to condylar head (R8)
 • Nature of occlusion (O):
(a) Normal (b) Malocclusion (c) Edentulous
 • Extent of soft tissue damage (S):
(a) Closed (b) Open intra- orally (c) Open extraorally (d) Open intra and
extraorally (e) Soft tissue defect
 • Presence of infection (I):
 (a) Yes (b) No
•
 Radiographic analysis of interfragmentary displacement
(D): (a) Mild (b) Moderate (c) Severe

35.  Passi D, Ram H, Singh G, Malkunje L. Total avulsion
of mandible in maxillofacial trauma. Ann Maxillofac
Surg. 2014;4(1):115-118. doi:10.4103/2231-
0746.133083

37. Clinical features:-
Extra-oral findings
 Swelling
 Ecchymosis
 Abrasion
 Laceration
 Facial deformity
 Paraesthesia or
anaesthesia on one or
both side of mandible
 Step deformity, crepitus,
bone tenderness

38. Intra – oral findings:-
 Coleman’s sign: lingual hematoma
 Buccal & lingual sulci ecchymosis
 Change of occlusion
 Mobility
 Pain, tenderness or limitation while performing
mandibular movements

39. Area specific clinical feature
 Fracture at angle
Step deformity at last
molar tooth
Premature dental
contact- inability to
close mouth- anterior
open bite
Trismus
Retrognathic occlusion
and flattened
appearance on both
surface

40.  Fracture of Body
Slight displacement- dearrangement of
occlusion
Premature contact on distal fragments-
displacing action of muscles attached to
the ramus
Coleman’s sign
Flattened appearance on lateral side
Impingement of airways- mylohyoid,
digastric or omohyoid pull the fragments

41.  Fracture of symphysis & parasymphysis
 Lingual hematoma and bone tenderness
 Posterior openbite/ unilateral open bite
 Posterior crossbite- midline symphysis fracture
 Retruded chin
 Severe concussion, loss of tongue control &
obstruction of airway.

42.  Fracture of coronoid process
Caused by reflex contracture of powerful
anterior fibers of temporalis
Difficult to diagnose
Painful movement especially during protrusion
• Fracture of ramus
Uncommon
Flattened appearance of lateral aspect
Severe trismus

43. Clinical Examination
 History
 Mechanism of injury
 Inspection / Palpation ( Extraoral / Intraoral)

44. History
 Chief Complaint
 History of presenting illness
 Loss of consciousness, vomiting, amnesia
 Systemic examination

45. Inspection
 Extra oral
1. Change in contour of
face
2. Swelling in the
region of mandible
3. Laceration on the
chin

46. • Intra oral
1. Mucosal & gingival tear
2. Ecchymosis
3. Occlusal changes

47. Deviation of jaw
Restriction of mouth
opening

48. Collapsed arch &
interfragmentary
mobility
Open bite & cross
bite due to unilateral
gagging of
occlusion
Occlusal step with
unilateral cross bite
Anterior open bite

49. Multiple fragmentation with
complete loss of occlusion
Unfavorable fracture line
causing displacement of
tooth
Sublingual hematoma-
Coleman’s sign

50. Palpation
Palpation of lower border of
mandible from behind the patient
Attention is paid to the step
deformities
Palpable in the region of angle and
ramus
The surgeon places little finger in the EAM with the pulp directed forwards whilst patient
moves the mandible

51. Bimanual Palpation
The abnormal mobility at the fracture site can be elicited
by the bimanual palpation. The mandible is grasped on
either side of the suspected fracture line in such a way
that the index finger is on the occlusal surface of the
teeth and the thumbs are on the inferior border. The
proximal and distal segments are moved in supero-
inferior and antero- posterior direction, to elicit abnormal
mobility

52. Radiological Examination
 OPG
 PA view
 PNS view
 Lateral oblique Radiograph
 Occlusal view
 CT scan

53. OPG View
Commonly used
Entire mandible is visualized
Disadvantage- difficult to determine buccal / lingual
bone/medial condylar displacement

54. PA View
Medial/ lateral displacement
Disadvantage- cannot visualise
condylar region

55. PNS View
Indicated for
visualizing
medial
displacement of
Condylar neck
The 4th & 5th
MacGregor lines
coincides with
mandible

56. Occlusal View
Because of distortion
in symphysis region
in an OPG, an
Occlusal view is
indicated in
symphysial fracture
Also shows Vertical
Favorability of Body
Fractures

57. CT Scan
Condylar
Fracture
Cervical Spine
Injury

58. Thank you!
 Mandibular fracture Part-2 will include
management of mandibular fracture….