Repositioning and fixation of simple, non displaced mandibular angle fractures by means of minimum exposure of the fracture site and fixation by wiring osteosynthesis.

1. Angle and ramus fracture,
simple wire fixation

2. Intraosseous wire fixation of angle fractures is a nonrigid
technique that requires 5-6 weeks of postoperative MMF. It is
indicated when plate/screw fixation is not available and the
mandibular ramus is likely to rotate upwards and forwards
because of the attached muscles. In such instances, closed
reduction may not be effective. The intraosseous wire will help
to prevent rotation of the mandibular ramus.

3. The intraosseous wire must be placed to resist the upward and forward direction in
which the ramus will tend to rotate. Therefore, it is prudent to place the hole through
the proximal fragment superiorly to the hole in the distal fragment. It is not necessary
for the intraosseous wire to engage both buccal and lingual cortices on each side of
the fracture. It is only necessary to engage the buccal cortices with the wire. Because
this is a nonrigid technique, 5-6 weeks of MMF must be applied after surgery.
Principles

4. Arch bars are applied to the teeth and MMF is secured. The patient is monitored for positional
changes of the mandibular ramus using x-rays. At 6 weeks MMF is released and fracture
stability determined by manipulation. The patient is placed on a soft diet and if the occlusion
maintains for a two-week period, the arch bars may be removed.

5. Exposure of fracture
The fracture should be exposed and any extractions determined necessary be performed.
Open reduction in dentate patients usually begins with fixation of the occlusion. However,
MMF is not desirable when using intraosseous wire fixation until the wire is to be tightened.
It is easier to drill the holes in the bone and to pass the wire while the patient’s jaws are
open.

6. The “Vestibular” incision or “Ward modified” incision can be used for standard fracture
fixation techniques. In order to more easily approach the operative field it is preferred to
extend the mesial cutting into the vestibule with a release incision. The region of the
mandibular angle & ramus can best be exposed by extending the standard vestibular incision
in a superior direction up the ascending ramus. The incision can be altered depending on the
area of the ramus/mandibular angle process that needs exposure and treatment.
Intraoral approach to the mandibular angle & ramus
Principles
Vestibular incisions
A) Vestibular incision B) “Ward” modified incision
Oral contamination is
not a contraindication
for an intraoral incision.

7. Sensory buccal nerve
The sensory buccal nerve crosses the upper anterior rim of the mandibular ascending ramus
in the region of the coronoid notch. It is usually below the mucosa running above the
temporalis muscle fibers. When the posterior vestibular incision is carried sharply along the
bony rim, the buccal nerve is at risk of transsection resulting in numbness in the buccal
mucosal region. Therefore, to protect the nerve, the posterior incision is to be extended
bluntly as soon as the lower coronoid notch is reached.

8. Sensory buccal nerve

9. Sensory buccal nerve
Mental nerve
The mental nerve is a branch of the fifth
cranial nerve (trigeminal nerve). This nerve
provides sensation to the anterior mandibular
vestibule, lip and chin. When the incisionis
extended posterior to the canine teeth, the
mental nerve can be damaged. Keep the
incision superior to the mental nerve in the
body region. Particularly in the extended
intraoral approach, care must be taken to
protect the mental nerve in the anterior body
region.

10. Mental nerve

11. photography of anatomical preparation
photography of anatomical preparation
showing

13. The bony attachments of the buccinator muscle run a course below the
mucogingival junction opposite to the molars and along the oblique line
ascending as the anterolateral rim of the ascending ramus. The attachments
extend back into the pterygomandibular raphe. The buccinator is innervated by
the buccal branch of the facial nerve. The muscle belongs to the mimetic muscle
system and has a unique functional structure allowing for movement comparable
to peristaltic motion. Its detachment can result in an impaired bolus transport.
Reminder: The buccinator muscle belongs to the mimic muscle system and has a
unique functional structure allowing for a movement comparable to a peristaltic
motion. The deep fibers run in parallel bundles from the modiolus to the
pterygomandibular raphe at the level of the occlusal plane (intercalar region) and
account for the buccinator mechanism building up a ridge towards the occlusal
plane. Its detachment can result in an impaired bolus transport out of the buccal
space which can be annoying for the patient. The buccinator is innervated by the
motor buccal branch of the facial nerve.

14. The lateral mucogingival vestibular incision transects the lower attachment of the buccinator
muscle. Stripping the mucoperiosteal flap laterally dislocates the lower border of the muscle.
To reattach the muscle, the sutures for wound closure in the lateral vestibular should not only
be superficial. The suture should catch all layers (mucosa and muscle) as a safeguard for
muscle reattachment.
The buccinator is innervated by the motor buccal branch of the facial nerve.

15. The buccinator muscle belongs to the mimic muscle system and has a unique functional structure
allowing for a movement comparable to a peristaltic motion. The deep fibers run in parallel bundles
from the modiolus to the pterygomandibular raphe at the level of the occlusal plane (intercalar
region) and account for the buccinator mechanism building up a ridge towards the occlusal plane. Its
detachment can result in an impaired bolus transport out of the buccal space which is troublesome
for the patient.
Reminder:

17. Vestibular incision
Unless contraindicated, infiltrate the area with a local anesthetic containing a vasoconstrictor.
Make an incision through the mucosa in the vestibule approximately 5 mm away from the
attached gingiva (in the mucogingival junction),extending up the external oblique ridge.

18. Step 1. Injection of Vasoconstrictor
The oral mucosa, submucosa, and facial muscles are lushly vascularized.
Submucosal injection of a vasoconstrictor can remarkably reduce the amount of
hemorrhage during incision and dissection.
Step 2. Incsion
In the body and posterior portion of the mandible, the incision is placed 3 to 5 mm
inferior to the mucogingival junction (see Fig. 8.10). Leaving unattached mucosa on
the alveolus facilitates closure. The posterior extent of the incision is made over the
external oblique ridge, traversing mucosa, submucosa, buccinator muscle,
buccopharyngeal fascia, and periosteum (Fig. 8.5A).

19. Photograph showing incision location when vestibular approach is used to expose the
ramus and posterior body of the mandible. Note that there is some unattached mucosa
remaining along the attached gingiva to facilitate closure.
The incision is usually no more superior than the occlusal
plane of the mandibular teeth to help prevent herniation
of the buccal fat pad into the surgical field, a nuisance
during surgery. The buccal portion of the buccal fat pad is
usually not more inferior than the level of the occlusal
plane The incision is usually no more superior than the
occlusal plane of the mandibular teeth to help prevent
herniation of the buccal fat pad into the surgical field, a
nuisance during surgery. The buccal portion of the buccal
fat pad is usually not more inferior than the level of the
occlusal plane (Fig. 8.4).
Placement of the incision at this level also may spare the
buccal artery and nerve, although their damage is more a
nuisance than a clinical problem. If the buccal artery is
severed, bleeding is easily controlled by coagulation.

20. The buccal fat pad consists of a main body and four extensions: buccal,
pterygoid, pterygomandibular, and temporal. The body is centrally positioned. The
buccal extension lies superficially within the cheek, while the pterygoid,
pterygomandibular, and temporal extensions are more deeply situated. The buccal
extension is the most superficial segment of the fat pad and imparts fullness to the
cheek. It enters the cheek below the parotid duct and extends along the anterior
border of the masseter as it descends into the mandibular retromolar region. It
overlies the main portion of the buccinator muscle as it crosses the cheek. In the
cheek, the fat pad is anterior to the ramus. Its caudal extension intraorally is on a
plane tangential with the occlusal surface of the mandibular third molar (see Fig.
8.4). Its anterior limit is marked by the facial vessels, which are in the same plane as
the buccal fat pad. The parotid duct lies superficial to the fat pad and then
penetrates the fat pad and buccinator to enter the oral cavity opposite the second
molar. The buccal extension of the fat pad is limited by the masseteric fascia. A deep
extension of the masseteric fascia blends with the fascia along the lateral surface of
the buccinator. This fascial layer lines the deep surface of the buccal fat that is in
contact with the buccinator.

21. The buccal fat pad first described by Marie Bichat in 1801 is
located in an extended three-dimensional compartment with its
main mass or cheek portion overlying the posterolateral aspect of
the buccinator muscle and the maxillary tuberosity, which is partly
covered by the anterior border of the masseter muscle. The major
processes of the fat pad stretch into deep temporal,
pterygomaxillary and pterygoid region. The fat is distinct from
facial fat and similar to orbital fat in consistency and its globule-like
structure, to which it connects through the infraorbital fissure. The
facial vessels run along the anterior border of the cheek portion.
The fascial layers (capsule) enveloping the buccal fat pad on the
medial surface next to the buccinator muscle are rarely ruptured in
a subperiosteal dissection along the mandibular body and angle.
However, when going up the ramus subsequent to a vertical
division of the buccinator muscle anterior to the
pterygomandibular raphe in order to reach beyond the coronoid
notch the inner capsule of the fat pad can be breached leading to a
herniation that will obstruct the vision in the surgical field.

22. Step 3. Subperiosteal Dissection of the Mandible
Subperiosteal dissection of the mandibular body is relatively simple compared to that of
the symphysis because there are fewer Sharpey fibers inserting into the bone.
Dissection can then proceed
posteriorly along the lateral surface
of the mandibular body/ramus. The
surgeon should stay within the
periosteal envelope to prevent
lacerating the facial vessels, which
are just superficial to the
periosteum (Fig. 8.2).
Figure 8.2 Anatomic dissection of the mandibular body showing
relation of facial vessels to bone. The only tissue between them is
the periosteum.

23. Facial Vessels
The facial artery and vein are usually not encountered during the mandibular vestibular approach
unless dissection through the periosteum occurs in the region of the mandibular antegonial notch.
The facial artery arises from the external
carotid artery in the carotid triangle of the
neck. At or close to its origin, it is crossed by
the posterior belly of the digastric muscle,
the stylohyoid muscles, and the hypoglossal
nerve. In the submandibular triangle, the
facial artery ascends deep to the
submandibular gland, grooving its deep and
superior aspect, and then passes
superficially to reach the inferior border of
the mandible. As the artery crosses the
mandible at the anterior border of the
masseter muscle, it is covered on its
superficial surface by skin and platysma
muscle, and its pulsations can be felt at this
location.

24. Vessels
The facial vessels cross the inferior border of the mandible at the level
corresponding to the anterior border of the masseter muscle. The vessels are
embedded in the lower extensions of the buccal fat pad.

25. Vessels
Facial artery and vein

26. Facial artery and vein
The artery is always located
anterior to the vein. A
periosteal layer separates
the vascular bundle from
the lateral bony surface of
the mandible.

27. The facial vein is the drainage of the
angular and ultimately labial vessels.
It is usually located more posterior
and superficial to the artery. Of
surgical significance, however, is the
fact that the facial artery and vein are
close to the mandible in the region of
the inferior border. The only structure
that separates the vessels from the
bone is the periosteum (see Fig. 8.2).
Figure 8.2 Anatomic dissection of the mandibular body showing
relation of facial vessels to bone. The only tissue between them is the
periosteum.

28. Subperiosteal dissection of the ramus.
Posteriorly, the incision leaves the crest at the
second molar region and extends laterally to
avoid the lingual nerve, which may be directly
over the third molar area. Placing the incision
over the ascending ramus helps to avoid the
lingual nerve.
Dissection can then proceed posteriorly along
the lateral surface of the mandibular
body/ramus. The surgeon should stay within
the periosteal envelope to prevent lacerating
the facial vessels, which are just superficial to
the periosteum (Fig. 8.2).

29. Subperiosteal dissection along the anterior
edge of the ascending ramus strips the
buccinator attachments, allowing the muscle
to retract upward, minimizing the chance of
herniation of the buccal fat pad (Fig. 8.4).
Temporalis muscle fibers may be stripped
easily by inserting the sharp end of a
periosteal elevator between the fibers and the
bone as high on the coronoid process as
possible, and stripping downward (see Fig.
8.13).
A notched right-angle retractor(see Fig. 8.14)
may be placed on the anterior border of the
coronoid process to retract the mucosa,
buccinator, and temporalis tendon superiorly
during stripping. Stripping some of the tissue
from the medial side of the ramus will widen
the access. After stripping the upper one third
of the coronoid process, a curved Kocher
clamp can be used as a self-retaining retractor
grasping the coronoid process.
Figure 8.14 Notched right-angle retractor. The ‘‘V’’-shaped
notch is positioned on the ascending ramus and the retractor
is pulled superiorly to retract tissues.

30. While the buccal tissues are
retracted laterally with a right-
angle retractor, the masseter
muscle is stripped from the lateral
surface of the ramus (Fig. 8.13).
Sweeping the periosteal elevator
superoinferiorly strips the muscle
cleanly from the bone. Although
direct visualization may be poor,
the posterior and inferior borders
of the mandible are readily
stripped of pterygomasseteric
fibers using periosteal elevators, J-
strippers, or both. Dissection can
continue superiorly, exposing the
condylar neck and the entire
sigmoid notch. To maintain

31. exposure of the ramus, Bauer retractors
(see Fig. 8.15) inserted into the sigmoid
notch and/or under the inferior border are
useful (see Fig. 8.16). The LaVasseur-Merrill
retractor is another useful device that
slides behind and clutches the posterior
border of the mandible to hold the
masseter in a lateral position.
Figure 8.15 Bauer retractors. The flanges at right angle to
the shaft are used to engage the sigmoid notch and/or
inferior border of the mandible, allowing retraction of the
masseter muscle.
Figure 8.16 Exposure after insertion of Bauer retractors.
Note the flange of one retractor is in the sigmoid notch
and the flange of the other is under the inferior border of
the mandible.

32. This clinical image shows the fracture exposed, reduced, and MMF secured.

33. The intraosseous wire must be placed to resist the upward and forward direction
in which the ramus will tend to rotate. Therefore, it is prudent to place the hole
through the proximal fragment superiorly to the hole in the distal fragment.
It is not necessary for the intraosseous wire to engage both buccal and lingual
cortices on each side of the fracture. It is only necessary to engage the buccal
cortices with the wire.
Because this is a nonrigid technique, 5–6 weeks of MMF must be applied after
surgery.

34. A 1.5 mm hole is drilled through the buccal cortex of the distal fragment. A second hole,
located more superiorly, is drilled through the buccal cortex of the proximal fragment.
If the terminal molar is extracted as part of the procedure, the holes enter the socket. If no
tooth is extracted, the holes enter the medullary space and exit into the fracture.
The holes can be drilled with a drill inserted through the oral cavity or alternatively, a
Steinmann pin can be inserted transcutaneously to drill the holes.

35. Applying internal wire fixation
A 0.5 mm wire (24 gauge) is passed through the holes and preliminarily twisted
together. Prior to final tightening of the wire, the patient must be placed into occlusion
and secured with MMF. The intraosseous wire is then tightened, cut, and twisted down to
the bone.

36. Case example
Panoramic and PA x-rays show left simple angle fracture associated with ...

37. … an impacted third molar.

38. Because it is anticipated that the second molar might be removed in addition to the third molar the
soft-tissue incision is made as demonstrated.

39. Subperiosteal dissection exposes the fracture and the impacted third molar.

40. The impacted third molar is being removed because it interfered with fracture reduction.

41. The second molar is also removed because there is a large bony defect along the posterior root.

42. After making two holes, the wire is then passed from the extraction site out the hole in the proximal
fragment.

43. The wire is then preliminarily tightened. Prior to final tightening, the patient should be placed into MMF.

44. The wire has been tightened, cut, and bent down to lay against the bone.

45. To facilitate closure over the second molar extraction site, the flap is undermined with scissors.

46. Note that the flap has now been mobilized.

47. The flap has been closed over the extraction site.

48. MMF is secured and left in position for 5–6 weeks. Note this patient’s preexisting malocclusion.

49. Postoperative panoramic and PA x-rays show reduction of the fracture, ...

50. .. the position of the intraosseous wire, and MMF.

51. Closure of the intraoral incision
After thoroughly irrigating the wound and checking for hemostasis the incision is closed
using interrupted or running resorbable sutures.
Wound closure

52. Step 4. Closure
Closure is adequate in one layer, except in the anterior region. Closure is begun in the
posterior areas with resorbable suture. The pass of the needle should grab mucosa,
submucosa, the cut edge of the facial muscles, and the periosteum, if possible, The mucosa
is then closed with a running resorbable suture.
A suspension dressing, such as elastic tape, is useful for several days after the mandibular
buccal vestibular approach has been performed, to prevent hematoma and to maintain the
position of the repositioned facial muscles (Fig. 8.18F).

53. Surgical dressing
An elastic pressure dressing covering the ramus/condylar process region helps support the soft tissues
and prevent prevent hematoma formation.

54. Intraoral approach to condyle
The lateral surface of the ramus and condylar process is exposed in a subperiosteal plane to visualize the fracture. Right-
angled retractors and fiberoptic lighting would facilitate this procedure. The fracture must be reduced adequately before
fixation is applied. The fixation can be done either by transbuccal or right-angled instrumentation.
The surgeon has the option of treating the fracture through the intraoral approach under direct vision or may opt for
endoscopic assistance.
Exposure of fracture

55. Intraoral approach to condyle
The image shows a clinical example of the transbuccal trocar instrumentation to reduce and fix a
fracture of the condylar process.

56. Safe zones
The safe zones for pin placement are located circumferentially around the whole continuity of the
mandible along the lower and posterior borders and the condylar processes. There is one zone in
the subcondylar neck that is crossed by the facial nerve trunk in an anterior-posterior direction
which represents a high-risk zone for nerve injury. Therefore, this area should be avoided.
The condylar process itself can be used for K-wires outside the joint capsule. The posterior border
of the ramus and the bone in the lower border of the outer angle region have the thinnest cross
section of the whole safe zone but the intrabony nerve structures are running in a curvature
located superiorly and medially.
Safe zones

57. The mandibular canal containing the inferior alveolar nerve limits the vertical height of the safe zone
cranially in the mandibular body and angle. The vicinity of the mental foramen should be avoided due
to variances in the course of the mandibular canal next to the bony opening.
In the symphyseal area although there is a tiny continuation of the mandibular canal (incisal canal)
the whole bone stock beneath the tooth apices is available for pin placement.

58. Bony cross sections and intraosseous structures
•Tooth roots
•Mandibular canal/inferior alveolar nerve/no man’s land