Download MBBS (Bachelor of Medicine and Bachelor of Surgery) 4th Year (Final Year) ENT Mandibular fracture Handwritten Notes
FRACTURES OF
MANDIBLE
Anagha K Karun
Roll number: 13
Classified according to their location
Occurrence :Condylar fractures > fractures of the Angle > Body >
Symphysis
, (mnemonic CABS).
Most of the mandibular fractures are the result of direct trauma;
however, Condylar fractures are caused by indirect trauma to the
chin or opposite side of the body of mandible.
Displacement of mandibular fractures is determined by
(i) the pul of muscles attached to the fragments,
(i ) directionof fracture line
(i i) bevel of the fracture.
CLINICAL FEATURES
In fractures of condyle, if fragments are not displaced, pain and trismus are the main
features and tenderness is elicitedat the site of fracture.
If fragments are displaced, there is in addition Malocclusion of teeth and deviation of jaw
to the opposite side on opening the mouth.
Most of the fractures of angle, body and symphysis can be diagnosed by intraoral and
extraoral palpation.
Step deformity, malocclusion of teeth, ecchymosis of oral mucosa, tenderness at the site of
fracture and crepitus may be seen.
DIAGNOSIS
X-rays useful in mandibular fractures are
PA view of the skull (for condyle),
right and left oblique views of mandible and
the panorex view.
TREATMENT
In closed methods, interdental wiring and intermaxillary fixation are useful.
External pin fixation can also be used.
In open methods, fracture site is exposed and Fixed by direct interosseous
wiring. This is further strengthened by a wire tied in a figure of eight
manner.
Compressions plates are available to fix the fragments.
With their use, prolonged immobilization and intermaxillary fixation can be
avoided.
Immobilization of mandible beyond 3 weeks,
in Condylar fractures, can cause Ankylosis of
temporomandibular joints. Therefore,
intermaxil ary wires are removed and jaw
exercises started
n If occlusion is stil disturbed, intermaxil ary
wires are reapplied for another week and
the process repeated til the bite and jaw
movements are normal
FRACTURES OF
ZYGOMA
(TRIPOD FRACTURE)
After nasal bones,zygoma is the second most frequently fractured bone.
Cause : direct trauma
Lower segment of zygoma is pushed medially and posteriorly resulting in
flattening of malar prominence and a step deformity at the infraorbital
margin .
Zygoma is separated at its 3 processes.
Fracture line passes through zygomaticofrontal suture,orbital
floor,infraorbital margin and foramen,anterior wall of maxil ary sinus and
zygomaticotemporal suture.
Orbital contents may herniate into maxil ary sinus.
CLINICAL FEATURES
1. Flattening of malar prominence
2. Step deformity of infraorbital margin
3. Anaesthesia in the distribution of infraorbital nerve
4. Trismus, due to depression of zygoma on the underlying
coronoid process
5. Oblique palpebral fissure, due to the displacement of lateral palpebral
ligament
6. Restricted ocular movements, due to entrapment of inferior rectus muscle. It
may cause diplopia.
7. Periorbital emphysema, due to escape of air from the
maxil ary sinus on nose blowing
DIAGNOSIS
Waters' or exaggerated Waters' view
Maxil ary sinus may show clouding due to the presence of blood.
Comminution with depression of orbital floor and herniation of
orbital contents cannot be seen on plain X-rays.
CT scan of the orbital wil be more useful
TREATMENT
Only displaced fractures require treatment. Open reduction and
internal wire fixation gives best results.
Fracture is exposed at the frontozygomatic suture through lateral
brow incision and reduced by passing an elevator behind
the zygoma. Wire fixation is done at frontozygomatic suture
and infraorbital margin. The latter is exposed by a separate
incision in the lower lid. Fracture of orbital floor can also be
repaired through this incision.
Transantral approach is less favourable.
Antrum is exposed as in Caldwel ?Luc operation, blood is aspirated,
fracture reduced and then stabilized by a pack in the antrum.
Fractures of orbital floor can also be reduced. Antral pack
is removed in about 10 days through the buccal incision,
which is left open at the end of operation, or through the
intranasal antrostomy route.
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This post was last modified on 11 August 2021