Transcript Radiographic interpretation of infection & trauma

RADIOGRAPHIC
INTERPRETATION OF
INFECTION & TRAUMA
Diagnostic imaging of
maxillofacial and fascial space
infections
Anatomical extent of the process
 Surgically drainable abscesses and fluid
collections
 Demonstrating and assessing associated
complications

Plain film examination
•
•
•
Periapical X ray
Panoramic radiograph : odntogentic infection
Anteroposterior and lateral view
: cervical soft tissue (airway)
submandibular, parapharyngeal,
retropharyngeal space (airway compromise)
Periapical X ray
Abscess adjacent to primary tooth
Anatomic location
Caries and periapical lesion
牙周病

除了牙周病外，尚有
何種疾病?
pericoronitis

Preoperative clinical
aspects. Proptotic left
globe, periorbital
swelling preventing
spontaneous opening
of the eye,
subconjunctival
ecchymosis, and
impairment of ocular
motility to the right
side

CT scan in axial view.
Maxillary sinus filled
with pus. Close
relationship between
upper molar root
apexes and maxillary
sinus (C). Intraoral view
of residual root of tooth
#26 affected by
extensive carious lesion
(D).
Sinusitis

Upper molars
Sinusitis (water’s view)
Prevertebral Space
Infection(lateral view)

X-ray neck P.A. View :
Showing severe acute
deviation of trachea
to Rt. side
Computed tomograph


3-dimensional picture
Gray scales :
more negative --- black
more positive --- white



CT readily assess the
integrity of cortical
bone
Short time required for
CT examination
Relative low cost
compared to MRI
Computed tomograph






CT numbers :
Hounsfield units(HU)
Air : -1000 HU
Fat : -80 to -100 HU
Water : 0 HU
Blood : 60 to 110 HU
Bone : 1000 HU
(A)
Sublingual space (long black
arrow), submandibular space
(long white arrow), mylohyoid
muscle (star), hyoglossus
muscle (black arrowhead). The
root of the tongue is
identified by the genioglossus
(black circle) and the lingual
septum (white arrowhead).
The lateral boundary of the
submandibular space is
formed by the fascial layers
on the medial margin of the
platysma muscle (dashed
white arrow).
•
•
(C) Inset: schematic of
coronal plane through
the oral cavity. The
shaded purple area
illustrates the horseshoe
shaped configuration of
the submandibular
space and the bilateral
continuity of the space
ventral to the mylohyoid
and anterior belly of the
digastric muscles.
•
(B) Coronal CT view at the
level of the oral cavity.
Sublingual space (long
black arrow),
submandibular space
(long white arrow),
mylohyoid muscle (star),
genioglossus (black circle),
and the lingual septum
(white arrowhead),
platysma muscle (dashed
white arrow), buccinator
muscle (curved arrow).
•
Schematic diagram of the
relationship of the tooth
roots to the sublingual,
submandibular, and buccal
spaces. Infection
extending through the
lingual cortex from
premolar and molar teeth
will involve the sublingual
space, whereas infection
from molar teeth will
involve the submandibular
space.
•
Submandibular space
abscess or phlegmon.
Axial contrast-enhanced
CT (A) shows a large fluid
collection within the right
submandibular space
(arrow), with thickening of
the buccinator muscle on
the lateral aspect of the
mandible and stranding in
the subcutaneous tissues
representing myositis and
cellulits respectively.

(B) Axial bone CT
shows an
endodontically treated
(root canal) second
molar root with apical
periodontitis (C).
Ludwigs angina
Ludwigs angina
•
Acute respiratory distress.
Axial (A) and coronal (B)
contrast-enhanced CTs
demonstrate extensive edema
and soft tissue thickening of
the tongue, sublingual, and
submandibular space seen
clinically as angioedema,
cellulitis, and hematoma. A
calcification lies within the
genioglossus muscle (arrow),
representing either a foreign
body or displaced sialolith
and is the likely initiating
factor.
Magnetic resonance imaging





3 D (以往CT只有2 D)
T1 image : good
anatomical detail
T2 image : very
sensitive in detecting
disease processes
T1 : fat, highly
proteinaceous tissue
T2 : water content
MRI
Sialolithiasis
•
Sialolithiasis. (A) Axial
contrast-enhanced CT.
Calcified sialolith in
Wharton's duct at the
junction of the superficial
lobe with the deep lobe
of the submandibular
gland. (B) Axial contrastenhanced CT from the
same patient in A. The
black arrow points to a
thickened and enhancing
wall of the dilated
submandibular duct..
Sialolithiasis
•
(C) Contrast-enhanced axial T1weighted MRI of a different
patient demonstrating a calcified
sialolith in left Wharton's duct
(arrow). (D) Axial T2 weighted
MRI of the same patient in C
showing the sialolith with
surrounding fluid (arrow). The
actual size of this stone was
approximately 20% smaller than
measured on the MRIs. Size
inaccuracies for sialoliths
generally would only affect
sialoendoscopic or interventional
retrieval or lithotripsy.
Radiographic interpretation trauma
Radiographic examination
Presence of root fracture
 Degree of extrusion or intrusion
 Presence of preexisting periapical disease
 Extent of root development
 Size of the pulp chamber and root canal
 Presence of jaw fractures
 Tooth fragments and foreign bodies lodged in
soft tissue

有幾處有 Fracture lines
Anatomic distribution of mandibular
fracture
Maxillary fracture


Infraorbital fracture
Lateral wall fracture
Waters view

Peri-oral soft tissue
avulsion and

Maxillary fractures,
comminuted
mandibular
ramus/body fractures
and bilateral condyle
fractures.
Le Fort midfacial fractures

3-D CT reconstruction
showing a Le Fort type
1 fracture
LeFort Fracture II
LeFort Fracture III
Zygomatic complex fracture
Zygomaticomaxillary arch Fracture
Submental-vertex view
The End