Transcript Imaging OF OTOMANDIBULAR DYSPLASIA: ABOUT 10 CASES

A.Ben Abdallah, K.Mrad Dali, M.Omezzine*, I.Chaabani, N.Mama, K.Kadri,
H.Moulahi, K.Tlili
Radiology service, Sahloul Hospital
*MaxilloFacial surgery service, Sahloul Hospital
HN14
INTRODUCTION
Otomandibular dysplasia is a condition in
which the lower half of one side of the face is
underdeveloped and does not grow normally.
 It is sometimes also referred to as hemifacial
microsomia, first and second brachial arch
syndrome, oral-mandibular-auricular
syndrome, lateral facial dysplasia,
or otomandibular dysostosis.
 The syndrome varies in severity, but always
includes the underdevelopment of the ear
and the mandible. This is the second most
common facial birth defect after clefts

OBJECTIVES
To illustrate the imaging aspects of otomandibular dysplasia through a study of
10 cases.
 To highlight the contribution of imaging
in the preoperative assessment of the
lesions of oto-mandibular dysplasia.

PATIENTS AND METHODS
Retrospective study about 10 pediatric
cases
 7 boys and 3 girls,
 Aged from 5 months to 10 years old.
 All patients underwent a computed
tomography scan (CT).

RESULTS








CT revealed skeletal anomalies in all cases
variable mandibular hypoplasia (n=10) (table1)
temporo-mandibular joint anomalies (n=8)
zygoma hypoplasia (n=6)
pterygoid hypoplasia (n=4)
Soft tissue anomalies (table3): muscle
hypoplasia were observed in 7 cases and
parotid gland hypoplasia in 3 cases and
agenesic in 3 cases
Hypoplasia of the tympanic cavity was present in
7 patients whith ossicular anomaly in 6 cases.
Other craniofacial anomalies was seen (table2).
Table 1
Mandible anomalies
Ascending
ramus
hypoplasia
10
Mandibar
condyle
7
Maxillar
anomalies
TM joint
deformity
8
Reduced
hight
Ear malformations
External meatal
Middle ear cavity
atretic
hypoplasia
2
hypoplasia
6
4
absent
7
ossicles
atretic
1
Aberrant
course of
the facial
nerve
hypoplasic
1
malformed
6
2
3
Others craniofacial anomalies
mastoid
hypoplasia
Number
Zygomatic
arch
hypoplasia
3
6
Styloid
Process
hypoplasia
3
Orbit anomalies
Table 2
2
Soft tissus anomalies
Number
Mastication muscles hyploasia
Parotid gland
masseter
hypoplasia
8
temporal
7
pterygoid
7
3
absent
3
present
4
Table 3
Case n°1:
A 2 years old boy
e
a
b
f
(c,d) coronal CT scan shows
pterygoid process hypoplasia (red arrow),
abnormal right TM joint (arrows) with dysplastic
condylar process
(e,f) axial CT scan shows hypoplactic
c
d
(a,b) 3D bone reconstruction
middle ear cavity (arrowhead) with atretic
ossicles and external meatal atresia (arrow).
reveal mandibular ramus,condyle
and coronoid process hypoplasia, zygomatic arch hypoplasia (blue arrow)
styloid hypoplasia ( yellow arrow) and reduced high of the maxillar (*)
Case n°1
c
a
b
Coronal (a,b) and axial (c,d) CT scan show
hypoplasia of muscles of mastication: masseter (arrowhead),
temporal (red arrow) and pterygoid (yellow arrow). It shows also
agenesis of the parotid gland
d
Case n°2: 8 year old boy who had malformed left external ear since birth.
(a)3D bone
reconstruction
shows left
mandibular and
maxillary severe
hypoplasia (*)with
hypoplastic
zygoma arch
(arrow).
a
b
c
(b,c) CT scan show
an absent condylar
process, hypoplastic
condyle with abnormal
TM joint (arrow) and
hypoplastic pterygoid
process (arrowhead)
(d) axial CT scan
d
e
f
(e,f) axial CT scan reveal soft-tissu anomalies: hypoplastic masseter, temporal
and pterygoid muscles (arrows) and hypoplastic parotid gland (*).
reveal external meatal
atresia, agenetic
middle ear with
hypoplastic and
unpneumatized
mastoid.
Case n°3: A 11 years old boy
(a,b) coronal CT scan and 3D bone
reconstruction: hypoplastic mandibular
condyle with TM joint dislocation (arrow).
b
a
e
(e)axial CT scan shows minor muscles
hypoplasia (arrow) with normal parotid
gland.
c
d
Coronal (c) and axial(e) CT scan: agenesis of external meatal, hypoplastic
middle ear cavity, malformated ossicles (arrow) and hypoplastic
and unpneumatized mastoid (*).
Case n°4: A 9 years old boy
Axial CT scan (a,b) and 3D bone reconstruction
(c,d): mandibular condyle hypoplasia (arrow) with
normal ramus. There is an external meatal agenesis and
hypoplastis ossicles (arrowheads).
(e,f) axial and coronal CT scan show
masseter,pterygoid and temporal
muscle hypoplasia (arrows)with hypoplastic
parotid gland (*)
Cas n°5: A 6 years old boy
a
b
3D bone reconstruction shows a more
dramatic appearance of asymmetric hypoplasia
of the mandible and hypoplastic zygomatic arch
(a,b) CT scan reveals hypoplastic external
meatal , middle ear cavity and ossicles (arrows)
(c,d) axial CT scan shows musles
of mastication hypoplasia (arrows)
agenesis of parotid gland (*)
c
d
Case n°6: A 10 years old boy
b
a
c
CT scan and 3D bone reconstruction show
a left hemifacial microsoma which associate
hypoplastic ramus (c,e) , mandibular condyle
(b) with anomaly of TM joint (b) , hypoplastic
pterygoid process( a) and zygomatic arch (e).
d
e
Case n°6
a
b
e
(e) axial CT image shows masseter muscle
hypoplasia with hypoplastic parotid gland
c
d
( a,b,c,d) axial and coronal CT images reveal agenesis of external meatal (yellow arrow)and middle ear
constituents (red arrows) and show an aberrant course of the 3rd portion of facial nerve (arrowhead)
DISCUSSION
Hemifacial microsomia is a congenital
malformation in which there is a deficiency in
the amount of hard and soft tissue on one side
of the face. It is primarily a syndrome of the first
branchial arch,
 It a syndrome involving underdevelopment of
the temporomandibular joint, mandibular ramus,
masticatory muscles and the ear
 There may be cardiac, vertebral, and central
nervous system defects, in addition to
craniofacial anomalies.

Discussion
Otomandibular dysostosis (OMD) is the
second most common congenital facial
anomaly after cleft lip/palate with a
reported incidence of about 1 in 5600
live births.
 Males appear to be more frequently
affected than females (7 boys for 3 girls
in our study).
 It is usually unilateral (70%) and always
asymetrical if it exhibits bilaterality.

Discussion
The phenotype is highly variable
 The clinical picture varies from slight
asymetry in the face to sever
underdevelopment of one face half with
orbital implications, a partially formed ear
or even total absence of the ear.
 In 48% of the cases, the condition is a part
of a larger syndrome such as Goldenhar
Syndrome (when epibulbar dermoids and
vertebral anomalies are seen along with
other findings of HFM)

Discussion
A panoramic radiograph provides an excellent
overview of the osseous structures of the
mandible and maxillofacial complex.
 The relationship of the mandible and maxilla to
the cranial base can be established initially with
a lateral cephalometric radiograph.
 Computed tomography (CT) can provide both a
three dimensional rendition of the soft tissue
and an image of the under lying bone
 Information on comparative muscle
development can be assessed through CT or
magnetic resonance imaging on a case by
case basis.

Imaging findings: Craniofacial anomalies
1-Mandible
 The most obvious skeletal deformity (all our
cases),
 The ascending ramus can be absent or reduced
in height. It was the most common anomaly in
our study,
 The chin is deviated towards the affected side
 The mandibular condyle may be hypoplastic
and malformed
 The TM joint deformity can range from mild
hypoplasia of the codyle with normal joint
anatomy to a grossly disorganized joint anatomy
and pseudo-articulation of the condyle at the
cranial base.
Craniofacial anomalies
S. Pruzansky’s mandible
hypoplasia classification
Grade I: minimal hypoplasia of mandible
Grade II: functioning but deformed TM joint with anteriorly and mdially dispalced
condyle
Grade III: absence of the ramus and glenoid fossa
Craniofacial anomalies
2-Maxillar
 Is also reduced in height, present only in 2 cases in our
study
 Eruption of mandible and maxillary molllars is delayed
3-Ear
 The meatal atresia and middle ear anomalies are
almost constant findings (from 66 to 99%) (all cases),
 The external ear malformations vary from complete
aplasia to a crumpled, distorted pinna along with ear
tags
 Supernumerary ear tags may occur anywhere from the
tragus to the angle of the mouth.
 Middle ear cavity is small and ossicles may be absent,
hypoplastic and/or malformed
 The mastoid is always hypoplastic and unpneumatized
Craniofacial anomalies
4-Other craniofacial bones anomalies
 The zygoma arch may be decreased in
length or absent (60% in our study)
 The mastoid process can be hypoplastic
 The styloid process may be short or
absent , present in only 3 patients
 The orbit may be reduced in dimensions
and frontal bone can be flattered
 Clinical microphthalmia or anophthalmia
has been reported and the ipsilateral
eye may be at a lower level than that on
the opposite side.
Craniofacial anomalies
5-Extraskeletal anomalies
 Hypoplasia of facial muscles, such as the
masseter, temporal, pterygoid, and those of
facial expression on the involved side can be
observed (80% in our study)
 Hypoplasia or aplasia of the parotid gland
 Narrowing of the palpebral fissure occurs on
the affected side in about 10% of patients
 A coloboma of the upper eyelid is frequently
encountered
 Associated cleft lip and/or palate is found in
7% of patients
Craniofacial anomalies
Epibulbar dermoids may be seen in
Goldenhar Syndrome
 Hypoplasia and / or paresis of palatal
muscles and pharynx, alongwith tongue
musculature is also reported
6-Cranial nerve anomalies
 Sensorineural hearing loss and facial
nerve dysfunction are common
 Aberrant course of the facial nerve,
 Total or partial hypoplasy of the nerve.
 Only 3 patients have aberrant course of
the facial nerve without nerve paralysis.

Imaging findings: Extrafacial anomalies
Cranial CT scan can revel hypoplasia of
cerebrum and corpus callosum as well as
hydrocephalus
 Approximately, 50% of patients have
congenital heart disease
 40% to 60% of HFM patients exhibit
occipitalization of the atlas, cuneiform vertebra,
cervi cal complete or partial synostosis of 2 or
more vertebrae, supernumerary vertebrae,
spinal bifida, and anomalous ribs.
 No extrafacial anomalies were seen in our
study

Imaging findings: classification

The wide spectrum of anomalies
associated with HFM has made systematic
and inclusive classification difficult.
Classification of the disease aids in
diagnosis, treatment planning, prognostic
predications, and data evaluation.

the 2 popular classification systems used
for HFM, namely, the skeletal, auricular,
and soft tissue (SAT) system, and the orbit,
mandible, ear, nerve, and soft tissue
(OMENS) system.
Skeletal categories
Auricle categories
Soft tissue categories
S1 = Small mandible with
A0 = Normal
T1 = Minimal contour defect with
normal shape
no cranial nerve involvement
S2 = Condyle, ramus, and
A1 = Small, malformed
T2= Moderate defect
sigmoid notch identifiable but
grossly distorted; mandible
strikingly different in size and
shape from normal
auricle retaining characteristic
features
S3 = Mandible severely
A2 = Rudimentary auricle
T3 = Major defect with obvious
malformed, ranging from poorly
identifiable ramal components to
complete agenesis of ramus
with hook at cranial and
corresponding to the helix
facial scoliosis, possible severe
hypoplasia of cranial nerves, parotid
gland, muscles of mastication; eye
involvement; clefts of face or lips
S4 = An S3 mandible plus
A3 = Malformed lobule with
orbital involvment with gross
posterior recession of lateral and
inferior orbital rims
rest of pinna absent
S5 = The S4 defects plus
orbital dystopia and frequently
hypoplasia and asymmetrical
neurocranium with a flat
temporal fossa
The skeletal, auricle, and soft tissue (SAT) classification system of HFM
Orbit
Mandible
Ear
Facial nerve
Soft tissue
O0 = Normal
M0 = Normal
E0 = Normal ear
N0 = No facial nerve
S0 = No obvious soft
involvement
tissue or muscle
deficiency
orbital size
position
mandible
O1 = Abnormal
M1 = Mandible and
E1 = Mild
N1 = Upper facial nerve
S1 = Minimal
orbital size
glenoid fossa are
small with a short
ramus
hypoplasia and
cupping with all
structures present
involvement (temporal
and zygomatic branches)
subcutaneous/muscle
deficiency
N2 = Lower facial nerve
S2 = Moderate between
involvement (buccal,
mandibular, and cervical
branches)
the 2 extremes,S1 and
N3 = All branches of
S3 = Severe soft tissue
M2 = Mandibular
ramus is short and
abnormally shaped
Subdivision A and B
are based on relative
positions of condyle
and TMJ
M3 = Complete
absence
of ramus, glenoid
fossa, and TMJ.
Submental vertex
views were used
to distinguish
mandibular type 2A
from type 2B.
Type O, an apparently
normal mandible has
not been included in
previous classification
systems
facial nerve affected.
Other involved nerves
were also analyzed, eg,
trigeminal N5 (sensory),
hypoglossal N12;
remaining cranial nerves
are signified by the
appropriate number in
superscript
S3
deficiency due to
subcutaneous and
muscular
hypoplasmia
The orbit, mandible, ear, facial nerve, and soft tissue (OMENS) classification system of HFM
CONCLUSION
The modern imaging opened a possibility of
precise exploration of oto-mandibular
dysplasia
 The techniques of browsing by CT scan and
the software of image processing allow to
carry out a true anatomical dissection of the
whole of these malformative syndromes
 The SAT and OMENS classification systems
allows to delineate the condition of OMD to
provide a rational basis for treatment choice.
