Title: A Case of Isolated Hemifacial Microsomia

Authors: Dr Abimanyu S

Co-authors :, Dr Joice Upendra kumar ,Dr Tukaram Dr Satyendra Raghuvanshi

Institution: Dept of Radiology, Command Hospital, Airforce, Bangalore, India

• A 5yrs old male child was referred for HRCT of temporal bone with a

clinical diagnosis left EAC atresia.

• The clinical assessment at radiology clinic revealed, that the patient was

second child in his family, born out of non consanguineous marriage.

There was no history of perinatal and post natal hypoxic insult, no family

history of congenital abnormalities and no history of a known terotogenic

drug intake by mother during the confinement.

Clinical examination

• On examination, there was no

developmental delay. The face

was asymmetrical and triangular

with Hypoplasia of left side. The

left external ear was hypoplastic

and malformed with no external

ear opening. A pre auricular tag

was present. (Written consent has

been taken from patient)

• Patient was unable to puff air in

his left cheek and appose his left

eyelids. However there was no

evidence of deviation of mouth

and he could frown his forehead.

This could be due to left lower

motor neuron type of facial

paresis or due to Hypoplasia of

left side of face.

HRCT

Coronal reformatted image at the level of EAC shows complete absence of EAC

Normal side Affected side

Coronal reformatted CT images at the level of TMJ reveal hypoplatic glenoid fossa and condyle of the mandible.

Normal side Abnormal side

Axial images at the level of middle ear shows. Hypoplastic middle ear cavity with absence of middle ear ossicles and atresia of EAC. Also note absence off mastoid aircells. Inner ear appears normal

Coronal reformatted image of left inner ear. There is depressed tegmen tympani because of hypoplastic middle ear canal. There is an abnormal anterior displacement of facial nerve. Inner ear

appears normal

Axial image showing hypoplastic medial and lateral pterigoid muscles, masseter and temporalis muscles

Volume rendered saggital image shows hypoplatic malformed mandible pseudo articulates with hypoplatic malformed zygomatic arch and absence of

glenoid fossa (Type II TMJ ).Also note absence of EAC.

Discussion

• In view of the above clinical and radiological features the following

differentials were considered:

1. Hemifacial microsomia

2. Golden har syndrome

3. Trechers Collins syndrome

• Additional imaging was done to confirm the diagnosis. MRI whole spine

revealed no segmental abnormality. Echocardiography was normal. This

ruled out the Golden har syndrome.

• Unilateral involvement, absence of family history of similar abnormality

and other ocular and nasal features of Treacher Collin syndrome were

absent. Thus establishing a diagnosis of Hemifacial Microsomia.

• Hemifacial microsomia is clinical spectrum of variable hypoplasia of

derivatives of 1st and 2nd branchial arches and this is the 2nd most common

congenital abnormality of face with an incidence of 1 in 3500 live births.

However it is an under diagnosed entity[1-3].

• This not genetic disorder and the proposed etiology is

hemorrhage/hematoma in 1st and 2nd branchial arches around 4th week of

intrauterine life[ 4 ]. This might occur due to a teratogenic drug intake by

the mother during early confinement[4 ].

Clinical and radiological features

• Three types of abnormalities can occur around temporomandibular joint.[ 5 ]

– Type I: Mild hypoplasia of the ramus

– Type II:

– Type IIA- The condyle and ramus are small with a normal temporo

mandibular joint

– Type IIB- Hypoplastic condyle and ramus, displaced towards midline, with a

flattened head of mandibular condyle, absent glenoid fossa with

psuedoarticulation of the temporo mandibular joint.

– Type III: The ramus is reduced to a thin lamina of bone or may be absent.No

evidence of a temporomandibular joint

Other skeletal abnormalities reported are[6&8]:

• There is descent of tegmen tympani which gives a gutter-shaped depression in

the floor of the middle cranial fossa. Maxilla is reduced in vertical height.[7]

• Zygoma is hypoplastic in all dimension or may be absent

• Orbit –Reduced size in all dimensions

• Hypoplastic mastoid process with partial / complete absence pneumatization

• Hypoplastic /absent styloid process

• Flattened frontal bone

• Ear abnormalities reported include[6&8]:

– Pre auricular skin tag.

– Atresia of external auditory canal

– Fusion of malformed hypoplastic malleus and incus to atretic lateral

wall

– Variable hypoplasia of ossicles

– Absence of ossicles

• Facial nerve abnormalities reported include:

– Absence of intracranial portion.

– Absence of brain stem nucleus

– Abnormal course of facial nerve- Anterior displacement of descending

tympanic portion

References

[1]Cohen M.M. Jr, Rollnick B.R., Kaye C.I.: Oculoauriculovertebral

spectrum: an updated critique. Cleft Palate Craniofac. J. 1989, 26, 276–

286.

[2] Dhillon M., Mohan R.P., Suma G.: Hemifacial microsomia: a

clinicoradiological report of three cases. J. Oral Sci. 2010, 52, 319–324.

[3] Monahan R., Seder K., Patel P., Alder M., Grud S., O’Gara M.: Hemifacial

microsomia: etiology, diagnosis and treatment. J. Am. Dent. Assoc. 2001,

132, 1402–1408.

[4] Poswillo D.: The pathogenesis of the first and second branchial arch

syndrome. Oral Surg. Oral Med. Oral Pathol. 1973, 35, 302–328.

[5] Pruzansky S.: Not all dwarfed mandibles are alike. Birth Defects 1969, 5,

120.

[6] Kane A.A., Lo L.J., Christensen G.E., Vannier M.W., Marsh J.L.:

Relationship between bone and muscles of mastication in hemifacial

microsomia. Plast. Reconstr. Surg. 1997, 99, 990–997.

[7] Peter .D.Phlebs :The petrous temporal bone ; Text book of radiology and

imaging ;David Sutton.2003,52,1604-1605

[8] Raymond W., Angelisa M. Paladin., Samson Lee. , Michael L.

Cunningham: Hemifacial Microsomia in Pediatric Patients:Asymmetric

Abnormal Development of the First and Second Branchial Arches. AJR

2002;178:1523–1530 0361–803X/02/1786–1523

Acknowledgements:

• Gp Capt A Alam,MD,DNB,Sr Adv and HOD, Department of Radiodiagnosis, Command hospital, Airforce Bangalore

• Col RA George,MD,DNB, Sr Adv, Department of radiodiagnosis, Command hospital, Airforce Bangalore

• Gp Capt H Sahni, MD,DNB,DM(Interventional and neuroradiology ) Sr Adv and HOD, Department of radiodiagnosis, Base hospital, Delhi

• Wg Cdr Samresh Sahu ,MD,DNB,Assistant professor ,Department of radiodiagnosis ,INHS ,Aswhni

• Wg Cdr Rohit Aggarwal .MD,DNB,Assistant professor ,Department of radiodiagnosis ,Command hospital, Airforce Bangalore

• Wg Cdr A Raheem .MD,DNB,Assistant professor ,Department of radiodiagnosis ,Command hospital, Airforce Bangalore