|Year : 2008 | Volume
| Issue : 5 | Page : 34-40
Hemifacial microsomia: A case report
R Kapur1, R Kapur2, S Sheikh3, S Jindal3, S Kulkarni3
1 Department of Pedodontia and Preventive Dentistry, MM College of Dental Sciences and Research, Mullana, District Ambala, Haryana 133 203, India
2 Department of Endodontics and Conservative Dentistry, MM College of Dental Sciences and Research, Mullana, District Ambala, Haryana 133 203, India
3 Department of Oral Medicine and Radiology, MM College of Dental Sciences and Research, Mullana, District Ambala, Haryana 133 203, India
Department of Pedodontia and Preventive Dentistry, MM College of Dental Sciences and Research, Mullana, District Ambala, Haryana 133 203
| Abstract|| |
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, involving underdevelopment of the temporomandibular joint, mandibular ramus, masticatory muscles and the ear. The affected ear may have an external soft-tissue malformation in addition to being lower set than on the contra lateral side. Hearing loss may result from underdevelopment of the osseous components of the auditory system and a diminished or absent external auditory meatus. Occasionally, second branchial arch defects involving the facial nerve and facial muscles coexist with Hemifacial microsomia. Radiographic examination in case of Hemifacial microsomia is of limited value because of superimposition of normal and abnormal bony structures. The skeletal and soft-tissue findings of a patient with Hemifacial microsomia who underwent three-dimensional computerized tomography is presented here to improve our knowledge and diagnostic skill of this uncommon entity.
Keywords: Hemifacial microsomia, hypoplasia, micropthalmia, microtia, three-dimensional computerized tomography.
|How to cite this article:|
Kapur R, Kapur R, Sheikh S, Jindal S, Kulkarni S. Hemifacial microsomia: A case report. J Indian Soc Pedod Prev Dent 2008;26:34-40
|How to cite this URL:|
Kapur R, Kapur R, Sheikh S, Jindal S, Kulkarni S. Hemifacial microsomia: A case report. J Indian Soc Pedod Prev Dent [serial online] 2008 [cited 2013 May 24];26:34-40. Available from: http://www.jisppd.com/text.asp?2008/26/5/34/41754
| Introduction|| |
Hemifacial microsomia is a developmental syndrome in which one side of the face is underdeveloped, usually including the bony jaws and overlying soft tissues; usually (but not always) the ear is involved (microtia).
Hemifacial microsomia is the second most common developmental craniofacial anomaly after cleft lip and palate and affects one of every 5600 live births. , More than 15 terms, including Goldenhar's syndrome and oculoauriculovertebral dysplasia, have been applied to this disease, with each term representing the perspectives of different specialists. Diagnostic imaging is important in the presurgical evaluation of patients with this anomaly; however, the broad spectrum of abnormalities encountered in patients with hemifacial microsomia can be confusing. 
The purpose of the present case report is to critically evaluate the radiological and clinical features of Hemifacial microsomia from the literature and to add one new case to improve our knowledge and diagnostic skill of this uncommon entity.
Hemifacial microsomia results from the abnormal development of the first and second branchial arches and the first branchial membrane. These arches are the mounds of tissue that contribute to the development of facial structures (cheek bones, upper and lower jaws and ear). Neural crest cells migrate to the developing arches and are responsible for the correct formation of these structures. Damage to, or disruption of, these cells result in the facial abnormalities of hemifacial microsomia and related syndromes. 
Although the general presentations of hemifacial microsomia--such as unilateral microtia, macrostomia, and hypoplasia of the mandibular ramus and condyle are well known, the effects on the teeth are not well-documented. Some studies have shown that the mesiodistal dimensions of the mandibular second primary molar and the mandibular permanent first molar teeth on the affected side in hemifacial microsomia were significantly smaller compared with those of normal teeth. Furthermore, in the maxillary and mandibular first permanent molars and the maxillary and mandibular first and second primary molars, the teeth in the apparently "normal" side of hemifacial microsomia were also significantly reduced in the mesiodistal dimensions. Comparison of overall dimensions revealed that all primary and permanent molars in hemifacial microsomia were significantly smaller in the mesiodistal dimensions compared with control teeth.  A general gradient effect was observed, with the most posterior tooth in each arch being the most severely affected and no effect being seen in the canines and the incisors. These findings suggest that the dental lamina in hemifacial microsomia is affected, and support the hypothesis that its pathogenesis involves an abnormality of the neural crest.
| Case Report|| |
A 5 year old male patient reported to the Department of Paediatric Dentistry, M.M. College of Dental Sciences and Research, Mullana, Ambala, complaining of pain in upper left second deciduous molar. Patient's mother also complains of asymmetry of patient's face and deafness and malformation of left ear since birth. Pain in the tooth was dull and intermittent in nature and more severe at night. History revealed that patient was surgically treated for torticollis of left side at the age of 1 year since he was not able to move his neck on left side. Magnetic resonance imaging scanning of brain and vertebrae was done which did not reveal any abnormality. There was no relevant history of congenital disorders in the family.
Extra oral: Face of the patient is bilaterally asymmetrical with deviation of lower jaw towards left side shifting the midline of mandible [Figure 1]. Left ear was small in size and aberrantly placed with presence of preauricular skin tags [Figure 2]. External auditory meatus on left side could not be traced. Left side of the face appeared to be flat. Palpatory findings on affected side revealed depressed temporal bone, absence of coronoid, condyle and muscles like masseter, temporalis, medial and lateral pterygoids. The Parotid gland seemed hypoplastic on the left side and fullness of cheek was absent on left side. There was no abnormality seen in eyes, nose, lips, ribs, neck movements and skin.
Intra oral: Intra oral examination showed high palatal vault [Figure 3]. Maxillary left deciduous second molar was carious. Maxillary deciduous left central incisor was missing with adequate contact between Maxillary deciduous right central incisor and left lateral incisor. Mesiodistal dimensions of mandibular left posterior teeth were less as compared to right side.
Then patient was subjected to Intra Oral Periapical radiograph in relation to 61 and 65, maxillary occlusal, left lateral oblique and panoramic radiography.
Intra Oral Periapical radiograph of 61 region revealed missing 61 and 21 with presence of 11, 12, 13, 22 and 23 [Figure 4]. Intra Oral Periapical radiograph of 65 revealed radiolucency in the coronal portion of 65 involving pulp suggestive of pulpitis. Maxillary occlusal radiograph revealed missing 61 and 21 with presence of 11, 12, 13, 22 and 23 [Figure 5].
Left lateral oblique and panoramic radiograph disclosed hypoplasia of ramus of mandible with missing coronoid process and condyle on left side [Figure 6],[Figure 7].
Computerized Tomographic Scan
To confirm the findings patient was sent to department of Radiology in Medical College where axial Computerized Tomographic Scan of face with 3-Dimentional reconstruction was done and Computerized Tomography of temporal bone was done to look for ear anomalies.
3-Dimentional Computerized Tomography Scan revealed complete absence of condyle and glenoid fossa [Figure 8] with hypoplastic ramus and coronoid process of left side [Figure 9]. It also revealed complete missing of temporalis muscle [Figure 10] with hypoplastic masseter and medial and lateral pterygoids muscles [Figure 10]. Hypoplasia of left parotid gland was seen [Figure 11]. There was evidence of bony cleft palate of right side [Figure 12]. Bony part of external auditory canal was completely atretic however cartilaginous part was seen with deformed pinna [Figure 13]. Middle ear was atretic. In left inner ear vestibule, vestibular aqueduct and internal auditory canal were dilated suggestive of vestibular deformity. Cochlea was normal [Figure 14]. There was evidence of otitis media on right side with bilateral sinusitis. Bilateral eye balls and optic nerves were normal [Figure 15],[Figure 16],[Figure 17].
| Discussion|| |
The term Hemifacial Microsomia was first used by Gorlin to refer to patients with unilateral microtia, macrostomia, and failure of formation of the mandibular ramus and condyle. ,, It is the second most common craniofacial malformation after cleft lip and palate. In the past, Hemifacial Microsomia has been the perview of various medical specialists, each preoccupied with 1 or 2 anatomic areas and each with a particular technical expertise. Reconstructive surgeons have struggled with the external ear anomalies, microphthalmia, soft tissue and muscle defects. Otolaryngologists have been concerned with hearing disorders, middle ear anomalies and airway obstruction. Oral surgeons and orthodontists have focused on occlusal and jaw abnormalities.
These specialists, all concerned with Hemifacial Microsomia , are beginning to work together in craniofacial teams. Prosthodontists also become members of craniofacial teams to offer expertise in prosthetic reconstruction of the external ear using craniofacial implants as a support or as a retention system for prosthetic rehabilitation.
Because of an extraordinarily wide range of phenotypic expression, various nomenclature are applied to Hemifacial Microsomia such as Goldenhar-Gorlin syndrome More Details, first arch syndrome, lateral facial dysplasia, unilateral craniofacial microsomia, otomandibular dysostosis, oculoauriculovertebral dysplasia, auriculo-branchiogenic dysplasia, and oculoauriculovertebral spectrum.
The etiology is unresolved and complicated. Teratogenic and genetic components have been examined by many investigators. Reports indicate that several teratogenic agents, such as retinoic acid, primidone, and thalidomide, have produced Hemifacial Microsomia in infants born to pregnant women exposed to those agents. Poswillo produced facial anomalies in laboratory animals by maternal intake of 10 mg/Kg thalidomide or 60 mg/Kg Triazene. He believed that either total or incomplete development of stapedial artery caused by an expanding hematoma could trigger a localized necrosis in the derivetives of first and second branchial arches which would cause Hemifacial Microsomia. Granstrom also induced microtia and other craniofacial defects in rats by injecting excessive dose of retinoic acid or etretinate to pregnant rats. Research is leading in the direction of a suggestion that the possible etiological factor could be disruption in the blood supply to the first and second branchial arches in the first 6-8 weeks of pregnancy. ,,,,
Though there is extreme variability of expression for Hemifacial Microsomia , it is especially recognized by facial asymmetry. This is due in part to absence, hypoplasia, and/or displacement of the pinna, but the degree of involvement is markedly variable. Maxillary, temporal, and malar bones on the involved side are somewhat reduced in size and flattened. Malformation of the external ear may vary from a complete aplasia to a crumpled, distorted pinna that is displaced anteriorly and inferiorly.
Occasionally, bilateral anomalous pinnas are noted. Approximately 40% of patients with microtia have varying degrees of the syndrome. Conduction deafness due to middle ear abnormalities and/or absence or deficiency of the external auditory meatus has been noted in 30% to 50% of cases. Supernumerary ear tags may occur anywhere from the tragus to the angle of the mouth.
Intraoral deformities include hyperplastic or aplastic teeth and enamel. Common oral manifestations of Hemifacial Microsomia include a significant delay of tooth development on the affected side, frequent absence of mandibular third molar on the affected side, and increased frequency of missing teeth on the affected side. The incidence of delayed tooth development with Hemifacial Microsomia is proportional to the extent of mandibular deformity. ,,,
Hypodontia is found particularly in the mandibular second premolars involving the affected side. Chalky opacifications of enamel are occasionally found on the maxillary central and lateral incisors of the underdeveloped side as a marker of development for Hemifacial Microsomia .
Patients may have minimal underdevelopment of the condyle to unilateral aplasia of the mandibular ramus and/or condyle with absence of the glenoid fossa; 50% to 70% of Hemifacial Microsomia patients have agenesis of the ramus on the affected side. The maxilla is narrowed on the involved side with decreased palatal width. Associated cleft lip and/or palate is found in 7% of Hemifacial Microsomia patients. Hypoplasia of facial muscles, such as the masseter, temporalis, pterygoids, and those of facial expression on the involved side has also been observed. Narrowing of the palpebral fissure occurs on the affected side in about 10% of patients. Clinical microphthalmia or anophthalmia has been reported and the ipsilateral eye may be at a lower level than that on the opposite side. Unilateral colobomas of the superior lid is a common finding. Skeletal alterations are other common anomalies of Hemifacial Microsomia ; 40% to 60% of Hemifacial Microsomia patients exhibit occipitalization of the Atlas More Details, cuneiform vertebra, cervical complete or partial synostosis of 2 or more vertebrae, supernumerary vertebrae, spinal bifida, and anomalous ribs. ,,,,
In the most severe cases of hemifacial microsomia there is underdevelopment of: the external and middle ear, the side of the skull, thickness of cheek tissue, the upper and lower jaws, teeth and some facial nerves.
The absence of certain cheek muscles or nerves, which supply those muscles, can result in an asymmetrical smile. Cheek tissue (fat and muscle) is often underdeveloped which makes one side of the face fuller than the other.
Ear deformities range from mild to almost a complete absence of the external ear. The ear canal is often absent or blind-ended (aural artresia). 
The goal of surgeries is to improve facial symmetry and functioning. ,,,, Due to growth and development issues, treatment can be broken down into age segments:
- Newborn : Vital functions - breathing, eating and sleeping must be assessed immediately. Once the airway is secure (in severe cases this requires a temporary tracheostomy), attention is paid to feeding to ensure that the infant can thrive (a temporary feeding tube may be required).
- 2-4 years : Mildly affected children require no treatment during this time. In those cases where the lower jaw (mandible) is severely underdeveloped, it is reconstructed using a rib bone graft or lengthened with a bone distraction device. Bone distraction requires only a short operation to insert the device with parents turning a screw at home to gradually lengthen the mandible. This is a painless process avoiding painful bone grafts and scarring.
Following lengthening of the mandible, the gap between the upper and lower teeth on that side requires an orthodontist to insert a retainer to allow the upper teeth to grow into the gap and contact the lower teeth. In this way, the mouth and teeth are leveled.
- 6-8 Years: Reconstruction of the external ear may take place in patients who are not severely affected. Severe facial asymmetry requires reconstruction of the jaw and cheekbone contour, delaying ear reconstruction.
- 8-10 Years : In terms of appearance, this is crucial time in the treatment program. Soft tissue and its blood supply from another part of the body (i.e. back or abdomen) are transferred to the cheek to create fullness.
- Teenage Years : Jaw surgery may be performed on those patients whose mild condition did not require it in early childhood. The lower jaw growth that occurs in adolescence may require those severely affected to undergo further surgery.
There is both pre- and post surgical orthodontic treatment as a result of surgical movement of the jaws.
This article would not be complete without a mention of Goldenhar syndrome. This is a variant of hemifacial microsomia which in addition to asymmetrical bone and tissue development of the face and microtia (missing or abnormally developed ear), features vertebral skeletal anomalies such as a form of scoliosis or defects of the cervical spine (neck). Moreover, children with Goldenhar syndrome display ear tags, benign tumors at the rim of the cornea that leads to astigmatism or lazy eyes and colobomas or missing eyelids.
Malformations of the spinal column that set this condition apart from other craniofacial syndromes include: open spine (spina bifida), fusion of the top of the spine to the lower edge of the skull, incomplete asymmetric spinal column development and more than the normal number of vertebrae. ,,
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