|Year : 2012 | Volume
| Issue : 3 | Page : 215-219
Prosthodontic rehabilitation of hemifacial microsomia
Laxman Singh Kaira1, Varun Singla2, Ashish Aggarwal3, HR Dayakara4
1 Department of Dentistry, Veer Chandra Singh Garhwali Government Medical Sciences and Research Institute, Srinagar Garhwal, Uttrakhand, India
2 Department of Prosthodontics, K D Dental College, Mathura, India
3 Department of Oral Medicine, Institute of Dental Sciences, Bareilly, Uttarpradesh, India
4 Department of Prosthodontics, Bapuji Dental College, Davangere, Karnataka, India
|Date of Web Publication||19-Feb-2013|
Laxman Singh Kaira
Department of Prosthodontic, Crown and Bridge and Maxillofacial Prosthestics, Institute of Dental Sciences, Institute of Dental Sciences, Pilibhit Bypass Road, Bareilly, Uttar Pradesh
Hemifacial microsomia, a developmental anomaly involving the first and second branchial arches, is one of the most common craniofacial anomalies. This disorder affects orofacial structures with varying clinical features. It is also associated with underdevelopment of the temporomandibular joint, mandibular ramus, masticatory muscles, ears, and occasionally defects in facial nerve and muscles. Physical deformities affecting face, ears, eyes, and oral cavity can pose esthetic and functional problems. The rehabilitation of these patients should be multidisciplinary including prosthodontic management as these patients present with complex clinical features. Treatment approach depends on patient's age, extent of physical and psychological deformity. The fabrication of auricular prosthesis is considered to be one of the most difficult replacements in maxillofacial rehabilitation. The severe undercuts and pronounced convolutions of the ear's surface present a challenge in simulating a natural proportioned prosthesis. This paper presents an outline in basic fabrication of prosthetic ear by conventional technique where the wax pattern is fabricated from the impression of an individual with a similarly proportioned ear.
Keywords: Ear prosthesis, goldenhar syndrome, hemifacial microsomia
|How to cite this article:|
Kaira LS, Singla V, Aggarwal A, Dayakara H R. Prosthodontic rehabilitation of hemifacial microsomia
. SRM J Res Dent Sci 2012;3:215-9
|How to cite this URL:|
Kaira LS, Singla V, Aggarwal A, Dayakara H R. Prosthodontic rehabilitation of hemifacial microsomia
. SRM J Res Dent Sci [serial online] 2012 [cited 2020 May 28];3:215-9. Available from: http://www.srmjrds.in/text.asp?2012/3/3/215/107407
| Introduction|| |
Hemifacial microsomia (HM) is considered to be the second most common congenital anomaly of face after cleft lip/palate. The incidence of HM is 1 per 5600 live births.  The female to male ratio is 2:3, and there is also a 3:2 ratio of right side versus left side involvement. ,, HM is a hereditary condition involving face, wherein the skull may be underdeveloped on the affected side. It may also show abnormalities of eye including dermoids or notches in the eyelid. The orbit can be small or may be entirely absent on the affected side. The face looks vertically shorter because the mandible on the affected side will be underdeveloped. The ear may be underdeveloped or even absent resulting in the defective hearing. 
There are different degrees of this condition namely craniofacial microsomia and Goldenhar syndrome. People with Goldenhar syndrome may also have neck problems; most commonly fusion of or bony ridges between bones of neck. Goldenhar syndrome is also called occulo-auricular dysplasia or OAV. 
Although 'Hemifacial' refers to one half of the face, the condition is bilateral in 31% of the cases, with one side being more affected than the other. ,, In 48% of the cases, the condition is a part of Goldenhar syndrome.  The clinical picture of HM varies from a little asymmetry in the face to severe under-development of one facial half with orbital implications, a partially-formed ear, or even a total absence of the ear. Auditory problems (conduction deafness) as a result of malformations in the middle ear and facial nerve dysfunction (temporal and zygomatic branch)  are very common in these patients; 30-50% of the patients have auditory problems. 
Intra-oral structures can also be affected in this condition: Agenesis of third molar and second premolar may be present on the affected side, as well as supernumerary teeth, enamel malformations, delay in tooth development, and hypoplastic teeth.  The masseter, temporal and pterygoid muscles, and the muscles of facial expression are hypoplastic on the affected side. The degree of under-development of the bone is directly related to the hypoplasia of the muscle, to which they are attached. 
Since hemifacial microsomia can cause physical and psychological deformity of individuals, treatment at early age can provide profounding results in overall growth and development. Syndrome's complex deformities correction requires multidisciplinary approach including prosthodontist, plastic surgeon, oral surgeon, and speech therapist.
| Case Report|| |
A 13-year-old female patient reported to the Department of Prosthodontics, Darshan Dental College, Udaipur, Rajasthan with the chief complaint of missing lower front teeth. History of presenting illness revealed that the patients had missing lower front teeth since birth. She also gave a history of congenitally missing left ear and was not able to hear from that side properly since birth. Medically history and the family history were non-contributory. On general physical examination, it was found that all the vital signs were within the normal limits. Extraoral examination revealed hypoplastic mandible. Also, the patient had a small ear tag on left side [Figure 1].
On examining the patient intraorally, all the teeth were present, except the mandibular central incisors. There was increased overjet and overbite. Other findings included high arched palate. Radiographic investigations confirmed the condition as hemifacial microsomia.
This patient was convinced for rehabilitation of ear defect with ear prosthesis. Treatment was initiated with psychological counseling and reassured treatment outcome regularly during treatment.
Fabrication of ear prosthesis
Diagnostic impressions of ear remnants were made using irreversible hydrocolloid material (Alginate, Zelgan 2002, Dentsply, India; batch no. Z090218) [Figure 2], and custom trays were fabricated with spacer with objective not to distort flabby remnant ear during final impression procedure. Final impressions were made using elastomeric impression material (Impregnum Penta Medium Body, Pearson Dental Supplies).
A donor with same size of unaffected ear was selected, and impression was made with putty elastomeric impression materials (Aquasil Putty, Dentsply, Germany; batch no. 0811003044) for preparation of wax patterns.
For the fabrication of the wax pattern, molten wax was poured in mould and retrieved after cooling. Wax patterns were adjusted according to remaining ears [Figure 3]. The patterns were fastened to ear band and tried on facial cast and then on the patient [Figure 4]. The patterns were finalized according to location, size, symmetry, and characterization. RTV silicone (Multisil RTV, SP Sai Biomed Mumbai, India) was used for the fabrication of prosthesis. After that, the wax patterns were invested in flask using stone (Gold Stone, Asian Chemicals, India; batch no. 309251/25) as investing medium [Figure 5].
Intrinsic stains (Stains, SP Sai Biomed Mumbai, India) were incorporated incrementally till the basic patient's skin tone was achieved [Figure 6]. Cotton fibers and rare earth pigments were added to first layer of silicone material to mimic rough surface and capillaries of a natural ear.  Colour distribution was done according to natural ears.
Prosthesis was luted with the spectacle (with zero number glasses), which was given to the patient, and ear band using cynoacrylate prosthesis was tried on patient's face. Extrinsic staining was done using artist's oil color (Camel Artist's Oil Colour, Camlin Ltd., Mumbai, India), and final modifications were made. Patient was instructed about the limitations, use, and maintenance of prosthesis [Figure 7]. Patient was happy with the prosthesis and at post-insertion appointments, it was noticed that the patient had trimmed her long hairs, which she used to keep hiding ear deformity.
| Discussion|| |
Hemifacial microsomia is mostly unilateral (70%) and always asymmetrical if it exhibits bilaterally.  The clinical picture of HFM varies from slight asymmetry in the face to severe underdevelopment of one facial half with orbital implications, a partially formed ear, or even total absence of the ear.  Sensorineural hearing loss and facial nerve dysfunction are common in HFM. Auditory problems are present in 30-50% of patients.  Patient may need a hearing aid at an early age depending on severity of hearing loss. The BAHA (Bone Anchored Hearing Aid) is considered to be a better device than the conventional hearing aid because it provides support and retention for the hearing aid, has less skin irritation, and is esthetically pleasing.  The sounds children recognize in first year of development are important for speech development. Previously, it was believed that children with hemifacial microsomia have lesser intelligence, but later, it was found to be associated with hearing problem. Children who are treated at early age with hearing aids were as intelligent as other children.
There are 4 grades of microsomia
Grade 1: A slightly small ear identifiable structures and a small but present external ear canal.
Grade 2: A partial or hemi ear with a closed off or stenotic external ear canal producing a conductive hearing loss.
Grade 3: Absence of the external ear with a small peanut vestigial structure and an absence of the external ear canal and ear drum.
Grade 4: Absence of ear or anotia. The most common type is grade III. 
Treatment options for hemifacial microsomia includes surgical, orthodontic, and prosthetic treatment.
Hemifacial microsomia is a progressive skeletal and soft tissue deformity with the earliest skeletal manifestations in mandible. The hypoplastic mandible interferes with normal downward growth of the maxilla and is consistent with asymmetrical skeletal growth. Mandibular distortion becomes worse and produces secondary deformation of the maxilla, nose and orbit as the contralateral side grows. Thus, correction of the mandibular abnormality in childhood establishes a more 'functional matrix' for symmetric mid-facial growth and unlocks the growth potential of the adjacent structures, minimizing secondary deformity, and improves function and appearance. , Principles of timing for surgical reconstruction of facial deformity are based on age, severity, and psychologic considerations. For severe deformity, such as orbital dystopia, osteotomies can be conducted from the age of 2 and onward.  The surgical reconstruction of ear results in morphology that is less similar to opposite ear because of its complex nature and is considered to be one of the most demanding challenges for a plastic surgeon.  The different options for auricular reconstruction includes rib graft reconstruction- since implant is patients own living cartilage, the ear continues to grow as the child does. This is preferred after age six so that rib is large enough to provide the donor material necessary. Also, reconstruction of ear can be done using med por polyethylene plastic implant. 
The prosthetic involvement in providing a patient with an implant-retained auricular prosthesis can be considered in 2 stages: Pre-surgical and post-surgical phases; clinical and laboratory procedures are given in [Table 1]. There to 4 months between implant placement and final prosthesis fabrication are required for osseointegration. 
Prosthetic ears appear very realistic and require few minutes of daily care. They are made of silicone, which is colored to match the individual color of the skin and are attached using adhesives or implants to which magnets or bar clips are used. The optional age to start wearing a prosthesis is 6-9 years.  Now new techniques are being used for creating auricular prosthesis with a computer-aided design/Manufacture (CAD-CAM).  Rehabilitation of presented case with ear prosthesis showed significant improvement in patient's social life. Patient had overcome problems of interaction, social life and had begun going to school, and her self-confidence was increased. The results of presented case show role of maxillofacial rehabilitation in achieving and improving affected individual's psychology.
Children from the ages 5 to 12 are considered at a higher risk for complications because of thinner and softer emporal bones and are at an increased risk for a disruptive accident injury. Tjellstrom reported that during placement of craniofacial implants for hearing aids, 12% were in contact with the duramater, the wall of the sigmoid sinus was seen at the bottom of the implant site in another 12%, and mastoid air cells were seen in 25%. Children with severe craniofacial defects pose special problems relative to the implant site because of aberrant facial nerve course, low middle cranial fossa dura, and small mastoid. Placements of implants in areas of bone resorption may decrease the functional life of implants during active craniofacial growth in HFM patients. Moreover, long-term stability of implants may be further compromised at puberty when the mastoid air cells undergo their greatest development. ,,
Autogenous ear reconstruction with cartilage remains a technical challenge for the plastic surgeon because of the intricate configuration of a human ear. Technology for tissue-engineered generation of new bone, cartilage, and liver offers great potential for improving the outcome of tissue regeneration. Tissue engineering is defined as a science, in which the material properties of synthetic compounds are manipulated to enable formation of new functional tissue. ,
| Conclusion|| |
In spite of all the latest techniques being available, many of these treatments are unaffordable to most of patients. An alternative cost-effective but at the same time cosmetically acceptable treatment materials are necessary so that many of the patients who do not come forward for treatment can't be targeted for rehabilitation. With latest technologies like rapid prototyping, implant-retained prosthesis, one can enhance quality of rehabilitation, but rehabilitation at earlier age with removable prosthesis can be of psychological benefit improving affected quality of life.
| Acknowledgment|| |
The Author would like to thank the patient for providing consent to use her photograph in this article.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7]