|Year : 2022 | Volume
| Issue : 3 | Page : 300-304
Bridging form and function: A bilateral auricular prosthesis
Ayush Srivastava, Ranjoy Hazra, Dinesh Kumar
Department of Prosthodontics and Crown and Bridge, Army Dental Center (Research and Referral), New Delhi, India
|Date of Submission||14-Dec-2021|
|Date of Decision||17-Apr-2022|
|Date of Acceptance||18-Apr-2022|
|Date of Web Publication||18-Jul-2022|
Department of Prosthodontics and Crown and Bridge, Army Dental Center (Research and Referral), New Delhi - 110 010
Source of Support: None, Conflict of Interest: None
Unfortunate loss or absence of an ear has a far-reaching impact on an individual psyche. Auricular defects are seen commonly due to trauma, congenital abnormalities, and malignancies which result in disfigurment of the pinna. Rehabilitation of an auricular defect with a custom-made auricular prosthesis improves social acceptance and self-confidence in an individual. Auricular defects present reconstructive challenges, especially if they are bilateral. Surgical reconstruction provides effective results for defects; however, for some patients, surgical intervention is contraindicated. This case report describes an innovative technique to rehabilitate patients with auricular defects with mixed hearing loss and bilateral microtia using a multidisciplinary approach. The patient was provided with a functional auricular prosthesis. The prime purpose of the treatment rendered was to restore the lost auricular structure to the patient's satisfaction comfortably and cost-effectively. An early rehabilitation promotes physical as well as psychological healing of the patient.
Keywords: Auricular prosthesis, bone-anchored hearing aid, microtia
|How to cite this article:|
Srivastava A, Hazra R, Kumar D. Bridging form and function: A bilateral auricular prosthesis. J Indian Prosthodont Soc 2022;22:300-4
|How to cite this URL:|
Srivastava A, Hazra R, Kumar D. Bridging form and function: A bilateral auricular prosthesis. J Indian Prosthodont Soc [serial online] 2022 [cited 2022 Dec 7];22:300-4. Available from: https://www.j-ips.org/text.asp?2022/22/3/300/351286
| Introduction|| |
It is the God-given right of every human being to appear human. Few areas of prosthodontics offer more challenges to the technical skills or higher satisfaction for the rehabilitation of function and esthetics in the patient with widespread anatomic defects and deformities of the maxillofacial region. Although there have been remarkable advances in the surgical management of oral and facial defects, satisfactory repair by plastic surgery alone is mostly a compromise. Hence, the demand for maxillofacial prostheses for the rehabilitation of such patients has intensified in the recent years.
In today's image-conscious society, quality of life is severely compromised by physical defects, especially involving the orofacial region. Auricular defects range from minor deformities to complete anotia, due to congenital or acquired reasons. Prosthetic reconstruction has evolved into becoming an established alternative to techniques using autogenous tissues. Requirements of an ideal prosthesis are esthetics, retention, stability, correct alignment and positioning, biocompatibility, and longevity.
| Case Report|| |
A 5-year-old daughter of a serving soldier was referred to the department of prosthodontics from the department of ENT with a chief complaint of deformed ears on both sides since birth. Medical history elicited reduced hearing and delayed speech since birth. The parents had a nonconsanguineous marriage and neither her twin brother presented with similar complaints. On general examination, the patient was moderately built and nourished, and she was well oriented to time, place, and person. The face was bilaterally symmetrical and her complexion was fair. Investigative neurosensory tests and tuning-fork tests were conducted to screen for conductive hearing loss; brain-evoked response auditory was carried out to identify hearing impairment in the child, and it evaluates the auditory nerve response to different sounds. High-resolution computed tomography was carried out to check the suitability for surgical intervention if required. All the investigative tests suggested a bilateral conductive hearing loss.
Based on the observations and investigations, a diagnosis of bilateral congenital microtia with grade two microtia with respect to the right ear and grade three with respect to the left ear with aural atresia was made [Figure 1]. We along with the department of ENT formulated a five-phase treatment plan where phase one included patient education and motivation, phase two included fabrication of a silicon prothesis, phase three included provision of removable bone-anchored hearing aid (BAHA), phase four included the incorporation of this BAHA within the prosthesis, and phase five were the follow-up and maintenance phase. A dual-mode of retention was planned to utilize the redundant tissue as well as the hairband.
Clinical and treatment report
The patients' twin brother was selected for the donor impression [Figure 2], considering the same age and average facial measurements. Petroleum jelly was coated on the hair and tissue adjacent to the ear and a cotton plug was placed into the ear canal. The irreversible hydrocolloid (Zelgan 2002; Dentsply, Delhi) impression of both donor and patient was made by utilizing modified impression trays consisting of a plastic bowl and cup [Figure 3]. The impressions were poured in Type IV die stone (Kalabhai Karson, Mumbai). A wax pattern was fabricated from the donor impression. The prepared wax pattern was then adapted to the respective defect sites on the patient's cast. Orientation lines were marked on the patient's face and the wax pattern was tried on for the verification of fit, angulation, dimension, and esthetics [Figure 4]. Silicone shade matching was carried out using the trial and error method. The wax pattern was flasked using the three-stage pour technique. The first pour was for the base layer. After the separating medium was applied, the second pour was done on the concave surface of the ears. The counter pour, i.e., the third pour, was done after the separating medium was applied. After every pour, orientation grooves were made to enable re-positioning of all the components. Once the entire assembly was set, dewaxing was done. It was ensured that there was no residue of wax or it would interfere with the vulcanization of silicone rubber. A hollow plastic sleeve was incorporated into the mold before packing, behind the helix using cyanoacrylate for the attachment of the headband [Figure 5]. Incremental packing of the heat vulcanized silicone (Technovent Pvt. Ltd) was done for the prevention of incorporation of voids. This was followed by clamping to remove the flash. This was then processed at 100° centigrade temperature for 1 h as per the manufacturer's instructions. The silicone prosthesis was retrieved and thoroughly cleaned using acetone [Figure 6], followed by trimming, adjustment by rubber trimmers, and impartment of fine detailing by extrinsic staining.
The hairband was adjusted according to the patient's head circumference till a uniform close fit was achieved and inserted into the plastic sleeve attachment of the prosthesis [Figure 7]. The assembly was then tried on. The BAHA Softband was developed by the Entific Company. It comprises an elastic band with a plastic snap connector as coupling mechanism for a standard BAHA. The snap connector disc is pressed against the skin of the head at a bony location, such as the mastoid or the forehead. Conventionally, this assembly comes attached with a soft elastic head band as supplied by the company, but the processor assembly can be detached as in our case from the elastic band and placed at a specific location from where bone conduction can take place. The BAHA sound processor assembly was attached to the prosthesis metallic headband by crimping it with universal pliers in between its loops at the location suggested by the ENT department [Figure 8]. The evaluations were performed with verbal speech and language tests, by the ENT specialist with only this assembly in place.
|Figure 8: Hairband adjustment and BAHA incorporation. BAHA: Boneanchored hearing aid|
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Once it was approved, the BAHA incorporated hairband was attached to the patients' soft headband using cyanoacrylate resin segmentally for concealing the BAHA as well as the hairband [Figure 9]. The patient was shown the preoperative and postoperative comparison photographs [Figure 10]. Posttreatment instructions were given to the parents for the maintenance of the prosthesis.
The patient was recalled for review visits at 3 days, 1 week, 3 weeks, and 2 months. The prosthesis assembly was well maintained by the patient, the parents informed that the patient was progressively getting better adapted to the prosthesis, and the response to voiced commands significantly improved apart from the aesthetics.
At the 2-month visit, the button cell of the BAHA processor was replaced by gently stripping the soft head band from the metal hair band substructure. The parents brought a new variety of headband, which they wanted to get replaced. The batteries and headband were replaced and prosthesis was returned to the patient.
| Discussion|| |
Auricular defects may occur due to hereditary or developmental causes. The congenital defects may arise due to anomalies of the 1st and 2nd branchial arches which result in anotia or microtia. In microtia, the external auditory canal is absent and the presence of a small remnant of deformed cartilage, whereas the absence of the whole ear is called anotia. Treacher Collins syndrome and Goldenhar's syndrome are the most common syndromes associated with the same. Among others, bilateral absence of the ear is seen in <10% of all cases.
The classification of Weerda combines the suggestions of various authors and provides an overview based on the increasing levels of deformity and the necessary surgical intervention.
In Grade I malformations, most structures of the normal auricle are present. The examples include prominent ears, macrotia, cryptotia, cleft ear, moderate cup ear deformities, earlobe deformities, and other minor auricular deformities. Grade II includes severe cup ear deformities and the mini ear (concha type microtia). Some of the ear structures are extant but, for a complete reconstruction, additional skin and/or cartilage are needed. In Grade III, none of the normal structures are present. This group includes unilateral or bilateral rudimentary auricle and anotia. In particular, Grade III dysplasia is often associated with the changes in the external auditory canal including aural atresia, malformations of the middle ear, and sometimes even dysplasia of the petrous bone with facial anomalies and the facial nerve being affected on the ipsilateral side. In such cases, additional skin and cartilage or other materials are required for total reconstruction.
In very young children with bilateral congenital aural atresia, surgical intervention is not an option and bone-conduction hearing aids have proved to be the only effective treatment. Conventional bone conduction hearing aids are not popular because there are several major drawbacks. The BAHA is known to be more comfortable to wear and it is highly efficient in audiological terms. To offer them the advantage of bone-conduction hearing without the disadvantages of conventional bone-conduction hearing aids, the BAHA Softband was developed.
Extensive surgical procedures may sacrifice a large part of anatomic retentive features which compromises retention of the maxillofacial prosthesis.
Various means of retention can be categorized into:
- Anatomical anchorage - by utilizing tissue undercuts/concavities
- Mechanical anchorage - by external devices such as eyeglasses, headbands or straps, stud clips, snap buttons, magnets
- Chemical anchorage - with adhesives
- Surgical anchorage - with implants.
Our algorithm for treating the congenital auricular deformity was to provide for the hearing ability first and to manage the esthetics as well. After that, we discussed with the parents, the different methods for rehabilitation. Prosthetic restoration of maxillofacial defects has always been limited by the unavailability of adequate materials. Although there is a spectacular improvement in material sciences and technologies, the quest for the ideal material that resembles or duplicates human skin is still on.
Deformities of the external ear can affect psychosocial well-being and hearing. The current gold-standard reconstructive treatment is autologous costal cartilage grafting despite the vast morbidity profile. Tissue engineering using stem cells and 3D printing can create patient-specific reconstructed auricles with superior cosmetic outcomes and reduced morbidity. However, surgery is not always the solution keeping a multifactorial outlook for the treatment and weighing the merits and demerits. The progress made in the development of the silicones as well as percutaneous titanium implants allow for rehabilitation of patients with microtia with an inconspicuous camouflage that most patients desire. Auricular prostheses may be used as a rescue procedure in failed auricular reconstruction or as a definitive treatment option.
Digital technology improves the clinical outcome of maxillofacial prostheses by increasing fabrication accuracy, reducing treatment time, and facilitating a replacement prostheses in the future. A facial scanner can be used to acquire overall facial data. However, an intraoral scanner is more suitable for recording detailed surface data. In addition, the combined use of a facial and intraoral scanner can produce a prosthesis with accurately reproduced skin texture. One of the drawbacks is the inability of the digital scan to record functional movements which can lead to instability of the facial prosthesis and poor adaptation to the bed tissue during function. Rapid manufacturing has not been routinely used because of the unavailability of printable silicone material.
Maxillofacial prosthetist as a member of the Anaplastology team can rehabilitate the disfigurement with more durable and life-like prosthesis using the latest research, advancements, materials, and techniques in our field to create confidence and a sense of well-being to our patients. Advancement in technology has a profound impact on the maxillofacial restoration of form and function.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the legal guardian has given his consent for images and other clinical information to be reported in the journal. The guardian understands that names and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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