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Marcelo Coelho Goiato, Department of Dental Materials and Prosthodontics, Araçatuba Dental School, UNESP, Rua José Bonifácio, 1193, Vila Mendonça, 16015-050, Araçatuba, SP, Brazil. Tel.: +55 1836363287 Fax: +55 1836363245 E-mail: firstname.lastname@example.org
Rehabilitation with ear prosthesis linked to osseointegrated implants
Background: The absence of an ear, which can be the result of a congenital malformation, surgical tumour resection or traumatic injury, is a significant aesthetic problem. Attachment of ear prostheses with adhesives can cause local irritation for the wearer and affect the colour of the prostheses. Use of implants in craniofacial reconstruction can improve the retention and stability of prostheses giving to patient greater comfort and security relative to adhesive attachment.
Objective: The aim of this report was to present a clinical case of a mutilated patient who was rehabilitated by means of installing an ear prosthesis fixed through osseointegrated implants.
Materials and methods: The patient had two implants installed in the mastoid region that were linked by a bar, and a clip-type system was used. The ear prosthesis was constructed from medical-use silicone, pigmented to match the patient’s skin colour and linked to the retention system.
Conclusion: The patient’s rehabilitation was satisfactory from both a functional and an aesthetic point of view, making it possible for the patient to return to a normal social life and regain lost self-esteem.
Extraoral implants created for the purpose of retaining facial prostheses have been used to improve support, stability and retention of prostheses relative to adhesive attachment of prostheses. There is a need to evaluate implant-affixed prostheses both in terms of clinical experiences and long-term treatment outcome1,2.
The patients who may benefit from implant-affixed prostheses include individuals who have undergone tumour resection surgery in the head and shoulder regions as well as individuals who have suffered mutilating traumatic injuries affecting structures such as the ocular globe, ear, nose or even the maxillar or mandibular bones3,4. In some cases, patients need rehabilitation beyond that which can be achieved surgically3–6.
With today’s early diagnostic facilities and high-efficiency treatments, there is a need in clinical planning for strategies aimed at achieving complete rehabilitation of disfigured patients, including employment of prosthetic treatments7. Oral maxillofacial surgery involving anchored or retained osseointegrated implants can provide highly satisfactory functional, aesthetic and social rehabilitation7–9, especially in cases where patients cannot be treated by conventional prosthesis or where there are no other rehabilitative alternatives.
The loss of an auricle affects hearing, despite the presence of an intact external auditory canal and inner ear, because the auricle normally functions to gather sound and direct it into the ear canal. Furthermore, the auricle acts as a resonator, slightly amplifying lower frequency sounds. The auricle also contributes to sound localisation, especially together with the other ear6,10. Thus, effective auricle prostheses are of particular interest as they can provide both aesthetic and functional improvements. The objective of this study was to describe the rehabilitation of a mutilated patient by means of an ear prosthesis retained by an osseointegrated implant.
A 56-year-old man with leucoderma presented at the Araçatuba Dentistry Faculty with loss of the auricular appendage seeking an oral maxillofacial prosthesis (Fig. 1). During anamnesis, he reported having lost part of the structure in a work accident. Loss of the right auricular structure was observed in the physical examination, and the patient also mentioned having frequent hearing problems because of the absence of the organ, as well as behavioural changes, such as anxiety, shyness, difficulties in interacting with family and friends and problems with focusing his eyes mainly by the difficulty of supporting the use of glasses at work, because their profession is electrician requires careful consideration.
The treatment consisted of placing an ear prosthesis over an implant, using the bar-clip retention system. With this technique, a titanium intraosseous implant is first implanted, and then, after osseointegration, the implant was connected to another titanium element (UCLA-type abutments; SIN, SP, Brazil) designed to retain the prosthesis. The final silicone exterior prosthesis can be attached to the titanium element by clips.
Potential implant sites in the patient were evaluated using computed tomography (CT), and the CT findings were used in surgical and prosthetic procedure planning7. A two-stage surgical procedure was performed. The peri-implant bone area was thinned to minimise soft tissue reactions and granulation tissue. Drill speeds in the range of 750–900 rpm were used, and irrigation with physiological saline solution was applied during drilling. After raising the soft tissue flap, the target bone area was smoothed and the implantation sites were marked with a 2.3-mm-diameter round burr. Next, the implant sites were prepared with profile and stop drills. Two auricular implants (3.75 × 10 mm; SIN) were placed in the mastoid bone (Fig. 2A).
After soft tissue healing and confirmation of osseointegration at 24 weeks post-surgery, the abutments were inserted and the screws positioned (Fig. 2B). Fourteen days later, the screws were removed so that the position of the implants could be adjusted. Hair adjacent to the ear was coated with petroleum jelly (Vaseline; Chesebrough-Pond’s USA Co, Greenwich, Conn, New York, NY, USA), and cotton was placed in the ear canal11. Impressions of the abutments were made with impression cylinders using an elastomeric impression material (Zetaplus; Zhermack Spa, Badia Polesine, Rovigo, Italy). Once the impression was checked, the original impression cylinders were dismantled, screwed into laboratory analogues and placed in the impressions. The impression was poured in a type V dental stone (Durone, Dentisply Ind. Co., Petópolis, RJ, Brazil) (Fig. 2C).
The infrastructure was refined on the obtained model, and the final model was then cast in commercially pure titanium (Ti c.p., Tritan; Dentaurum GmbH & Co. KG, Ispringen, Germany). After the infrastructure was finalised, the accuracy of the metal frameworks’ fit was verified on the patient to evaluate the adaptation and passive fit of the implants (Fig. 2D)12. Once the verification process was complete, the ear prosthesis was sculpted in wax, and the form, size, fit, position and aesthetics were verified on the patient (Fig. 2E). The wax pattern was adapted to the metal infrastructure, and then a clinical aesthetic trial was performed on the patient.
To improve the adhesion between the silicone prosthetic component and the retention system, an acrylic resin device adapted to the base of the auricular prosthesis was made and applied13. The retention system clips were affixed to this device (Fig. 2F), and the entire apparatus was included in a flask. Mechanical adjustments were made to the acrylic resin device, and a bed of adhesive (Silastic Medical Adhesive Type A; Dow Corning Corporation, Midland, MI, USA) was placed on the surface of the device to promote better adhesion between the silicone and the thermopolymerised acrylic resin. The auricular prosthesis was made using MDX4-4210 (Dow Corning Corporation) facial silicone, coloured with inorganic pigments to match the patient’s skin colour. After preparation of the silicone, the prosthesis was finished with scissors and sandpaper. After the prosthesis was installed, the patient was taught how to use it properly and how to clean it (Fig. 3A,B)14.
A case of a mutilated patient who was rehabilitated with an ear prosthesis fixed via osseointegrated implants installed in the mastoid region was reported. The implants were linked by a bar, and a clip-type system was used. The ear prosthesis was constructed with pigmented silicone. The prosthetic provided a satisfactory outcome from both a functional and an aesthetic point of view, making it possible for the patient to return to a normal social life and regain lost self-esteem.
Reconstruction to correct facial defects can be accomplished surgically or prosthetically, depending on defect site, size, aetiology and severity, as well as the patient’s age and desires15. Recently developed surgical reconstruction techniques, including microsurgical tissue transfer and autogenous or alloplastic grafts, can be used to reconstruct facial defects in many patients6. However, surgical reconstruction may be limited because of several factors including insufficient residual tissue, compromised vascularity following radiation, inadequacy of the donor site or an undesirable aesthetic result. Surgical reconstruction might also be decided against because of the age of the patient, the patient’s general medical condition or patient preferences16,17. When such limitations are an issue, prosthetic rehabilitation is the treatment of choice3,9.
Before the introduction of extraoral implants, retention of craniofacial prostheses was achieved primarily with adhesives. There are difficulties and limitations associated with the use of adhesives, including skin reactions, unreliable adhesion, edge distortion and risk of the prosthesis being dislodged by movements of the mimetic muscles7,9. This risk of a prosthesis dislodging can limit the wearers’ activities, constraining them as they must take precautions not to dislodge their prosthetic devices9.
The aforementioned restrictions are reduced or even eliminated when prostheses can be retained or fixed to the skeleton, allowing patients to undertake activities more freely and thus achieve a better quality of life. Osseointegrated implants can be employed to achieve this higher standard of rehabilitation3,4,11–13,18–20. They are an excellent means of retaining prostheses, allowing prostheses to be retained by means of mechanical retainers such as clips, o-rings or magnets, while obviating problems associated with the use of adhesives and constraints stemming from concerns related to detachment of prostheses in public. Furthermore, easy access to the defect region makes it easier to track the area of the operation, allowing for early diagnosis of any complications5,20. Indeed, the use of osseointegrated implants to retain facial prostheses has become an integral part of treatment planning for facial reconstruction since the 1970s15,18.
Numerous attachments are available for the retention of implant-retained prostheses. Implant-retained auricular prostheses usually require a bar with clips or retentive elements in addition to the prosthetic ear10. Installing a titanium osseointegrated ear prosthesis is a safe and useful procedure for children, as well as adults, with or without microtia. This option should be offered to patients as it has low complication and high acceptance rates among patients21.
The anatomical site into which an implant is inserted influences the success rate. In most studies, implants placed in the auricular region have had a better prognosis than those placed in other facial areas22,23. This difference may be related to the good quality of the bone and the thin and immobile soft tissue in this region7. Notwithstanding these advantages, implant placement in the mastoid region is more complicated than intraoral dental implantation. The greater severity of complications associated with auricular region implants may be because of a greater potential for incidental injuries to intracranial structures. Furthermore, there are difficulties, not only with primary surgery and soft tissue inflammation but also with possible secondary surgery for implant removal, which may cause serious complications. Early removal may be required in some cases to avoid long-term complications24.
Patients with auricular epistheses that are fixed on the abutments of osseointegrated implants may have problems during some activities, such as during bathing or sleeping. Also, it may be difficult to protect these epitheses from external factors such as rain, sun and cold weather8. Many patients have complained shortly after episthesis installation of a separation between the silicone and the retention device because of repeated insertion and removal of the prosthesis. By this reason, devices made of acrylic resin are recommended to minimise risk of this problem. Acrylic resin is known to adhere well to both silicon and the metal or plastic of the retention system.
Extraoral prostheses can be made of silicone elastomers, acrylic resin or a combination of these materials25. Silicone has been used for over 50 years in maxillofacial prosthetics owing to its desirable properties including flexibility, biocompatibility, the ability to accept intrinsic and extrinsic colourants, translucency, chemical and physical inertness, mouldability and ease of cleaning1,2,9,26. Intrinsic colouring using inorganic pigments is more stable than the use of organic pigments8. Therefore, in the present case, the silicone was coloured intrinsically with oil dye and the prosthetic ear was fashioned extrinsically using the same pigment. The final appearance of a prosthesis depends on the maxillofacial prosthetics team. Through a painstaking process of manufacturing and artistry, auricular prostheses can be made to closely match the opposite ear. The colouring should be made to correspond with the patient’s own complexion, including the presence of freckles and capillaries8.
Although prosthetic reconstruction requires surgical techniques that are less demanding than autogenous reconstruction, construction of the prosthesis is a time-consuming task requiring experience and expertise27.
Problems experienced by maxillofacial prostheses wearers are reduced, as a specialist team applies all the practice and experience and maintains a regular follow-up. The patients’ prosthetic rehabilitation allows for satisfactory aesthetic recuperation and well-being, while psychological therapy allows for patients’ re-insertion in social and familiar environment to make them feel more happy and safe28.
Knowledge on the part of health professionals, including dental surgeons, of the importance of prosthetic facial rehabilitation is important as facial mutilations provoke morphofunctional and psychosocial changes, isolating the bearer from family and friends, as well as potentially stigmatising them as bearers of a mark that separates them from others. Through prosthetic facial reconstitution, affected individuals can be reintegrated into society and achieve an improved quality of life, returning the patient to its activities, receiving salary and promoting the family a guarantee of better life, as occurred in the presently reported case.
Implant-retained auricular prostheses offer disfigured patients many advantages, including convenience, security, consistent prosthesis retention and positioning, elimination of the need for adhesives and maintenance of marginal integrity and longevity.