Implant-retained auricular prostheses: a clinical challenge

Digital workflow for auricular prosthesis fabrication with a negative mold

A prosthesis for a patient with a complete auricle defect can be fabricated with computer-aided design and computer-aided manufacturing, significantly reducing the number of patient visits and improving the efficiency of the production process. This technique provides a digital workflow for designing virtual patterns and negative molds for an auricular prosthesis.

Rehabilitation of Auricular Defect with Implant-Retained Auricular Prosthesis - A Case Report

Rationale:

Maxillofacial defect is of great concern physically, emotionally, and psychologically for a patient. However, it is an even bigger challenge for a team attempting rehabilitation, as a crucial decision has to be made between surgical approach and/or prosthetic rehabilitation. However, if both are combined, it will result in best of esthetics and function with ease of maintainance, resulting in a sucessful rehabilitation. This case report represents a case of auricular defect rehabilitated with a combination of implants and bar-retained silicone prosthesis.

Patient Concern:

A 38-year-old male patient with right auricular defect reported with the main concern of esthetic rehabilitation of a lost part of the external ear.

Diagnosis:

With through evaluation and examination, a diagnosis of acquired partial auricular defect of the right side secondary to trauma was established.

Treatment:

An implant-retained auricular prosthesis was planned for this case. Surgically, three intraoral implants were placed in the mastoid bone, and after healing, bar framework was fabricated and attached. Finally, silicone prosthesis was fabricated and delivered to the patient.

Outcome:

A successful rehabilitation was carried out in this case using implants and bar attachment for retention of the silicone prosthesis. This prosthesis provided excellent retention and restored the appearance and confidence of the patient.

Take-away Lessons:

Rehabilitation of the auricular defect can be carried out with surgical approach, which involves multiple surgeries, and still, the results may not be esthetically favorable. Prosthetic rehabilitation is an option, but retention is generally a hindrance. However, implant-retained prosthesis has really paved a way for rehabilitation of the maxillofacial defect esthetically and more reliably. Cone-beam computerized tomography (CT) can be used for planning and evaluation instead of CT, which will save the patient from a lot of radiation exposure. Hence, in the maxillofacial defect, attempts should be made to explore the option of implant-retained prosthesis.

Tissue engineered human ear pinna derived from decellularized goat ear cartilage: clinically useful and biocompatible auricle construct

Surgery of the entire ear pinna even today presents a challenge to reconstructive surgeons, in the absence of a universally acceptable, quality construct for clinical use. In this article, the authors present a technique to generate a flexible, human size ear with the aim to meet this limitation for ear reconstructive surgeries. The construct was engineered by using a decellularized goat ear cartilage. This was characterized by hematoxylin-eosin (H/E), diamidino-2-phenylindole (DAPI), Masson's trichrome (MT), Alcian Blue (AB) staining and Scanning Electron Microscopy (SEM) for extracellular matrix (ECM) analysis. The decellularization protocol followed yielded complete removal of all cellular components without changing the properties of the ECM. In vivo biocompatibility of the ear pinna showed demonstrable recellularization. Recellularization was tracked using HE, DAPI, MT, AB staining, toluidine staining, SEM, vascular-associated protein (VAP) and CD90⁺ expressing cells. VAP expression revealed specific vasculogenic pattern (angiogenesis). CD90⁺ expression reflected the presence of the stromal cell. The graft maintained the properties of ECM and displayed chondrocyte recruitment. In summary, the decellularized goat ear pinna (cartilage) exhibited xenograft biocompatibility, stable mechanical properties and in vivo chondrocyte recruitment. Subsequently developed tissue-engineered ear pinna offer potential for cartilage flexibility and individualization of ear shape and size for clinical application.

Utilizing DICOM data to generate custom computer-aided designing and computer-aided machining polyetheretherketone healing abutments for an ear prosthesis

Soft tissue healing around implants may turn out to be the most decisive factor in the success or failure of the prosthesis. Dimension, configuration, and material of the healing abutments play a pivotal role in achieving optimal soft tissue architecture around implants. Digital imaging with computer-aided designing and computer-aided machining (CAD-CAM) technology, has made it easier to illustrate, design, replicate maxillofacial structures, and generate its supporting elements in a reliable, faster, and more convenient manner. This case report highlights the issue relevant to the implant-supported prosthetic replacement, on a site previously attempted for surgical reconstruction of the missing ear. Presurgical DICOM data were used to obtain custom CAD-CAM polyetheretherketone (PEEK) healing abutments on implants in a patient with an excessive amount of tissue in the missing right ear region. It is probably the first extraoral use of PEEK as a healing abutment in the workflow of implant retained maxillofacial prosthetics. No issue warranting the removal of the PEEK component was observed during the duration of its use.

Implant prognosis in irradiated versus non-irradiated nasal, orbital and auricular sites

The purpose of this systematic review was to evaluate implant survival in irradiated nasal, auricular, orbital sites and to compare them with non-irradiated respective sites. Four electronic databases and seven related journals were searched until December and March 2018, respectively. A total of 7892 articles were identified, 18 of which were included in this review; one non-randomized clinical trial, two prospective cohort, eight retrospective cohort and seven cross-sectional studies. Using the ROBIN-I Cochrane tool for risk assessment, 13 studies were judged at serious, one at moderate and four at critical risk of bias. Thirteen were included in 18 meta-analyses, the results of which showed a significant difference between irradiated and non-irradiated sites, favouring non-irradiated with risk ratio (RR) = 0.93, 95% confidence interval (CI) 0.89-0.97, P=0.001. Comparisons among nasal, auricular and orbital sites revealed no significant differences, whether in irradiated or non-irradiated patients at P<0.05. Hence, it was concluded that, within the limitations of this review, survival of craniofacial implants is negatively affected by radiotherapy, especially in orbital sites. Level of evidence is moderate. Therefore, further prospective cohort studies with calculated sample sizes, restricted or properly managed confounders and no deviations from intended interventions might produce different results.

Complex functional and epithetic rehabilitation after ablation of recurrent retroauricular basal cell carcinoma - a case study

The reconstruction of extended defects of the concha poses a complex challenge for plastic surgeons. In cases of subtotal ablation, an alternative method designed especially for elderly oncological patients consists of epithetic rehabilitation. However, inserting an implant-retained concha epithesis proves challenging in patients with antecedents of deep resections involving the mastoid process. In the present case study, we report on the long-term treatment course (2009-2017) of a 79-year-old male patient suffering from a recurrent basal cell carcinoma of the retroauricular region. Following tumor resection, along with lateral mastoidectomy, reconstruction, and adjuvant radiotherapy, functional and esthetic deficits primarily due to peripheral facial nerve palsy were successfully managed using a multistep procedure. The procedure was completed by inserting an implant-retained concha epithesis, resulting in improved quality of life. Due to prior lateral mastoidectomy, ultra-short implants (4 mm) were inserted, partially at atypical positions. For maintaining healthy periimplant soft tissue, aftercare comprised cold plasma treatment. This oncologic case demonstrates the therapeutic necessity of using a broad spectrum of reconstructive procedures, along with their limitations, in a critical anatomic region. Specific features include the presentation of a workflow using ultra-short implants in a compromised mastoid region. Surgeons should consider alternative implant positions in the event of any compromised mastoid process. A particular emphasis has been put on meticulous aftercare to preserve healthy periimplant soft tissues.

Prosthetics in Facial Reconstruction

Reconstruction of the head and neck can be a challenging undertaking owing to numerous considerations for successful rehabilitation. Although head and neck defects were once considered irretrievably morbid and associated with a poor quality of life, advances in surgical technique has immensely contributed to the well-being of these patients. However, all patients are not suitable surgical candidates and many have sought nonsurgical options for functional and cosmetic restoration. As such, the advent of prostheses has ameliorated those concerns and provided a viable alternative for select patient populations. Prosthetic reconstruction has evolved significantly over the past decade. Advances in biocompatible materials and imaging adjuncts have spurred further discovery and forward progress. A multidisciplinary approach to head and neck reconstruction focused on appropriate expectations and patient-centered goals is most successfully coordinated by a team of head and neck surgeons, maxillofacial surgeons, and prosthetic specialists. The aim of this article is to provide a comprehensive review of the current trends for prosthetic rehabilitation of head and neck defects, and further elaborate on the limitations and advancements in the field.

Survival and complications of implants to support craniofacial prosthesis: A systematic review

OBJECTIVE

To assess the survival rate of craniofacial implants (CIs) to support facial prosthesis/epithesis and the prevalence of surgical/biological complications based on previously published studies.

METHODS

An electronic search was undertaken in March/2016. Only studies with a minimum of 5 patients were included. Untransformed proportions of implant failures for different regions were calculated. A meta-analysis evaluated the influence of radiotherapy on the failure rates. A meta-regression was performed considering the follow-up period as covariate.

RESULTS

Seventy publications included 2355 patients and 8184 CIs (545 failures). The probability of a failure was 5.5% for all CIs (95%CI 4.5-6.5, P < 0.001), 1.2% for CIs in the auricular region (95%CI 0.8-1.5, P < 0.001), 12.2% for the nasal region (95%CI 9.0-15.5, P = 0.017), and 12.1% for the orbital region (95%CI 9.3-15.0, P < 0.001). Radiotherapy statistically affected the CIs rates (OR 5.80, 95%CI 3.77-8.92, P < 0.00001). There was no statistically significant influence of the follow-up time on the proportion of implant failures (P = 0.814). Soft tissue adverse reactions were the most common complications.

CONCLUSIONS

Implants placed in the auricular region have a lower probability of failure than those in the nasal and orbital regions. Soft tissue adverse reactions were the most common complications. Radiotherapy significantly affected the CIs failure rates.