Facial defects restored with extraoral implant-supported prostheses

Oculopalpebral prosthesis prototype design using the additive manufacturing technique: A case study

Three-dimensional (3D) printing technology has advanced for applications in the field of reconstructive surgery. This study reports the application of a comprehensive methodology to obtain an anatomical model, using computed tomography and 3D printing, to treat a patient with cancer who designed a prototype oculopalpebral prosthesis for the reconstruction of the affected area of the face (left eye). A personalized prototype was obtained, which adapted to the face of the person, and improved the aesthetics and quality of life. The applied techniques helped to make definitive prostheses using materials that could be permanent. The training and tests carried out in this study favored the understanding and assimilation of the technology and the possibility of applying it to patients in need of facial prosthetic rehabilitation.

Combination prosthetic design providing a superior retention for mid-facial defect rehabilitation: A Case Report

Large maxillofacial defects from malignant tumor treatment are rarely rehabilitated by surgical reconstruction alone. Ameloblastic carcinoma, a rare aggressive odontogenic malignant tumor, requires wide surgical excision to gain a tumor-free margin. In the post-surgical defect, prosthetic rehabilitation is the treatment of choice to restore function and esthetics. Moreover, an intra-oral prosthesis such as an obturator restores speech, mastication and deglutition. Retention of the obturator is a major problem while rehabilitating large defects. The existing anatomical structures from the defect with the help of magnet attachments are suitable to enhance retention, stability and support of the prostheses. This case report presents a patient with an intraoral and extra-oral combination defect following surgical resection of ameloblastic carcinoma and describes the prosthetic techniques and design considerations for a magnet-retained obturator and mid-facial prosthesis. An implant-retained mid-facial prosthesis was fabricated. The retention of combined prostheses was obtained from the remaining right posterior teeth only. The patient had an unfavorable defect due to the large size and presence of scar contracture that vertically tends to dislodge the obturator. Magnet attachments were used to combine the facial and oral prosthesis, minimize the vertical dislodging forces and enhance retention. In addition, the retention was also gained from the scar band at lower border of mid-facial defect that avoided the need for more implants surgery. Magnet attachment with anatomical structure of the mid-facial defect provides an acceptable means of retention in large extraoral-intraoral combinations defects, improving the function, esthetic and the patients' quality of life. Key words:Mid-facial prosthesis, obturator, magnet attachment, maxillectomy.

A systematic comparison of bar-clips versus magnets

STATEMENT OF PROBLEM

Currently, which type of suprastructure is preferred when fabricating implant-retained craniofacial prostheses is unknown.

PURPOSE

The purpose of this systematic review was to identify the best retention system (bar-clips versus magnets) for implant-retained craniofacial prostheses.

MATERIAL AND METHODS

This systematic review was conducted and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A systematic search of Medline/PubMed and Web of Science databases for clinical trials was conducted on implant-retained craniofacial prostheses published between 2005 and 2015. English-language studies that directly compared different types of retention systems or presented information on implant survival, periimplant soft tissue reactions, and prosthetic complications were included. Nonclinical studies were excluded to eliminate bias.

RESULTS

A total to 173 studies were identified, of which 10 satisfied the inclusion criteria. In total, 492 participants were included in these studies. Four selected studies displayed detailed information with regard to the number of implant failures according to the retention system. As reported, 29 (18.2%) of 159 implants with magnets failed, whereas 25 (31.6%) of 79 implants with bars failed. Overall auricular superstructures showed the highest survival (99.08%). In addition, 55.4% of all participants in the selected studies showed grade 0 of periimplant soft tissue reactions.

CONCLUSIONS

A systematic search for clinical studies resulted in few studies with a short-term follow-up and small number of participants. The limited data collected indicated that magnets show fewer complications than bar superstructures; however, no hard conclusions could be drawn. Further research, preferably in the form of clinical trials, is needed to validate these findings.

A simplified technique for orientation of a bone anchored auricular prostheses: a clinical report

BACKGROUND

A simple technique was presented in this clinical report for orientation of a bone anchored auricular prosthesis.

METHODS

The proposed technique includes drawing the intact ear on a transparent celluloid paper or radiographic film and flipping it to the opposite side and relating it to the fixed anatomical features on the face of patient.

RESULTS

The drawing, by this way provides a simple and easy way to duplicate and transfer the exact size and position of the intact ear to the defect side.

CONCLUSIONS

This technique provides a simple, safe, inexpensive and time saving yet, an accurate and effective surgical template that orients the craniofacial implants to the confines of the definitive auricular prosthesis. It is indicated for restoration of single missing external ear either in aplasia, injuries and total resection.

Extraoral implants in the rehabilitation of craniofacial defects: implant and prosthesis survival rates and peri-implant soft tissue evaluation

PURPOSE

Few reports have evaluated cumulative survival rates of extraoral rehabilitation and peri-implant soft tissue reaction at long-term follow-up. The objective of this study was to evaluate implant and prosthesis survival rates and the soft tissue reactions around the extraoral implants used to support craniofacial prostheses.

MATERIALS AND METHODS

A retrospective study was performed of patients who received implants for craniofacial rehabilitation from 2003 to 2010. Two outcome variables were considered: implant and prosthetic success. The following predictor variables were recorded: gender, age, implant placement location, number and size of implants, irradiation status in the treated field, date of prosthesis delivery, soft tissue response, and date of last follow-up. A statistical model was used to estimate survival rates and associated confidence intervals. We randomly selected 1 implant per patient for analysis. Data were analyzed using the Kaplan-Meier method and log-rank test to compare survival curves.

RESULTS

A total of 150 titanium implants were placed in 56 patients. The 2-year overall implant survival rates were 94.1% for auricular implants, 90.9% for nasal implants, 100% for orbital implants, and 100% for complex midfacial implants (P = .585). The implant survival rates were 100% for implants placed in irradiated patients and 94.4% for those placed in nonirradiated patients (P = .324). The 2-year overall prosthesis survival rates were 100% for auricular implants, 90.0% for nasal implants, 92.3% for orbital implants, and 100% for complex midfacial implants (P = .363). The evaluation of the peri-implant soft tissue response showed that 15 patients (26.7%) had a grade 0 soft tissue reaction, 30 (53.5%) had grade 1, 6 (10.7%) had grade 2, and 5 (8.9%) had grade 3.

CONCLUSIONS

From this study, it was concluded that craniofacial rehabilitation with extraoral implants is a safe, reliable, and predictable method to restore the patient's normal appearance.

The potential of cohesive silicone for facial prosthetic use: a material property study and a clinical report

PURPOSE

Prosthetic reconstruction of a facial defect can help to reduce disfigurement and restore the social functioning of the patient. Several methods for holding a prosthesis in place exist, including the use of osseointegrated implants and medical adhesive agents; however, since the treatment options for some patients may be restricted by various health conditions and other limitations, including allergies to adhesive agents, a history of radiation therapy, and financial issues, other options that suit individual demands are required. The objectives of this study were to test the hypothesis that adhesive characteristics could be bestowed on silicone elastomers by altering their catalyst/base silicone ratios (CBR) and to examine the effect of the thickness of the cohesive silicone layer of a prosthesis on its initial adhesive strength.

MATERIALS AND METHODS

The adhesive strengths of specimens with CBRs ranking from 1/10 to 1/70 were examined by the rolling ball tack test. A tensile test was used to evaluate the tensile adhesive strengths of specimens made of layers of cohesive silicone (CBR 1/60) and normal silicone (CBR 1/10) with different thicknesses. Auricular prostheses containing cohesive silicone on the skin side were applied to a 50-year-old man with defects in both auricular regions and with reduced manual dexterity due to serious burns.

RESULTS

The rolling distance was reduced with a decrease in CBR, and a thinner cohesive silicone (CBR 1/60) layer demonstrated a higher peak load. On clinical application, the adhesion of the auricular prosthesis containing cohesive silicone was improved by expanding the adhesive area and altering the thickness of the cohesive silicone layer, resulting in sufficient adhesion and easier handling than that achieved using an adhesive agent 1 year post delivery.

CONCLUSION

These results suggest that cohesive silicone can be used as a glueless retentive material for facial prostheses.

Maxillofacial prosthetic rehabilitation in the UK: a survey of maxillofacial prosthetists' and technologists' attitudes and opinions

Maxillofacial prostheses are constructed by maxillofacial prosthetists and technologists (MPTs), as an alternative treatment when maxillofacial defects cannot be surgically fulfilled. A questionnaire was conducted surveying 220 MPTs working in all UK maxillofacial units about their opinions, attitudes, and experience regarding several aspects related to maxillofacial silicone prostheses. Numbers and percentages of maxillofacial prostheses, their retention method, serviceability, reduced serviceability causes, and digital technologies (DT) used in constructing prostheses were analysed. Thousand hundred and ninety-three prostheses were constructed (42% ocular, 31% auricular, 13% orbital, 12% nasal, 1% composite, more than one facial prosthesis). Adhesives commonly retained orbital (48%) and nasal (45%) prostheses. Implant-retained bars commonly retained auricular prostheses (70%). Ocular prostheses were entirely retained by undercuts. Implant-retained prostheses remained serviceable for twice as long (19-24 months) as adhesive-retained prostheses (7-12 months). Causes for prosthesis replacement included colour changes (71%), poor maintenance (41%), and silicone tear (37%). Thirty-one percent of MPTs used DT computer software and programs for designing and constructing maxillofacial prostheses. In conclusion, adhesives, implant-retained bars and magnets are commonly used retentive methods. Prosthesis failure is caused mainly by colour change, poor maintenance, silicone tear and delamination. Different DTs are used by one-third of MPTs.

A surgical guide for craniofacial implant placement for an implant-retained auricular prosthesis

Craniofacial implants provide excellent stability and retention for auricular prosthetic rehabilitation. Accurate location of implants is important to achieve optimal prosthetic results. This article describes an alternative procedure for fabricating an acrylic resin surgical template for craniofacial implant placement with the assistance of a 6-inch contour duplication gauge.