Osseointegrated implant-retained auricular prosthesis constructed using cone-beam computed tomography and a prosthetically driven digital workflow: a case report

Applications of CAD/CAM Technology for Craniofacial Implants Placement and Manufacturing of Auricular Prostheses-Systematic Review

This systematic review was aimed at gathering the clinical and technical applications of CAD/CAM technology for craniofacial implant placement and processing of auricular prostheses based on clinical cases. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, an electronic data search was performed. Human clinical studies utilizing digital planning, designing, and printing systems for craniofacial implant placement and processing of auricular prostheses for prosthetic rehabilitation of auricular defects were included. Following a data search, a total of 36 clinical human studies were included, which were digitally planned and executed through various virtual software to rehabilitate auricular defects. Preoperative data were collected mainly through computed tomography scans (CT scans) (55 cases); meanwhile, the most common laser scanners were the 3dMDface System (3dMD LLC, Atlanta, Georgia, USA) (6 cases) and the 3 Shape scanner (3 Shape, Copenhagen, Denmark) (6 cases). The most common digital design software are Mimics Software (Mimics Innovation Suite, Materialize, Leuven, Belgium) (18 cases), Freeform software (Freeform, NC, USA) (13 cases), and 3 Shape software (3 Shape, Copenhagen, Denmark) (12 cases). Surgical templates were designed and utilized in 35 cases to place 88 craniofacial implants in auricular defect areas. The most common craniofacial implants were Vistafix craniofacial implants (Entific Medical Systems, Goteborg, Sweden) in 22 cases. A surgical navigation system was used to place 20 craniofacial implants in the mastoid bone. Digital applications of CAD/CAM technology include, but are not limited to, study models, mirrored replicas of intact ears, molds, retentive attachments, customized implants, substructures, and silicone prostheses. The included studies demonstrated a predictable clinical outcome, reduced the patient's visits, and completed the prosthetic rehabilitation in reasonable time and at reasonable cost. However, equipment costs and trained technical staff were highlighted as possible limitations to the use of CAD/CAM systems.

The cutting edge of customized surgery: 3D-printed models for patient-specific interventions in otology and auricular management-a systematic review

PURPOSE

3D-printing (three-dimensional printing) is an emerging technology with promising applications for patient-specific interventions. Nonetheless, knowledge on the clinical applicability of 3D-printing in otology and research on its use remains scattered. Understanding these new treatment options is a prerequisite for clinical implementation, which could improve patient outcomes. This review aims to explore current applications of 3D-printed patient-specific otologic interventions, including state of the evidence, strengths, limitations, and future possibilities.

METHODS

Following the PRISMA statement, relevant studies were identified through Pubmed, EMBASE, the Cochrane Library, and Web of Science. Data on the manufacturing process and interventions were extracted by two reviewers. Study quality was assessed using Joanna Briggs Institute's critical appraisal tools.

RESULTS

Screening yielded 590 studies; 63 were found eligible and included for analysis. 3D-printed models were used as guides, templates, implants, and devices. Outer ear interventions comprised 73% of the studies. Overall, optimistic sentiments on 3D-printed models were reported, including increased surgical precision/confidence, faster manufacturing/operation time, and reduced costs/complications. Nevertheless, study quality was low as most studies failed to use relevant objective outcomes, compare new interventions with conventional treatment, and sufficiently describe manufacturing.

CONCLUSION

Several clinical interventions using patient-specific 3D-printing in otology are considered promising. However, it remains unclear whether these interventions actually improve patient outcomes due to lack of comparison with conventional methods and low levels of evidence. Further, the reproducibility of the 3D-printed interventions is compromised by insufficient reporting. Future efforts should focus on objective, comparative outcomes evaluated in large-scale studies.