Mandibular Angle Contouring Using Porous Polyethylene Stock or PEEK-based Patient Specific Implants. A Critical Analysis

Jawline improvement using patient-specific angle implants with virtual planning in orthognathic surgery

There has been a recent increase in the global demand for jawline augmentation. Managing angle definition in patients undergoing orthognathic surgery remains challenging owing to the characteristics of classic mandibular osteotomy, which mostly allows sagittal mandibular movements but cannot modify the ramus height. The advent of computer-assisted surgical planning and computer-aided design/computer-aided manufacturing techniques for patient-specific implant fabrication has introduced new methods for jawline management. In this study, we aimed to assess jawline improvement using patient-specific angle implants in 18 patients undergoing orthognathic surgery with standard osteotomies. Since jawline's shape is an aesthetic refinement of orthognathic surgery, it has to be assessed with the inclusion of the soft tissues. Therefore, this study focused on jawline improvement by comparing the preoperative and postoperative 3D-photographs of each patient's face using the VECTRA H2 Imaging System camera device and software. Quantitative analysis revealed that the mean volumetric angle expansion was 4.6 mm (males, 4.71 mm; females, 4.48 mm). Qualitative and quantitative analyses revealed that the jaw angle parameters were concordant with the ideal female and male jaw angle parameters proposed in the literature. Patient-specific titanium angle implants are a promising and safe method for jawline improvement in patients undergoing orthognathic surgery.

3D Printing Applications for Craniomaxillofacial Reconstruction: A Sweeping Review

The field of craniomaxillofacial (CMF) surgery is rich in pathological diversity and broad in the ages that it treats. Moreover, the CMF skeleton is a complex confluence of sensory organs and hard and soft tissue with load-bearing demands that can change within millimeters. Computer-aided design (CAD) and additive manufacturing (AM) create extraordinary opportunities to repair the infinite array of craniomaxillofacial defects that exist because of the aforementioned circumstances. 3D printed scaffolds have the potential to serve as a comparable if not superior alternative to the "gold standard" autologous graft. In vitro and in vivo studies continue to investigate the optimal 3D printed scaffold design and composition to foster bone regeneration that is suited to the unique biological and mechanical environment of each CMF defect. Furthermore, 3D printed fixation devices serve as a patient-specific alternative to those that are available off-the-shelf with an opportunity to reduce operative time and optimize fit. Similar benefits have been found to apply to 3D printed anatomical models and surgical guides for preoperative or intraoperative use. Creation and implementation of these devices requires extensive preclinical and clinical research, novel manufacturing capabilities, and strict regulatory oversight. Researchers, manufacturers, CMF surgeons, and the United States Food and Drug Administration (FDA) are working in tandem to further the development of such technology within their respective domains, all with a mutual goal to deliver safe, effective, cost-efficient, and patient-specific CMF care. This manuscript reviews FDA regulatory status, 3D printing techniques, biomaterials, and sterilization procedures suitable for 3D printed devices of the craniomaxillofacial skeleton. It also seeks to discuss recent clinical applications, economic feasibility, and future directions of this novel technology. By reviewing the current state of 3D printing in CMF surgery, we hope to gain a better understanding of its impact and in turn identify opportunities to further the development of patient-specific surgical care.

Customed 3D-printed Polyetheretherketone (PEEK) Implant for Secondary Salvage Reconstruction of Mandibular Defects: Case Report and Literature Review

Given the insufficient height of single-barrel fibula and inadequate bone volume of double-barrel vascularized fibula in mandibular reconstruction, it is a better choice to combine the upper full-thickness vascularized fibula with the lower half-thickness nonvascularized fibula. However, the nonvascularized fibula may fail due to complications, affecting the facial shape and occlusal function. Polyetheretherketone is a thermoplastic polymer used for bone defect reconstruction due to its good mechanical properties and biocompatibility. This case report mainly presents a secondary salvage reconstruction of the mandible by using customed 3-dimensional-printing polyetheretherketone, which restored the continuity and symmetry of the mandible, improved the patient's facial shape, and restored functional occlusion through dental implants. After a 28-month follow-up, no complications occurred, and the patient was satisfied with the final restoration.

The Use of 3D Technology in the Management of Residual Asymmetry following Orthognathic Surgery: A Case Report

The purpose of this case report was to present the aesthetic result of the reconstruction of facial residual asymmetry after orthognathic surgery using a patient-specific three-dimensional (3D) mold and a custom-made polymethyl methacrylate implant. Through computer-aided design (CAD), the healthy contralateral side of the mandible was superimposed onto the side with the defect. Exocad Gallway (exocad GmbH, Darmstadt, Germany) was used to design the patient-specific implants (PSIs) of the right mandibular angle. Next, the implant mold was created using the Meshmixer software (Version 3.5, Autodesk Inc., San Rafael, CA, USA) and fabricated using additive manufacturing. During the surgical procedure, the patient-specific implant (PSI) was cast inside the resin mold using Simplex P bone cement (Stryker, Mahwah, NJ, USA). The implant was fixed using three screws. Combining both indirect (involving the dental laboratory) and direct (with surgical intervention) approaches, this innovative hybrid method, which incorporates both computer-aided design and additive manufacturing (AM), not only enhanced facial aesthetics, functional rehabilitation, and patient quality of life but also mitigated the potential risks linked to conventional grafting methods.

Vertical augmentation of a severely atrophied posterior mandibular alveolar ridge for a dental implant using a patient-specific 3D printed PCL/BGS7 scaffold: A technical note

Vertical bone augmentation for dental implants in the posterior mandibular region with significant bone resorption is challenging. For this purpose, methods such as block bone grafting with screw fixation, particulate bone grafting with titanium mesh or barrier membrane, and distraction osteogenesis have been used, and autogenous block bone grafting is considered the gold standard. However, the autogenous block bone grafting has the following disadvantages: bone harvesting is challenging, and block bone contouring according to the recipient site is time-consuming and laborious. Therefore, in this study, we report the use of particulate bone with a polycaprolactone/bioactive glass-7 scaffold, designed, and three-dimensionally printed preoperatively, to resolve the above-mentioned challenges.

Mandibular Fracture in a Hemifacial Microsomia Patient following Implant Failure and Hardware Infection: A Case Report

Hemifacial microsomia (HFM) is a complex congenital condition with heterogeneous malformations of the facial skeleton that almost always involves mandibular hypoplasia. Here we introduce a unique case in which a patient with HFM had initially successful optimization of facial symmetry using a polyetheretherketone implant for mandibular augmentation. However, multiple factors associated with the intraoperative and postoperative course, including hardware failure and infection, led to diminished mechanical strength of the mandible, ultimately resulting in a mandibular fracture. In this unique case presentation of HFM, we discuss the various factors that contributed to mandibular weakness and increased susceptibility to fracture.

Clinical application of 3D-printed PEEK implants for repairing mandibular defects

The aim of this study was to investigate and discuss the efficacy of 3D-printed PEEK implants in personalized reconstruction of mandibular segmental defects. This study was a single-center case series. Six patients who underwent mandibular reconstruction with a custom-made 3D-printed PEEK implant were enrolled. Patient demographics, photographs, computed tomography (CT), and other clinical data were collected and analyzed pre- and postoperatively. The average patient age was 60.0 ± 15.09 years. The mean operative time was 213.33 ± 30.77 min, and the postoperative follow-up time ranged from 10 to 24 months. Mandibular segmental defects ranged from the symphysis to the condyle. Five patients did not have any postoperative complications and were satisfied with the cosmetic and functional results. One patient had to undergo removal of the PEEK implant because of implant exposure at 10 months after surgery. PEEK implants can repair different forms of defect in the mandible, maintaining the original shape of the mandible, whilst not affecting mandible functions, such as mastication and temporomandibular joint movement. However, PEEK implantation requires the strict selection of appropriate indications, especially with regard to the evaluation of soft-tissue conditions in the implanted area.

Mandibular recontouring with polyetheretherketone (PEEK) patient-specific implants

The definition of the mandibular angle profile is a common challenge for oral and maxillofacial surgeons. Accurate diagnosis and treatment planning are mandatory in order to properly manage soft and hard tissues. The use of several biomaterials is described in the literature. The present paper reports the treatment of a defect in the right mandibular angle in otomandibular syndrome sequelae by positioning polyetheretherketone (PEEK) patient-specific implants (PSI) in a 25-year-old patient who previously underwent orthognathic surgery. Satisfactory aesthetic results were achieved with no complications 12 months after surgery. Considering its advantageous physical properties and the low rate of postoperative complications reported in the literature, PEEK can increase the treatment options for recontouring not only the upper third and the middle third of the face, but also of the lower third, in particular in cases of large three-dimensional defects.

Reconstruction of Mandibular Contour Defect Using Patient-Specific Titanium Implant Manufactured by Selective Laser Melting Method

The purpose of this study was to evaluate the surgical accuracy and postoperative stability of patient-specific titanium implants (PSTIs) manufactured by the selective laser melting method and applied for mandibular contour reconstruction. For 2 patients who showed asymmetry of the mandibular angle after mandibuloplasty, including angle reduction, reconstructive surgeries of the mandibular contour defects were performed using PSTI. Patient-specific titanium implant was three-dimensional designed using a mirror image similar to the shape of the contralateral side, and 3 screw holes were formed, avoiding the inferior alveolar nerve. Patient-specific titanium implant was applied intraorally, and screw fixation was performed via a transbuccal approach. Surgical accuracy and postoperative stability were evaluated by comparing preoperative three-dimensional design with immediate postoperative computed tomography (CT), and immediate postoperative CT with postoperative 6-month CT, respectively. Both patients were satisfied with the surgical results, and no complications were observed. Surgical accuracy was defined as a mean Hausdorff distance <0.4mm, and postoperative stability was defined as a mean Hausdorff distance <0.3mm. Our results suggest that PSTI by the selective laser melting method for augmentation of the mandibular border is useful as an additional cosmetic surgery.

A Multi-Criteria Assessment Strategy for 3D Printed Porous Polyetheretherketone (PEEK) Patient-Specific Implants for Orbital Wall Reconstruction

Pure orbital blowout fractures occur within the confines of the internal orbital wall. Restoration of orbital form and volume is paramount to prevent functional and esthetic impairment. The anatomical peculiarity of the orbit has encouraged surgeons to develop implants with customized features to restore its architecture. This has resulted in worldwide clinical demand for patient-specific implants (PSIs) designed to fit precisely in the patient's unique anatomy. Material extrusion or Fused filament fabrication (FFF) three-dimensional (3D) printing technology has enabled the fabrication of implant-grade polymers such as Polyetheretherketone (PEEK), paving the way for a more sophisticated generation of biomaterials. This study evaluates the FFF 3D printed PEEK orbital mesh customized implants with a metric considering the relevant design, biomechanical, and morphological parameters. The performance of the implants is studied as a function of varying thicknesses and porous design constructs through a finite element (FE) based computational model and a decision matrix based statistical approach. The maximum stress values achieved in our results predict the high durability of the implants, and the maximum deformation values were under one-tenth of a millimeter (mm) domain in all the implant profile configurations. The circular patterned implant (0.9 mm) had the best performance score. The study demonstrates that compounding multi-design computational analysis with 3D printing can be beneficial for the optimal restoration of the orbital floor.