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

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.

Digital workflow for graft harvest and positioning in deficient anterior mandibles versus conventional technique: Randomized controlled trial

BACKGROUND

The cortical shell technique is frequently associated with technical drawbacks, such as the lack of anatomical guidance during shell harvest and graft. This study aims to assess the horizontal bone gain and accuracy of a digitalized protocol that incorporates two interlocking patient-specific stackable guides (PSSGs) to control the shell harvest, positioning, and fixation.

PATIENTS AND METHODS

Twenty patients with deficient anterior mandibles were randomly allocated; 10 patients received freehand symphyseal shell harvest and fixation (the control group), whereas the other 10 received fully guided harvest and graft (study group) using (PSSGs), the first aided an accurate shell harvest, whereas the second conveyed shell fixation. The interposition gap among both groups was loaded with an equal mix of xenogeneic and autogenous particulates. The mean radiographic bone gain among both groups was calibrated 6 months postoperatively, and the accuracy of the digital plan was assessed by superimposing and comparing the virtually planned horizontal bone dimensions with the immediate postoperative actual bone dimensions.

RESULTS

The mean 6-month postoperative horizontal bone gain value of the study group was recorded as (4.97 ± 0.73) mm versus (4.45 ± 0.61) mm for the control group, with a statistically insignificant mean gain difference of (0.52) mm, (p = 0.101). The mean virtual preplanned horizontal bone gain was recorded (5.4 ± 0.6) versus (5.4 ± 0.6) for the immediate postoperative actual bone gain, which was also statistically insignificant (p = 0.9).

CONCLUSION

The (PSSGs) provided a precise method for graft harvest, position, and fixation, resulting in satisfactory alveolar ridge dimensions with intimate accuracy.

Use of Plant Extracts in Polymeric Scaffolds in the Regeneration of Mandibular Injuries

Severe loss of bone mass may require grafting, and, among the alternatives available, there are natural biomaterials that can act as scaffolds for the cell growth necessary for tissue regeneration. Collagen and elastin polymers are a good alternative due to their biomimetic properties of bone tissue, and their characteristics can be improved with the addition of polysaccharides such as chitosan and bioactive compounds such as jatoba resin and pomegranate extract due to their antigenic actions. The aim of this experimental protocol was to evaluate bone neoformation in experimentally made defects in the mandible of rats using polymeric scaffolds with plant extracts added. Thirty rats were divided into group 1, with a mandibular defect filled with a clot from the lesion and no graft implant (G1-C, n = 10); group 2, filled with collagen/chitosan/jatoba resin scaffolds (G2-CCJ, n = 10); and group 3, with collagen/nanohydroxyapatite/elastin/pomegranate extract scaffolds (G3-CHER, n = 10). Six weeks after surgery, the animals were euthanized and samples from the surgical areas were submitted to macroscopic, radiological, histological, and morphometric analysis of the mandibular lesion repair process. The results showed no inflammatory infiltrates in the surgical area, indicating good acceptance of the scaffolds in the microenvironment of the host area. In the control group (G1), there was a predominance of reactive connective tissue, while in the grafted groups (G2 and G3), there was bone formation from the margins of the lesion, but it was still insufficient for total bone repair of the defect within the experimental period standardized in this study. The histomorphometric analysis showed that the mean percentage of bone volume formed in the surgical area of groups G1, G2, and G3 was 17.17 ± 2.68, 27.45 ± 1.65, and 34.07 ± 0.64 (mean ± standard deviation), respectively. It can be concluded that these scaffolds with plant extracts added can be a viable alternative for bone repair, as they are easily manipulated, have a low production cost, and stimulate the formation of new bone by osteoconduction.

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.

Mechanical and Surface Characteristics of Selective Laser Melting-Manufactured Dental Prostheses in Different Processing Stages

Due to the expansion of the use of powder bed fusion metal additive technologies in the medical field, especially for the realization of dental prostheses, in this paper, the authors propose a comparative experimental study of the mechanical characteristics and the state of their microscale surfaces. The comparison was made from material considerations starting from two dental alloys commonly used to realize dental prostheses: Ni-Cr and Co-Cr, but also technologies for obtaining selective laser melting (SLM) and conventional casting. In addition, to compare the performances with the classical casting technology, for the dental prostheses obtained through SLM, the post-processing stage in which they are in a preliminary finishing and polished state was considered. Therefore, for the determination of important mechanical characteristics and the comparative study of dental prostheses, the indentation test was used, after which the hardness, penetration depths (maximum, permanent, and contact depth), contact stiffness, and contact surface were established, and for the determination of the microtopography of the surfaces, atomic force microscopy (AFM) was used, obtaining the local areal roughness parameters at the miniaturized scale-surface average roughness, root-mean-square roughness (RMS), and peak-to-peak values. Following the research carried out, several interesting conclusions were drawn, and the superiority of the SLM technology over the classic casting method for the production of dental prostheses in terms of some mechanical properties was highlighted. At the same time, the degree of finishing of dental prostheses made by SLM has a significant impact on the mechanical characteristics and especially the local roughness parameters on a miniaturized scale, and if we consider the same degree of finishing, no major differences are observed in the roughness parameters of the surfaces of the prostheses produced by different technologies.

Patient-Specific Implants in Maxillofacial Reconstruction - A Case Report

Rationale

The successful utilisation of three dimensional (3D) techniques in engineering a titanium patient specific implant (PSI) for a patient who underwent hemimaxillectomy following post COVID mucormycosis infection.

Patient Concerns

Issues related to problems associated with resection following mucormycosis, such as occlusal function, aesthetics and facial asymmetry.

Diagnosis

The patient affected by mucormycosis was left with Aramany class 1 and Cordeiro type II sub total maxillectomy defect.

Treatment

The patient was operated for mucormycosis followed by reconstruction with patient specific implant.

Outcome

Positive clinical outcomes, including improved facial symmetry, function and psychological well being with immediate replacement of the teeth, the benefits of which far outweigh the traditional approach.

Take away Lessons

The advances in the use of PSI by integration of 3D printing and computer aided design computer aided manufacturing (CAD-CAM) technology for extensive and challenging defects in the maxillofacial region have been highlighted in this case report.