Recent advances in the reconstruction of cranio-maxillofacial defects using computer-aided design/computer-aided manufacturing

Efficacy of Three-Dimensional Printing in the Management of Frontal Bone Trauma

Objectives  Craniomaxillofacial (CMF) trauma surgery is difficult because of its unique architecture and vast range of injuries in the head and neck area. This study sought to determine the potential of employing preoperative three-dimensional (3D)-printed models to improve frontal fracture healing outcomes. Methods  This prospective cohort clinical trial involved 20 patients who were surgically fitted and had a frontal bone fracture, as evidenced by computed tomography. The patients were separated into two groups: Group A: patients with frontal bone trauma reduced using 3D printing; and Group B: patients with frontal bone trauma reduced without 3D printing. Results  Compared to Group B, Group A had a considerably shorter operational time ( p  < 0.001). The esthetic results, complications, and functional outcomes were not significantly different between the two groups. All patients in Groups A and B underwent accurate radiographic evaluations (correct placement of the titanium mesh). Conclusion  3D printing in preoperative planning improves frontal fracture repair with respect to operative length but does not reduce intraoperative blood loss or improve postoperative function compared with normal management.

A Comprehensive AI Framework for Superior Diagnosis, Cranial Reconstruction, and Implant Generation for Diverse Cranial Defects

Cranioplasty enables the restoration of cranial defects caused by traumatic injuries, brain tumour excisions, or decompressive craniectomies. Conventional methods rely on Computer-Aided Design (CAD) for implant design, which requires significant resources and expertise. Recent advancements in Artificial Intelligence (AI) have improved Computer-Aided Diagnostic systems for accurate and faster cranial reconstruction and implant generation procedures. However, these face inherent limitations, including the limited availability of diverse datasets covering different defect shapes spanning various locations, absence of a comprehensive pipeline integrating the preprocessing of medical images, cranial reconstruction, and implant generation, along with mechanical testing and validation. The proposed framework incorporates a robust preprocessing pipeline for easier processing of Computed Tomography (CT) images through data conversion, denoising, Connected Component Analysis (CCA), and image alignment. At its core is CRIGNet (Cranial Reconstruction and Implant Generation Network), a novel deep learning model rigorously trained on a diverse dataset of 2160 images, which was prepared by simulating cylindrical, cubical, spherical, and triangular prism-shaped defects across five skull regions, ensuring robustness in diagnosing a wide variety of defect patterns. CRIGNet achieved an exceptional reconstruction accuracy with a Dice Similarity Coefficient (DSC) of 0.99, Jaccard Similarity Coefficient (JSC) of 0.98, and Hausdorff distance (HD) of 4.63 mm. The generated implants showed superior geometric accuracy, load-bearing capacity, and gap-free fitment in the defected skull compared to CAD-generated implants. Also, this framework reduced the implant generation processing time from 40-45 min (CAD) to 25-30 s, suggesting its application for a faster turnaround time, enabling decisive clinical support systems.

Novel Approaches for the Treatment of Maxillofacial Defects

Maxillofacial defects, located in a region characterized by a complex interplay of soft and hard tissues, along with a sophisticated capillary and neural network, have long posed significant challenges in both clinical practice and research [...].

Three-axis load analysis of high-speed handpiece on dental training teeth and computer-aided design/computer-aided manufacturing blocks

This study aimed to evaluate and compare the mechanical properties of dental training teeth with subtractive and additive computer-aided design/computer-aided manufacturing (CAD/CAM) materials used to fabricate dental simulation models. Therefore, the three-axis load generated during cutting movements, including drilling and milling performed using a dental handpiece, was measured and compared. The samples were cut vertically downward by 1.5 mm, horizontally by 6 mm, and vertically upward at a constant speed (1 mm/s), while the rotational speed of the bur was maintained at 200,000 rotations per minute. A three-axis load cell was used to measure the X-, Y-, and Z-axis loads on the specimen. The median value of the X-, Y-, and Z-axis measurements and the resultant load during the vertical-downward, horizontal, and vertical-upward movements were compared using a one-way analysis of variance and Tukey's post hoc test. For vertical downward movement, the drilling force of the dental training teeth was lower than that of Vita Enamic® and similar to that of Lava™ Ultimate. In contrast to subtractive CAD/CAM blocks, the drilling force of the dental training teeth was higher than that of 3D-printed resin blocks. Regarding horizontal movement, the milling force of dental training teeth was lower than that of Vita Enamic®. In contrast, the milling force of Nissin was similar to that of Lava™ Ultimate, while that of Frasaco was lower. Furthermore, compared to additive CAD/CAM blocks, the milling force of the dental training teeth was higher than that of 3D-printed resin blocks. Regarding vertical upward movement, the resultant loads of dental training teeth was lower than that of Vita Enamic®. Similarly, the resultant load of Nissin was similar to that of Lava™ Ultimate, while that of Frasaco was lower. Additionally, compared to additive CAD/CAM blocks, the resultant loads of the dental training teeth were similar to those of the 3D-printed resin blocks.

A Stage-Wise Residual Attention Generation Adversarial Network for Mandibular Defect Repairing and Reconstruction

Surgical reconstruction of mandibular defects is a clinical routine manner for the rehabilitation of patients with deformities. The mandible plays a crucial role in maintaining the facial contour and ensuring the speech and mastication functions. The repairing and reconstruction of mandible defects is a significant yet challenging task in oral-maxillofacial surgery. Currently, the mainly available methods are traditional digitalized design methods that suffer from substantial artificial operations, limited applicability and high reconstruction error rates. An automated, precise, and individualized method is imperative for maxillofacial surgeons. In this paper, we propose a Stage-wise Residual Attention Generative Adversarial Network (SRA-GAN) for mandibular defect reconstruction. Specifically, we design a stage-wise residual attention mechanism for generator to enhance the extraction capability of mandibular remote spatial information, making it adaptable to various defects. For the discriminator, we propose a multi-field perceptual network, consisting of two parallel discriminators with different perceptual fields, to reduce the cumulative reconstruction errors. Furthermore, we design a self-encoder perceptual loss function to ensure the correctness of mandibular anatomical structures. The experimental results on a novel custom-built mandibular defect dataset demonstrate that our method has a promising prospect in clinical application, achieving the best Dice Similarity Coefficient (DSC) of 94.238% and 95% Hausdorff Distance (HD95) of 4.787.

Custom CAD/CAM Peek Implants for Complex Orbitocranial Reconstruction: Our Experience with 15 Patients

Bone defects within the cranio-orbital complex present unique challenges in terms of surgical planning and reconstruction. This article presents a novel approach using PEEK material and advanced surgical technologies to address these challenges. A retrospective analysis of 15 patients who underwent craniofacial reconstruction using patient-specific polyetheretherketone (PEEK) implants between 2016 and 2021 was carried out. Comprehensive preoperative planning was performed, utilizing advanced imaging techniques and specialized software for virtual surgical planning. Patient-specific PEEK PSIs were designed and manufactured based on the preoperative plan. Intraoperative navigation was used to guide the surgical procedure, enabling precise osteotomy and optimal implant placement. This article describes the step-by-step process and the tools utilized in each phase. The etiologies were as follows: meningioma in seven cases, benign lesions in five cases, malignant tumors in two cases, and trauma sequelae in one case. In all cases, 3D-printed PEEK implants were utilized to achieve precise reconstruction. No major complications were described. In one case, an implant replacement was needed with successful outcomes. Our study demonstrates the feasibility and effectiveness of using PEEK patient-specific implants for personalized craniofacial reconstruction. The combination of advanced imaging, virtual planning, and CAD-CAM technology contributes to improved surgical outcomes in terms of oncologic margin control, functional restoration, and aesthetic results.

Patient-Specific Implants for Correction of Midfacial Aging

The nasolabial folds (NLFs) may be shallowed with the use of nostril base augmentation. This study aimed to design and customize patient-specific implants (PSIs) with computer-aided design/computer-aided manufacturing (CAD/CAM) to correct NLF deepening caused by midfacial aging. The patient's head computed tomography data obtained and were used for reconstruction. The PSIs were customized by CAD/CAM techniques, which were implanted into a nasal base for shallow NLFs caused by midfacial aging. Preoperative and postoperative photos and a wrinkle severity rating scale were used to evaluate the changes in NLFs. Also, the global esthetic improvement scale was used to investigate the surgical satisfaction of patients. Eleven patients (22 NLFs) received PSIs in the nasal base (22 implants). The customized PSI matched well with premaxilla, reducing the difficulty of operation. After 3 to 12 months of follow-up, PSI was stable without foreign body reaction or inflammatory reaction. Postoperative wrinkle severity rating scale scores showed that NLF severity was reduced in all patients, with a significant esthetic improvement compared with preoperatively ( P < 0.01). The global esthetic improvement scale showed an extremely satisfied improved NLF in 27.27% of patients, much improved in 63.63%, and improved in 9.90% (2/22), and none reported change or poor NLF. Patient satisfaction with their midface appearance differed significantly before and after surgery ( P < 0.01). Individualized PSI designed with high precision and matching degree by CAD and prepared using CAM could be applied to overcome the limitations of noncustomized implants.

Osteogenic differentiation of 3D-printed porous tantalum with nano-topographic modification for repairing craniofacial bone defects

Introduction: Congenital or acquired bone defects in the oral and cranio-maxillofacial (OCMF) regions can seriously affect the normal function and facial appearance of patients, and cause great harm to their physical and mental health. To achieve good bone defect repair results, the prosthesis requires good osteogenic ability, appropriate porosity, and precise three-dimensional shape. Tantalum (Ta) has better mechanical properties, osteogenic ability, and microstructure compared to Ti6Al4V, and has become a potential alternative material for bone repair. The bones in the OCMF region have unique shapes, and 3D printing technology is the preferred method for manufacturing personalized prosthesis with complex shapes and structures. The surface characteristics of materials, such as surface morphology, can affect the biological behavior of cells. Among them, nano-topographic surface modification can endow materials with unique surface properties such as wettability and large surface area, enhancing the adhesion of osteoblasts and thereby enhancing their osteogenic ability. Methods: This study used 3D-printed porous tantalum scaffolds, and constructed nano-topographic surface through hydrothermal treatment. Its osteogenic ability was verified through a series of in vitro and in vivo experiments. Results: The porous tantalum modified by nano-topographic surface can promote the proliferation and osteogenic differentiation of BMSCs, and accelerate the formation of new bone in the Angle of the mandible bone defect of rabbits. Discussion: It can be seen that 3D-printed nano-topographic surface modified porous tantalum has broad application prospects in the repair of OCMF bone defects.

Clinical Stability of Bespoke Snowman Plates for Fixation following Sagittal Split Ramus Osteotomy of the Mandible

Maxillofacial skeletal surgery often involves the use of patient-specific implants. However, errors in obtaining patient data and designing and manufacturing patient-specific plates and guides can occur even with accurate virtual surgery. To address these errors, bespoke Snowman plates were designed to allow movement of the mandible. This study aimed to compare the stability of bespoke four-hole miniplates with that of a bespoke Snowman plate for bilateral sagittal split ramus osteotomy (SSRO), and to present a method to investigate joint cavity changes, as well as superimpose virtual and actual surgical images of the mandible. This retrospective study included 22 patients who met the inclusion criteria and underwent orthognathic surgery at a university hospital between 2015 and 2018. Two groups were formed on the basis of the plates used: a control group with four-hole bespoke plates and a study group with bespoke Snowman plates. Stability was assessed by measuring the condyle-fossa space and superimposing three-dimensional virtual surgery images on postoperative cone-beam computed tomography (CBCT) scans. No significant differences were observed in the condyle-fossa space preoperatively and 1 year postoperatively between the control and study groups. Superimposing virtual surgery and CBCT scans revealed minimal differences in the landmark points, with no variation between groups or timepoints. The use of bespoke Snowman plates for stabilizing the mandible following SSRO exhibited clinical stability and reliability similar to those with bespoke four-hole plates. Additionally, a novel method was introduced to evaluate skeletal stability by separately analyzing the condyle-fossa gap changes and assessing the mandibular position.

Applications of three-dimensional imaging techniques in craniomaxillofacial surgery: A literature review

Three-dimensional (3D) imaging technologies are increasingly used in craniomaxillofacial (CMF) surgery, especially to enable clinicians to get an effective approach and obtain better treatment results during different preoperative and postoperative phases, namely during image acquisition and diagnosis, virtual surgical planning (VSP), actual surgery, and treatment outcome assessment. The article presents an overview of 3D imaging technologies used in the aforementioned phases of the most common CMF surgery. We searched for relevant studies on 3D imaging applications in CMF surgery published over the past 10 years in the PubMed, ProQuest (Medline), Web of Science, Science Direct, Clinical Key, and Embase databases. A total of 2094 articles were found, of which 712 were relevant. An additional 26 manually searched articles were included in the analysis. The findings of the review demonstrated that 3D imaging technology is becoming increasingly popular in clinical practice and an essential tool for plastic surgeons. This review provides information that will help researchers and clinicians consider the use of 3D imaging techniques in CMF surgery to improve the quality of surgical procedures and achieve satisfactory treatment outcomes.

3D printing titanium grid scaffold facilitates osteogenesis in mandibular segmental defects

Bone fusion of defect broken ends is the basis of the functional reconstruction of critical maxillofacial segmental bone defects. However, the currently available treatments do not easily achieve this goal. Therefore, this study aimed to fabricate 3D-printing titanium grid scaffolds, which possess sufficient pores and basic biomechanical strength to facilitate osteogenesis in order to accomplish bone fusion in mandibular segmental bone defects. The clinical trial was approved and supervised by the Medical Ethics Committee of the Chinese PLA General Hospital on March 28th, 2019 (Beijing, China. approval No. S2019-065-01), and registered in the clinical trials registry platform (registration number: ChiCTR2300072209). Titanium grid scaffolds were manufactured using selective laser melting and implanted in 20 beagle dogs with mandibular segmental defects. Half of the animals were treated with autologous bone chips and bone substances incorporated into the scaffolds; no additional filling was used for the rest of the animals. After 18 months of observation, radiological scanning and histological analysis in canine models revealed that the pores of regenerated bone were filled with titanium grid scaffolds and bone broken ends were integrated. Furthermore, three patients were treated with similar titanium grid scaffold implants in mandibular segmental defects; no mechanical complications were observed, and similar bone regeneration was observed in the reconstructed patients' mandibles in the clinic. These results demonstrated that 3D-printing titanium grid scaffolds with sufficient pores and basic biomechanical strength could facilitate bone regeneration in large-segment mandibular bone defects.

Microfabrication approaches for oral research and clinical dentistry

Currently, a variety of laboratory tools and strategies have been developed to investigate in vivo processes using in vitro models. Amongst these, microfabrication represents a disruptive technology that is currently enabling next-generation biomedical research through the development of complex laboratory approaches (e.g., microfluidics), engineering of micrometer scale sensors and actuators (micropillars for traction force microscopy), and the creation of environments mimicking cell, tissue, and organ-specific contexts. Although microfabrication has been around for some time, its application in dental and oral research is still incipient. Nevertheless, in recent years multiple lines of research have emerged that use microfabrication-based approaches for the study of oral diseases and conditions with micro- and nano-scale sensitivities. Furthermore, many investigations are aiming to develop clinically relevant microfabrication-based applications for diagnostics, screening, and oral biomaterial manufacturing. Therefore, the objective of this review is to summarize the current application of microfabrication techniques in oral sciences, both in research and clinics, and to discuss possible future applications of these technologies for in vitro studies and practical patient care. Initially, this review provides an overview of the most employed microfabrication methods utilized in biomedicine and dentistry. Subsequently, the use of micro- and nano-fabrication approaches in relevant fields of dental research such as endodontic and periodontal regeneration, biomaterials research, dental implantology, oral pathology, and biofilms was discussed. Finally, the current and future uses of microfabrication technology for clinical dentistry and how these approaches may soon be widely available in clinics for the diagnosis, prevention, and treatment of relevant pathologies are presented.

Investigating the accuracy of mandibulectomy and reconstructive surgery using 3D customized implants and surgical guides in a rabbit model

BACKGROUND

This study aimed to analyze the accuracy of the output of three-dimensional (3D) customized surgical guides and titanium implants in a rabbit model, and of mandibulectomy, reconstructive surgery, and surgical outcome; additionally, the correlation between surgical accuracy and surgical outcomes, including the differences in surgical outcome according to surgical accuracy, was analyzed.

RESULTS

The output of implants was accurately implemented within the error range (- 0.03-0.03 mm), and the surgical accuracy varied depending on the measured area (range - 0.4-1.1 mm). Regarding surgical outcomes, angle between the mandibular lower borders showed the most sensitive results and distance between the lingual cusps of the first molars represented the most accurate outcomes. A significant correlation was noted between surgical accuracy in the anteroposterior length of the upper borders pre- and postoperatively and the angle between the mandibular lower borders (regression coefficient = 0.491, p = 0.028). In the group wherein surgery was performed more accurately, the angle between the mandibular lower borders was reproduced more accurately (p = 0.021). A selective laser melting machine accurately printed the implants as designed. Considering the positive correlation among surgical accuracy in the mandibular upper borders, angle between the mandibular lower borders, and more accurately reproduced angle between the mandibular lower borders, the angle between the mandibular lower borders is considered a good indicator for evaluating the outcomes of reconstructive surgery.

CONCLUSION

To reduce errors in surgical outcomes, it is necessary to devise a positioner for the surgical guide and design a 3D surgical guide to constantly maintain the direction of bone resection. A fixed area considering the concept of three-point fixation should be selected for stable positioning of the implant; in some cases, bilateral cortical bone fixation should be considered. The angle between the mandibular lower borders is a sensitive indicator for evaluating the outcomes of reconstructive surgery.

Aesthetic Reconstruction of Onco-surgical Mandibular Defects Using Free Fibular Flap with and without CAD/CAM Customized Osteotomy Guide: A Randomized Controlled Clinical Trial

BACKGROUND

Reconstruction of mandibular defects following ablative surgery remains a challenge even for experienced surgeons. Virtual planning and guided surgery, including computer-aided design/computer-aided manufacturing (CAD/CAM), afford optimized ways by which to plan complex surgery. This study aimed to evaluate and compare aesthetic outcome and surgical efficiency of free fibular flap (FFF) with and without CAD/CAM customized osteotomy guide (COG) for reconstruction of onco-surgical mandibular defects.

METHODS

Twenty-two patients indicated for segmental mandibulectomy were randomly assigned to either CAD/CAM with COG group or that without COG- Model based reconstruction (MB group) at a 1:1 ratio. Aesthetic outcomes were evaluated by means of morphometric assessment and comparison for each differential area (DAr) and angle (DAn) in the affected side to the contralateral side of the mandible using computerized digital imaging analysis (CDIA) based on the post-operative 3D CT-scan. Subjective evaluation was performed using the Visual Analogue Scale (VAS) and Patient's Satisfaction Score (PSS). Surgical efficiency was a secondary outcome and evaluated as total operative time and ischemia time.

RESULTS

The mean sagittal DAr was significantly lower in the COG group (277.28 ± 127.05 vs. 398.67 ± 139.10 mm², P = 0.045). Although there was an improvement in the axial DAr (147.61 ± 55.42 vs. 183.68 ± 72.85 mm²), the difference was not statistically significant (P = 0.206). The mean differences (Δ) in both sagittal and coronal DAn were significantly lower in the COG group than in the MB group (6.11 ± 3.46 and 1.77 ± 1.12° vs. 9.53 ± 4.17 and 3.44 ± 2.34°), respectively. There were no statistically significant differences in the axial DAn between the two groups (P = 0.386). The PSS was significantly higher in the COG group, reflecting better aesthetic satisfaction than in the MB group (P = 0.041). The total operation and ischemia time were significantly shorter in favor of the COG group with a mean of (562.91 ± 51.22, 97.55 ± 16.80 min vs. 663.55 ± 53.43, 172.45 ± 21.87 min), respectively.

CONCLUSION

The CAD/CAM with COG is more reliable and highly valuable in enhancing aesthetic outcomes and surgical efficiency of mandibular reconstruction by FFF compared to that without COG (MB reconstruction).

TRIAL REGISTRATION

This trial was registered at ClinicalTrials.gov .

REGISTRATION NUMBER

NCT03757273. Registration date: 28/11/2018.

The effect of bone defect size on the 3D accuracy of alveolar bone augmentation performed with additively manufactured patient-specific titanium mesh

OBJECTIVE

Additively manufactured (3D-printed) titanium meshes have been adopted in the dental field as non-resorbable membranes for guided bone regeneration (GBR) surgery. However, according to previous studies, inaccuracies between planned and created bone volume and contour are common, and many reasons have been speculated to affect its accuracy. The size of the alveolar bone defect can significantly increase patient-specific titanium mesh design and surgical difficulty. Therefore, this study aimed to analyze and investigate the effect of bone defect size on the 3D accuracy of alveolar bone augmentation performed with additively manufactured patient-specific titanium meshes.

METHODS

Twenty 3D-printed patient-specific titanium mesh GBR surgery cases were enrolled, in which 10 cases were minor bone defect/augmentation (the planned bone augmentation surface area is less than or equal to 150 mm² or one tooth missing or two adjacent front-teeth/premolars missing) and another 10 cases were significant bone defect/augmentation (the planned bone augmentation surface area is greater than 150 mm² or missing adjacent teeth are more than two (i.e. ≥ three teeth) or missing adjacent molars are ≥ two teeth). 3D digital reconstruction/superposition technology was employed to investigate the bone augmentation accuracy of 3D-printed patient-specific titanium meshes.

RESULTS

There was no significant difference in the 3D deviation distance of bone augmentation between the minor bone defect/augmentation group and the major one. The contour lines of planned-CAD models in two groups were basically consistent with the contour lines after GBR surgery, and both covered the preoperative contour lines. Moreover, the exposure rate of titanium mesh in the minor bone defect/augmentation group was slightly lower than the major one.

CONCLUSION

It can be concluded that the size of the bone defect has no significant effect on the 3D accuracy of alveolar bone augmentation performed with the additively manufactured patient-specific titanium mesh.

3d cranial reconstruction using titanium implant - a case report

Cranioplasty is a neurosurgical procedure done to cover the defective or deficient skull bone. The cranial reconstruction rejuvenates the patient by protecting and restore intracranial structures and pressure thus improving the esthetic appearance. Thus improves the neurological and psychological wellbeing of the patient. The blending Advancement of computer technology in medical and dental science allowed the 3D reconstruction of several anatomical structures for various medical procedures by designing the custom-made implants.

Procedure

This case report describes the methodology used to design a custom-made cranial implant for a 38-year-old patient who had traumatic injury in the right temporosagital region of the skull caused by a road traffic accident . 3D reconstruction of the cranial vault was done using CAD designing and Selective laser melting (SLM) technology printing.

Discussion

The presicion of the prosthesis was good thereby the surgical time was reduced and eliminates any errors in operating theatre and successfully implanted. The patient's esthetics was restores , allowing the patient to safely perform daily activities with full confidence.

Conclusion

The use of 3D reconstruction techniques in managing exhaustive surgeries aids to reduces the possibility of errors during surgery, precise and passive fit and provides better implant stability. Thus 3D printing technology has boomed its use in various field of medicine.

Polycystin-2 mediates mechanical tension-induced osteogenic differentiation of human adipose-derived stem cells by activating transcriptional co-activator with PDZ-binding motif

Human adipose-derived stem cells (hASCs) have multi-directional differentiation potential including osteogenic differentiation. Mechanical stimulation is thought to be a key regulator of bone remodeling and has been proved to promote osteogenic differentiation of mesenchymal stem cells. However, the mechanism how mechanical tension-induced osteogenesis of hASCs still remains poor understood. Polycystin-2 (PC2), a member of the transient receptor potential polycystic (TRPP) family, is involved in cilia-mediated mechanical transduction. To understand the role of PC2 in osteogenic differentiation under mechanical stimuli in hASCs, PKD2 gene was stably silenced by using lentivirus-mediated shRNA technology. The results showed that mechanical tension sufficiently enhanced osteogenic differentiation but hardly affected proliferation of hASCs. Silencing PKD2 gene caused hASCs to lose the ability of sensing mechanical stimuli and subsequently promoting osteogenesis. PC2 knock-out also reduced the cilia population frequency and cilia length in hASCs. TAZ (transcriptional coactivator with PDZ-binding motif, also known as Wwtr1) could mediate the genes regulation and biological functions of mechanotransduction signal pathway. Here, mechanical tension also enhanced TAZ nuclear translocation of hASCs. PC2 knock-out blocked tension-induced upregulation of nuclear TAZ and suppress tension-induced osteogenesis. TAZ could directly interact with Runx2, and inhibiting TAZ could suppress tension-induced upregulation of Runx2 expression. In summary, our findings demonstrated that PC2 mediate mechanical tension-induced osteogenic differentiation of hASCs by activating TAZ.

Current Trends in the Reconstruction and Rehabilitation of Jaw following Ablative Surgery

Simple Summary

The Maxilla and mandible provide skeletal support for of the middle and lower third of our faces, allowing for the normal functioning of breathing, chewing, swallowing, and speech. The ablative surgery of jaws in the past often led to serious disfigurement and disruption in form and function. However, with recent strides made in computer-assisted surgery and patient-specific implants, the individual functional reconstruction of the jaw is evolving rapidly and the prompt rehabilitation of both the masticatory function and aesthetics after jaw resection has been made possible. In the present review, the recent advancements in jaw reconstruction technology and future perspectives will be discussed.

Abstract

The reconstruction and rehabilitation of jaws following ablative surgery have been transformed in recent years by the development of computer-assisted surgery and virtual surgical planning. In this narrative literature review, we aim to discuss the current state-of-the-art jaw reconstruction, and to preview the potential future developments. The application of patient-specific implants and the “jaw-in-a-day technique” have made the fast restoration of jaws’ function and aesthetics possible. The improved efficiency of primary reconstructive surgery allows for the rehabilitation of neurosensory function following ablative surgery. Currently, a great deal of research has been conducted on augmented/mixed reality, artificial intelligence, virtual surgical planning for soft tissue reconstruction, and the rehabilitation of the stomatognathic system. This will lead to an even more exciting future for the functional reconstruction and rehabilitation of the jaw following ablative surgery.

Reconstruction of maxillofacial bone defects using patient-specific long-lasting titanium implants

The objective of this retrospective study is to verify the effectiveness and safety of patient-specific titanium implants on maxillofacial bones, with a long-term follow-up. Total 16 patients with various maxillofacial defects underwent reconstruction using patient-specific titanium implants. Titanium implants, manufactured by electron beam melting, selective laser sintering, or milling, were inserted into the maxilla, mandible, or zygoma. Long-term follow‐up (36.7 ± 20.1 months) was conducted after the surgery. Bone fusion of the titanium implant body, postoperative infection, implant malunion, functional results, patient satisfaction, subsidence, osteolysis around the implants, and complications were recorded and analyzed at the last follow-up. Of the 28 implants, only one failed to unite with the bone; therefore, revision surgery was performed. No osteolysis or subsidence around the titanium implants nor adverse events were observed; the mean VAS score for satisfaction was 9. All patients enrolled in this trial were esthetically and functionally satisfied with their surgical results, and fixation failure and esthetic dissatisfaction complications were well resolved. Patient-specific titanium showed satisfactory outcomes when used to treat various oral and maxillofacial defects. A 3D printed titanium implant can be effectively used in the reconstruction of the zygoma and mandible instead of autogenous bone without donor site morbidity.

Mandibular Body Reconstruction Utilizing a Three-Dimensional Custom-Made Porous Titanium Plate: A Four-Year Follow-Up Clinical Report

A clinical case of a 42-year-old woman patient, who had a mandibular reconstruction utilizing a three-dimensional (3D) custom-made porous titanium plate dental restoration, is presented. She showed a recurrence of a unicystic ameloblastoma involving the left hemimandible. The patient declined to be managed by a bone-free flap. A mandibular resection in the healthy areas was provided, followed by reconstruction utilizing a 3D custom-made porous titanium plate dental restoration with a hybrid dental prosthesis. The 3D rehabilitation was created considering slim tomodensitometric sections. The cutting guides and custom-created 3D plate were fabricated employing medical software via computer-aided design and fabricating with locations planned for healing abutments. The patient was contented with the rehabilitation, and the condition continued stable at the four-year follow-up.

Applications of 3D-Printed PEEK via Fused Filament Fabrication: A Systematic Review

Polyether ether ketone (PEEK) is an organic polymer that has excellent mechanical, chemical properties and can be additively manufactured (3D-printed) with ease. The use of 3D-printed PEEK has been growing in many fields. This article systematically reviews the current status of 3D-printed PEEK that has been used in various areas, including medical, chemical, aerospace, and electronics. A search of the use of 3D-printed PEEK articles published until September 2021 in various fields was performed using various databases. After reviewing the articles, and those which matched the inclusion criteria set for this systematic review, we found that the printing of PEEK is mainly performed by fused filament fabrication (FFF) or fused deposition modeling (FDM) printers. Based on the results of this systematic review, it was concluded that PEEK is a versatile material, and 3D-printed PEEK is finding applications in numerous industries. However, most of the applications are still in the research phase. Still, given how the research on PEEK is progressing and its additive manufacturing, it will soon be commercialized for many applications in numerous industries.

Bone Regeneration of a 3D-Printed Alloplastic and Particulate Xenogenic Graft with rhBMP-2

This study aimed to evaluate the bone regeneration capacity of a customized alloplastic material and xenograft with recombinant human bone morphogenetic protein-2 (rhBMP-2). We prepared hydroxyapatite (HA)/tricalcium phosphate (TCP) pure ceramic bone blocks made using a 3D printing system and added rhBMP-2 to both materials. In eight beagle dogs, a total of 32 defects were created on the lower jaws. The defective sites of the negative control group were left untreated (N group; 8 defects), and those in the positive control group were filled with particle-type Bio-Oss (P group; 12 defects). The defect sites in the experimental group were filled with 3D-printed synthetic bone blocks (3D group; 12 defects). Radiographic and histological evaluations were performed after healing periods of 6 and 12 weeks and showed no significant difference in new bone formation and total bone between the P and 3D groups. The 3D-printed custom HA/TCP graft with rhBMP-2 showed bone regeneration effects similar to that of particulate Bio-Oss with rhBMP-2. Through further study and development, the application of 3D-printed customized alloplastic grafts will be extended to various fields of bone regeneration.

Effect of rhBMP-2 applied with a 3D-printed titanium implant on new bone formation in rabbit calvarium

OBJECTIVE

This study sought to compare the biocompatibility of a three-dimensional (3D)-printed titanium implant with a conventional machined titanium product, as well as the effect of such implant applied with recombinant human Bone Morphogenetic Protein Type 2 (rhBMP-2) for guided bone regeneration.

METHODOLOGY

Disk-shaped titanium specimens fabricated either by the conventional machining technique or by the 3D-printing technique were compared by MC3T3-E1 cells cytotoxicity assay. New bone formation was evaluated using a rapid prototype titanium cap applied to the calvaria of 10 rabbits, which were divided into two groups: one including an atelopeptide collagen plug on one side of the cap (group I) and the other including a plug with rhBMP-2 on the other side (group II). At six and 12 weeks after euthanasia, rabbits calvaria underwent morphometric analysis through radiological and histological examination.

RESULTS

Through the cytotoxicity assay, we identified a significantly higher number of MC3T3-E1 cells in the 3D-printed specimen when compared to the machined specimen after 48 hours of culture. Moreover, morphometric analysis indicated significantly greater bone formation at week 12 on the side where rhBMP-2 was applied when evaluating the upper portion immediately below the cap.

CONCLUSION

The results suggest that 3D-printed titanium implant applied with rhBMP-2 enables new bone formation.

Tessier Number 3 and 4 Clefts: Clinical Presentation and Associated Clefts in a South African Population

INTRODUCTION

The defects found in Tessier clefts number 3 and number 4 come in various forms in different patients. These variations have to a great extent affected not only documentation of these craniofacial defects but invariably their treatment and communication amongst craniofacial researchers. This study has not only documented the clinical presentation of these clefts in a South African population but has also incorporated the clinical presentation of Tessier clefts number 3 and 4 from different regions of the world.

METHODS

The records of 8 patients, who had been treated for either Tessier clefts number 3 or 4, were reviewed and compared with 16 studies pulled from the literature systematically. The defects recorded as well as associated clefts and other congenital malformations were documented, and findings were compared.

RESULTS

The anatomical and clinical presentation of the patients was compared to the reviewed literature and the different parameters were documented. In addition, associated clefts were also recorded in the study-it was noted that the association pattern recorded in Tessier cleft number 4 in this study did not conform to its traditional counterpart.

CONCLUSION

This study concluded that the clinical presentations of these clefts, however variable, seem to have a similar presentation worldwide. Additionally, associated clefts do not conform to the original Tessier classification system and therefore it is imperative for these patterns to be clearly mapped out.

A Review of 3D Printing in Dentistry: Technologies, Affecting Factors, and Applications

Three-dimensional (3D) printing technologies are advanced manufacturing technologies based on computer-aided design digital models to create personalized 3D objects automatically. They have been widely used in the industry, design, engineering, and manufacturing fields for nearly 30 years. Three-dimensional printing has many advantages in process engineering, with applications in dentistry ranging from the field of prosthodontics, oral and maxillofacial surgery, and oral implantology to orthodontics, endodontics, and periodontology. This review provides a practical and scientific overview of 3D printing technologies. First, it introduces current 3D printing technologies, including powder bed fusion, photopolymerization molding, and fused deposition modeling. Additionally, it introduces various factors affecting 3D printing metrics, such as mechanical properties and accuracy. The final section presents a summary of the clinical applications of 3D printing in dentistry, including manufacturing working models and main applications in the fields of prosthodontics, oral and maxillofacial surgery, and oral implantology. The 3D printing technologies have the advantages of high material utilization and the ability to manufacture a single complex geometry; nevertheless, they have the disadvantages of high cost and time-consuming postprocessing. The development of new materials and technologies will be the future trend of 3D printing in dentistry, and there is no denying that 3D printing will have a bright future.

The personal limitations checklist: human factors insights from air accidents to reduce intraoperative harm

High Reliability Organisations (HRO), including healthcare and aviation, have a common focus on risk management. The human element is a 'weak link' which may result in accidents or adverse events taking place. Surgeons and other healthcare professionals can learn from aviation's rigorous approach to the role of human factors (HF) in such events, and how we can minimise them. Air Accident Investigation Branch (AAIB) reports show that fatal accidents are frequently caused by pilots flying outside their own personal limits, those of the aircraft or environment. Similarly, patient morbidity or mortality may occur if surgeons work outside personal their capability, with poor procedure selection and patient optimisation, or with a team or theatre environment not suited to the procedure. We introduce the personal limitations checklist - a tool adapted from aviation that allows surgeons to define their limits in advance of any decision to operate, and develop critical self-reflection. It also allows management of patient expectations, shared decision making, and flattening of team hierarchy. The minimum skills, patient characteristics, team and theatre resources for any given procedure to proceed are defined. If the surgeon is 'out of limits', redressing these factors, seeking additional assistance, or thorough patient consenting may be required for the safe conduct of the procedure. We explore external pressures that could cause a surgeon to exceed both personal and organisational limits.

The influence of initial defect morphology of alveolar ridge on volumetric change of grafted bone following guided bone regeneration in the anterior maxilla region: an exploratory retrospective study

Background

This study aimed to explore the influence of initial ridge defect morphology on the outcome of guided bone regeneration (GBR) in the anterior maxilla region.

Methods

Cone beam computed tomography (CBCT) examinations of patients who participated in a previous randomized controlled trial were used to assess linear and volumetric changes of bone grafts (LCB and VCB) from immediately (T0) to 6 months (T1) after surgery. The three-dimensional (3D) surface rendering of the initial defect was reconstructed, and morphological variables were defined in mesial-distal, buccal-lingual, and coronal-apical directions. The Spearman correlation, logistic regression model, and receiver operating characteristic (ROC) analyses were used to assess the possible association between initial defect morphological variables and VCB.

Results

A total of 62 eligible patients were included in this study. The median value of LCB was less than 20% at different levels, while the corresponding value of VCB was 52.0%. The Spearman correlation analysis showed that the standard deviation of buccal-lingual distance (BL_SD) was negatively associated with VCB (r=-0.315, P=0.013), whereas the ratio of maximum coronal-apical/mesial-distal distance (R_mCA/mMD) was positively related to VCB (r=0.607, P<0.001). The multivariate regression analysis revealed that the prognosis effect of BLSD (OR: 0.220, 95% CI: 0.074 to 0.655, P=0.0047) and R_mCA/mMD (OR: 7.045, 95% CI: 2.361 to 21.024, P=0.0017) remained significant. ROC curve analysis showed that R_mCA/mMD could be used to correctly classify VCB in 78.9% patients and BLSD in 71.0% of patients, as classified by the median of VCB. The discrimination value of BLSD and R_mCA/mMD revealed the areas under curve (AUC) of 0.71 (95% CI: 0.545 to 0.883) and 0.74 (95% CI: 0.573 to 0.913), respectively.

Conclusions

Within the limitations of this study, the present data confirmed the effect of initial ridge morphology on the GBR outcome in the anterior maxilla region. Specifically, a defect morphology with more BLSD and/or lower R_mCA/mMD may significantly decrease the resorption amount of grafted bone.

Polyetheretherketone and Its Composites for Bone Replacement and Regeneration

In this article, recent advances in the development, preparation, biocompatibility and mechanical properties of polyetheretherketone (PEEK) and its composites for hard and soft tissue engineering are reviewed. PEEK has been widely employed for fabricating spinal fusions due to its radiolucency, chemical stability and superior sterilization resistance at high temperatures. PEEK can also be tailored into patient-specific implants for treating orbital and craniofacial defects in combination with additive manufacturing process. However, PEEK is bioinert, lacking osseointegration after implantation. Accordingly, several approaches including surface roughening, thin film coating technology, and addition of bioactive hydroxyapatite (HA) micro-/nanofillers have been adopted to improve osseointegration performance. The elastic modulus of PEEK is 3.7-4.0 GPa, being considerably lower than that of human cortical bone ranging from 7-30 GPa. Thus, PEEK is not stiff enough to sustain applied stress in load-bearing orthopedic implants. Therefore, HA micro-/nanofillers, continuous and discontinuous carbon fibers are incorporated into PEEK for enhancing its stiffness for load-bearing applications. Among these, carbon fibers are more effective than HA micro-/nanofillers in providing additional stiffness and load-bearing capabilities. In particular, the tensile properties of PEEK composite with 30wt% short carbon fibers resemble those of cortical bone. Hydrophobic PEEK shows no degradation behavior, thus hampering its use for making porous bone scaffolds. PEEK can be blended with hydrophilic polymers such as polyglycolic acid and polyvinyl alcohol to produce biodegradable scaffolds for bone tissue engineering applications.

Stress distribution on different bar materials in implant-retained palatal obturator

Implant-retained custom-milled framework enhances the stability of palatal obturator prostheses. Therefore, to evaluate the mechanical response of implant-retained obturator prostheses with bar-clip attachment and milled bars, in three different materials under two load incidences were simulated. A maxilla model which Type IIb maxillary defect received five external hexagon implants (4.1 x 10 mm). An implant-supported palatal obturator prosthesis was simulated in three different materials: polyetheretherketone (PEEK), titanium (Ti:90%, Al:6%, V:4%) and Co-Cr (Co:60.6%, Cr:31.5%, Mo:6%) alloys. The model was imported into the analysis software and divided into a mesh composed of nodes and tetrahedral elements. Each material was assumed isotropic, elastic and homogeneous and all contacts were considered ideal. The bone was fixed and the load was applied in two different regions for each material: at the palatal face (cingulum area) of the central incisors (100 N magnitude at 45°); and at the occlusal surface of the first left molar (150 N magnitude normal to the surface). The microstrain and von-Mises stress were selected as criteria for analysis. The posterior load showed a higher strain concentration in the posterior peri-implant tissue, near the load application side for cortical and cancellous bone, regardless the simulated material. The anterior load showed a lower strain concentration with reduced magnitude and more implants involving in the load dissipation. The stress peak was calculated during posterior loading, which 77.7 MPa in the prosthetic screws and 2,686 με microstrain in the cortical bone. For bone tissue and bar, the material stiffness was inversely proportional to the calculated microstrain and stress. However, for the prosthetic screws and implants the PEEK showed higher stress concentration than the other materials. PEEK showed a promising behavior for the bone tissue and for the integrity of the bar and bar-clip attachments. However, the stress concentration in the prosthetic screws may represent an increase in failure risk. The use of Co-Cr alloy can reduce the stress in the prosthetic screw; however, it increases the bone strain; while the Titanium showed an intermediate behavior.

An Exploration of Multidisciplinary Team Care With Digital Technology for Complicated Cranio-Maxillofacial Bone Defects and Fractures

OBJECTIVE

Early treatment of fractures of the cranio-maxillofacial complex (CMFC) is challenging and likely to result in craniofacial deformity. Multidisciplinary team (MDT) care has developed very rapidly and has recently been accepted in cancer treatment. Therefore, the authors explored the application of MDT care with digital technology in CMFC fractures.

STUDY DESIGN

A 29-year-old man presented for treatment of CMFC fractures and bone defects. An MDT of oral surgeons, ophthalmic surgeons, neurological surgeons, and other experts was convened. After CT scan and three-dimensional reconstruction, the authors performed personalized surgery that included 9 specialists over an 8-hour period.

RESULTS

The operation was successful and all fractures achieved clinical stability. At 1-month follow-up, appropriate appearance and functional recovery had been achieved.

CONCLUSION

In this study, MDT care with digital technology was very effective and had low associated costs. The involvement of more disciplines in MDT care may result in fewer complications.

Clinical and volumetric outcomes after vertical ridge augmentation using computer-aided-design/computer-aided manufacturing (CAD/CAM) customized titanium meshes: a pilot study

Background

One of the most recent innovations in bone augmentation surgery is represented by computer-aided-design/computer-aided-manufacturing (CAD/CAM) customized titanium meshes, which can be used to restore vertical bone defects before implant-prosthetic rehabilitations. The aim of this study was to evaluate the effectiveness/reliability of this technique in a consecutive series of cases.

Methods

Ten patients in need of bone augmentation before implant therapy were treated using CAD/CAM customized titanium meshes. A digital workflow was adopted to design virtual meshes on 3D bone models. Then, Direct Metal Laser Sintering (DMLS) technology was used to produce the titanium meshes, and vertical ridge augmentation was performed according to an established surgical protocol. Surgical complications, healing complications, vertical bone gain (VBG), planned bone volume (PBV), lacking bone volume (LBV), regenerated bone volume (RBV), average regeneration rate (RR) and implant success rate were evaluated.

Results

All augmented sites were successfully restored with definitive implant-supported fixed partial dentures. Measurements showed an average VBG of 4.5 ± 1.8 mm at surgical re-entry. Surgical and healing complications occurred in 30% and 10% of cases, respectively. Mean values of PBV, LBV, and RBV were 984, 92, and 892 mm³, respectively. The average RR achieved was 89%. All 26 implants were successfully in function after 1 year of follow-up.

Conclusions

The results of this study suggest that the bone augmentation by means of DMLS custom-made titanium meshes can be considered a reliable and effective technique in restoring vertical bone defects.

Correction of malocclusion using sliding fibula osteotomy with sagittal split ramus osteotomy after mandible reconstruction

Background

Fibula free flap mandible reconstruction is the standard procedure after wide resection of the mandible. Establishment and maintenance of normal occlusion are important in mandible reconstruction both intraoperatively and after surgery. However, scar formation on the surgical site can cause severe fibrosis and atrophy of soft tissue in the head and neck region.

Case presentation

Here, we report a case of severe soft tissue atrophy that appeared along with scar formation after mandibular reconstruction through the fibular free flap procedure. This led to normal occlusion collapse after it was established, and the midline of the mandible became severely deviated to the affected side that was replaced with the fibula free flap, leading to facial asymmetry. We corrected the malocclusion with a secondary operation: a sagittal split ramus osteotomy on the unaffected side and a sliding osteotomy on the previous fibula graft. After a healing time of 3 months, implants were placed on the fibula graft for additional occlusal stability.

Conclusion

We report satisfactory results from the correction of malocclusion after fibula reconstruction using sliding fibula osteotomy and sagittal split ramus osteotomy. The midline of the mandible returned to its original position and the degree of facial asymmetry was reduced. The implants reduced difficulties that the patient experienced with masticatory function.

A retrospective descriptive study of cranioplasty failure rates and contributing factors in novel 3D printed calcium phosphate implants compared to traditional materials

BACKGROUND

Failure rates with cranioplasty procedures have driven efforts to improve graft material and reduce reoperation. One promising allograft source is a 3D-printed titanium mesh with calcium phosphate filler. This study evaluated failure rates and pertinent characteristics of these novel 3D-grafts compared to traditional materials.

METHODS

Sixty patients were retrospectively identified who underwent a cranioplasty between January 2015-December 2017. Specific data points related to graft failure were collected for all surgical admissions, from the primary injury to their most recent. These included, but were not limited to, initial physical exam findings, vitals, comorbid conditions, surgery length, estimated blood loss, incision type, and need for revision. Failure rates of 3D-printed allografts were compared to traditional grafts.

RESULTS

A total of 60 subjects were identified who underwent 71 unique cranioplasty procedures (3D = 13, Synthetic = 12, Autologous = 46). There were 14 total failures, demonstrating a 19.7% overall failure rate. Specifically, 15.4% (n = 2) of 3D, 19.6% (n = 9) of autologous, and 25.0% (n = 3) of synthetic grafts required revision. Patients receiving 3D-grafts had the shortest overall mean surgery times (200.8 ± 54.3 min) and lowest infection rates (7.7%) compared to autologous (210.5 ± 47.9 min | 25.0%) and synthetic models (217.6 ± 77.3 min | 8.7%), though significance was unable to be determined. Tobacco use and trap-door incisions were associated with increased failure rates relative to straight or curved incisions in autologous grafts. Cranioplasties performed less than 3 months after craniectomy appeared to fail more often than those performed at least three months after craniectomy, for the synthetic group.

CONCLUSION

We concluded that 3D-printed cranioplasty grafts may lead to lower failure rates and shorter surgery times compared to traditional cranioplasty materials in our limited population. 3D-implants hold promise for cranial reconstruction after TBI.

Oral health-related quality of life in tumour patients treated with patient-specific dental implants

Dental rehabilitation after surgically acquired bone deficiency related to tumour treatment remains a challenge. The insertion of patient-specific implants geared to the contour of the remaining bone is a feasible method of supporting fixed or removable dentures. As oral health-related quality of life (OHRQoL) is of great interest in these cases, 12 individuals treated with patient-specific implants for severe bone deficiency were surveyed and their Oral Health Impact Profile (OHIP) scores after dental rehabilitation were evaluated. The OHIP-G53 questionnaire was used to measure overall treatment outcomes. The distribution of OHIP sum-scores for participants treated with patient-specific implants was almost homogeneous when compared to those cited in the literature for patients treated with conventional dental implants. OHIP items related to functional impairment and physical pain showed the highest scores (occurring occasionally), and financial loss related to treatment was frequently stated. Moreover, higher scores were detected in almost all OHIP dimensions for participants with patient-specific implant-supported removable dentures. Conversely, those treated with patient-specific dental implants and fixed dentures showed lower psychosocial impact scores and equal or superior OHRQoL. Hence, patient-specific dental implants, especially combined with fixed dentures, can lead to a positive OHRQoL in patients with severe bone deficiencies related to tumour therapy.

Classification of the journal category "oral surgery" in the Scopus and the Science Citation Index Expanded: flaws and suggestions

Objectives

The aim of this study was to evaluate the journal category “oral surgery” in Scopus and in the Science Citation Index Expanded (SCIE).

Materials and Methods

The Journal of Oral and Maxillofacial Surgery (JOMS), The Journal of the Korean Association of Oral and Maxillofacial Surgeons (JKAOMS), and The Journal of Prosthodontic Research (JPR) were selected from the Scopus list of journals as oral surgery journals. Maxillofacial Plastic and Reconstructive Surgery (MPRS) was selected from PubMed as a Scopus oral surgery title. From these titles, 10 recently published articles were collected and used for reference analysis.

Results

The percentage of citations from oral surgery journals was 26.7%, 24.5%, and 40.1% for JKAOMS, MPRS, and JOMS, respectively. In total, 1.1% of JPR's citations were from oral surgery journals and significantly fewer from other journals (P<0.001). The percentage of citations from dentistry journals excluding oral surgery journals was 11.9%, 34.4%, and 15.8% for JKAOMS, MPRS, and JOMS, respectively. For JPR, 80.6% of citations were from dentistry journals and significantly more were from other journals (P<0.001).

Conclusion

Selected samples revealed that JPR is incorrectly classified as an oral surgery journal in Scopus. In addition, the scientific interaction among JKAOMS, MPRS, and JOMS was different to JPR in the reference analysis.

Subtotal calvarial vault reconstruction utilizing a customized polyetheretherketone (PEEK) implant with chimeric microvascular soft tissue coverage in a patient with syndrome of the trephined: A case report

The syndrome of the trephined is a neurologic phenomenon that manifests as sudden decline in cognition, behavior, and sensorimotor function due to loss of intracranial domain. This scenario typically occurs in the setting of large craniectomy defects, resulting from trauma, infection, and/or oncologic extirpation. Cranioplasty has been shown to reverse these symptoms by normalizing cerebral hemodynamics and metabolism. However, successful reconstruction may be difficult in patients with complex and/or hostile calvarial defects. We present the case of a 48-year-old male with a large cranial bone defect, who failed autologous cranioplasty secondary to infection, and developed rapid neurologic deterioration leading to a near-vegetative state. Following debridement and antibiotic therapy, delayed cranioplasty was accomplished using a polyetheretherketone (PEEK) implant with free chimeric latissimus dorsi/serratus anterior myocutaneous flap transfer for vascularized resurfacing. Significant improvements in cognition and motor skill were noted in the early postoperative period. At 6-month follow-up, the patient had regained the ability to speak, ambulate and self-feed—correlating with evidence of cerebral/ventricular re-expansion on computed tomography. Based on our findings, we advocate delayed alloplastic implantation with total vascularized soft tissue coverage as a viable alternative for reconstructing extensive, hostile calvarial defects in patients with the syndrome of the trephined.

Fabrication of dental implants by the additive manufacturing method: A systematic review

STATEMENT OF PROBLEM

Placement of dental implants depends, among other factors, on anatomic conditions such as sufficient bone height and thickness. Thus, individualized dental implants seem to offer benefits for patients with alveolar bone resorption. Additive manufacturing has allowed for the fabrication of custom implants with microscale resolution and, although the efficiency of the process is unclear, is a potential process for manufacturing dental implants.

PURPOSE

The purpose of this systematic review was to evaluate the current situation of additive manufacturing techniques for fabricating dental implants.

MATERIAL AND METHODS

An electronic search was performed in the databases PubMed, Lilacs, Cochrane Library, and Science Direct, with the terms "additive manufacturing" AND "dental implants," "rapid prototyping" AND "dental implants," "3 D printing" AND "dental implants," "electron beam melting" AND "dental implants," "selective laser melting" AND "dental implants." The articles were screened, and the final selection of articles was obtained by using the inclusion and exclusion criteria.

RESULTS

The database search resulted in 1322 articles, which were screened for title and/or summary according to the inclusion criteria. From the selected 38 articles, 30 remained after applying the exclusion criteria. These were read completely, resulting in a selection of 13 articles for this systematic review. Owing to the great variety of articles with different objectives, the results were based on a descriptive analysis of the following topics: additive manufacturing technique and material, printed structure and implant design, implant characteristics, mechanical analysis, surface treatment, and osseointegration.

CONCLUSIONS

Additive manufacturing is a new technology that may solve many problems in diverse fields. In dentistry, however, further studies are needed to improve the method for manufacturing custom dental implants because no standard methodology is available. Moreover, the advantages and disadvantages of the process are not yet clearly defined.

3D Printing-Encompassing the Facets of Dentistry

This narrative review presents an overview on the currently available 3D printing technologies and their utilization in experimental, clinical and educational facets, from the perspective of different specialties of dentistry, including oral and maxillofacial surgery, orthodontics, endodontics, prosthodontics, and periodontics. It covers research and innovation, treatment modalities, education and training, employing the rapidly developing 3D printing process. Research-oriented advancement in 3D printing in dentistry is witnessed by the rising number of publications on this topic. Visualization of treatment outcomes makes it a promising clinical tool. Educational programs utilizing 3D-printed models stimulate training of dental skills in students and trainees. 3D printing has enormous potential to ameliorate oral health care in research, clinical treatment, and education in dentistry.