Precise positioning of an intraoral distractor using augmented reality in patients with hemifacial microsomia

Augmented Reality Navigation in Craniomaxillofacial/Head and Neck Surgery

Objective

This study aims to (1) develop an augmented reality (AR) navigation platform for craniomaxillofacial (CMF) and head and neck surgery; (2) apply it to a range of surgical cases; and (3) evaluate the advantages, disadvantages, and clinical opportunities for AR navigation.

Study Design

A multi-center retrospective case series.

Setting

Four tertiary care academic centers.

Methods

A novel AR navigation platform was collaboratively developed with Xironetic and deployed intraoperatively using only a head-mounted display (Microsoft HoloLens 2). Virtual surgical plans were generated from computed tomography/magnetic resonance imaging data and uploaded onto the AR platform. A reference array was mounted to the patient, and the virtual plan was registered to the patient intraoperatively. A retrospective review of all AR-navigated CMF cases since September 2023 was performed.

Results

Thirty-three cases were reviewed and classified as either trauma, orthognathic, tumor, or craniofacial. The AR platform had several advantages over traditional navigation including real-time 3D visualization of the surgical plan, identification of critical structures, and real-time tracking. Furthermore, this case series presents the first-known examples of (1) AR instrument tracking for midface osteotomies, (2) AR tracking of the zygomaticomaxillary complex during fracture reduction, (3) mandibular tracking in orthognathic surgery, (4) AR fibula cutting guides for mandibular reconstruction, and (5) integration of real-time infrared visualization in an AR headset for vasculature identification.

Conclusion

While still a developing technology, AR navigation provides several advantages over traditional navigation for CMF and head and neck surgery, including heads up, interactive 3D visualization of the surgical plan, identification of critical anatomy, and real-time tracking.

Artificial Intelligence Applications in Pediatric Craniofacial Surgery

Artificial intelligence is rapidly transforming pediatric craniofacial surgery by enhancing diagnostic accuracy, improving surgical precision, and optimizing postoperative care. Machine learning and deep learning models are increasingly used to analyze complex craniofacial imaging, enabling early detection of congenital anomalies such as craniosynostosis, and cleft lip and palate. AI-driven algorithms assist in preoperative planning by identifying anatomical abnormalities, predicting surgical outcomes, and guiding personalized treatment strategies. In cleft lip and palate care, AI enhances prenatal detection, severity classification, and the design of custom therapeutic devices, while also refining speech evaluation. For craniosynostosis, AI supports automated morphology classification, severity scoring, and the assessment of surgical indications, thereby promoting diagnostic consistency and predictive outcome modeling. In orthognathic surgery, AI-driven analyses, including skeletal maturity evaluation and cephalometric assessment, inform optimal timing and diagnosis. Furthermore, in cases of craniofacial microsomia and microtia, AI improves phenotypic classification and surgical planning through precise intraoperative navigation. These advancements underscore AI's transformative role in diagnostic accuracy, and clinical decision-making, highlighting its potential to significantly enhance evidence-based pediatric craniofacial care.

CAD/CAM surgical guides and pre-bent distractors: Enhancing precision in MDO for severe dentofacial deformities secondary to TMJ ankylosis

BACKGROUND

This study aimed to compare the different outcomes of mandibular distraction osteogenesis (MDO) using computer-aided design and manufacturing (CAD/CAM) surgical guides accompanied by pre-bent distractors versus CAD/CAM surgical guides with commercial distractors.

METHODS

Twenty-eight patients with severe dentofacial deformities secondary to unilateral temporomandibular joint ankylosis (TMJA) were retrospectively enrolled. Ten parameters associated with MDO were measured preoperatively, virtually, and postoperatively. The hard-tissue digital model was reconstructed using Mimics Research 17.0, and imaging data were collected and analyzed using Freeform Plus software 12.0, Geomagic Studio 12.0, and IBM SPSS Version 20.0.

RESULTS

Twenty-eight patients underwent MDO with subsequent adjunctive surgery and were evaluated. Thirteen patients underwent CAD/CAM surgical guides with pre-bent distractors (group A), while fifteen underwent CAD/CAM guides with commercial distractors (group B). Both techniques achieved optimal occlusion and satisfactory appearance. Statistical analysis showed group A demonstrated a more accurate control of vector direction during MDO compared to group B (p < 0.05). Additionally, group A also exhibited a shorter subsequent treatment duration and less relapse compared to group B (p < 0.05).

CONCLUSIONS

CAD/CAM surgical guides with pre-bent distractors can significantly enhance surgical accuracy in controlling the vector direction of MDO for correcting dentofacial deformities secondary to TMJA, leading to a reduction in subsequent treatment duration and occurrence.

Is Overlain Display a Right Choice for AR Navigation? A Qualitative Study of Head-Mounted Augmented Reality Surgical Navigation on Accuracy for Large-Scale Clinical Deployment

BACKGROUND

During the course of the past two decades, head-mounted augmented reality surgical navigation (HMARSN) systems have been increasingly employed in a variety of surgical specialties as a result of both advancements in augmented reality-related technologies and surgeons' desires to overcome some drawbacks inherent to conventional surgical navigation systems. In the present time, most experimental HMARSN systems adopt overlain display (OD) that overlay virtual models and planned routes of surgical tools on corresponding physical tissues, organs, lesions, and so forth, in a surgical field so as to provide surgeons with an intuitive and direct view to gain better hand-eye coordination as well as avoid attention shift and loss of sight (LOS), among other benefits during procedures. Yet, its system accuracy, which is the most crucial performance indicator of any surgical navigation system, is difficult to ascertain because it is highly subjective and user-dependent. Therefore, the aim of this study was to review presently available experimental OD HMARSN systems qualitatively, explore how their system accuracy is affected by overlain display, and find out if such systems are suited to large-scale clinical deployment.

METHOD

We searched PubMed and ScienceDirect with the following terms: head mounted augmented reality surgical navigation, and 445 records were returned in total. After screening and eligibility assessment, 60 papers were finally analyzed. Specifically, we focused on how their accuracies were defined and measured, as well as whether such accuracies are stable in clinical practice and competitive with corresponding commercially available systems.

RESULTS AND CONCLUSIONS

The primary findings are that the system accuracy of OD HMARSN systems is seriously affected by a transformation between the spaces of the user's eyes and the surgical field, because measurement of the transformation is heavily individualized and user-dependent. Additionally, the transformation itself is potentially subject to changes during surgical procedures, and hence unstable. Therefore, OD HMARSN systems are not suitable for large-scale clinical deployment.

Augmented reality in implantology: Virtual surgical checklist and augmented implant placement

OBJECTIVES

Aim of the present study was to create a pedagogical checklist for implant surgical protocol with an augmented reality (AR) guided freehand surgery to inexperienced surgeons using a head mounted display (HMD) with tracking.

METHODS

The anatomical model of a patient with two missing mandibular teeth requiring conventional single-tooth implants was selected. The computed tomography (CT) scans were extracted and imported into segmentation and implant planning software. A Patient-specific dental splint through an intermediate strut, supported 3D-printed QR code. A checklist was generated to guide surgical procedure. After tracking, the AR-HMD projects the virtual pre-surgical plan (inferior alveolar nerve (IAN), implant axis, implant location) onto the real 3D-printed anatomical models. The entire drilling sequence was based on the manufacturer's recommendations, on 3D-printed anatomical models. After the implant surgical procedure, CT of the 3D-printed models was performed to compare the actual and simulated implant placements. All procedures in the study were performed in accordance with the Declaration of Helsinki.

RESULTS

In total, two implants were placed in a 3D-printed anatomical model of a female patient who required implant rehabilitation for dental agenesis at the second mandibular premolar positions (#35 and #45). Superimposition of the actual and simulated implants showed high concordance between them.

CONCLUSION

AR in education offers crucial surgical information for novice surgeons in real time. However, the benefits provided by AR in clinical and educational implantology must be demonstrated in other studies involving a larger number of patients, surgeons and apprentices.

Enhancing Surgical Vision: Augmented Reality in Otolaryngology-Head and Neck Surgery

Augmented reality (AR) technology has become widely established in otolaryngology-head and neck surgery. Over the past 20 years, numerous AR systems have been investigated and validated across the subspecialties, both in cadaveric and in live surgical studies. AR displays projected through head-mounted devices, microscopes, and endoscopes, most commonly, have demonstrated utility in preoperative planning, intraoperative guidance, and improvement of surgical decision-making. Specifically, they have demonstrated feasibility in guiding tumor margin resections, identifying critical structures intraoperatively, and displaying patient-specific virtual models derived from preoperative imaging, with millimetric accuracy. This review summarizes both established and emerging AR technologies, detailing how their systems work, what features they offer, and their clinical impact across otolaryngology subspecialties. As AR technology continues to advance, its integration holds promise for enhancing surgical precision, simulation training, and ultimately, improving patient outcomes.

Exploring the potential role for extended reality in Mohs micrographic surgery

Mohs micrographic surgery (MMS) is a cornerstone of dermatological practice. Virtual reality (VR) and augmented reality (AR) technology, initially used for entertainment, have entered healthcare, offering real-time data overlaying a surgeon's view. This paper explores potential applications of VR and AR in MMS, emphasizing their advantages and limitations. We aim to identify research gaps to facilitate innovation in dermatological surgery. We conducted a PubMed search using the following: "augmented reality" OR "virtual reality" AND "Mohs" or "augmented reality" OR "virtual reality" AND "surgery." Inclusion criteria were peer-reviewed articles in English discussing these technologies in medical settings. We excluded non-peer-reviewed sources, non-English articles, and those not addressing these technologies in a medical context. VR alleviates patient anxiety and enhances patient satisfaction while serving as an educational tool. It also aids physicians by providing realistic surgical simulations. On the other hand, AR assists in real-time lesion analysis, optimizing incision planning, and refining margin control during surgery. Both of these technologies offer remote guidance for trainee residents, enabling real-time learning and oversight and facilitating synchronous teleconsultations. These technologies may transform dermatologic surgery, making it more accessible and efficient. However, further research is needed to validate their effectiveness, address potential challenges, and optimize seamless integration. All in all, AR and VR enhance real-world environments with digital data, offering real-time surgical guidance and medical insights. By exploring the potential integration of these technologies in MMS, our study identifies avenues for further research to thoroughly understand the role of these technologies to redefine dermatologic surgery, elevating precision, surgical outcomes, and patient experiences.

From bench to bedside - current clinical and translational challenges in fibula free flap reconstruction

Fibula free flaps (FFF) represent a working horse for different reconstructive scenarios in facial surgery. While FFF were initially established for mandible reconstruction, advancements in planning for microsurgical techniques have paved the way toward a broader spectrum of indications, including maxillary defects. Essential factors to improve patient outcomes following FFF include minimal donor site morbidity, adequate bone length, and dual blood supply. Yet, persisting clinical and translational challenges hamper the effectiveness of FFF. In the preoperative phase, virtual surgical planning and artificial intelligence tools carry untapped potential, while the intraoperative role of individualized surgical templates and bioprinted prostheses remains to be summarized. Further, the integration of novel flap monitoring technologies into postoperative patient management has been subject to translational and clinical research efforts. Overall, there is a paucity of studies condensing the body of knowledge on emerging technologies and techniques in FFF surgery. Herein, we aim to review current challenges and solution possibilities in FFF. This line of research may serve as a pocket guide on cutting-edge developments and facilitate future targeted research in FFF.

Mandibular resection and defect reconstruction guided by a contour registration-based augmented reality system: A preclinical trial

The aim of this study was to verify the feasibility and accuracy of a contour registration-based augmented reality (AR) system in jaw surgery. An AR system was developed to display the interaction between virtual planning and images of the surgical site in real time. Several trials were performed with the guidance of the AR system and the surgical guide. The postoperative cone beam CT (CBCT) data were matched with the preoperatively planned data to evaluate the accuracy of the system by comparing the deviations in distance and angle. All procedures were performed successfully. In nine model trials, distance and angular deviations for the mandible, reconstructed fibula, and fixation screws were 1.62 ± 0.38 mm, 1.86 ± 0.43 mm, 1.67 ± 0.70 mm, and 3.68 ± 0.71°, 5.48 ± 2.06°, 7.50 ± 1.39°, respectively. In twelve animal trials, results of the AR system were compared with the surgical guide. Distance deviations for the bilateral condylar outer poles were 0.93 ± 0.63 mm and 0.81 ± 0.30 mm, respectively (p = 0.68). Distance deviations for the bilateral mandibular posterior angles were 2.01 ± 2.49 mm and 2.89 ± 1.83 mm, respectively (p = 0.50). Distance and angular deviations for the mandible were 1.41 ± 0.61 mm, 1.21 ± 0.18 mm (p = 0.45), and 6.81 ± 2.21°, 6.11 ± 2.93° (p = 0.65), respectively. Distance and angular deviations for the reconstructed tibiofibular bones were 0.88 ± 0.22 mm, 0.84 ± 0.18 mm (p = 0.70), and 6.47 ± 3.03°, 6.90 ± 4.01° (p = 0.84), respectively. This study proposed a contour registration-based AR system to assist surgeons in intuitively observing the surgical plan intraoperatively. The trial results indicated that this system had similar accuracy to the surgical guide.

Preclinical Application of Augmented Reality in Pediatric Craniofacial Surgery: An Accuracy Study

Background: Augmented reality (AR) allows the overlapping and integration of virtual information with the real environment. The camera of the AR device reads the object and integrates the virtual data. It has been widely applied to medical and surgical sciences in recent years and has the potential to enhance intraoperative navigation. Materials and methods: In this study, the authors aim to assess the accuracy of AR guidance when using the commercial HoloLens 2 head-mounted display (HMD) in pediatric craniofacial surgery. The Authors selected fronto-orbital remodeling (FOR) as the procedure to test (specifically, frontal osteotomy and nasal osteotomy were considered). Six people (three surgeons and three engineers) were recruited to perform the osteotomies on a 3D printed stereolithographic model under the guidance of AR. By means of calibrated CAD/CAM cutting guides with different grooves, the authors measured the accuracy of the osteotomies that were performed. We tested accuracy levels of ±1.5 mm, ±1 mm, and ±0.5 mm. Results: With the HoloLens 2, the majority of the individuals involved were able to successfully trace the trajectories of the frontal and nasal osteotomies with an accuracy level of ±1.5 mm. Additionally, 80% were able to achieve an accuracy level of ±1 mm when performing a nasal osteotomy, and 52% were able to achieve an accuracy level of ±1 mm when performing a frontal osteotomy, while 61% were able to achieve an accuracy level of ±0.5 mm when performing a nasal osteotomy, and 33% were able to achieve an accuracy level of ±0.5 mm when performing a frontal osteotomy. Conclusions: despite this being an in vitro study, the authors reported encouraging results for the prospective use of AR on actual patients.

Feasibility of a Robot-Assisted Surgical Navigation System for Mandibular Distraction Osteogenesis in Hemifacial Microsomia: A Model Experiment

This study aimed to investigate the feasibility and accuracy of osteotomy and distractor placement using a robotic navigation system in a model surgical experiment of mandibular distraction osteogenesis for hemifacial microsomia. Imaging data from 5 patients with Pruzansky-Kaban type II (IIa: 4; IIb: 1) mandibular deformities were used to print 3D models for simulated mandibular distraction osteogenesis. In the experimental group, a robot-assisted surgical navigation system was used to perform the surgery under robotic guidance following registration, according to the preoperative design. Conventional surgery was performed in the control group, in which the operation was based on intraoperative estimations of the preoperative design by experienced surgeons. The accuracies of the osteotomy and distractor placement were assessed based on distance and angular error. Osteotomy accuracy was higher in the experimental group than in the control group, and the distance error ( t =9.311, P <0.001) and angular error ( t =5.385, P =0.001) were significantly reduced. The accuracy of distractor placement was also significantly higher in the experimental group, while the distance error ( t =3.048, P =0.016) and angular error ( t =3.524, P =0.024) were significantly reduced. The present results highlight the feasibility of robot-assisted distraction osteogenesis combined with electromagnetic navigation for improved surgical precision in clinical settings.

User's image perception improved strategy and application of augmented reality systems in smart medical care: A review

BACKGROUND

Augmented reality (AR) is a new human-computer interaction technology that combines virtual reality, computer vision, and computer networks. With the rapid advancement of the medical field towards intelligence and data visualisation, AR systems are becoming increasingly popular in the medical field because they can provide doctors with clear enough medical images and accurate image navigation in practical applications. However, it has been discovered that different display types of AR systems have different effects on doctors' perception of the image after virtual-real fusion during the actual medical application. If doctors cannot correctly perceive the image, they may be unable to correctly match the virtual information with the real world, which will have a significant impact on their ability to recognise complex structures.

METHODS

This paper uses Citespace, a literature analysis tool, to visualise and analyse the research hotspots when AR systems are used in the medical field.

RESULTS

A visual analysis of the 1163 articles retrieved from the Web of Science Core Collection database reveals that display technology and visualisation technology are the key research directions of AR systems at the moment.

CONCLUSION

This paper categorises AR systems based on their display principles, reviews current image perception optimisation schemes for various types of systems, and analyses and compares different display types of AR systems based on their practical applications in the field of smart medical care so that doctors can select the appropriate display types based on different application scenarios. Finally, the future development direction of AR display technology is anticipated in order for AR technology to be more effectively applied in the field of smart medical care. The advancement of display technology for AR systems is critical for their use in the medical field, and the advantages and disadvantages of various display types should be considered in different application scenarios to select the best AR system.

A data-centric artificial intelligent and extended reality technology in smart healthcare systems

Extended reality (XR) solutions are quietly maturing, and their novel use cases are already being investigated, particularly in the healthcare industry. By 2022, the extended reality market is anticipated to be worth $209 billion. Certain diseases, such as Alzheimer's, Schizophrenia, Stroke rehabilitation stimulating specific areas of the patient's brain, healing brain injuries, surgeon training, realistic 3D visualization, touch-free interfaces, and teaching social skills to children with autism, have shown promising results with XR-assisted treatments. Similar effects have been used in video game therapies like Akili Interactive's EndeavorRx, which has previously been approved by the Food and Drug Administration (FDA) as a treatment regimen for children with attention deficit hyperactivity disorder (ADHD). However, while these improvements have received positive feedback, the field of XR-assisted patient treatment is in its infancy. The growth of XR in the healthcare sphere has the potential to transform the delivery of medical services. Imagine an elderly patient in a remote setting having a consultation with a world-renowned expert without ever having to leave their house. Rather than operating on cadavers in a medical facility, a surgical resident does surgery in a virtual setting at home. On the first try, a nurse uses a vein finder to implant an IV. Through cognitive treatment in a virtual world, a war veteran recovers from post-traumatic stress disorder (PTSD). The paper discusses the potential impact of XR in transforming the healthcare industry, as well as its use cases, challenges, XR tools and techniques for intelligent health care, recent developments of XR in intelligent healthcare services, and the potential benefits and future aspects of XR techniques in the medical domain.

Augmented reality hologram combined with pre-bent distractor enhanced the accuracy of distraction vector transfer in maxillary distraction osteogenesis, a study based on 3D printed phantoms

BACKGROUND

Vector control is a significant concern in maxillary distraction osteogenesis (DO). Distraction vector planning on the patient's 3D-printed skull phantom is more intuitive for surgeons and cost-efficient than virtual surgical planning. However, the accuracy of transferring the planned vector to intraoperative (vector transfer) according to the shape of the pre-bent footplate alone is relatively limited. The application of augmented reality (AR) in surgical navigation has been studied for years. However, few studies have focused on its role in maxillary DO vector transfer. This study aimed to evaluate the accuracy of AR surgical navigation combined with the pre-bent distractor in vector transfer by comparing it with the pre-bent distractor alone.

METHODS

Ten patients with maxillary hypoplasia were enrolled with consent, and three identical 3D-printed skull phantoms were manufactured based on per patient's corresponding pre-operative CT data. Among these, one phantom was for pre-operative planning (n = 10), while and the other two were for the AR+Pre-bending group (n = 10) and the Pre-bending group (n = 10) for the experimental surgery, respectively. In the Pre-bending group, the distraction vector was solely determined by matching the shape of footplates and maxillary surface. In the AR+Pre-bending group, the distractors were first confirmed to have no deformation. Then AR surgical navigation was applied to check and adjust the vector in addition to the steps as in the Pre-bending Group.

RESULTS

For the angular deviation of the distraction vector, the AR+Pre-bending group was significantly smaller than the Pre-bending group in spatial (p < 0.001), x-y plane (p = 0.002), and y-z plane (p < 0.001), and there were no significant differences in the x-z plane (p = 0.221). The AR+Pre-bending group was more accurate in deviations of the Euclidean distance (p = 0.004) and the y-axis (p = 0.011). In addition, the AR+Pre-bending group was more accurate for the distraction result.

CONCLUSIONS

In this study based on 3D printed skull phantoms, the AR surgical navigation combined with the pre-bent distractor enhanced the accuracy of vector transfer in maxillary DO, compared with the pre-bending technique alone.

Preliminary study of the accuracy and safety of robot-assisted mandibular distraction osteogenesis with electromagnetic navigation in hemifacial microsomia using rabbit models

This study aimed to investigate the accuracy and safety of mandibular osteotomy and distraction device positioning in distraction osteogenesis assisted by an electromagnetic navigation surgical robot. Twelve New Zealand white rabbits were randomly divided into two groups after computed tomography. The control group underwent a procedure based on the preoperative three-dimensional design and clinical experience. Animals in experimental group underwent a procedure with robotic assistance after registration. The accuracies of osteotomy and distraction device positioning were analysed based on distance and angular errors. The change in ramus length after a 1 cm-extension of the distraction device was for assessing distraction effect. The preparation, operative and osteotomy times, intraoperative bleeding, and teeth injury were used for safety assessment. In the experimental group, the distance (t = 2.591, p = 0.011) and angular (t = 4.276, p = 0.002) errors of osteotomy plane, and the errors in distraction device position (t = 3.222, p = 0.009) and direction (t = 4.697, p = 0.001) were lower; the distraction effect was better (t = 4.096, p = 0.002). There was no significant difference in the osteotomy time and bleeding; however, the overall operative and preparation times were increased in the experimental group, with a reduced rate of teeth damage. Robot-assisted mandibular distraction osteogenesis with electromagnetic navigation in craniofacial microsomia is feasible, safe, significantly improves surgical precision.

3D Printing and Virtual Surgical Planning in Oral and Maxillofacial Surgery

Compared to traditional manufacturing methods, additive manufacturing and 3D printing stand out in their ability to rapidly fabricate complex structures and precise geometries. The growing need for products with different designs, purposes and materials led to the development of 3D printing, serving as a driving force for the 4th industrial revolution and digitization of manufacturing. 3D printing has had a global impact on healthcare, with patient-customized implants now replacing generic implantable medical devices. This revolution has had a particularly significant impact on oral and maxillofacial surgery, where surgeons rely on precision medicine in everyday practice. Trauma, orthognathic surgery and total joint replacement therapy represent several examples of treatments improved by 3D technologies. The widespread and rapid implementation of 3D technologies in clinical settings has led to the development of point-of-care treatment facilities with in-house infrastructure, enabling surgical teams to participate in the 3D design and manufacturing of devices. 3D technologies have had a tremendous impact on clinical outcomes and on the way clinicians approach treatment planning. The current review offers our perspective on the implementation of 3D-based technologies in the field of oral and maxillofacial surgery, while indicating major clinical applications. Moreover, the current report outlines the 3D printing point-of-care concept in the field of oral and maxillofacial surgery.

Augmented Reality and Virtual Reality in Dentistry: Highlights from the Current Research

Many modern advancements have taken place in dentistry that have exponentially impacted the progress and practice of dentistry. Augmented reality (AR) and virtual reality (VR) are becoming the trend in the practice of modern dentistry because of their impact on changing the patient’s experience. The use of AR and VR has been beneficial in different fields of science, but their use in dentistry is yet to be thoroughly explored, and conventional ways of dentistry are still practiced at large. Over the past few years, dental treatment has been significantly reshaped by technological advancements. In dentistry, the use of AR and VR systems has not become widespread, but their different uses should be explored. Therefore, the aim of this review was to provide an update on the contemporary knowledge, to report on the ongoing progress of AR and VR in various fields of dental medicine and education, and to identify the further research required to achieve their translation into clinical practice. A literature search was performed in PubMed, Scopus, Web of Science, and Google Scholar for articles in peer-reviewed English-language journals published in the last 10 years up to 31 March 2021, with the help of specific keywords related to AR and VR in various dental fields. Of the total of 101 articles found in the literature search, 68 abstracts were considered suitable and further evaluated, and consequently, 33 full-texts were identified. Finally, a total of 13 full-texts were excluded from further analysis, resulting in 20 articles for final inclusion. The overall number of studies included in this review was low; thus, at this point in time, scientifically-proven recommendations could not be stated. AR and VR have been found to be beneficial tools for clinical practice and for enhancing the learning experiences of students during their pre-clinical education and training sessions. Clinicians can use VR technology to show their patients the expected outcomes before the undergo dental procedures. Additionally, AR and VR can be implemented to overcome dental phobia, which is commonly experienced by pediatric patients. Future studies should focus on forming technological standards with high-quality data and developing scientifically-proven AR/VR gadgets for dental practice.

The application of augmented reality in craniofacial bone fracture reduction: study protocol for a randomized controlled trial

Background

Augmented reality (AR) is a new technology that increases users’ perception of the real world. The purpose of this study is to evaluate the efficacy and safety of augmented reality navigation system in treatment with craniofacial fracture reduction.

Methods

This will be a single-center prospective randomized controlled trial. Twenty-two patients will be assigned to two groups of 11, and those with zygomaticomaxillary complex fractures will undergo preoperative three-dimensional CT modeling and have operational plans designed. The control team will use traditional optical navigation to perform the surgery, and the experimental team will use an AR navigation system. The primary outcome measures will be the accuracy of the key points of surgical area between the preoperational surgical plan and post-operation. The secondary outcome measures will be the blood loss, operation time, bone reduction time, hospital time, and complication rate. The findings obtained through this study are expected to evaluate efficacy and safety of the augmented reality navigation system in the treatment of zygomaticomaxillary complex fractures.

Discussion

This controlled trial of augmented reality navigation system in treatment with zygomaticomaxillary complex fracture reduction will clarify the efficacy and safety of this technology by measuring the accuracy of the key points of surgical area and blood loss, operation and bone reduction times, hospital stay duration, and complication rates. This is a single-center study, and the results are expected to promote the application of augmented reality in craniofacial fracture reduction to improve surgery accuracy and efficacy.

Trial registration

Chinese Clinical Trial Registry ChiCTR1900022626. Registered on April 19, 2019.

Total elbow arthroplasty using an augmented reality-assisted surgical technique

BACKGROUND

Precision placement of implants in total elbow arthroplasty (TEA) using conventional surgical techniques can be difficult and riddled with errors. Modern technologies such as augmented reality (AR) and 3-dimensional (3D) printing have already found useful applications in many fields of medicine. We proposed a cutting-edge surgical technique, augmented reality total elbow arthroplasty (ARTEA), that uses AR and 3D printing to provide 3D information for intuitive preoperative planning. The purpose of this study was to evaluate the accuracy of humeral and ulnar component placement using ARTEA.

METHODS

Twelve upper extremities from human frozen cadavers were used for experiments performed in this study. We scanned the extremities via computed tomography prior to performing TEA to plan placement sites using computer simulations. The ARTEA technique was used to perform TEA surgery on 6 of the extremities, whereas conventional (non-ARTEA) techniques were used on the other 6 extremities. Computed tomography scanning was repeated after TEA completion, and the error between the planned and actual placements of humeral and ulnar components was calculated and compared.

RESULTS

For humeral component placement, the mean positional error ± standard deviation of ARTEA vs. non-ARTEA was 1.4° ± 0.6° vs. 4.4° ± 0.9° in total rotation (P = .002) and 1.5 ± 0.6 mm vs. 8.6 ± 1.3 mm in total translation (P = .002). For ulnar component placement, the mean positional error ± standard deviation of ARTEA vs. non-ARTEA was 5.5° ± 3.1° vs. 19.5° ± 9.8° in total rotation (P = .004) and 1.5 ± 0.4 mm vs. 6.9 ± 1.6 mm in total translation (P = .002). Both rotational accuracy and translational accuracy were greater for joint components replaced using the ARTEA technique compared with the non-ARTEA technique (P < .05).

CONCLUSION

Compared with conventional surgical techniques, ARTEA had greater accuracy in prosthetic implant placement when used to perform TEA.

Application of Augmented Reality Navigation in Treatment With Fibrosis Dysplasia

OBJECTIVE

In order to reduce the possibility of accidental injury to neurovascular and important tissues, this research conduct preoperative design and intraoperative guidance for fibrous dysplasia through augmented reality technology.

METHODS

Five patients with fibrous dysplasia were selected for three-dimensional (3D) computed tomography (CT) scan and 3D model was reconstructed. Considering the navigation plan was comprehensively, the guide plate (composed of card groove, connector, and fixator) was designed and 3D printed. Three-dimensional software was used to unify the coordinates of the surgical plan and the guide plate, and the relative position was fixed. Then, the virtual and real overlapping registration is completed on the physical model. Pattern recognition technology is used to identify pre-defined markers in the video images before operation. Finally, the registration results are superimposed into the surgical field of vision to guide and remind surgeons.

RESULTS

In this study, the navigation based on augmented reality technology was used in the surgical treatment of 5 cases patients with fibrous dysplasia. The 3D navigation information was displayed in real time in the operative field. The operation was accurate and the postoperative effect was good.

CONCLUSIONS

This paper introduces an effective visual navigation surgical method in treatment with fibrous dysplasia. The augmented-reality based navigation system achieves individualized precise treatment by displaying 3D navigation directly in the surgical field. It is an effective auxiliary method for future research on craniofacial surgery.

AUGMENTED REALITY NAVIGATION FRAMEWORK FOR TOTAL HIP ARTHROPLASTY SURGERY

In a total hip arthroplasty surgery, correctly implanting the artificial acetabulum and the femoral head is essential for a successful treatment. An augmented reality (AR) navigation framework is proposed in this paper to provide accurate surgical guidance in a total hip arthroplasty procedure. The AR framework consists of three parts: (1) preoperative surgical planning to generate virtual information for AR; (2) computer vision-based tracking for the real-time localization of both acetabular cup positioner and bony landmarks during surgery; (3) registration of a virtual object onto a real-world operative field to properly overlay the preoperative surgical planning data onto a three-dimensional (3D)-printed pelvis model. The cost-effective framework is designed with our clinical partner based on real surgical conditions. The bony landmarks are automatically detected and used for the registration between virtual and real objects. The AR performance is evaluated with a pelvis model, and it presents mean errors of 2.2[Formula: see text]mm and 0.8∘ in position and orientation, respectively, between real and virtual spaces. These small errors are within the tolerance of positive surgical outcomes.

A Novel Precise Optical Navigation System for Craniomaxillofacial Surgery Registered With an Occlusal Splint

BACKGROUND

An augmented reality tool allows visual tracking of real anatomical structures and superimposing virtual images, so it can be used for navigation of important structures during surgery.

OBJECTIVES

The authors have developed a new occlusal splint-based optical navigation system for craniomaxillofacial surgery. In this study, the authors aim to measure the accuracy of the system and further analyze the main factors influencing precision.

METHODS

Ten beagle dogs were selected and a three-dimensional model was established through computed tomography scanning, dental model making, and laser scanning, and then registration was performed according to the tooth marking points. The bilateral mandibular osteotomy was performed on Beagle dogs under navigation system based on the occlusal splint. The left side was taken to compare the deviation between the preoperative plan and the surgical results, and the accuracy of distance and angle and the stability of the system were analyzed.

RESULTS

The average position deviation between the preoperative design and intraoperative navigation was: 0.01 ± 0.73 mm on the lateral height of the mandibular ramus, 0.26 ± 0.57 mm on the inner height of the mandibular ramus, and 0.20 ± 0.51 mm on the osteotomy length. The average angle deviation is 0.94° ± 1.38° on the angle between the mandibular osteotomy plane and ramus plane and 0.66° ± 0.97° on the angle of the retained mandibular angle. And most of the data showed good consistency.

CONCLUSIONS

In summary, the accuracy of the system can meet clinical requirements and can be used as a useful tool to improve the accuracy of craniomaxillofacial surgery.

Augmented reality in craniomaxillofacial surgery: added value and proposed recommendations through a systematic review of the literature

This systematic review provides an overview of augmented reality (AR) and its benefits in craniomaxillofacial surgery in an attempt to answer the question: Is AR beneficial for craniomaxillofacial surgery? This review includes a description of the studies conducted, the systems used and their technical characteristics. The search was performed in four databases: PubMed, Cochrane Library, Embase, and Web of Science. All journal articles published during the past 11 years related to AR, mixed reality, craniomaxillofacial, and surgery were considered in this study. From a total of 7067 articles identified using AR- and surgery-related keywords, 39 articles were finally selected. Based on these articles, a classification of study types, surgery types, devices used, metrics reported, and benefits were collected. The findings of this review indicate that AR could provide various benefits, addressing the challenges of conventional navigation systems, such as hand-eye coordination and depth perception. However, three main concerns were raised while performing this study: (1) it is complicated to aggregate the metrics reported in the articles, (2) it is difficult to obtain statistical value from the current studies, and (3) user evaluation studies are lacking. This article concludes with recommendations for future studies by addressing the latter points.

An integrated augmented reality surgical navigation platform using multi-modality imaging for guidance

An integrated augmented reality (AR) surgical navigation system that potentially improves intra-operative visualization of concealed anatomical structures. Integration of real-time tracking technology with a laser pico-projector allows the surgical surface to be augmented by projecting virtual images of lesions and critical structures created by multimodality imaging. We aim to quantitatively and qualitatively evaluate the performance of a prototype interactive AR surgical navigation system through a series of pre-clinical studies. Four pre-clinical animal studies using xenograft mouse models were conducted to investigate system performance. A combination of CT, PET, SPECT, and MRI images were used to augment the mouse body during image-guided procedures to assess feasibility. A phantom with machined features was employed to quantitatively estimate the system accuracy. All the image-guided procedures were successfully performed. The tracked pico-projector correctly and reliably depicted virtual images on the animal body, highlighting the location of tumour and anatomical structures. The phantom study demonstrates the system was accurate to 0.55 ± 0.33mm. This paper presents a prototype real-time tracking AR surgical navigation system that improves visualization of underlying critical structures by overlaying virtual images onto the surgical site. This proof-of-concept pre-clinical study demonstrated both the clinical applicability and high precision of the system which was noted to be accurate to <1mm.

Preliminary clinical experience of robot-assisted surgery in treatment with genioplasty

Genioplasty is the main way to treat diseases such as chin asymmetry, dysplasia and overdevelopment, which involve the three-dimensional direction abnormalities of the chin. Since this kind of surgery mainly uses intraoral incisions, the narrow surgical field of intraoral incisions and the surrounding important neurovascular tissues make it easy for complications, to occur during the osteotomy process, which results in greater surgical risks. The first craniofacial-plastic surgical robot (CPSR-I) system is developed to complete the precise positioning and improve the surgeon's force perception ability. The Kalman filtering method is adopted to reduce the interference of sensor signal noise. An adaptive fuzzy control system, which has strong robustness and adaptability to the environment, is designed to improve the stability of robot-assisted surgical operations. To solve the problem of the depth perception, we propose an automatic bone drilling control strategy that combines position and force conditions to ensure that the robot can automatically stop when the bone is penetrated. On the basis of model surgery and animal experiments, preliminary experiments were carried out clinically. Based on the early results of 6 patients, the robot-assisted approach appears to be a safe and effective strategy for genioplasty.

The Challenge of Dental Education After COVID-19 Pandemic - Present and Future Innovation Study Design

The present work suggests research and innovation on the topic of dental education after the COVID-19 pandemic, is highly justified and could lead to a step change in dental practice. The challenge for the future in dentistry education should be revised with the COVID-19 and the possibility for future pandemics, since in most countries dental students stopped attending the dental faculties as there was a general lockdown of the population. The dental teaching has an important curriculum in the clinic where patients attend general dentistry practice. However, with SARS-CoV-2 virus, people may be reluctant having a dental treatment were airborne transmission can occur in some dental procedures. In preclinical dental education, the acquisition of clinical, technical skills, and the transfer of these skills to the clinic are extremely important. Therefore, dental education has to adapt the curriculum to embrace new technology devices, instrumentations systems, haptic systems, simulation based training, 3D printer machines, to permit validation and calibration of the technical skills of dental students.

Fully Automatic Robot-Assisted Surgery for Mandibular Angle Split Osteotomy

With the development of computer-assisted surgery, preoperational design is detailed in software. However, it is still a challenge for surgeons to realize the surgical plan in the craniofacial surgery. Robot-assisted surgery has advantages of high accuracy and stability. It is suitable for the high-stress procedures like drilling, milling, and cutting. This study aims to verify the feasibility for automatic drilling without soft tissues in model test based on an industrial robot platform.This study chose the data from digital laboratory in Shanghai 9th People's Hospital. The mandibular was reconstructed in software and surgical plan was also designed. Then, the coordinate data was input to the robot's software and matrix conversion was calculated by 4 marked points. The trajectory generation was calculated by inverse kinematics for target coordinates and robot coordinates. The model was fixed and calibrated for automatic drilling. At last, the accuracy was calculated by optic scanning instrument.The installment and preparation cost 10 minutes, the drilling procedure cost 12 minutes. The outside position error was (1.71 ± 0.16) mm, the inside position error was (1.37 ± 0.28) mm, the orientation error was (3.04 ± 1.02)°. Additionally, a total of 5 beagles were tested, with an accuracy error of (2.78 ± 1.52) mm. No postoperative complications occurred.This is the first study reported for robot-assisted automatic surgery in craniofacial surgery. The result shows it is possible to realize the automatic drilling procedure under the condition of no interference like soft tissues. With the development of artificial intelligence and machine vision, robot-assisted surgery may help surgeons to fulfill more automatic procedures for craniofacial surgery.

Virtual and augmented reality for preoperative planning in plastic surgical procedures: A systematic review

BACKGROUND

Virtual and augmented reality (VR and AR) are fast-developing technologies that allow the three-dimensional visualization of digital information.

OBJECTIVE

This systematic review aimed to compare the application of VR and AR to conventional methods in preoperative planning of plastic surgical procedures.

METHOD

A systematic literature search was conducted in Embase, Medline (Ovid), Web-of-Science, Cochrane, and Google Scholar databases on October 11, 2019. All literature comparing AR and/or VR with conventional methods for preoperative planning was collected. Only articles that studied at least one of the following outcomes were included: technical accuracy of the procedure, operative time, complications, and costs of total intervention.

RESULTS

No articles on VR were found. Six articles were found on interventions performed with AR assistance. AR showed to be significantly better for the accuracy of osteotomies in mandibular angle osteotomies and intraoral mandible distraction compared to conventional methods. For synostotic plagiocephaly and orbital hypertelorism correction, the use of AR demonstrated a precise osteotomy. Intraoperative perforator identification in DIEP flap procedures was more accurate with AR compared to Doppler ultrasound. Harvesting time (p < 0.012) and operative time (p < 0.01) in DIEP-flap procedures and mandibular angle osteotomies, respectively, were significantly reduced if AR was used. No articles were found regarding the costs of using AR for preoperative planning.

CONCLUSION

AR technology has the potential to assist the plastic surgeon in operating more accurately, safely, and fast. Studies on VR technology for preoperative planning in plastic surgery are lacking. More comparative studies are necessary, including data on clinical outcomes and cost-effectiveness.

Early hemi-mandibular lengthening by distraction osteogenesis contributes to compensatory maxillary growth

Mandibular distraction osteogenesis at an early age is the standard hemifacial microsomia treatment. Nevertheless, the recurrence rate remains high and the definition of early age is controversial. We explored the optimal timing for mandibular distraction, when the surrounding skeleton, such as maxilla, can grow compensatory, to reduce recurrence. Hemifacial microsomia patients were prospectively divided into Groups A (1-3 years old) and B (4-6 years old), according to maxillary and mandibular growth curves. Computed tomography scans were obtained before distractor implantation and after removal surgery. Maxillary volume increase percentage was the main outcome indicator; other indicators (maxillary symmetry and complications) were secondary outcomes. Fifty-eight patients were enrolled and all but one patient in Group A (failed distraction) completed the study. Two patients had facial nerve injury and another two had mouth-opening limitation, which was relieved after coracoid resection. The difference in percentage increase in maxillary volume between the affected and unaffected sides was 5.06 ± 2.73% and 3.18 ± 1.99% in Groups A and B, respectively, suggesting better compensatory growth in younger patients (P = 0.004). Maxillary symmetry was apparently elevated after mandibular distraction. Mandibular distraction osteogenesis was confirmed to be feasible and safe at age <4 years.

Augmenting prehospital care

INTRODUCTION

The challenging environment of prehospital casualty care demands providers to make prompt decisions and to engage in lifesaving interventions, occasionally without them being adequately experienced. Telementoring based on augmented reality (AR) devices has the potential to decrease the decision time and minimise the distance gap between an experienced consultant and the first responder. The purpose of this study was to determine whether telementoring with AR glasses would affect chest thoracotomy performance and self-confidence of inexperienced trainees.

METHODS

Two groups of inexperienced medical students performed a chest thoracotomy in an ex vivo pig model. While one group was mentored remotely using HoloLens AR glasses, the second performed the procedure independently. An observer assessed the trainees' performance. In addition, trainees and mentors evaluated their own performance.

RESULTS

Quality of performance was found to be superior with remote guidance, without significant prolongation of the procedure (492 s vs 496 s, p=0.943). Moreover, sense of self-confidence among participant was substantially improved in the telementoring group in which 100% of the participants believed the procedure was successful compared with 40% in the control group (p=0.035).

CONCLUSION

AR devices may have a role in future prehospital telementoring systems, to provide accessible consultation for first responders, and could thus positively affect the provider's confidence in decision-making, enhance procedure performance and ultimately improve patient prognosis. That being said, future studies are required to estimate full potential of this technology and additional adjustments are necessary for maximal optimisation and implementation in the field of prehospital care.

Image Overlay Surgery Based on Augmented Reality: A Systematic Review

Augmented Reality (AR) applied to surgical guidance is gaining relevance in clinical practice. AR-based image overlay surgery (i.e. the accurate overlay of patient-specific virtual images onto the body surface) helps surgeons to transfer image data produced during the planning of the surgery (e.g. the correct resection margins of tissue flaps) to the operating room, thus increasing accuracy and reducing surgery times. We systematically reviewed 76 studies published between 2004 and August 2018 to explore which existing tracking and registration methods and technologies allow healthcare professionals and researchers to develop and implement these systems in-house. Most studies used non-invasive markers to automatically track a patient's position, as well as customised algorithms, tracking libraries or software development kits (SDKs) to compute the registration between patient-specific 3D models and the patient's body surface. Few studies combined the use of holographic headsets, SDKs and user-friendly game engines, and described portable and wearable systems that combine tracking, registration, hands-free navigation and direct visibility of the surgical site. Most accuracy tests included a low number of subjects and/or measurements and did not normally explore how these systems affect surgery times and success rates. We highlight the need for more procedure-specific experiments with a sufficient number of subjects and measurements and including data about surgical outcomes and patients' recovery. Validation of systems combining the use of holographic headsets, SDKs and game engines is especially interesting as this approach facilitates an easy development of mobile AR applications and thus the implementation of AR-based image overlay surgery in clinical practice.

The New Frontier: A Review of Augmented Reality and Virtual Reality in Plastic Surgery

Mixed reality, a blending of the physical and digital worlds, can enhance the surgical experience, leading to greater precision, efficiency, and improved outcomes. Various studies across different disciplines have reported encouraging results using mixed reality technologies, such as augmented and virtual reality. To provide a better understanding of the applications and limitations of this technology in plastic surgery, we performed a systematic review of the literature in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The initial query of the National Center for Biotechnology Information database yielded 2544 results, and only 46 articles met our inclusion criteria. The majority of studies were in the field of craniofacial surgery, and uses of mixed reality included preoperative planning, intraoperative guides, and education of surgical trainees. A deeper understanding of mixed reality technologies may promote its integration and also help inspire new and creative applications in healthcare.

Augmented reality for dental implantology: a pilot clinical report of two cases

BACKGROUND

Despite the limited number of articles dedicated to its use, augmented reality (AR) is an emerging technology that has shown to have increasing applications in multiple different medical sectors. These include, but are not limited to, the Maxillo-facial and Dentistry disciplines of medicine. In these medical specialties, the focus of AR technology is to achieve a more visible surgical field during an operation. Currently, this goal is brought about by an accurate display of either static or dynamic diagnostic images via the use of a visor or specific glasses. The objective of this study is to evaluate the feasibility of using a virtual display for dynamic navigation via AR. The secondary outcome is to evaluate if the use of this technology could affect the accuracy of dynamic navigation.

CASE PRESENTATION

Two patients, both needing implant rehabilitation in the upper premolar area, were treated with flapless surgery. Prior to the procedure itself, the position of the implant was virtually planned and placed for each of the patients using their previous scans. This placement preparation contributed to a dynamic navigation system that was displayed on AR glasses. This, in turn, allowed for the use of a computer-aided/image-guided procedure to occur. Dedicated software for surface superimposition was then used to match the planned position of the implant and the real one obtained from the postoperative scan. Accuracies, using this procedure were evaluated by way of measuring the deviation between real and planned positions of the implants. For both surgeries it was possible to proceed using the AR technology as planned. The deviations for the first implant were 0.53 mm at the entry point and 0.50 mm at the apical point and for the second implant were 0.46 mm at the entry point and 0.48 mm at the apical point. The angular deviations were respectively 3.05° and 2.19°.

CONCLUSIONS

From the results of this pilot study, it seems that AR can be useful in dental implantology for displaying dynamic navigation systems. While this technology did not seem to noticeably affect the accuracy of the procedure, specific software applications should further optimize the results.

Current state of the art in the use of augmented reality in dentistry: a systematic review of the literature

Background

The aim of the present systematic review was to screen the literature and to describe current applications of augmented reality.

Materials and methods

The protocol design was structured according to PRISMA-P guidelines and registered in PROSPERO. A review of the following databases was carried out: Medline, Ovid, Embase, Cochrane Library, Google Scholar and the Gray literature. Data was extracted, summarized and collected for qualitative analysis and evaluated for individual risk of bias (R.O.B.) assessment, by two independent examiners. Collected data included: year of publishing, journal with reviewing system and impact factor, study design, sample size, target of the study, hardware(s) and software(s) used or custom developed, primary outcomes, field of interest and quantification of the displacement error and timing measurements, when available. Qualitative evidence synthesis refers to SPIDER.

Results

From a primary research of 17,652 articles, 33 were considered in the review for qualitative synthesis. 16 among selected articles were eligible for quantitative synthesis of heterogenous data, 12 out of 13 judged the precision at least as acceptable, while 3 out of 6 described an increase in operation timing of about 1 h. 60% (n = 20) of selected studies refers to a camera-display augmented reality system while 21% (n = 7) refers to a head-mounted system. The software proposed in the articles were self-developed by 7 authors while the majority proposed commercially available ones. The applications proposed for augmented reality are: Oral and maxillo-facial surgery (OMS) in 21 studies, restorative dentistry in 5 studies, educational purposes in 4 studies and orthodontics in 1 study. The majority of the studies were carried on phantoms (51%) and those on patients were 11 (33%).

Conclusions

On the base of literature the current development is still insufficient for full validation process, however independent sources of customized software for augmented reality seems promising to help routinely procedures, complicate or specific interventions, education and learning. Oral and maxillofacial area is predominant, the results in precision are promising, while timing is still very controversial since some authors describe longer preparation time when using augmented reality up to 60 min while others describe a reduced operating time of 50/100%.

Trial registration

The following systematic review was registered in PROSPERO with RN: CRD42019120058.

Effective Application of Mixed Reality Device HoloLens: Simple Manual Alignment of Surgical Field and Holograms

The technology used to add information to a real visual field is defined as augmented reality technology. Augmented reality technology that can interactively manipulate displayed information is called mixed reality technology. HoloLens from Microsoft, which is a head-mounted mixed reality device released in 2016, can display a precise three-dimensional model stably on the real visual field as hologram. If it is possible to accurately superimpose the position/direction of the hologram in the surgical field, surgical navigation-like use can be expected. However, in HoloLens, there was no such function. The authors devised a method that can align the surgical field and holograms precisely within a short time using a simple manual operation. The mechanism is to match the three points on the hologram to the corresponding marking points of the body surface. By making it possible to arbitrarily select any of the three points as a pivot/axis of the rotational movement of the hologram, alignment by manual operation becomes very easy. The alignment between the surgical field and the hologram was good and thus contributed to intraoperative objective judgment. By using the method of this study, the clinical usefulness of the mixed reality device HoloLens will be expanded.

Grand Adventure of Augmented Reality in Landscape of Surgery

Computer as an integral part of continual advancements in medicine has experienced tremendous development to minimize the risks and improving the precision of the surgery. Our review included multi-disciplinary publications in English from 2014 to 2017 using Springer, Oxford library, Elsevier, PubMed, Google Scholar, and Springer search engines using terms of “augmented reality (AR), “plastic surgery,” and “surgery “ and “Augmented Reality Ethics and challenges”. It was shown that AR has been successfully effective in different branches of surgery, but with concerns and challenges like acceptance, privacy, different physical, security and behavioral threats. To come over them partially, a methodological approach for cyber threat landscape proactive exploration has been suggested.

Augmented reality for temporomandibular joint arthrocentesis: a cadaver study

Temporomandibular joint (TMJ) arthroscopic procedures require the identification of a skin puncture point. The puncture point is conventionally estimated using the surface anatomy of the canthal-tragus line. However, the conventional puncture technique has been reported to fail at the first attempt in 18% of cases. We propose an augmented reality (AR) system-based method to identify the puncture point on the skin. A three-dimensional virtual model was reconstructed from computed tomography images of a cadaver head, and its rendered image was superimposed on the cadaver head before skin puncture. The skin puncture point was marked on the skin under the guidance of the AR system. The TMJ was punctured through the mark and the endoscope was introduced through the puncture point. The outcome of the procedure was classified as successful or unsuccessful based on the visualization of the TMJ. The system was applied on the left and right sides of three cadaver heads. Puncture with the AR method was successful in all six cases. This study presents a system to provide AR visualization during TMJ arthrocentesis to increase the precision of skin puncture. However, a comparative study of the AR method with the conventional method is required to evaluate its advantages.

Precision of a Novel Craniofacial Surgical Navigation System Based on Augmented Reality Using an Occlusal Splint as a Registration Strategy

The authors have developed a novel augmented reality (AR)-based navigation system (NS) for craniofacial surgery. In this study, the authors aimed to measure the precision of the system and further analyze the primary influencing factors of the precision. The drilling of holes into the mandibles of ten beagle dogs was performed under the AR-based NS, and the precision was analyzed by comparing the deviation between the preoperational plan and the surgical outcome. The AR-based NS was successfully applied to quickly and precisely drill holes in the mandibles. The mean positional deviation between the preoperative design and intraoperative navigation was 1.29 ± 0.70 mm for the entry points and 2.47 ± 0.66 mm for the end points, and the angular deviation was 1.32° ± 1.17°. The precision linearly decreased with the distance from the marker. In conclusion, the precision of this system could satisfy clinical requirements, and this system may serve as a helpful tool for improving the precision in craniofacial surgery.

Augmented reality in dentistry: a current perspective

Augmentation reality technology offers virtual information in addition to that of the real environment and thus opens new possibilities in various fields. The medical applications of augmentation reality are generally concentrated on surgery types, including neurosurgery, laparoscopic surgery and plastic surgery. Augmentation reality technology is also widely used in medical education and training. In dentistry, oral and maxillofacial surgery is the primary area of use, where dental implant placement and orthognathic surgery are the most frequent applications. Recent technological advancements are enabling new applications of restorative dentistry, orthodontics and endodontics. This review briefly summarizes the history, definitions, features, and components of augmented reality technology and discusses its applications and future perspectives in dentistry.

A Novel Augmented Reality-Based Navigation System in Perforator Flap Transplantation - A Feasibility Study

BACKGROUND

In perforator flap transplantation, dissection of the perforator is an important but difficult procedure because of the high variability in vascular anatomy. Preoperative imaging techniques could provide substantial information about vascular anatomy; however, it cannot provide direct guidance for surgeons during the operation. In this study, a navigation system (NS) was established to overlie a vascular map on surgical sites to further provide a direct guide for perforator flap transplantation.

METHODS

The NS was established based on computed tomographic angiography and augmented reality techniques. A virtual vascular map was reconstructed according to computed tomographic angiography data and projected onto real patient images using ARToolKit software. Additionally, a screw-fixation marker holder was created to facilitate registration. With the use of a tracking and display system, we conducted the NS on an animal model and measured the system error on a rapid prototyping model.

RESULTS

The NS assistance allowed for correct identification, as well as a safe and precise dissection of the perforator. The mean value of the system error was determined to be 3.474 ± 1.546 mm.

CONCLUSIONS

Augmented reality-based NS can provide precise navigation information by directly displaying a 3-dimensional individual anatomical virtual model onto the operative field in real time. It will allow rapid identification and safe dissection of a perforator in free flap transplantation surgery.