Search

Background: This study aimed to investigate the range of angles and depths necessary for effective entry into the TMJ using CBCT images, focusing on classical Holmlund Hellsing points and a two-needle approach. Methods: A retrospective cohort of CBCT images from January 2020 to November 2023 was analysed using 3D analysis to determine the variance in the required angles and depths. Results: The average age of the 68 participants included in the study was 29.5 ± 11.1, 58.8% of the participants were female and 41.2% were male. The anterior needle measurements showed a relatively low standard deviation(SD) in depth(SD:3.6) with a low variance coefficient(12.5%), whereas the axial and coronal angles exhibited greater variability(SD:9.1 and 7.6, respectively). For the posterior needles, moderate SDs in depth(SD:3.5) and greater variabilities in axial and coronal angles(SD:9.6 and 5.3, respectively) were observed. A weak negative correlation was observed between the axial angle of the posterior needle and age(p: 0.028, Pearson r: -0.29) Anterior needle depth (p:0.037) and posterior needle axial angle(p:0.014) were greater in males than females. The anterior needle depth in patients with temporamandibular disease was greater than in those without(p:0,03). Conclusion: There were significant differences in the angle measurements for both anterior and posterior needles, but lower variance in depth. The depths and angles of the needles did not correlate with age. [ABSTRACT FROM AUTHOR]

Background: Intraosseous vascular anomalies in the facial skeleton present significant diagnostic and therapeutic challenges due to complex anatomy. These anomalies represent about 0.5–1% of bony neoplastic and tumor-like lesions, usually presenting as a firm, painless mass. Most described intraosseous vascular malformations are venous malformations (VMs) and, more rarely, arteriovenous malformations. Objectives: The objectives of this work are to show our experience, protocol and the applications of computer planning, virtual surgery, CAD-CAM design, surgical navigation, and computer-assisted navigated piezoelectric surgery in the treatment of facial intraosseous vascular anomalies and to evaluate the advantages and disadvantages. Methods: Three females and one male with periorbital intraosseous vascular anomalies were treated using en-block resection and immediate reconstruction with a custom-made PEEK prosthesis. One lesion was in the supraorbital rim and orbital roof, one in the frontal bone and orbital roof, and two in the zygomatic region. We accomplished the resection and reconstruction of the lesion using virtual planning, CAD-CAM design, surgical navigation and piezoelectric device navigation. Results: There were no complications related to the surgery assisted with navigation. With an accuracy of less than 1 mm, the procedure may be carried out in accordance with the surgical plan. The surgeon's degree of uncertainty during deep osteotomies and in locations with low visibility was decreased by the use of the navigated piezoelectric device. Conclusions: Resection and reconstruction of facial intraosseous vascular anomalies benefit from this new surgical strategy using CAD-CAM technologies, computer-assisted navigated piezoelectric surgery, and surgical navigation. [ABSTRACT FROM AUTHOR]

Abstract Background This study aimed to investigate the range of angles and depths necessary for effective entry into the TMJ using CBCT images, focusing on classical Holmlund Hellsing points and a two-needle approach. Methods A retrospective cohort of CBCT images from January 2020 to November 2023 was analysed using 3D analysis to determine the variance in the required angles and depths. Results The average age of the 68 participants included in the study was 29.5 ± 11.1, 58.8% of the participants were female and 41.2% were male. The anterior needle measurements showed a relatively low standard deviation(SD) in depth(SD:3.6) with a low variance coefficient(12.5%), whereas the axial and coronal angles exhibited greater variability(SD:9.1 and 7.6, respectively). For the posterior needles, moderate SDs in depth(SD:3.5) and greater variabilities in axial and coronal angles(SD:9.6 and 5.3, respectively) were observed. A weak negative correlation was observed between the axial angle of the posterior needle and age(p: 0.028, Pearson r: -0.29) Anterior needle depth (p:0.037) and posterior needle axial angle(p:0.014) were greater in males than females. The anterior needle depth in patients with temporamandibular disease was greater than in those without(p:0,03). Conclusion There were significant differences in the angle measurements for both anterior and posterior needles, but lower variance in depth. The depths and angles of the needles did not correlate with age.

Abstract Introduction Orthognathic surgery (OGS) is a highly sophisticated surgical technique that aims to repair a variety of skeletal and dental abnormalities, including misaligned jaws and teeth. It requires precise preoperative preparation and advanced surgical skills, which are typically learned through years of practical experience in operating rooms or laboratory-based surgical training facilities utilizing cadavers or models. The traditional physical hands-on method of surgical training is still used at OGS. However, this method requires a longer time of preparation. Currently, mixed reality (MR)—a combination of virtual reality and augmented reality technology—is an innovation of OGS. The present study aimed to present a comprehensive review of studies that assessed the advantages of utilizing mixed reality technology in OGS. Methods A modified Population, Intervention, Comparison, Outcome strategy was performed using a combination of electronic (PubMed, Cochrane, Embase) and manual searches between 2013 and 2023 exploring mixed reality (MR) technology in OGS in the last 10 years. The inclusion criteria were limited to the patient and study model focusing on the clinical application of MR and the associated field of OGS. Result The initial search indicated 1731 studies, of which 17 studies were included for analysis. The main results indicated that the use of MR technology in OGS led to high accuracy and time reduction as primary outcomes and cost-effectiveness and skill improvement as secondary outcomes. The review firmly concluded that MR technology exhibited a positive impact on students, trainees, and oromaxillofacial surgeons. However, due to the heterogeneity of the included studies, meta-analyses could not be performed. Collectively, these findings provide strong evidence for the advantages of MR technology in orthognathic surgery. Conclusion MR technology significantly improves OGS planning efficiency by providing pre-surgical information and serving as an intraoperative navigation tool, reducing surgical time without compromising outcomes. Virtual training using MR technology exerts a positive impact on knowledge and skill improvement for OGS. This innovative technology will revolutionize the healthcare system and enhance patient care.

Introduction: Orthognathic surgery (OGS) is a highly sophisticated surgical technique that aims to repair a variety of skeletal and dental abnormalities, including misaligned jaws and teeth. It requires precise preoperative preparation and advanced surgical skills, which are typically learned through years of practical experience in operating rooms or laboratory-based surgical training facilities utilizing cadavers or models. The traditional physical hands-on method of surgical training is still used at OGS. However, this method requires a longer time of preparation. Currently, mixed reality (MR)—a combination of virtual reality and augmented reality technology—is an innovation of OGS. The present study aimed to present a comprehensive review of studies that assessed the advantages of utilizing mixed reality technology in OGS. Methods: A modified Population, Intervention, Comparison, Outcome strategy was performed using a combination of electronic (PubMed, Cochrane, Embase) and manual searches between 2013 and 2023 exploring mixed reality (MR) technology in OGS in the last 10 years. The inclusion criteria were limited to the patient and study model focusing on the clinical application of MR and the associated field of OGS. Result: The initial search indicated 1731 studies, of which 17 studies were included for analysis. The main results indicated that the use of MR technology in OGS led to high accuracy and time reduction as primary outcomes and cost-effectiveness and skill improvement as secondary outcomes. The review firmly concluded that MR technology exhibited a positive impact on students, trainees, and oromaxillofacial surgeons. However, due to the heterogeneity of the included studies, meta-analyses could not be performed. Collectively, these findings provide strong evidence for the advantages of MR technology in orthognathic surgery. Conclusion: MR technology significantly improves OGS planning efficiency by providing pre-surgical information and serving as an intraoperative navigation tool, reducing surgical time without compromising outcomes. Virtual training using MR technology exerts a positive impact on knowledge and skill improvement for OGS. This innovative technology will revolutionize the healthcare system and enhance patient care. [ABSTRACT FROM AUTHOR]

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This clinical report presents a technique to reconstruct extensively resected mandibles using a combination of autologous bone grafts and additive manufacturing techniques. Mandibular defects, often arising from trauma, tumors, or congenital anomalies, can severely impact both function and aesthetics. Conventional reconstruction methods have their limitations, often resulting in suboptimal outcomes. In these reports, we detail clinical cases where patients with different mandibular defects underwent reconstructive surgery. In each instance, autologous grafts were harvested to ensure the restoration of native bone tissue, while advanced virtual planning techniques were employed for precise graft design and dental implant placement. The patients experienced substantial improvements in masticatory function, speech, and facial aesthetics. Utilizing autologous grafts minimized the risk of rejection and complications associated with foreign materials. The integration of virtual planning precision allowed customized solutions, reducing surgical duration and optimizing implant positioning. These 2 cases underscores the potential of combining autologous grafts with virtual planning precision and dental implants produced by additive manufacturing for mandible reconstruction. [ABSTRACT FROM AUTHOR]

Backgrounds: Tooth loss in the posterior maxilla often necessitates dental implant placement, but the maxillary sinus anatomy poses challenges, especially during sinus floor elevation. Mesially angled implants are an alternative for total edentulism, but for single tooth deficiencies, palatally angled implants may offer a solution. This study evaluates the prevalence of avoiding sinus floor elevation by placing palatally angled implants in cases with a single missing tooth. Methods: A retrospective study at Ahmet Keleşoğlu Faculty of Dentistry involved 100 participants with a single missing tooth and prior CBCT scans. Virtual implants were placed using OnDemand3D (version 1.0.7462) software. On CBCT sections, implants were angled palatally to avoid sinus or nasal cavity perforation. Statistical analysis was conducted using R and MedCalc (version 4.3.2) software. Results: Of the participants (60% female, average age 50.45), 76 edentulous regions required sinus elevation. The implant placeability rates varied across zones (second molar: 39.3%, first molar: 63.1%, second premolar: 78.5%). Implant placement at a palatal angle was significantly higher in the second premolar and first molar regions. Statistically significant differences were observed in the implant placeability between regions. Conclusions: This study supports the feasibility of avoiding sinus floor elevation through palatally angled implants in specific cases, reducing the associated complications. [ABSTRACT FROM AUTHOR]

Objective Clinical Considerations Conclusions Clinical Significance This article aims to showcase the implementation of a digital workflow in addressing a case of multifactorial excessive gingival display in a patient with high esthetic demands, incorporating both surgical and restorative interventions in a single session.A 28‐year‐old female patient presented with excessive gingival display, attributed to a combination of short teeth due to altered passive eruption, lip hyperactivity, and a sub‐nasal depression that lodged the upper lip during spontaneous smiling. The multidisciplinary treatment strategy encompassed surgical crown lengthening, the placement of a biovolume in the maxillary concavity, and the rehabilitation of the six anterior teeth with direct composite resin, all done in a single session. Smilecloud Biometrics was used to digitally plan the smile, and the final wax‐up/mock‐up was approved by the patient prior to any irreversible procedure. A digital planning center (GuiderLab) enabled the materialization of the virtual planning and the printing of the periodontal surgical guide, the biovolume, and the resin layering guides for the restorative technique.Adopting a digital workflow in multidisciplinary cases with excessive gingival display leads to predictable and more expedited outcomes, ensuring a favorable result between soft and hard tissues.Excessive gingival display is a condition with multifactorial etiologies, including dentoalveolar, periodontal, skeletal, or muscular origins, or a combination of these factors. The diagnoses of altered passive eruption and a hypermobile upper lip are common in daily clinical practice and can be successfully managed through surgical crown lengthening and filling of the maxillary concavity, respectively. To achieve the desired outcome, restorative procedures often complement these surgical interventions. [ABSTRACT FROM AUTHOR]

Osteosarcomas arising within the pterygomaxillary/infratemporal fossa region are rare among the pediatric population. Survival rates are most influenced by tumor resection with negative margins, which can be dependent on surgical accessibility of the tumor site. The pterygomaxillary/infratemporal fossa location poses several challenges to safe and adequate tumor resection, including proximity of the facial nerve and great vessels and scarring associated with traditional transfacial approaches. In this article, we present the case of a 6-year-old boy with an osteosarcoma of the left pterygomaxillary/infratemporal fossa region successfully managed with an "oncoplastic" approach, incorporating the use of CAD/CAM and mixed reality technologies. [ABSTRACT FROM AUTHOR]

Chondrosarcoma is among the most common primary bone tumors in adults. In the mandible, chondrosarcoma is a very uncommon malignant cartilage‐producing tumor. This case report shows how virtual planning combined with other digital technologies may improve masticatory function rehabilitation in patients with enlarged mandibular chondrosarcoma. The present study reports a case of a 52‐year‐old male patient who was initially diagnosed with a mandible chondroma, which was successfully excised with no evidence of malignant transformation. Nevertheless, the patient's symptoms recurred after 10 years, and a subsequent diagnosis of mandible chondrosarcoma was established, prompting the need for subtotal mandible resection and reconstruction with a fibula‐free flap. Following a healing period, the patient underwent dental implant surgery to restore the mandibular dental arch, which was performed utilizing computer‐aided design and computer‐aided manufacturing technology, with fully guided implant placement facilitated by virtual planning. In this case report, the implant position data merging process is described from the digital impression and control model to ensure optimal passive fit of the full‐arch zirconia prosthesis and discuss the importance of occlusal adjustments to avoid technical and biological complications. Virtual planning and digital technologies are crucial for the effective management of mandibular defects, allowing for accurate treatment and complete restoration of mandibular function. Their use leads to improved patient outcomes and quality of life. As technology advances, their importance in treating complex medical conditions is only expected to grow. [ABSTRACT FROM AUTHOR]

Abstract Background The placement of implants into the alveolar socket right after tooth extraction is called immediate implant placement (IIP). This approach has its particularities depending on which region of the jaws is involved. The anterior mandible region is peculiar due to the presence of mandibular incisors, which have the shortest roots among all permanent teeth. Purpose This study aimed to investigate the factors that could be associated with the risk of either cortical bone wall perforation or invasion of the 2 mm secure distance from the surrounding anatomical structures (defined as unsafe implant placement), with IIP in the maxillary aesthetic zone, in a cone-beam computed tomography (CBCT) virtual study. Materials and methods CBCT exams from 239 eligible subjects were investigated. Implants were virtually placed in two distinct positions: prosthetically-driven (along the long axis of the existing tooth) and bone-driven position (according to the available bone and with regard to nearby anatomical structures). Correlation between several variables was tested, and binary logistic regression analysis in order to assess of the possible associations between covariates and unsafe placement was performed. Results Safe placing implants was significantly higher for the bone-driven in comparison to the prosthetically-driven position (22.2% vs. 3.3%, respectively), and the 2-mm secure distance from anatomical structures was not possible to respect in the majority of cases (77.6% vs. 82.9%, respectively). Covariates associated with a higher risk of unsafe placement were tooth region (CI in relation to IL and CA), decrease of labial concavity angle (LCA), decrease of mandible basal bone height (MBBH), and decrease in mandibular bone thickness at the tooth apex level (MBT0). Conclusion The possibility of safely placing immediate implants in the anterior mandible is significantly higher for bone-driven than in prosthetically driven position. Presurgical virtual planning with CBCT is a great tool for minimizing the risk of implant unsafe placement with regards to the anatomical conditions in the mandible.

Although a smaller size field of view (FOV) of cone-beam computerized tomography (CBCT) reduces radiation exposure, its effect on the accuracy of static computer-aided implant surgery (s-CAIS) remains unknown. This study aimed to evaluate the impact of the size of FOV on the accuracy of s-CAIS and to investigate if the arch affects this effect. A total of 32 implant sites on 8 identical scannable models (maxillae and mandibles) were randomly allocated to 2 FOV sizes: test (5 × 5 cm) and control (10 × 10 cm). All models were scanned with an intraoral scanner (IOS). With the registration of the surface scan and CBCT image, a prosthetic-driven implant position was planned. Following the fabrication of surgical templates, a single-blinded surgeon placed all implants with the fully guided s-CAIS protocol. IOS captured the implant positions with the scan body attached. Implant-planning software measured the angular deviation, 3-dimensional (3D) deviation at the crest, and 3D deviation at the apex between preplanned and actual implant positions. Two-way analysis of variance was used to analyze the effect of FOV and arch on the deviations. The size of FOV did not show a significant effect (P >.198) on angular deviation, 3D deviation at the crest, or 3D deviation at the apex. No significant difference was found when comparing the effect of the size of FOV between the maxillary and mandibular implants. In conclusion, the use of small FOV CBCT demonstrated comparable accuracy of s-CAIS to the use of medium FOV CBCT. [ABSTRACT FROM AUTHOR]

Background: The placement of implants into the alveolar socket right after tooth extraction is called immediate implant placement (IIP). This approach has its particularities depending on which region of the jaws is involved. The anterior mandible region is peculiar due to the presence of mandibular incisors, which have the shortest roots among all permanent teeth. Purpose: This study aimed to investigate the factors that could be associated with the risk of either cortical bone wall perforation or invasion of the 2 mm secure distance from the surrounding anatomical structures (defined as unsafe implant placement), with IIP in the maxillary aesthetic zone, in a cone-beam computed tomography (CBCT) virtual study. Materials and methods: CBCT exams from 239 eligible subjects were investigated. Implants were virtually placed in two distinct positions: prosthetically-driven (along the long axis of the existing tooth) and bone-driven position (according to the available bone and with regard to nearby anatomical structures). Correlation between several variables was tested, and binary logistic regression analysis in order to assess of the possible associations between covariates and unsafe placement was performed. Results: Safe placing implants was significantly higher for the bone-driven in comparison to the prosthetically-driven position (22.2% vs. 3.3%, respectively), and the 2-mm secure distance from anatomical structures was not possible to respect in the majority of cases (77.6% vs. 82.9%, respectively). Covariates associated with a higher risk of unsafe placement were tooth region (CI in relation to IL and CA), decrease of labial concavity angle (LCA), decrease of mandible basal bone height (MBBH), and decrease in mandibular bone thickness at the tooth apex level (MBT0). Conclusion: The possibility of safely placing immediate implants in the anterior mandible is significantly higher for bone-driven than in prosthetically driven position. Presurgical virtual planning with CBCT is a great tool for minimizing the risk of implant unsafe placement with regards to the anatomical conditions in the mandible. [ABSTRACT FROM AUTHOR]

Aims: Proper preoperative planning benefits fracture reduction, fixation, and stability in tibial plateau fracture surgery. We developed and clinically implemented a novel workflow for 3D surgical planning including patient-specific drilling guides in tibial plateau fracture surgery. Methods: A prospective feasibility study was performed in which consecutive tibial plateau fracture patients were treated with 3D surgical planning, including patient-specific drilling guides applied to standard off-the-shelf plates. A postoperative CT scan was obtained to assess whether the screw directions, screw lengths, and plate position were performed according the preoperative planning. Quality of the fracture reduction was assessed by measuring residual intra-articular incongruence (maximum gap and step-off) and compared to a historical matched control group. Results: A total of 15 patients were treated with 3D surgical planning in which 83 screws were placed by using drilling guides. The median deviation of the achieved screw trajectory from the planned trajectory was 3.4° (interquartile range (IQR) 2.5 to 5.4) and the difference in entry points (i.e. plate position) was 3.0 mm (IQR 2.0 to 5.5) compared to the 3D preoperative planning. The length of 72 screws (86.7%) were according to the planning. Compared to the historical cohort, 3D-guided surgery showed an improved surgical reduction in terms of median gap (3.1 vs 4.7 mm; p = 0.126) and step-off (2.9 vs 4.0 mm; p = 0.026). Conclusion: The use of 3D surgical planning including drilling guides was feasible, and facilitated accurate screw directions, screw lengths, and plate positioning. Moreover, the personalized approach improved fracture reduction as compared to a historical cohort. Cite this article: Bone Jt Open 2024;5(1):46–52.

Virtual planning has revolutionized orthognathic surgery (OGS), marking a significant advancement in the field. This study aims to showcase the practical application of our established 3D average skull template as a guiding framework for surgical planning, and to share valuable insights from our clinical experience. We enrolled 30 consecutive Taiwanese patients (18 females and 12 males) who underwent two-jaw orthognathic surgery with surgical simulation, utilizing the average skull template for planning. Results indicate the method's applicability and precision. By adhering to the surgical plan, post-operative outcomes closely aligned with the average skull template, showing negligible deviations of less than 2 mm. Moreover, patients expressed high satisfaction with post-surgery facial changes, with the chin appearance receiving the highest satisfaction scores, while the lowest scores were attributed to nose appearance. Notably, the substantial change in lower jaw position post-mandibular setback surgery contributed to increased satisfaction with the chin position. In conclusion, this study does not seek to replace established surgical planning methods, but underscores that utilizing an average skull as a surgical design template provides a viable, accurate, and efficient option for OGS patients. [ABSTRACT FROM AUTHOR]

Craniomaxillofacial (CMF) surgery is a challenging and very demanding field that involves the treatment of congenital and acquired conditions of the face and head. Due to the complexity of the head and facial region, various tools and techniques were developed and utilized to aid surgical procedures and optimize results. Virtual Surgical Planning (VSP) has revolutionized the way craniomaxillofacial surgeries are planned and executed. It uses 3D imaging computer software to visualize and simulate a surgical procedure. Numerous studies were published on the usage of VSP in craniomaxillofacial surgery. However, the researchers found inconsistency in the previous literature which prompted the development of this review. This paper aims to provide a comprehensive review of the findings of the studies by conducting an integrated approach to synthesize the literature related to the use of VSP in craniomaxillofacial surgery. Twenty-nine related articles were selected as a sample and synthesized thoroughly. These papers were grouped assigning to the four subdisciplines of craniomaxillofacial surgery: orthognathic surgery, reconstructive surgery, trauma surgery and implant surgery. The following variables – treatment time, the accuracy of VSP, clinical outcome, cost, and cost-effectiveness – were also examined. Results revealed that VSP offers advantages in craniomaxillofacial surgery over the traditional method in terms of duration, predictability and clinical outcomes. However, the cost aspect was not discussed in most papers. This structured literature review will thus provide current findings and trends and recommendations for future research on the usage of VSP in craniomaxillofacial surgery. [ABSTRACT FROM AUTHOR]

Background: Mandibular angle is the most common site for fractures, accounting for 23–42% of all cases of mandibular fractures. A customized fixation system is designed directly for a specific patient, which reduces the time spent bending and fixing the plate during the operation. This study was designed to assess the effect of CAD/CAM customized V pattern plate versus standard miniplates fixation in mandibular angle fracture. Materials and Methods: This prospective randomized clinical trial included 26 patients suffering from mandibular angle fracture. Patients were selected from Oral and Maxillofacial Surgery Department, Faculty of Dentistry, Cairo University and Ahmed Maher Teaching Hospital. Study group (13) needed open reduction and internal fixation by using CAD/CAM V plate with surgical guide, while control group (13) needed open reduction and internal fixation by using standard superior–inferior miniplate fixation. The patients were then followed up for one year postoperatively. Results: It showed that there was a statistical difference between the study group and the control group regarding postoperative pain, occlusion, and maximal interincisal opening (p value < 0.05%). There was no statistical difference (p value > 0.05%) in the postoperative panoramic radiograph that was taken within the postoperative 1st week in both groups, while the increase in mean bone density was statistically significant (p value < 0.05%) from 6 months to one year postoperatively. Conclusion: CAD/CAM customized V pattern plate is a suitable plate design because it offers sufficient stability for normal bone healing, the creation of an ideal occlusion, an early return to function, and adequate postoperative radiographic outcomes. Trial Registration: It was registered at ClinicalTrials.gov. Registration number: NCT03761524. Registration date: 03.12.2018. [ABSTRACT FROM AUTHOR]

This clinical report presents a technique to reconstruct extensively resected mandibles using a combination of autologous bone grafts and additive manufacturing techniques. Mandibular defects, often arising from trauma, tumors, or congenital anomalies, can severely impact both function and aesthetics. Conventional reconstruction methods have their limitations, often resulting in suboptimal outcomes. In these reports, we detail clinical cases where patients with different mandibular defects underwent reconstructive surgery. In each instance, autologous grafts were harvested to ensure the restoration of native bone tissue, while advanced virtual planning techniques were employed for precise graft design and dental implant placement. The patients experienced substantial improvements in masticatory function, speech, and facial aesthetics. Utilizing autologous grafts minimized the risk of rejection and complications associated with foreign materials. The integration of virtual planning precision allowed customized solutions, reducing surgical duration and optimizing implant positioning. These 2 cases underscores the potential of combining autologous grafts with virtual planning precision and dental implants produced by additive manufacturing for mandible reconstruction.

Backgrounds: Tooth loss in the posterior maxilla often necessitates dental implant placement, but the maxillary sinus anatomy poses challenges, especially during sinus floor elevation. Mesially angled implants are an alternative for total edentulism, but for single tooth deficiencies, palatally angled implants may offer a solution. This study evaluates the prevalence of avoiding sinus floor elevation by placing palatally angled implants in cases with a single missing tooth. Methods: A retrospective study at Ahmet Keleşoğlu Faculty of Dentistry involved 100 participants with a single missing tooth and prior CBCT scans. Virtual implants were placed using OnDemand3D (version 1.0.7462) software. On CBCT sections, implants were angled palatally to avoid sinus or nasal cavity perforation. Statistical analysis was conducted using R and MedCalc (version 4.3.2) software. Results: Of the participants (60% female, average age 50.45), 76 edentulous regions required sinus elevation. The implant placeability rates varied across zones (second molar: 39.3%, first molar: 63.1%, second premolar: 78.5%). Implant placement at a palatal angle was significantly higher in the second premolar and first molar regions. Statistically significant differences were observed in the implant placeability between regions. Conclusions: This study supports the feasibility of avoiding sinus floor elevation through palatally angled implants in specific cases, reducing the associated complications.

AbstractCraniomaxillofacial (CMF) surgery is a challenging and very demanding field that involves the treatment of congenital and acquired conditions of the face and head. Due to the complexity of the head and facial region, various tools and techniques were developed and utilized to aid surgical procedures and optimize results. Virtual Surgical Planning (VSP) has revolutionized the way craniomaxillofacial surgeries are planned and executed. It uses 3D imaging computer software to visualize and simulate a surgical procedure. Numerous studies were published on the usage of VSP in craniomaxillofacial surgery. However, the researchers found inconsistency in the previous literature which prompted the development of this review. This paper aims to provide a comprehensive review of the findings of the studies by conducting an integrated approach to synthesize the literature related to the use of VSP in craniomaxillofacial surgery. Twenty-nine related articles were selected as a sample and synthesized thoroughly. These papers were grouped assigning to the four subdisciplines of craniomaxillofacial surgery: orthognathic surgery, reconstructive surgery, trauma surgery and implant surgery. The following variables – treatment time, the accuracy of VSP, clinical outcome, cost, and cost-effectiveness – were also examined. Results revealed that VSP offers advantages in craniomaxillofacial surgery over the traditional method in terms of duration, predictability and clinical outcomes. However, the cost aspect was not discussed in most papers. This structured literature review will thus provide current findings and trends and recommendations for future research on the usage of VSP in craniomaxillofacial surgery.

Background: Virtual surgical planning allows surgeons to meticulously define surgical procedures by creating a digital replica of patients' anatomy. This enables precise preoperative assessment, facilitating the selection of optimal surgical approaches and the customization of treatment plans. In neck surgery, virtual planning has been significantly underreported compared to craniofacial surgery, due to a multitude of factors, including the predominance of soft tissues, the unavailability of intraoperative navigation and the complexity of segmenting such areas. Augmented reality represents the most innovative approach to translate virtual planning for real patients, as it merges the digital world with the surgical field in real time. Surgeons can access patient-specific data directly within their field of view, through dedicated visors. In head and neck surgical oncology, augmented reality systems overlay critical anatomical information onto the surgeon's visual field. This aids in locating and preserving vital structures, such as nerves and blood vessels, during complex procedures. In this paper, the authors examine a series of patients undergoing complex neck surgical oncology procedures with prior virtual surgical planning analysis. For each patient, the surgical plan was imported in Hololens headset to allow for intraoperative augmented reality visualization. The authors discuss the results of this preliminary investigation, tracing the conceptual framework for an increasing AR implementation in complex head and neck surgical oncology procedures. [ABSTRACT FROM AUTHOR]

OBJECTIVES: Our analysis focuses on the advantages of virtual surgical planning (VSP) compared to a conventional treatment method as well as on a wider range of parameters influencing the surgical procedure, postoperative care, morbidity and lastly, the survival rate of these patients. BACKGROUND: Patients with extensive bone defects of different etiologies of the upper or lower jaw who underwent complex reconstructive surgery with a free fibula flap (FFF). METHODS: We retrospectively analyzed data from a total of 34 patients (12 female and 22 male) whose defects were reconstructed with an osteomyocutaneus FFF. The data were collected over a period of 6 years from 2017 to 2023. We divided the patients into two groups, namely those who underwent conventional surgical treatment (5 patients) and those who underwent computer-planned surgical treatment (29 patients). RESULTS: The duration of surgery showed a significant difference between the VSP group and the conventional group (t(32) = 3.316; p < 0.01), with the VSP group having a significantly shorter surgery time (M= 8:10; SD = 1:18) compared to the conventional group (M = 10:52; SD = 2:41). The independent t-test revealed significant differences between the VSP group (M = 45.967; SD 14.548) and conventional group (M = 17.61; SD = 24.996) for the dose of unfractionated heparin per kilogram administrated immediately after vascular micro anastomosis (t(32) = -3.609; p < 0.001). CONCLUSION: Among all the risk factors, administering a higher unfractionated dosage of heparin administered immediately after completing the anastomosis was identified as a significant predictor of postoperative complications. Using VSP in cases of advanced stage head and neck malignancy for salvage surgery is highly recommended. Shorter duration of these comprehensive surgeries in the VSP group leads to a significantly favorable outcome (Tab. 2, Fig. 2, Ref. 19). [ABSTRACT FROM AUTHOR]

Obstructive sleep apnoea (OSA) is a syndrome with a high burden on public health. Maxillomandibular advancement (MMA) has proven to be a highly effective treatment option. This retrospective analysis evaluated the safety of maxillomandibular advancement with rotation in patients with OSA. A total of 63 patients with OSA were included in this study. Surgical treatment by maxillomandibular advancement was virtually planned based on preoperative cone beam computed tomography (CBCT). A 3D printed guide and a customised implant were used for surgical transfer. The safety of MMA was evaluated based on the necessity of postoperative intermediate care unit (IMCU) stay, duration of stay in hospital, and recording of medical complications. A total of 63.5% of the OSA patients treated by MMA (n = 40/63) were postoperatively transferred from the recovery room directly to the regular ward, while 36.5% of the patients (n = 23/63) stayed on IMCU for at least one night. On average, the length of hospitalisation was four days after surgery. One patient from the ward group and one patient from the IMCU group developed a major complication according to Clavian-Dindo classification grade IV. MMA is a safe surgical procedure. The necessity for postoperative monitoring in an IMCU setting should be based on an individual risk evaluation. However, since major complications can occur, MMA should be performed as an inpatient procedure in a hospital with available intensive medicine care. This study underlines the safety of MMA in OSA patients. [ABSTRACT FROM AUTHOR]

Background. In revision hip arthroplasty (RHA), establishing the center of rotation (COR) can be technically challenging due to the acetabular bone destruction that is usually present, particularly in severe cases such as Paprosky type II and III defects. The aim of this study was to demonstrate the use of open-source medical image reconstruction software and low-cost 3D anatomical models in pre-surgical planning of RHA. Methods. A total of 10 patients, underwent RHA and were included in the study. Computed tomography (CT) scans were performed for all cases, before surgery and approximately 1 week after the procedure. The reconstruction of CT data, 3D virtual planning of the COR and positioning of acetabular cups, including their inclination and anteversion angles, was carried out using the free open source software platform 3D Slicer. In addition, anatomical models of the pelvis were built on a desktop 3D printer from polylactic acid (PLA). Preoperative and postoperative reconstructed imaging data were compared for each patient, and the position of the acetabular cups as well as the COR were evaluated for each case. Results. Analysis of the pre- and post-op center of rotation position data indicated statistically insignificant differences for the location of the COR on the X-axis (1.5 mm, t = 0.5741, p = 0.5868) with a fairly strong correlation of the results (r = −0.672, p = 0.0982), whilst for the location of the COR in the Y and Z-axes, there was statistical dependence (Y axis, 4.7 mm, t = 3.168 and p = 0.0194; Z axis, 1.9 mm, t = 1.887 and p = 0.1081). A strong correlation for both axes was also observed (Y and Z) (Y-axis, r = 0.9438 and p = 0.0014; Z-axis, r = 0.8829 and p = 0.0084). Analysis of inclination angle values showed a statistically insignificant difference between mean values (3.9 degrees, t = 1.111, p = 0.3092) and a moderate correlation was found between mean values (r = −0.4042, p = 0.3685). Analysis of the anteversion angle showed a statistically insignificant difference between mean values (1.9 degrees, t = 0.8671, p = 0.4192), while a moderate correlation between mean values was found (r = −0.4782, p = 0.2777). Conclusions. Three-dimensional reconstruction software, together with low-cost anatomical models, are very effective tools for pre-surgical planning, which have great potential use in orthopedic surgery, particularly RHA. In up and in- and up and out-type defects, it is essential to establish a new COR and to identify three support points within the revision acetabulum in order to correctly position acetabular cups. [ABSTRACT FROM AUTHOR]

Virtual planning in digital dentistry enables easier communication between technicians, clinicians, and patients, and faster performance. Dental computer-aided design (CAD) software programs have been used for this purpose. One of the most crucial steps in virtual planning is mounting and articulating the maxillary and mandibular arch 3D models to simulate and evaluate the occlusion as a part of the virtual mock-up. The aim of this article was to describe a more cost-effective digital technique utilizing a scanned interocclusal record for articulating the cast models virtually. For this purpose, the open source Autodesk Meshmixer software program was used. [ABSTRACT FROM AUTHOR]

Background/Aim: The primary aim was to evaluate the prevalence and localisation of dental injuries caused by osteosynthesis screws during orthognathic surgery, comparing two different CAD/CAM planning/surgical approaches through retrospective evaluation of post-operative computed tomography. Material and Methods: This study considered all patients who underwent orthognathic surgery from 2010–2019. The examination for dental root injuries between conventional osteosynthesis (Maxilla conventional cohort) and osteosynthesis with patient-specific implant (Maxilla PSI cohort) was performed by evaluating the post-operative CT scans. Results: A total of 126 patients were included in the study. Among the 61 patients of the Maxilla conventional cohort, 10 dental root injuries in 8 patients (13.1%) were detected in the post-operative CT scan, representing 1.5% (n = 10/651) of the osteosynthesis screws inserted in proximity of the alveolar crest. No dental injury occurred following osteosynthesis in the 65 patients of the Maxillary PSI cohort (n = 0/773 screws) (p < 0.001). During a mean follow-up period of 13 months after primary surgery, none of the injured teeth showed evidence of periapical alterations and no endodontic treatments were necessary. Conclusions: Maxillary positioning using CAD/CAM-fabricated drill/osteotomy guide and osteosynthesis with PSI can significantly reduce the risk for dental injury compared to the conventional procedure. However, the clinical significance of the detected dental injuries was rather minor. [ABSTRACT FROM AUTHOR]

Background: Symptomatic proximal humeral fracture sequelae (PHFS) represent a surgical challenge due to the altered bone and soft tissue morphology. The purpose of this study was to report the outcome of Multiplanar Corrective Humeral Osteotomies (MCHOs) in combination with reverse total shoulder arthroplasty (rTSA) performed following a three-dimensional (3D) preoperative planning and using a 3D-printed patient-specific surgical instrumentation (PSI) in type 1C, 1D, and 4 PHFS. Methods: In this prospective monocentric study, we enrolled patients affected by symptomatic PHFS type 1C, 1D, or 4 of Boileau’s classification, treated between 2018 and 2019 with rTSA associated to MCHO and followed-up at 12 and 24 mo. The preoperative and postoperative Constant Score (CS), visual analog scale, and Disabilities of the Arm, Shoulder and Hand (DASH) score were recorded. All patients underwent a preoperative computed tomography, then a dedicated software was used to run a segmentation algorithm on computed tomography images. Metaphyseal bone cuts were virtually performed before surgery in all patients, and a 3D-printed PSI was used to reproduce the planned osteotomies in vivo. Results: Twenty patients completed a 2-y follow-up. The mean (± standard deviation) CS, visual analog scale, and DASH values improve from 24.3 (± 8.8), 6.5 (± 1.3), 60.7 (± 9.6) preoperatively, to 67.7 (± 11.4), 1.6 (± 0.8), 24.1 (± 13.1) points after surgery, respectively. The minimally clinical important difference for CS and DASH score was achieved in 95% of patients. No major complication was observed. One patient showed an unexplained worsening of clinical scores between the 12 and the 24-mo follow-up, while in one patient bone resorption of the greater tuberosity was observed on radiographs at 2 y, with no clinical impact. Conclusion: The combination of preoperative 3D planning and intraoperative use of 3D-printed PSI to perform MCHO as concurrent procedure in the context of rTSA in the treatment of Boileau type 1C, 1D, and 4 PHFS may lead to a satisfactory clinical outcome at 2 y of follow-up.

Roya Moafi,1 Fredrik Nysjö,2 Johan Kämpe,1 Christopher Riben,1 Andreas Thor1 1Department of Oral and Maxillofacial Surgery, Uppsala University, Uppsala, Sweden; 2Department of Information Technology, Centre for Image Analysis, Uppsala University, Uppsala, SwedenCorrespondence: Roya Moafi, Department of Oral and Maxillofacial Surgery, Uppsala University Hospital, Akademiska Sjukhuset. Käkkirurgi, Uppsala, 751 85, Sweden, Tel +46 018 6116450, Fax +46 018 559129, Email Roya_moafi@msn.comAbstract: Restoring normal skeletal anatomy in patients with complex trauma to the mandible can be difficult, the difficulty often increasing with an edentulous mandible. This study describes a case of a displaced edentulous bilateral mandibular fracture, which was preoperatively planned with the in-house haptic-assisted surgery planning system (HASP). A model of the virtually restored mandible was 3D-printed at the hospital and a reconstruction plate was outlined beforehand with the printed mandible as a template and served as a guide during surgery. This case suggests HASP as a valuable preoperative tool in the planning phase when dealing with maxillofacial trauma cases. With the application of virtual planning, the authors could analyze the desired outcome and were further supported in surgery by the guidance of the reconstruction plate outlined on the restored model of the mandible.Keywords: case report, trauma, virtual planning, 3D-printing, reconstruction

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We sought to assess the feasibility of virtually assisted personalized tracheostomy tube (vapTT) implementation for patients with congenital airway anomalies (CAAs) and persistent tracheostomy tube (TT)–related respiratory failure at a tertiary pediatric hospital. Three patients (0‐18 years) with CAAs and recurrent TT‐related respiratory complications were managed with vapTT over 5 years. Patients underwent airway computed tomography acquisition with 3‐dimensional reconstruction and TT virtual modeling for shape customization. Models were transferred to Bivona for fabrication based on industry‐standard materials and processes. Clinical information and tracheoscopies assessing position, obstruction, and granulation were reviewed. Patients demonstrated resolution of visualized TT‐related obstruction, granulation, or ulceration and de‐escalation of respiratory support. Clinical events requiring urgent tracheoscopy decreased in all 3 patients. Sufficient relief of critical airway obstruction allowed progression of medical care and/or discharge. VapTTs are feasible for patients with CAA. This new frontier in personalized devices may serve uniquely challenging patient populations for whom standard treatments have failed. [ABSTRACT FROM AUTHOR]

Virtual planning is ideally suited for maxillofacial operations as it allows the surgeon to assess the bony and critical neurovascular structures and enables him to plan osteotomies and fracture reductions. This study aims to propose the use of titanium-based patient-specific implants (PSI), along with virtual surgical planning to assess the advantages and the complications in a case of orbital reconstruction. A three-dimensional model of the skull was generated using computed tomography (CT) data of a female patient using Mimics software (version 19, Materialize, Leuven, Belgium). Numerical PSI models were designed using 3-Matic software (version 13, Materialize, Leuven, Belgium) and the non-affected orbit as a template. Surgical virtual planning showed the suitability of the use of the numerical models in traumatic surgical rehabilitation. Moreover, the digital printing process enabled the trial of the designed PSIs on the patient's face before the surgery. Reconstruction Biomechanical studies are an essential part of understanding the limits of maxillofacial traumas. The surgical results confirmed the virtual predictions, and the orbital reconstruction seems to be more enhanced and facilitated. [ABSTRACT FROM AUTHOR]

Although the modifications of the aging face have been widely described, to our knowledge, there are no studies that quantitatively analyze the degree of soft tissues facial ptosis. Using a specific iPhone application, the faces of a heterogeneous group of volunteers were scanned and studied with the aim to virtually measure the entity of facial ptosis.Two facial scans, upright and supine, were performed by using the Bellus3D Face app for iPhone in a sample of 60 volunteers. We virtually superimposed the two scans, and then, we calculated the discrepancy between them through the Geomagic Design X 3D software. A multivariate regression statistical model was used to analyze the correlation between the mean discrepancy values compared to three main variables: age, BMI and gender. Mean ptosis increases with age (coeff. = 0.02; 95% CI = 0.01–0.02, p < 0.001), BMI (coeff. = 0.03; 95% CI = 0.01–0.05; p < 0.001) and has been found higher in females (female versus male: coeff. = 0.22; 95% CI = 0.13–0.31; p < 0.001). The method we used allowed us to measure the degree of ptosis, and to make a complete morphological study of the effect of gravity on the facial surface in a very accurate, low cost and easily reproducible way. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate effects of preoperative virtual planning and jaw reconstruction guided by dental implant rehabilitation on dental prosthesis rehabilitation after jaw reconstruction. Materials and Methods: Patients indicated for segmental jaw resection and who agreed to receive jaw reconstruction procedures were enrolled in the study. Appropriate surgical procedures were determined by a maxillofacial surgeon and a prosthodontist before surgery. The virtual design was created according to preoperative computed tomography. Patients were divided into navigation and non-navigation groups. Implant surgery was performed 6 months after reconstruction surgery. After treatment completion, factors such as survival rate of implants, site of reconstruction, type of graft, and type of prosthesis were compared. Results: In total, 29 patients were included in the study, with 16 patients in the non-navigation group and 13 in the navigation group. A total of 101 implants were inserted, and the implant success rate was 98.02% (2 implants extracted due to peri-implantitis). All patients received prosthetic treatment. Of the 13 navigation group patients, 9 received fixed implant-supported prostheses, whereas the other 4 received removable dentures. Of the 16 non-navigation group patients, 9 eventually received fixed implant-supported prostheses and 7 received removable dentures. There were no significant intergroup differences in terms of prosthesis type (P = .702). However, the proportion of fixed implant-supported prostheses in the navigation group was higher compared with the non-navigation group. Conclusion: Preoperative virtual planning and dental implant rehabilitation-- guided jaw reconstruction through preoperative designing can provide a good opportunity to achieve high rates of implant success and dental rehabilitation. This method can also benefit fixed implant-supported prosthetic restorations. Moreover, the use of navigation after virtual planning has no effect on the type of prosthetic reconstruction. [ABSTRACT FROM AUTHOR]

Objectives: The objective was to assess the accuracy of orthognathic surgical planning using three-dimensional virtual planning compared with conventional two-dimensional planning. Material and Methods: MEDLINE (PubMed), Embase and Cochrane Library search combined with hand-search of relevant journals was conducted to identify randomized controlled trials (RCTs) published in English through August 2nd, 2022. Primary outcomes included postsurgical accuracy of hard and soft tissue. Secondary outcomes included treatment planning time, intraoperative time, intraoperative blood loss, complications, financial expenses, and patient-reported outcome measures (PROMs). Quality and risk-of-bias assessment were evaluated by Cochrane risk of bias tool and GRADE system. Results: Seven RCTs characterised by low, high, and unclear risk of bias fulfilled inclusion criteria. Included studies disclosed conflicting results regarding accuracy of hard and soft tissue as well as treatment planning time. The intraoperative time was shortened, and financial expenses were increased with three-dimensional virtual surgical planning (TVSP), while no planning-related complications were revealed. Comparable improvement in PROMs were reported with TVSP and two-dimensional planning. Conclusions: Future orthognathic surgical planning will indisputable be performed by three-dimensional virtual planning. The financial expenses, treatment planning time, and intraoperative time will therefore probably decrease due to further development of three-dimensional virtual planning techniques. The hard and soft tissue accuracy between planned position and achieved surgical outcome seems to be improved by three-dimensional virtual planning compared with two-dimensional planning, although results are inconsistent. Further development of three-dimensional virtual planning involving cutting guides and patient-specific osteosynthesis plates are therefore needed to improve the accuracy of orthognathic surgical planning.

Featured Application: The development of this co-registration method that combines CBCT with photographic images and subsequent realistic image reconstruction can be used during the orthognathic surgical planning stage. Therefore, both orthodontists and maxillofacial surgeons will obtain more realistic and precise result predictions, allowing them to better clarify the patient's surgical prognosis. Orthognathic surgery is a procedure used to correct intermaxillary discrepancies, thus promoting significant improvements in chewing and breathing. During the surgical planning stage, orthodontists often use two-dimensional imaging techniques. The assessment is based on CBCT images and dental cast models to overcome these limitations; however, the evaluation of soft tissues remains complex. The aim of the present study was to develop a co-registration method of CBCT and photo images that would result in realistic facial image reconstruction. CBCT images were three-dimensionally rendered, and the soft tissues were subsequently segmented resulting in the cranial external surface. A co-registration between the obtained surface and a frontal photo of the subject was then carried out. From this mapping, a photorealistic model capable of replicating the features of the face was generated. To assess the quality of this procedure, seven orthodontists were asked to fill in a survey on the models obtained. The survey results showed that orthodontists consider the three-dimensional model obtained to be realistic and of high quality. This process can automatically obtain a three-dimensional model from CBCT images, which in turn may enhance the predictability of surgical-orthognathic planning. [ABSTRACT FROM AUTHOR]

Objectives: The objective was to assess the accuracy of orthognathic surgical planning using three-dimensional virtual planning compared with conventional two-dimensional planning. Material and Methods: MEDLINE (PubMed), Embase and Cochrane Library search combined with hand-search of relevant journals was conducted to identify randomized controlled trials (RCTs) published in English through August 2nd, 2022. Primary outcomes included postsurgical accuracy of hard and soft tissue. Secondary outcomes included treatment planning time, intraoperative time, intraoperative blood loss, complications, financial expenses, and patient-reported outcome measures (PROMs). Quality and risk-of-bias assessment were evaluated by Cochrane risk of bias tool and GRADE system. Results: Seven RCTs characterised by low, high, and unclear risk of bias fulfilled inclusion criteria. Included studies disclosed conflicting results regarding accuracy of hard and soft tissue as well as treatment planning time. The intraoperative time was shortened, and financial expenses were increased with three-dimensional virtual surgical planning (TVSP), while no planningrelated complications were revealed. Comparable improvement in PROMs were reported with TVSP and two-dimensional planning. Conclusions: Future orthognathic surgical planning will indisputable be performed by three-dimensional virtual planning. The financial expenses, treatment planning time, and intraoperative time will therefore probably decrease due to further development of three-dimensional virtual planning techniques. The hard and soft tissue accuracy between planned position and achieved surgical outcome seems to be improved by three-dimensional virtual planning compared with two-dimensional planning, although results are inconsistent. Further development of three-dimensional virtual planning involving cutting guides and patient-specific osteosynthesis plates are therefore needed to improve the accuracy of orthognathic surgical planning. [ABSTRACT FROM AUTHOR]

The ideal jaw reconstruction involves the restoration and maintenance of jaw continuity, jaw relations, joint alignment, and facial contour, and, most importantly, dental occlusal reconstruction. One of the essential requirements of achieving a consistent functional outcome is to place the bony reconstruction in the correct three-dimensional position as it relates to the other jaw segments and dentition. A protocol of occlusion-driven reconstruction of prefabricated fibular free flaps that are customized to the patient with surgical design and simulation (SDS)-planned osseointegrated implant installation was developed by our institution. This innovation introduced significant flexibility and efficiency to jaw reconstructions, but functional and cosmetic outcomes were dependent on the accuracy of the final reconstructions when compared to the SDS plan. The purpose of this study was to examine the accuracy of the SDS-planned fibular flap prefabrication in a cohort of patients undergoing jaw reconstruction. All patients that had undergone primary jaw reconstruction with prefabricated fibular free flaps were reviewed. The primary outcome of this study was the accuracy of the postoperative implant positions as compared to the SDS plan. A total of 23 implants were included in the analysis. All flaps survived, there was no implant loss postoperatively, and all the patients underwent all stages of the reconstruction. SDS planning of fibular flap prefabrication resulted in better than 2 mm accuracy of osteointegrated implant placement in a cohort of patients undergoing jaw reconstruction. This accuracy could potentially result in improved functional and cosmetic outcomes. [ABSTRACT FROM AUTHOR]

Purpose: Morphological variability of the skull is an important consideration for cranioplasty and implant design. Differences in morphology of the skull based on the ethnicity are known. In a previous study we could show the accuracy and benefits of virtual reconstructions based on a statistical shape model (SSM) for neurocranial defects. As the SSM is trained on European data, the question arises how well this model fares when dealing with patients with a different ethnic background. In this study we aim to evaluate the accuracy and applicability of our proposed method when deploying a cranial SSM generated from European data to estimate missing parts of the neurocranium in a Chinese population. Methods: We used the same data and methods as in our previous study and compared the outcomes when applied to Chinese individuals. A large unilateral defect on the right side and a bilateral defect were created. The outer surface of the cranial table was reconstructed from CT scans, meshed with triangular elements, and registered to a template. Principal component analysis together with Thin Plate Spines (TPS) deformation was applied to quantify modes of variation. The mesh to mesh distances between the original defects´ surfaces and the reconstructed surface were computed. Results: Comparing the Chinese test group with the European control group, regarding the entire defect the analysis shows no significant difference for unilateral defects (test vs. control group/0.46 mm ± vs. 0.44 mm). Reconstruction of bilateral defects exhibited only in slightly higher prediction errors than those of unilateral defects (0.49 mm ± vs. 0.45 mm). Conclusion: The proposed method shows a high accuracy that seems to be ethnical independent - with low error margins for virtual skull reconstruction and implant design.Clinical relevance: Metallic objects may severely impact image quality in several CBCT devices.

Objective: To evaluate the impact of reducing the radiographic field of view (FOV) on the trueness and precision of the alignment between cone beam computed tomography (CBCT) and intraoral scanning data for implant planning. Materials and Methods: Fifteen participants presenting with one of three clinical scenarios: single tooth loss (ST, n = 5), multiple missing teeth (MT, n = 5) and presence of radiographic artifacts (AR, n = 5) were included. CBCT volumes covering the full arch (FA) were reduced to the quadrant (Q) or the adjacent tooth/teeth (A). Two operators, an expert (exp) in virtual implant planning and an inexperienced clinician, performed multiple superimpositions, with FA‐exp serving as a reference. The deviations were calculated at the implant apex and shoulder levels. Thereafter, linear mixed models were adapted to investigate the influence of FOV on discrepancies. Results: Evaluation of trueness compared to FA‐exp resulted in the largest mean (AR‐A: 0.10 ± 0.33 mm) and single maximum discrepancy (AR‐Q: 1.44 mm) in the presence of artifacts. Furthermore, for the ST group, the largest mean error (−0.06 ± 0.2 mm, shoulder) was calculated with the FA‐FOV, while for MT, with the intermediate volume (−0.07 ± 0.24 mm, Q). In terms of precision, the mean SD intervals were ≤0.25 mm (A‐exp). Precision was influenced by FOV volume (FA < Q < A) but not by operator expertise. Conclusions: For single posterior missing teeth, an extended FOV does not improve registration accuracy. However, in the presence of artifacts or multiple missing posterior teeth, caution is recommended when reducing FOV. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effect of three-dimensional virtual pre-operative planning (3DVP) on the incidence of dorsal screw penetration after volar plating of distal radius fractures. Methods: A cross-sectional diagnostic imaging study was performed. Twenty out of 50 patients were randomly selected from our index prospective cohort (IPC): a prior study evaluating dorsal tangential views (DTVs) in reducing dorsal screw penetration in internal fixation of intra-articular distal radius fractures using post-operative CT scans to quantify screw protrusion. Pre-operative CTs from this cohort were now used for 3DVP by three experienced orthopaedic trauma surgeons (supplementary video). 3DVP was compared with the corresponding post-operative CT for assessing screw lengths and incidence of dorsal penetration. The Wilcoxon Signed Ranks test was used to compare screw lengths and the Fishers' exact for incidence of penetration. Results: Three surgeons performed 3DVP for 20 distal radius fractures and virtually applied 60 volar plates and 273 screws. Median screw length was shorter in the 3DVP when compared to IPC: 18 mm (range, 12–22) versus 20 mm (range, 14–26) (p < 0.001). The number of penetrating screws was 5% (13/273 screws) in the 3DVP group compared to 11% (10/91 screws) in the IPC (p = 0.047). Corresponding to a reduction in incidence of at least one dorsally penetrating screw in 40% of patients in the IPC group, to 18% in the 3DVP group (p = 0.069). Conclusion: Three-Dimensional Virtual Pre-Operative Planning (3DVP) may reduce the incidence of dorsally penetrating screws in patients treated with volar plating for intra-articular distal radius fractures. Level of evidence: II, diagnostic imaging study. [ABSTRACT FROM AUTHOR]