Current Status of Surgical Planning for Orthognathic Surgery: Traditional Methods versus 3D Surgical Planning

Advances of surgical robotics: image-guided classification and application

Surgical robotics application in the field of minimally invasive surgery has developed rapidly and has been attracting increasingly more research attention in recent years. A common consensus has been reached that surgical procedures are to become less traumatic and with the implementation of more intelligence and higher autonomy, which is a serious challenge faced by the environmental sensing capabilities of robotic systems. One of the main sources of environmental information for robots are images, which are the basis of robot vision. In this review article, we divide clinical image into direct and indirect based on the object of information acquisition, and into continuous, intermittent continuous, and discontinuous according to the target-tracking frequency. The characteristics and applications of the existing surgical robots in each category are introduced based on these two dimensions. Our purpose in conducting this review was to analyze, summarize, and discuss the current evidence on the general rules on the application of image technologies for medical purposes. Our analysis gives insight and provides guidance conducive to the development of more advanced surgical robotics systems in the future.

Deep learning segmentation of mandible with lower dentition from cone beam CT

OBJECTIVES

This study aimed to train a 3D U-Net convolutional neural network (CNN) for mandible and lower dentition segmentation from cone-beam computed tomography (CBCT) scans.

METHODS

In an ambispective cross-sectional design, CBCT scans from two hospitals (2009-2019 and 2021-2022) constituted an internal dataset and external validation set, respectively. Manual segmentation informed CNN training, and evaluations employed Dice similarity coefficient (DSC) for volumetric accuracy. A blinded oral maxillofacial surgeon performed qualitative grading of CBCT scans and object meshes. Statistical analyses included independent t-tests and ANOVA tests to compare DSC across patient subgroups of gender, race, body mass index (BMI), test dataset used, age, and degree of metal artifact. Tests were powered for a minimum detectable difference in DSC of 0.025, with alpha of 0.05 and power level of 0.8.

RESULTS

648 CBCT scans from 490 patients were included in the study. The CNN achieved high accuracy (average DSC: 0.945 internal, 0.940 external). No DSC differences were observed between test set used, gender, BMI, and race. Significant differences in DSC were identified based on age group and the degree of metal artifact. The majority (80%) of object meshes produced by both manual and automatic segmentation were rated as acceptable or higher quality.

CONCLUSION

We developed a model for automatic mandible and lower dentition segmentation from CBCT scans in a demographically diverse cohort including a high degree of metal artifacts. The model demonstrated good accuracy on internal and external test sets, with majority acceptable quality from a clinical grader.

Computerized Surgical Planning in Gender Affirming Facial Surgery

Computerized Surgical Planning (CSP) is a surgical tool that enables precise bony changes through the creation of custom cutting guides and/or custom plates. CSP has been shown to be a safe and effective tool in gender affirming facial surgery as well, specifically with regard to frontal sinus setback, zygomatic remodeling, genioplasty, and mandibular angle and body reshaping. CSP aids in trainee education, improves symmetry, reduces operative time, and can produce idealized results during complex revisions. Overall, CSP is a valuable tool in the field of gender affirming facial surgery that helps surgeons achieve optimal aesthetic and safety outcomes for patients.

Does the Implementation of Virtual Planning has a Significant Impact on Reducing the Revision Rate in Orthognathic Surgery?

PURPOSE

Conventional orthognathic surgical planning has limitations in accurately transferring the relationship between soft tissue and bone. Virtual planning offers enhanced accuracy and visualization through computer simulation. This study aimed to compare the need for reoperation between patients who underwent conventional and virtual surgical planning for orthognathic surgery.

MATERIAL AND METHODS

The study included 352 patients who underwent orthognathic surgery. Reoperation rates and reasons for reoperation were evaluated in patients with conventional model surgery planning (143 patients) and virtual planning (209 patients).

RESULTS

The reoperation rate was 7.69% for conventional surgery patients and 3.82% for virtual planning patients. Malocclusion was the most common reason for reoperation in both groups. Bilateral sagittal split ramus osteotomies (BSSO) and genioplasty were the most frequently performed revision procedures.

CONCLUSION

Virtual planning in orthognathic surgery may lead to a reduced reoperation rate compared with conventional planning methods. The accuracy, visualization, and interdisciplinary collaboration offered by virtual planning can improve surgical outcomes.

Long-term outcomes in virtual surgical planning for mandibular reconstruction: A cost-effectiveness analysis

OBJECTIVE

This study is an economic evaluation comparing virtual surgical planning (VSP) utilization to free hand mandibular reconstruction (FHR) for advanced oral cavity cancer, for which the cost effectiveness remains poorly understood. The proposed clinical benefits of VSP must be weighed against the additional upfront costs.

METHODS

A Markov decision analysis model was created for VSP and FHR based on literature review and institutional data over a 35-year time horizon. Model parameters were derived and averaged from systematic review and institutional experience. VSP cost and surgical time saving was incorporated. We accounted for long-term risks including cancer recurrence and hardware failure/exposure. We calculated cost in US dollars and effectiveness in quality-adjusted-life-years (QALYs). A health care perspective was adopted, discounting costs and effectiveness at 3%/year. Deterministic and probabilistic sensitivity analyses tested model robustness.

RESULTS

In the base case scenario, total VSP strategy cost was $49,498 with 8.37 QALYs gained while FHR cost was $42,478 with 8.27 QALY gained. An incremental cost-effectiveness ratio (ICER), or the difference in cost/difference in effectiveness, for VSP was calculated at $68,382/QALY gained. VSP strategy favorability was sensitive to variations of patient age at diagnosis and institutional VSP cost with one-way sensitivity analysis. VSP was less economically favorable for patients >75.5 years of age or for institutional VSP costs >$10,745. In a probabilistic sensitivity analysis, 55% of iterations demonstrated an ICER value below a $100,000/QALY threshold.

CONCLUSIONS/RELEVANCE

VSP is economically favorable compared to FHR in patients requiring mandibular reconstruction for advanced oral cancer, but these results are sensitive to the patient's age at diagnosis and the institutional VSP cost. Our results do not suggest if one "should or should not" use VSP, rather, emphasizes the need for patient selection regarding which patients would most benefit from VSP when evaluating quality of life and long-term complications. Further studies are necessary to demonstrate improved long-term risk for hardware failure/exposure in VSP compared to FHR.

Evolution of Virtual Surgical Planning Use Among Craniofacial Surgeons

Virtual surgical planning (VSP) has benefits in craniofacial surgery with growing popularity. However, while specific use cases are highlighted in the literature, no studies exist providing an overview of VSP use among craniofacial surgeons, and little is known about the extent of exposure to VSP during plastic surgery training. This study surveyed members of The American Society of Maxillofacial Surgeons (ASMS) to better characterize both the landscape of VSP use among practicing craniofacial surgeons and the extent of exposure to VSP throughout surgical training. An electronic survey was administered in the fall of 2023. Response data included surgeon demographics, VSP usage, including the use in residency/fellowship, procedures for which VSP is used, and assessment of VSP's impact on the surgeon's practice. Demographics and VSP use were analyzed using descriptive statistics, while categorical and continuous variables were analyzed using χ2 tests and t-tests, respectively. Of the 44 respondents, 40 (90.9%) completed a craniofacial surgery fellowship, and 18 (40.9%) utilized VSP in either residency or fellowship. In respondents' current practice, VSP is utilized most commonly for orthognathic surgery (n=32, 91.4%), postablative reconstruction (n=23, 82.1%), and facial feminization (n=11, 73.3%). Shorter operative time and improved esthetic outcomes were frequently reported as benefits derived from VSP use. Finally, surgeons in practice for less than 10 years were significantly more likely to have used VSP in both residency (OR=20.3, P<0.01) and in fellowship (OR=40.6, P<0.01) than those practicing for more than 10 years. These findings suggest that craniofacial surgeons apply VSP more commonly for certain procedure types. Our results additionally suggest that incorporation of VSP into residency and fellowship training has become significantly more common over time, with a pivot towards integration in the last decade.

Accuracy of maxillary repositioning surgery in teaching hospitals using conventional model surgery

PURPOSE

The aim of this study was to assess the accuracy of maxillary repositioning surgery in teaching hospitals using conventional model surgery.

MATERIALS AND METHODS

A total of 73 patients undergoing single-piece LeFort I osteotomies in the maxilla and bilateral sagittal split osteotomies in the mandible were included in the study. Preoperative and immediate postoperative cone-beam CT were compared in computer software (Dolphin3D©). Maxillary landmarks relative to the vertical and horizontal reference lines were evaluated. The difference between the planned and achieved maxillary positions was measured. Distance error in millimeters and achievement ratio (achieved displacement/planned displacement*100) were calculated for different maxillary movements.

RESULTS

Midline correction and advancement were the most accurate movements with an overall mean distance error of 0.53 mm and 0.63 mm respectively while posterior impaction and setback were the least accurate movements with 1.38 mm and 1.76 mm mean discrepancies, respectively. A significant difference was observed only in setback movement regarding the discrepancy value (P < .05). Although setback and down-graft movements tended to under-correction, all other movements were overcorrected. As the magnitude of maxillary movements increases, the accuracy decreases. In severe displacements (≥ 8 mm), the accuracy declines significantly (P < .05).

CONCLUSION

Classic cast surgery and manually fabricated intermediate splints in teaching hospitals yield accurate and acceptable results in the majority of cases (84.6%). The accuracy of maxillary repositioning decreases as the magnitude of displacement increases.

Predicting optimal patient-specific postoperative facial landmarks for patients with craniomaxillofacial deformities

Orthognathic surgery primarily corrects skeletal anomalies and malocclusion to enhance facial aesthetics, aiming for an improved facial appearance. However, this traditional skeletal-driven approach may result in undesirable residual asymmetry. To address this issue, a soft tissue-driven planning methodology has been proposed. This technique estimates bone movements based on the envisioned optimal facial appearance, thereby enhancing surgical accuracy and effectiveness. This study investigates the initial implementation phase of the soft tissue-driven approach, simulating the patient's ideal appearance by realigning distorted facial landmarks to an ideal state. The algorithm employs symmetrization and weighted optimization strategies, aligning projected optimal landmarks with standard cephalometric values for both facial symmetry and form, which are essential in orthognathic surgery for facial aesthetics. It also incorporates regularization to preserve the patient's facial characteristics. Validation through retrospective analysis of preoperative patients and normal subjects demonstrates this method's efficacy in achieving facial symmetry, particularly in the lower face, and promoting a natural, harmonious contour. Adhering to soft tissue-driven principles, this novel approach shows promise in surpassing traditional methods, potentially leading to enhanced facial outcomes and patient satisfaction in orthognathic surgery.

Redefining precision and efficiency in orthognathic surgery through virtual surgical planning and 3D printing: a narrative review

Orthognathic surgery, essential for addressing jaw and facial skeletal irregularities, has historically relied on traditional surgical planning (TSP) involving a series of time-consuming steps including two-dimensional radiographs. The advent of virtual surgical planning (VSP) and 3D printing technologies has revolutionized this field, bringing unprecedented precision and customization to surgical processes. VSP facilitates 3D visualization of the surgical site, allowing for real-time adjustments and improving preoperative stress for patients by reducing planning time. 3D printing dovetails with VSP, offering the creation of anatomical models and surgical guides, enhancing the predictability of surgical outcomes despite higher initial setup and material costs. The integration of VSP and 3D printing promises innovative and effective solutions in orthognathic surgery, surpassing the limitations of traditional methods. Patient-reported outcomes show a positive post-surgery impact on the quality of life, underlining the significant role of these technologies in enhancing self-esteem and reducing anxiety. Economic analyses depict a promising long-term fiscal advantage with these modern technologies, notwithstanding the higher initial costs. The review emphasizes the need for large-scale randomized controlled trials to address existing research gaps and calls for a deeper exploration into the long-term impacts and ethical considerations of these technologies. In conclusion, while standing on the cusp of a technological renaissance in orthognathic surgery, it is incumbent upon the medical fraternity to foster a collaborative approach, balancing innovation with scrutiny to enhance patient care. The narrative review encourages the leveraging of VSP and 3D printing technologies for more efficient and patient-centric orthognathic surgery, urging the community to navigate uncharted territories in pursuit of precision and efficiency in the surgical landscape.

Modern Image-Guided Surgery: A Narrative Review of Medical Image Processing and Visualization

Medical image analysis forms the basis of image-guided surgery (IGS) and many of its fundamental tasks. Driven by the growing number of medical imaging modalities, the research community of medical imaging has developed methods and achieved functionality breakthroughs. However, with the overwhelming pool of information in the literature, it has become increasingly challenging for researchers to extract context-relevant information for specific applications, especially when many widely used methods exist in a variety of versions optimized for their respective application domains. By being further equipped with sophisticated three-dimensional (3D) medical image visualization and digital reality technology, medical experts could enhance their performance capabilities in IGS by multiple folds. The goal of this narrative review is to organize the key components of IGS in the aspects of medical image processing and visualization with a new perspective and insights. The literature search was conducted using mainstream academic search engines with a combination of keywords relevant to the field up until mid-2022. This survey systemically summarizes the basic, mainstream, and state-of-the-art medical image processing methods as well as how visualization technology like augmented/mixed/virtual reality (AR/MR/VR) are enhancing performance in IGS. Further, we hope that this survey will shed some light on the future of IGS in the face of challenges and opportunities for the research directions of medical image processing and visualization.

Predicting Optimal Patient-Specific Postoperative Facial Landmarks for Patients with Craniomaxillofacial Deformities

Orthognathic surgery traditionally focuses on correcting skeletal abnormalities and malocclusion, with the expectation that an optimal facial appearance will naturally follow. However, this skeletal-driven approach can lead to undesirable facial aesthetics and residual asymmetry. To address these issues, a soft-tissue-driven planning method has been proposed. This innovative method bases bone movement estimates on the targeted ideal facial appearance, thus increasing the surgical plan's accuracy and effectiveness. This study explores the initial phase of implementing a soft-tissue-driven approach, simulating the patient's optimal facial look by repositioning deformed facial landmarks to an ideal state. The algorithm incorporates symmetrization and weighted optimization strategies, aligning projected optimal landmarks with standard cephalometric values for both facial symmetry and form, which are integral to facial aesthetics in orthognathic surgery. It also includes regularization to preserve the patient's original facial characteristics. Validated using retrospective analysis of data from both preoperative patients and normal subjects, this approach effectively achieves not only facial symmetry, particularly in the lower face, but also a more natural and normalized facial form. This novel approach, aligning with soft-tissue-driven planning principles, shows promise in surpassing traditional methods, potentially leading to enhanced facial outcomes and patient satisfaction in orthognathic surgery.

Are Virtually Designed 3D Printed Surgical Splints Accurate Enough for Maxillary Reposition as an Intermediate Orthognathic Surgical Guide

Background and Aim

The accuracy of the virtually-designed 3D-printed surgical splints requires investigation for the practical use of surgical plan in the operating room. This study aimed to compare the validity of the 3D-printed and the conventional intermediate splints and evaluate the outcomes after the surgical application of the 3D-printed splint compared with the predicted values.

Methods

In this study, ten patients with dentofacial deformity were recruited. Participants were analyzed by the conventional surgical planning and virtual surgical planning. The intermediate surgical splints were created by the conventional and 3D-printing methods. Maxillary movements in 3 spatial directions were measured in an articulator after the application of both splints. Correlation and agreement between the two methods were tested by intraclass correlation coefficient (ICC). After the confirmation of 3D printed splint validity for each patient, the surgery was performed using 3D printed splints. It is assumed that ideally cephalometric prediction values are going to be obtained using conventional acrylic splints (gold standard). So, as a second objective, the outcome of the surgically-applied 3D-printed splint was evaluated and compared with the predicted values and finally analyzed by the paired t-test.

Results

Based on the observations, there was an excellent agreement between the virtually-designed 3D-printed and conventional intermediate surgical splints (ICC ranged between 0.83 and 0.99 for linear values). There was a good cumulative agreement of ICC greater than 0.80. Overall, the mean linear measurements were not different between conventional and 3D-printed splint on the articulator. Also, there were no significant differences between the linear and angular measurements of 2D-cephalometric prediction and postoperation values.

Conclusion

The results showed cautiously the acceptable accuracy of the 3D-printed splints for several parameters in three spatial dimensions within the laboratory and clinical settings.

Is There a Need for Greater Emphasis on Clinical Facial Analysis than Cephalometrics & 3D Software Solutions in the Diagnosis and Treatment Planning of Patients with Dentofacial Deformities?

Purpose

This study is designed to evaluate the need for a greater emphasis on clinical facial analysis over cephalometrics in the diagnosis and treatment planning of patients with dentofacial deformities.

Materials and Method

A predetermined questionnaire study was designed to get the thought process of surgeons and consultants involved in orthognathic surgery from various parts of southern India. Two hundred and twenty-eight maxillofacial consultants were involved in the survey. Demographic information, type of professional practice, preferred tool in the diagnosis & treatment planning: Cephalometrics or 3D software solutions and flaw in the available tools were evaluated.

Results

The results of this study revealed that only 36.8% of the consultants felt that cephalometrics is the prime tool and 73.3% of the consultants felt that 3D software solutions were superior to cephalometrics in the diagnosis and treatment planning of patients with dentofacial deformities. However, 46% of the consultants preferred facial analysis as the prime tool with cephalometrics as an adjunct. Pertaining to the clinical outcome of their treated cases of dentofacial deformities, 61.8% of the consultants felt the need to address additional cosmetic issues following an orthognathic procedure. It was observed that 92.1% of the participants felt the need for greater emphasis on clinical facial analysis than cephalometrics.

Conclusion

Human faces should always be evaluated taking into consideration the various esthetic units of the face. Performing corrective jaw surgery merely based on cephalometric values inevitably fails to address the various other innate imbalances of the face. Hence, cephalometric data should only be considered as an adjunct to clinical judgment in the diagnosis and treatment planning of dentofacial deformities.

Male and Female Discrepancies in Anxiety, Depressive Symptoms, and Coping Strategies among Orthognathic Patients: A Cross-Sectional Analysis

With an increasing understanding of the differences between men and women's psychological experiences, this study aimed to probe the sex-based differences in anxiety, depressive symptoms, and coping strategies among orthognathic patients. The study hypothesis was that female patients would show higher levels of anxiety and depressive symptoms than males, and that coping mechanisms would differ between male and female sexes. A cross-sectional design was adopted, examining orthognathic patients from the Department of Oral and Maxillo-Facial Surgery at the Emergency Clinical Municipal Hospital in Timisoara, Romania, from 2020 to 2023. Eligible participants (18+ years with no prior orthognathic treatment) completed a comprehensive online questionnaire 6 weeks before scheduled surgery. This was composed of validated self-report instruments comprising the SF-36, GAD-7, and the PHQ-9, and the COPE-60, along with additional sociodemographic data. Of the 127 orthognathic patients analyzed (68 men and 59 women, aged 18 to 65 years, mean age 32), men rated their physical health status slightly better on the SF-36 scale. However, the most notable difference was in mental health, with females scoring higher on both the PHQ-9 (indicative of depression) and the GAD-7 (indicative of anxiety) scales. Specifically, female participants exhibited average PHQ-9 scores 1.8 points higher and GAD-7 scores 1.5 points higher than their male counterparts. Coping mechanisms also varied: 42% of male patients primarily employed "Disengagement" strategies, while 58% of females predominantly used "Engagement" and "Emotion Focused" strategies. Emotion-focused coping was associated with a 1.6-fold increased risk of depressive symptoms. Sex differences play a crucial role in the psychological experiences of orthognathic patients, evident in anxiety and depression levels, perceived health status, and coping strategies. This underlines the importance of sex-tailored psychological support in the preoperative phase for orthognathic surgery patients.

Digital template-guided genioplasty for patients with jaw deformity resulting from temporomandibular joint ankylosis: A comparison between single- and double-layer genioplasty

The aim of this study was to compare single- and double-layer digital template-assisted genioplasty for the correction of jaw deformity resulting from temporomandibular joint ankylosis (TMJA). Thirteen patients with jaw deformity resulting from TMJA who underwent lateral arthroplasty, costochondral graft, or total joint replacement combined with single- or double-layer digital template-assisted genioplasty were included. Computed tomography data were obtained for the preoperative design. Digital templates were designed and manufactured using three-dimensional printing to assist with the chin osteotomy and repositioning in single- or double-layer genioplasty. Of the 13 patients included, seven underwent single-layer genioplasty and six underwent double-layer genioplasty. The digital templates precisely reflected the osteotomy planes and repositioning of the chin segments intraoperatively. The radiographic evaluation showed that the patients who underwent double-layer genioplasty exhibited more chin advancement (11.95 ± 0.92 mm vs 7.50 ± 0.89 mm; P < 0.001) with a slightly larger mean surface error (1.19 ± 0.14 mm vs 0.75 ± 0.15 mm; P < 0.001) than those who underwent single-layer genioplasty. This indicates that double-layer genioplasty better promoted chin advancement and improved the facial shape, but was accompanied by more surgical error compared with the preoperative design. Furthermore, hardly any nerve damage was observed. Digital templates are useful for assisting in surgical procedures.

Role of Three-Dimensional Printing in Treatment Planning for Orthognathic Surgery: A Systematic Review

Three-dimensional (3D) printing refers to a wide range of additive manufacturing processes that enable the construction of structures and models. It has been rapidly adopted for a variety of surgical applications, including the printing of patient-specific anatomical models, implants and prostheses, external fixators and splints, as well as surgical instrumentation and cutting guides. In comparison to traditional methods, 3D-printed models and surgical guides offer a deeper understanding of intricate maxillofacial structures and spatial relationships. This review article examines the utilization of 3D printing in orthognathic surgery, particularly in the context of treatment planning. It discusses how 3D printing has revolutionized this sector by providing enhanced visualization, precise surgical planning, reduction in operating time, and improved patient communication. Various databases, including PubMed, Google Scholar, ScienceDirect, and Medline, were searched with relevant keywords. A total of 410 articles were retrieved, of which 71 were included in this study. This article concludes that the utilization of 3D printing in the treatment planning of orthognathic surgery offers a wide range of advantages, such as increased patient satisfaction and improved functional and aesthetic outcomes.

Modeling Methods in Craniofacial Virtual Surgical Planning

Despite the widespread use of virtual surgical planning (VSP), few papers describe the modeling methods used to generate the digital simulations that underpin VSP. This paper aims to review the modeling methods that are currently available for use in VSP and the implications of their use in clinical practice. A literature review was undertaken of the two broad categories of modeling techniques; contour-based planning-namely mirroring from the contralateral side, templating from a normative database, and extrapolation from surrounding landmarks-and occlusal-based planning (OBP). The indications for each modeling method were discussed, including mandibular/maxillary reconstruction, pediatric craniofacial surgery, and orthognathic, as well as the limitations to the accuracy of modeling types. Unilateral defects of the upper/midface, wherein contour accuracy is paramount, are best reconstructed using mirroring methods, whereas bilateral defects-or cases with asymmetry due to craniofacial dysmorphology-are most suited to normative-data-based methods. Cases involving resection of the alveolar margin, in which functional occlusion is the primary outcome are best managed with OBP. Similarly, orthognathic surgery typically uses OBP, although complex cases involving asymmetry, such as clefts, may benefit from a combination of OBP and normative data methods. The choice of modeling methods is, therefore, largely driven by the defect type and the goals of reconstruction.

Dental Root Injuries Caused by Osteosynthesis Screws in Orthognathic Surgery-Comparison of Conventional Osteosynthesis and Osteosynthesis by CAD/CAM Drill Guides and Patient-Specific Implants

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.

Accuracy of three-dimensional optical devices for facial soft-tissue measurement in clinical practice of stomatology: A PRISMA systematic review

BACKGROUND

The accuracy of 3-dimensional (3D) optical devices for facial soft-tissue measurement is essential to the success of clinical treatment in stomatology. The aim of the present systematic review was to summarize the accuracy of 3D optical devices used for facial soft-tissue assessment in stomatology.

METHODS

An extensive systematic literature search was performed in the PubMed/MEDLINE, Embase, Scopus and Cochrane Library databases for studies published in the English language up to May 2022 in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Peer-reviewed journal articles evaluating the facial soft-tissue morphology by 3D optical devices were included. The risk of bias was performed using the Quality Assessment Tool for Diagnostic Accuracy Studies-2 guidelines by the 2 reviewers. The potential publication bias was analyzed using the Review Manager software.

RESULTS

The query returned 1853 results. A total of 38 studies were included in this review. Articles were categorized based on the principle of devices: laser-based scanning, structured-light scanning, stereophotogrammetry and red, green, blue-depth camera.

CONCLUSION

Overall, the 3D optical devices demonstrated excellent accuracy and reliability for facial soft-tissue measurement in stomatology. red, green, blue-depth camera can collect accurate static and dynamic 3D facial scans with low cost and high measurement accuracy. Practical needs and availability of resources should be considered when these devices are used in clinical settings.

Three-dimensional printing in the field of oral and maxillofacial surgery

Advanced imaging techniques and modalities coupled with computer-assisted surgical planning and simulation has been in use in the field of medicine. However, it is worth noting that it is now being frequently used for the evaluation and exploration of the craniofacial structures. It had gained ingress in the planning as well as forecasting of the surgical outcomes of oral and maxillofacial surgical interventions. Numerous surgical guides and devices which are tailor-made can be fabricated using three-dimensional (3D) printing technology. The article is intended to put forth an overview of 3D printing technology and its applications in the field of oral and maxillofacial surgery.

Cybersickness Variability by Race: Findings From 6 Studies and a Mini Meta-analysis

Background

With the influx of medical virtual reality (VR) technologies, cybersickness has transitioned from a nuisance experienced during leisure activities to a potential safety and efficacy concern for patients and clinicians. To improve health equity, it is important to understand any potential differences in cybersickness propensity among demographic groups, including racial groups.

Objective

This study aims to explore whether cybersickness propensity differs across racial groups.

Methods

We collected self-reported cybersickness ratings from 6 racially diverse independent samples within 1 laboratory group (N=931). In these studies, the participants were asked to perform tasks in VR such as traversing environments, pointing at and selecting objects, and interacting with virtual humans.

Results

Significant racial differences in cybersickness were found in 50% (3/6) of studies. A mini meta-analysis revealed that, on average, Black participants reported approximately one-third of SD less cybersickness than White participants (Cohen d=−0.31; P<.001), regardless of the nature of the VR experience. There was no overall difference in reported cybersickness between the Asian and White participants (Cohen d=−0.11; P=.51).

Conclusions

Racial differences in cybersickness indicate that researchers, practitioners, and regulators should consider patient demographics when evaluating VR health intervention outcomes. These findings lay the groundwork for future studies that may explore racial differences in cybersickness directly.

Computer Aided Orthognathic Surgery: A General Method for Designing and Manufacturing Personalized Cutting/Repositioning Templates

Orthognathic surgery allows broad-spectrum deformity correction involving both aesthetic and functional aspects on the TMJ (temporo-mandibular joint) and on the facial skull district. The combination of Reverse Engineering (RE), Virtual Surgery Planning (VSP), Computer Aided Design (CAD), Additive Manufacturing (AM), and 3D visualization allows surgeons to plan, virtually, manipulations and the translation of the human parts in the operating room. This work’s aim was to define a methodology, in the form of a workflow, for surgery planning and for designing and manufacturing templates for orthognathic surgery. Along the workflow, the error chain was checked and the maximum error in virtual planning was evaluated. The three-dimensional reconstruction of the mandibular shape and bone fragment movements after segmentation allow complete planning of the surgery and, following the proposed method, the introduction of both the innovative evaluation of the transversal intercondylar distance variation after mandibular arch advancement/set and the possibility of use of standard plates to plan and realize a customized surgery. The procedure was adopted in one clinical case on a patient affected by a class III malocclusion with an associated open bite and right deviation of the mandible with expected good results. Compared with the methods from most recent literature, the presented method introduces two elements of novelty and improves surgery results by optimizing costs and operating time. A new era of collaboration among surgeons and engineer has begun and is now bringing several benefits in personalized surgery.

Custom Plates in Orthognathic Surgery: A Single Surgeon's Experience and Learning Curve

BACKGROUND

Virtual surgical planning (VSP) now allows for the fabrication of custom plates in orthognathic surgery. The senior author was an early adopter, using VSP and stereolithographic splints for over a decade, before transitioning to custom plates in 2019. The authors present our experience and learning curve with this new technology and compare results to a prior cohort of orthognathic patients.

METHODS

A retrospective chart review identified patients undergoing orthognathic surgery with the senior author between 2016 and 2021. All underwent VSP and stereolithographic splint formation, and then either traditional or custom-plate fixation. Demographics, perioperative variables, and postoperative outcomes were analyzed. Traditional fixation consisted of craniomaxillofacial plates, bent intraoperatively by the surgeon to adapt to the facial skeleton. Custom plates were prefabricated and prebent to fit drill holes outlined by customized cutting guides.

RESULTS

Forty-three patients underwent surgery in the study period, 25 (58.1%) with traditional fixation hardware and 18 (41.9%) with custom plates. The surgical technique evolved throughout the custom-plate cohort, with the most recent technique involving custom maxillary plate fixation and traditional mandibular plate fixation. When comparing this group of patients to the prior cohort of traditional fixation patients, operative time significantly decreased (mean 233 minutes versus 283 minutes, P = 0.044), without significant difference in complications.

CONCLUSIONS

Patient-specific cutting guides and custom plates allow for precise spatial positioning of the osteotomized jaw in the orthognathic surgery. Unsurprisingly, obstacles must be overcome in adopting this new technology; here, we outline our experience and technical modifications that have resulted in increased surgical efficiency with comparable outcomes.

Physical Versus Digital Orthognathic Surgical Planning

OBJECTIVE

Orthognathic occlusal repositioning wafers could be constructed virtually and 3D printed. This paper assessed the accuracy of a suggested virtual model to the conventionally established Glasgow model surgery.

DESIGN

Prospective study of the orthognathic surgery models digitally.

PARTICIPANTS

Seven patients who received bi-maxillary orthognathic surgeries for correction of dentofacial deformities.

METHODS

The patients were clinically assessed and their cone beam cmputerized tomography (CBCT) studied. Model surgery of each patient was performed conventionally using face-bow and semi-adjustable articulator. Same plan was executed virtually using Mimics (Materialise, Leuven, Belgium) and 3Matic (Materialise, Leuven, Belgium). Conventionally fabricated acrylic wafers as well as 3D printed wafers were CBCT scanned with the casts reflecting the archived repositioning dictated by the wafers. Paired sample t test was performed to compare accuracy between intermediate and final occlusal repositioning wafers within conventional and virtual technique groups.

RESULTS

The mean deviation in intermediate wafer group was 0.64 ± 0.33 mm; whereas the mean deviation in final wafer group was 0.53 ± 0.10 mm. Paired sample t test showed that there was no statistically significant difference in mean deviation between both groups (P = 0.403).

CONCLUSIONS

This virtual surgical wafer achieves a similar level of accuracy to the conventional Glasgow model surgery.

Current trends in orthognathic surgery

Orthognathic surgery has steadily evolved, gradually expanding its scope of application beyond its original purpose of simply correcting malocclusion and the facial profile. For instance, it is now used to treat obstructive sleep apnea and to achieve purely cosmetic outcomes. Recent developments in three-dimensional digital technology are being utilized throughout the entire process of orthognathic surgery, from establishing a surgical plan to printing the surgical splint. These processes have made it possible to perform more sophisticated surgery. The goal of this review article is to introduce current trends in the field of orthognathic surgery and controversies that are under active discussion. The role of a plastic surgeon is not limited to performing orthognathic surgery itself, but also encompasses deep involvement throughout the entire process, including the set-up of surgical occlusion and overall surgical planning. The authors summarize various aspects in the field of orthognathic surgery with the hope of providing helpful information both for plastic surgeons and orthodontists who are interested in orthognathic surgery.

Conformity of the Virtual Surgical Plan to the Actual Result Comparing Five Craniofacial Procedure Types

BACKGROUND

The "accuracy" of virtual surgical planning across multiple procedure types is not known. The authors aimed to compare the planned outcome from virtual surgical planning to the actual postoperative outcome for five craniofacial procedure types performed by a single surgeon: implant cranioplasty, cranial vault remodeling, orthognathic surgery, mandible reconstruction, and mandibular distraction.

METHODS

Stereolithography formats were obtained from virtual surgical planning and compared to postoperative computed tomographic scans for consecutive patients who underwent one of the five procedure types. Volumetric renderings of the operated bony region of interest were overlaid and compared using a Boolean operation to compute conformity (as a percentage of the region of interest). Conformity across procedure type was analyzed using analysis of variance and post hoc Bonferroni analysis, where appropriate.

RESULTS

One hundred thirty patients were included (51.5 percent male and 49.5 percent female; mean age, 27 years; 59 orthognathic surgery, 32 cranial vault remodeling, 16 mandible reconstruction, 12 mandibular distraction, and 11 implant cranioplasty patients). The highest tier of conformity was obtained for implant cranioplasty (median, 76.8 ± 10.3 percent) and mandible reconstruction (mean, 69.4 ± 11.2 percent), followed by orthognathic surgery (mean, 55.0 ± 7.3 percent) and mandibular distraction (median, 41.9 ± 20.3 percent), followed by cranial vault remodeling (mean, 22.2 ± 12.1 percent) (p < 0.001 between tiers and p > 0.05 among tiers).

CONCLUSIONS

Virtual surgical planning resulting in custom permanent implants and intraoperative guides provides more predictable results compared to virtual surgical planning used for procedures involving higher degrees of skeletal repositioning and postoperative movement (i.e., mandibular distraction and nonrigid cranial vault remodeling). In cases with expectedly lower conformity, excellent outcomes can be achieved with sound intraoperative judgment.

Is Le Fort I Distraction Enough to Treat Severe Midface Hypoplasia?

BACKGROUND

In severe cases of maxillary hypoplasia, Le Fort I distraction may be required for treatment. This study describes our experience with internal distraction devices and assesses our outcomes in patients with a negative overjet on average >15 mm.

METHODS

A retrospective review of patients with a history of cleft lip and/or palate who underwent Le Fort I distraction at our institution from 11/2007-11/2017 was performed. Data regarding demographics, procedural details and outcomes were collected and analyzed.

RESULTS

Twenty patients, 13 (65.0%) male and 7 (30.0%) female, were included. All (100%) patients had a history of cleft lip and/or palate and 2 (10.0%) of them had associated syndromes. All 20 patients underwent internal distraction. The average age at surgery was 17.8 years (range 15.2-20.7, SD 1.6 years). The average preoperative negative overjet was 19.27 mm (range 10-30, SD 5.63 mm). The mean total distraction length was 15.3 mm (range 0-30, SD 6.72 mm). There were no intraoperative complications, however, there were a total of 4 (20.0%) postoperative complications, 2 of which required reoperation due to device malfunction or displacement. 14 (70.0%) patients had repeat procedures to complete occlusal correction or correct relapse.

CONCLUSIONS

Maxillary distraction alone was insufficient for correction of maxillary discrepancies averaging >15 mm. Instead, it's utility may be in positioning the maxilla for a more viable final advancement and fixation procedure, rather than being solely responsible for achieving normal occlusion during distraction.

Pediatric Orthognathic Surgery: National Analysis of Perioperative Complications

BACKGROUND

Orthognathic surgery has traditionally been performed after skeletal maturity. Although these procedures are also being performed in children, the implications of earlier intervention and specific risk factors in this younger population remain unknown.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program Pediatric dataset was queried for orthognathic procedures performed in 2018. Complications, readmissions, and reoperations were analyzed with appropriate statistics.

RESULTS

Overall adverse event rate after orthognathic surgery in pediatric patients was 7.8% (n = 22 of 281), which were associated with having any comorbidity (P < 0.001), overall respiratory comorbidities (P = 0.004), structural pulmonary abnormality (P < 0.001), developmental delay (P = 0.035), structural central nervous system abnormality (P < 0.001), and neuromuscular disorder (P = 0.035). Most common complications were excessive bleeding (2.5%), surgical site infection (1.1%), and pneumonia (0.7%). Orthognathic surgery in children below 6 years of age is associated with significantly increased adverse events (P < 0.001), including surgical site infection (P < 0.001), pneumonia (P = 0.022), readmission (P < 0.001), and reoperation (P < 0.001). Le Fort I osteotomies (P < 0.001) and bilateral sagittal split osteotomies (P = 0.009) took significantly longer for older patients in the years of permanent dentition than younger patients in the years of deciduous dentition. Single- and double-jaw procedures in pediatric patients have similarly low adverse events (P all ≥0.130). Interestingly, bilateral sagittal split osteotomies performed before 13.5 years of age were associated with a higher risk of adverse events (P = 0.012), such that these younger patients were 7.1 times more likely to experience adverse events if their procedure was performed earlier.

CONCLUSIONS

Orthognathic surgery is relatively safe, but children in the years of deciduous dentition under 6 years of age have significantly increased risk of adverse events.

Advanced Three-Dimensional Technologies in Craniofacial Reconstruction

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Describe the evolution of three-dimensional computer-aided reconstruction and its current applications in craniofacial surgery. 2. Recapitulate virtual surgical planning, or computer-assisted surgical simulation, workflow in craniofacial surgery. 3. Summarize the principles of computer-aided design techniques, such as mirror-imaging and postoperative verification of results. 4. Report the capabilities of computer-aided manufacturing, such as rapid prototyping of three-dimensional models and patient-specific custom implants. 5. Evaluate the advantages and disadvantages of using three-dimensional technology in craniofacial surgery. 6. Critique evidence on advanced three-dimensional technology in craniofacial surgery and identify opportunities for future investigation.

SUMMARY

Increasingly used in craniofacial surgery, virtual surgical planning is applied to analyze and simulate surgical interventions. Computer-aided design and manufacturing generates models, cutting guides, and custom implants for use in craniofacial surgery. Three-dimensional computer-aided reconstruction may improve results, increase safety, enhance efficiency, augment surgical education, and aid surgeons' ability to execute complex craniofacial operations. Subtopics include image analysis, surgical planning, virtual simulation, custom guides, model or implant generation, and verification of results. Clinical settings for the use of modern three-dimensional technologies include acquired and congenital conditions in both the acute and the elective settings. The aim of these techniques is to achieve superior functional and aesthetic outcomes compared to conventional surgery. Surgeons should understand this evolving technology, its indications, limitations, and future direction to use it optimally for patient care. This article summarizes advanced three-dimensional techniques in craniofacial surgery with cases highlighting clinical concepts.

Accuracy and cost effectiveness of a waferless osteotomy approach, using patient specific guides and plates in orthognathic surgery: a systematic review

The aim of this systematic review is to evaluate the accuracy of waferless osteotomy procedures in orthognathic surgery with a secondary aim to determine the cost-effectiveness of the procedure. A literature search was conducted on the databases PubMed and Scopus, with PRISMA guidelines followed. An initial yield of 4149 articles were identified, ten of which met the desired inclusion criteria. The total sample of patients undergoing waferless osteotomies included in this review was 142 patients. Nine of the studies used surgical cutting guides along with customised surgical plates to eliminate the surgical wafer and one study used pre-bent locking plates instead of customised plates. The eligible articles determined their surgical accuracy by comparing the positions of bony or dental landmarks on the pre-operative and post-operative images. The articles all reported acceptable accuracy within previously established clinical parameters. The majority of authors concluded that it is an accurate surgical approach and can be cost effective which is often a barrier to novel techniques however there were studies that contrasted the view of the cost efficacy. Due to the lack of published randomised controlled trials, current evidence is not strong enough to recommend the use of surgical cutting guides and customised/pre-bent plates for orthognathic surgery.

Accuracy of mandibular proximal segment position using virtual surgical planning and custom osteosynthesis plates

The purpose of this study was to determine whether the use of custom osteosynthesis plates increased the accuracy of proximal segment position following bilateral sagittal split osteotomy in a cohort of 30 patients when compared to a control group of 25 patients who had surgery with conventional plates. Surgery was performed by a single surgeon between October 2015 and December 2017. Post-surgical cone beam computed tomography scans were segmented using Mimics Innovation Suite (Materialise NV), and surface-based superimposition was achieved using ProPlan CMF (Materialise NV). However, there was a tendency for the rotational error to be smaller in the custom group than in the control group. The root mean square error in both groups and for all variables fell within clinical parameters of 2 mm and 4°. In conclusion, the results of this study indicate that customized mandibular fixation plates do not necessarily improve the accuracy of the proximal segments post-surgically; however they may be of benefit in individual patients.

Postoperative CT findings of orthognathic surgery and its complications: A guide for radiologists

Orthognathic surgery is the standard procedure to correct congenital, developmental, or acquired dentofacial deformities. The maxillomandibular relationship corrected by orthognathic surgery can improve facial esthetics, masticatory function, articulation, and breathing. The most common types of osteotomies include the combination of Le Fort I osteotomy, bilateral sagittal split mandibular ramus osteotomy, and genioplasty. High-resolution low-dose computed tomography is useful for evaluating the facial skeleton and soft tissues after surgery as well as for depicting a variety of possible complications. This article reviews the postoperative imaging findings of the most common orthognathic surgeries and their potential complications on multidetector-row computed tomography.

Effect of computer-assisted design and manufacturing cutting and drilling guides accompanied with pre-bent titanium plates on the correction of skeletal class II malocclusion: a randomized controlled trial

This study was performed to assess the effect of correcting skeletal class II malocclusion based on the application of computer-assisted design and manufacturing (CAD/CAM) cutting and drilling guides accompanied with pre-bent titanium plates. Fifty patients with skeletal class II malocclusion were recruited into this prospective randomized controlled clinical trial and assigned to two groups. Patients underwent bilateral sagittal split ramus osteotomy directed by CAD/CAM cutting and drilling guides accompanied with pre-bent titanium plates (group A) or CAD/CAM splints (group B). Postoperative assessments were performed. Differences between the virtually simulated and postoperative models were measured. Patients in both groups had a satisfactory occlusion and appearance. More accurate repositioning of the proximal segment was found in group A than in group B when comparing linear and angular differences to reference planes; however, no significant difference was revealed for the distal segment. In conclusion, CAD/CAM cutting and drilling guides with pre-bent titanium plates can provide considerable surgical accuracy for the positional control of the proximal segments in bilateral sagittal split ramus osteotomy for the correction of skeletal class II deformities.

The value of surgical articulator MT in orthognathic model surgery: Technical note and case report

The utilize of surgical articulator MT may lead to a major reduction in time and effort that usually consuming in conventional model surgery and promoted for precise planning and surgery. It can be useful in the management of several cases of dentofacial deformities when virtual surgical planning is either unaffordable or unavailable.

Accuracy of Soft Tissue Prediction of 2 Virtual Planning Systems in Patients Undergoing Intraoral Quadrangular Le Fort II Osteotomy

Virtual surgical planning (VSP) is state of the art in routine clinical work. Visualization of soft tissue changes adds important information for surgical planning. The aim of this study was to evaluate accuracy of soft tissue prediction of 2 VSP systems in patients undergoing an intraoral quadrangular Le Fort II osteotomy.

Virtual Surgical Planning and the “In-House” Rapid Prototyping Technique in Maxillofacial Surgery: The Current Situation and Future Perspectives

Background: The first applications of computer-aided design/computer-aided manufacturing (CAD/CAM) in maxillofacial surgery date back to the 1980s. Since then, virtual surgical planning (VSP) has undergone significant development and is now routinely used in daily practice. Indeed, in an extraordinary period, such as that of the current COVID-19 pandemic, it offers a valuable tool in relation to the protection of healthcare workers. In this paper we provide a comprehensive summary of the clinical applications reported in the literature and review our experience using an in-house rapid prototyping technique in the field of maxillofacial surgery. methods: Our research was focused on reconstructive surgery, traumatology (especially in relation to orbital floor and zygomatic arch fractures), and COVID-19 masks. The first step was a radiographic study. Next, computed tomography (CT) scans were segmented in order to obtain a three-dimensional (3D) model. Finally, in the editing phase, through the use of specific software, a customized device for each patient was designed and printed. results: Four reconstructive procedures were performed with a perfect fitting of the surgical device produced by means of VSP. In nine orbital floor fracture cases a good overlapping of the mesh on the orbital floor was obtained. In sixteen zygomatic arch cases the post-operative CT scan showed an excellent fitting of the device and a correct fracture reduction. Regarding the COVID-19 period, six masks and shields produced proved to provide effective protection. conclusions: The timescale and costs required for the production of our “home-made” virtual design are low, which makes this method applicable to a large number of cases, for both ordinary and extraordinary activities.

Comparison of three different types of splints and templates for maxilla repositioning in bimaxillary orthognathic surgery: a randomized controlled trial

The selection and implementation of a plan for maxillary surgery is of the utmost importance in achieving the desired outcome for the patient undergoing two-jaw orthognathic surgery. Some splint-based and splintless methods, accompanied by computer-assisted techniques, are helpful in improving surgical plan implementation. However, randomized controlled trials focused on this procedure are lacking. This study included 61 patients who underwent bimaxillary surgeries. The patients were randomly assigned to a conventional resin occlusal splint (CROS) group, a digital occlusal splint (DOS) group, or a digital templates (DT) group, in a 1:1:1 ratio. The mean linear distance between the planned and actual postoperative positions of eight selected points on the surfaces of the maxillary teeth was selected as the outcome measure. The distance was significantly smaller in the DT group (1.17±0.66mm) when compared to both the CROS group (2.55±0.95mm, P<0.05) and DOS group (2.15±1.12mm, P<0.05). However, the difference between the CROS group and DOS group was not statistically significant. These findings indicate that using digital templates results in the best performance in transferring the surgical plan to the operation environment as compared to the other two types of splints. This suggests that the application of digital templates could provide a reliable treatment option.

A Meta-analysis and Systematic Review Comparing the Effectiveness of Traditional and Virtual Surgical Planning for Orthognathic Surgery: Based on Randomized Clinical Trials

PURPOSE

To explore the advantages of virtual surgical planning (VSP) and traditional surgical planning (TSP) to determine whether the current VSP technique is superior to the TSP technique for orthognathic surgery.

METHODS

An electronic search was carried out in the CENTRAL, PubMed, and Embase databases to identify randomized clinical trials (RCTs) that compared the VSP and TSP techniques regarding their surgical accuracy for hard tissue, prediction precision for soft tissue, required time for planning and surgery, cost and patient-reported outcomes.

RESULTS

Eight articles from 5 RCTs, involving 199 patients, were identified. The findings showed that the VSP and TSP techniques were similar in surgical accuracy for hard tissue in the sagittal plane, although the VSP technique was significantly more accurate in certain reference areas, especially in the anterior area of the maxilla. Both the VSP and TSP techniques had significantly better surgical accuracy for the maxilla than for the mandible. The VSP technique showed clinically significantly greater precision for soft tissue prediction in the sagittal plane. Patients who were treated via the VSP technique presented a more symmetrical frontal view, regardless of whether hard or soft tissue was involved. The VSP technique required more time for software planning, but it showed an advantage in time savings when considering the entire preoperative process. Accompanied by the use of an accurate computer-aided splint, the VSP technique could effectively reduce the operative time. Apart from the initial financial investment of software and hardware, the total cost of the VSP technique was similar to that of the TSP technique. Patients who were treated via the VSP or TSP technique showed similar improvements in quality-of-life.

CONCLUSIONS

Currently, the VSP technique has become a good alternative to the TSP technique for orthognathic surgery, especially regarding frontal-esthetic considerations. Studies reporting indicators with good representativeness and sensitivity using an identical comparative method are recommended.

Orthognathic Hardware Complications in the Era of Patient-Specific Implants

BACKGROUND

Patients undergoing orthognathic skeletal correction present with a variety of comorbidities that may affect surgical outcomes. The purpose of this study was to determine how patient risk factors and operative technique contribute to complication rates after orthognathic surgery in the era of patient-specific implants.

METHODS

Retrospective cohort analysis was conducted of pediatric patients undergoing Le Fort I osteotomy, bilateral sagittal split osteotomy, and/or genioplasty from 2014 to 2018. Patient risk factors, operative characteristics, and postoperative outcomes were gathered and compared with appropriate statistics.

RESULTS

Ninety-four patients met inclusion criteria, with an overall 1-year complication rate of 11.7 percent (11 of 94). Patient-specific mandibular plates are significantly associated with infection (p = 0.009; OR, 8.8), occurrence of any complication (p = 0.003; OR, 8.3), readmission (p < 0.001; OR, 11.1), and reoperation (p < 0.001; OR, 11.4). In patients with syndromes or history of cleft lip/palate, patient-specific mandibular plates are associated with infection (p = 0.006; OR, 10.3), readmission (p < 0.001; OR, 21.6), and reoperation (p < 0.001; OR, 22.9). In multivariate regression controlling for age, sex, syndrome status, and orofacial cleft history, use of patient-specific mandibular plates was associated with infection (p = 0.017; adjusted OR, 12.5), any complication (p = 0.007; adjusted OR, 11.8), readmission (p = 0.001; adjusted OR, 17.9), and reoperation (p = 0.001; adjusted OR, 18.9).

CONCLUSIONS

In the era of patient-specific orthognathic surgery, syndromic status and use of patient-specific mandibular plates are associated with increased infection, readmission, and reoperation because of hardware-related complications. The authors' data support increased caution and counseling with use of patient-specific mandibular implants in patients with syndromic status, history of orofacial cleft, and history of previous maxillomandibular surgery given increased risk of hardware-related complications.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Computer-Aided Design and Manufacturing Cutting and Drilling Guides with Prebent Titanium Plates Improve Surgical Accuracy of Skeletal Class III Malocclusion

BACKGROUND

The aim of this study was to evaluate the effects of the use of computer-aided design and manufacturing cutting and drilling guides with prebent titanium plates for the correction of skeletal class III malocclusion.

METHODS

In this prospective, randomized, controlled clinical trial, 46 patients with skeletal class III malocclusion were randomly assigned into two groups. The patients underwent bimaxillary surgery with computer-aided design and manufacturing cutting and drilling guides with prebent titanium plates (experimental group) or computer-aided design and manufacturing splints (control group). Preoperative and postoperative imaging data were collected and then analyzed using Mimics Research 19.0, Geomagic Studio, and IBM SPSS Version 21.0.

RESULTS

Deformity evaluation and posttreatment assessment were performed for all patients. The experimental group had fewer postoperative complications. Comparison of the linear and angular differences to facial reference planes revealed more accurate repositioning of the mandible and condyles in the experimental group, although the position of several landmarks still requires small adjustments.

CONCLUSION

Computer-aided design and manufacturing cutting and drilling guides with prebent titanium plates effectively corrected skeletal class III malocclusion, providing positional control of segments with reasonable surgical accuracy.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, II.

Trends in Utilization of Virtual Surgical Planning in Pediatric Craniofacial Surgery

INTRODUCTION

While the use of virtual surgical planning (VSP) has been well described in the adult craniofacial literature, there has been little written about pediatric uses or trends. The purpose of this study is to evaluate the evolving utilization of VSP for pediatric craniofacial procedures.

METHODS

The authors' prospective institutional review board-approved craniofacial registry was queried for index craniofacial procedures from January 2011 through December 2018. Data was collected regarding utilization of traditional surgical planning versus VSP, as well as the extent of VSP's influence on the operative procedure. These data were analyzed for trends over time and compared using appropriate statistics.

RESULTS

During the study period, a total of 1131 index craniofacial cases were performed, of which 160 cases (14.1%) utilized VSP. Utilization of VSP collectively increased over time, from 2.0% in 2011 to 18.6% in 2018 (P < 0.001). Utilization rates of VSP varied across procedures from 0% of craniosynostosis cases and fronto-orbital advancement cases to 67% of osteocutaneous free tissue transfers (P < 0.001). The most profound contributor to increase in VSP utilization was orthognathic surgery, utilized in 0% of orthognathic procedures in 2011 to 68.3% of orthognathic procedures in 2018 (P < 0.001).

CONCLUSIONS

Utilization of virtual surgical planning for pediatric craniofacial procedures is increasing, especially for complex orthognathic procedures and osteocutaneous free tissue transfers. Utilization patterns of individual components of the VSP system demonstrate unique footprints across the spectrum of craniofacial procedures, which reinforces the specific and variable benefits of this workflow for treating pediatric craniofacial disorders.

The Accuracy of Jaws Repositioning in Bimaxillary Orthognathic Surgery with Traditional Surgical Planning Compared to Digital Surgical Planning in Skeletal Class III Patients: A Retrospective Observational Study

Background: Technological progress has led to the transition to digital methods to perform surgical planning and to obtain surgical splints with CAD/CAM technologies. The present study aimed to compare the accuracy of jaw repositioning in bimaxillary orthognathic surgery using traditional and digital surgical planning in skeletal class III patients. Methods: This study included 60 skeletal class III patients divided into two groups based on the method used to perform surgical planning: traditional (T, n = 30) and digital (D, n = 30). For each patient, a 2D presurgical Visual Treatment Objective (VTO) was prepared and the outcome of the surgery was compared with that planned by using determined cephalometric measurements (ANB, SNA, SNB, Ar-Go-Me, S-Ar-Go). Statistical analysis showed that the measurements planned and those obtained after surgery were equivalent in Group D. For Group T, the analysis showed equivalence only for one of the considered measurements (ANB). By comparing the results of the two groups, Group D presented a lower level of error than Group T. Conclusions: Digital surgical planning performed significantly better in terms of accuracy of jaw repositioning than the traditional protocol.

3-Dimensional prediction of pre-surgical decompensation after atypical extractions and soft tissue simulation for ortho-surgical management of skeletal Class III malocclusion: A case report

Three dimensional imaging systems whether in the form of digital models, facial scanning or dolphin software play an important role in proper diagnosis and treatment planning of the orthosurgical cases. This case report highlights importance of three-dimensional treatment planning in the ortho-surgical management of the patient with skeletal Class III malocclusion involving atypical extraction. On clinical examination, patient had concave profile, prominent chin, deficient midface, flat cheekbone contour and prominent nasal projection. He had Class III molar and canine relation bilaterally with missing 12 (previously extracted), negative overbite and overjet with discordant maxillomandibular midlines. After 3-dimensional digital model set-up for occlusion planning and dolphin simulation for soft tissue prediction, extraction of left maxillary lateral incisor was planned followed by maxillary advancement and mandibular setback surgery and finish the occlusion in Class II molar relationship. After the orthodontic and orthognathic surgical treatment, the skeletal and dental imbalance was corrected, and most of the treatment objectives were achieved and patient was extremely satisfied with his facial profile. The treatment results were stable at the 3 years follow-up.