Customized virtual surgical planning in bimaxillary orthognathic surgery: a prospective randomized trial

Virtual surgical planning in craniomaxillofacial surgery: A systematic review and meta-analysis of accuracy, operative time, and cost-effectiveness

INTRODUCTION

Craniomaxillofacial surgeons address congenital, developmental, and acquired deformities of the cranium, face, and jaws, relying on precise planning for optimal outcomes. Virtual surgical planning (VSP) integrates digital imaging and computer-aided design to enhance preoperative planning and intraoperative precision.

METHODOLOGY

A systematic review and meta-analysis were conducted across databases, focusing on studies published between 2013 and 2023. The search terms included "Virtual Surgical Planning," "VSP," "Surgical Planning," "3D Printing," and "Craniofacial Surgeries" or "Craniomaxillofacial Surgeries." Articles that reported outcomes on operative time, accuracy, or cost were included.

RESULTS

A total of 146 studies were included in the final analysis. The outcomes were grouped into 3 key categories: accuracy, operative time, and cost-effectiveness. VSP showed a median deviation of 1.14 mm compared to 1.83 mm for non-VSP (P = 0.46). VSP groups had an average angular deviation of 2.67°, compared to 3.32° for non-VSP groups (P = 0.805). The average matching percentage was 96.12% for VSP, compared to 87.5% for non-VSP (P = 0.264). Operative time for VSP was 3.7 h compared to 4.32 h for non-VSP (P = 0.477). Cost analysis showed VSP at a lower average material cost ($2128) compared to non-VSP ($3416) (P = 0.294).

CONCLUSION

Although numerous studies highlight the advantages of VSP in the craniomaxillofacial field, our meta-analysis found no statistically significant differences compared to the traditional methods. Variability in study designs and outcome measures may contribute to these findings, highlighting the need for more standardized, procedure-specific research to fully assess the clinical impact of VSP.

Splintless maxillomandibular advancement for edentulous sleep apnoea patients: surgical accuracy and efficacy

The primary aim of this study was to assess the accuracy and predictability of a splintless treatment protocol for edentulous patients with moderate to severe obstructive sleep apnoea (OSA) undergoing maxillomandibular advancement (MMA). Ten consecutive edentulous patients treated with MMA were enrolled in this retrospective study. All cases were virtually planned, followed by computer-aided design of individual osteotomy cutting guides and patient-specific implants. For the maxilla, the mean discrepancy between the planned and achieved right to left, posterior to anterior, and cranial to caudal translations was 0.3 ± 0.2 mm, 1.0 ± 0.6 mm, and 0.8 ± 0.6 mm, respectively. There was a mean discrepancy of 0.5° ± 0.5°, 2.5° ± 2.0°, and 0.3° ± 0.4° for roll, pitch, and yaw of the maxilla, respectively. The mean discrepancy of the mandible osteotomy gap was 1.2 ± 1.0 mm on the right side and 0.8 ± 0.5 mm on the left. Surgical success was achieved in nine patients, one of whom met the criteria for surgical cure. On average, the apnoea-hypopnea index was reduced by 72%. The results of this study indicate that the splintless treatment protocol for MMA applied in edentulous OSA patients is highly accurate, predictable, and effective in the treatment of OSA.

Patient-Specific Orthognathic Solutions: Expert Opinion on Guidelines and Workflow

This document outlines guidelines for the use of three-dimensional virtual surgical planning in orthognathic surgery, with relevance to data acquisition, clinical diagnosis, data workflow sequencing, and operative considerations. A detailed description regarding fundamental principles of orthognathic assessment and planning is beyond the scope of this paper.

Use of Virtual Surgical Planning in Oral Surgery: A Systematic Review

Virtual surgical planning (VSP) represents a significant advancement in craniomaxillofacial surgery by utilizing 3D imaging and computer-aided techniques to enhance precision and improve surgical outcomes. This research aimed to evaluate the effectiveness of VSP in comparison to traditional surgical planning methods. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a systematic review of studies published between 2000 and 2024, sourced from MEDLINE/PubMed, Cochrane Library, and EMBASE. A total of 22 studies, including cohort, case-control, and randomized controlled trials, were analyzed to assess the impact of VSP on surgical accuracy, procedure duration, and patient outcomes. The findings revealed that VSP improves surgical accuracy and reduces operative times compared to conventional methods. However, challenges such as higher material costs and occasional inconsistencies in results remain. Despite these challenges, VSP holds significant potential to enhance precision and efficiency in oral surgery.

Feasibility of augmented reality combine patient-specific implants (PSI) applied to navigation in mandibular genioplasty: A phantom experiment

PURPOSE

Genitoplasty is becoming more and more common, and it is important to improve the accuracy of the procedure and simplify the procedure. This experiment explores the feasibility of using augmented reality (AR) technology combined with PSI titanium plates for navigational assistance in genioplasty performed on models, aiming to study the precision of such surgical interventions.

METHODS

Twelve genioplasty procedures were designed and implemented on 3D-printed resin mandibular models by the same surgeon using three different approaches: AR+3DT group (AR+PSI) , 3DT group (patient-specific titanium plate) , and a traditional free-hand group(FH group). Postoperative models were assessed using CBCT to evaluate surgical accuracy.

RESULTS

In terms of osteotomy accuracy, the AR group demonstrated a surgical error of 0.9440±0.5441 mm, significantly lower than the control group, which had an error of 1.685±0.8907 mm (P < 0.0001). In experiments positioning the distal segment of the chin, the overall centroid shift in the AR group was 0.3661±0.1360 mm, significantly less than the 2.304±0.9629 mm in the 3DT group and 1.562±0.9799 mm in the FH group (P < 0.0001). Regarding angular error, the AR+3DT group showed 2.825±1.373°, significantly <8.283±3.640° in the 3DT group and 7.234±5.241° in the FH group.

CONCLUSION

AR navigation technology combined with PSI titanium plates demonstrates higher surgical accuracy compared to traditional methods and shows feasibility for use. Further validation through clinical trials is necessary.

Virtual surgical planning in orthognathic surgery: A prospective evaluation of postoperative accuracy

OBJECTIVES

The development of 3D computer-assisted technologies over the past years has led to vast improvements in orthognathic surgery. The aim of the present study was to evaluate differences in maxillary position between 3D virtual surgical planning (VSP) and surgical results.

MATERIALS AND METHODS

We assessed data from 25 patients who underwent bimaxillary non-segmented orthognathic surgery with 3D VSP. Each patient underwent a postoperative CT scan within 40 days after surgery. We compared the STL (Standard Triangulation Language) file from the VSP with that obtained from the postoperative CT.

RESULTS

According to our comparative analysis, the postoperative and VSP 3D models did not statistically differ. The Lin concordance correlation coefficient was always >0.95 for each landmark, but in 21 patients (84 % of the sample) we identified at least one point with a difference of more than 1.5 mm between the postoperative and VSP 3D model on at least one axis. The most frequently observed differences corresponded to sagittal translation and pitch rotation.

CONCLUSIONS

An intraoperative clinical and aesthetic evaluation of the consequences of bone movements on patient face is strongly recommended, also when we use VSP because we may have clinically significant differences from the planning.

Effectiveness of Traditional and Virtual Surgical Planning in Orthognathic Surgery: A Systematic Review and Meta-Analysis

Orthognathic surgery, which corrects jaw deformities, requires meticulous planning to achieve optimal functional and aesthetic outcomes. Traditional surgical planning (TSP) relies on manual methods, whereas virtual surgical planning (VSP) uses computer-assisted simulations that may enhance accuracy and efficiency. Therefore, we conducted a systematic review to evaluate the effectiveness of VSP compared to TSP for orthognathic surgery. We adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and registered the protocol in the Prospective Register of Systematic Reviews (CRD42024618614). We searched electronic databases for studies comparing VSP and TSP. Two independent reviewers performed screening and data extraction. We assessed quality using the Cochrane Risk of Bias 2 (RoB 2) tool. We calculated the standardized mean difference (SMD) as the summary measure and used a random-effects model, considering p < 0.05 as statistically significant. We performed analyses using Review Manager (RevMan) version 5.3 (Cochrane Collaboration, London, UK). We included 10 qualitative synthesis and meta-analysis studies, evaluating data from 474 patients, of whom 244 underwent TSP and 230 underwent VSP. Included studies showed moderate to low risk of bias. We evaluated effectiveness in terms of planning time, surgical time, horizontal measurements, vertical measurements, and accuracy indicators for predicting outcomes. Meta-analysis revealed reduced planning time (SMD = 3.19 (-5.74 to 0.64)) and surgical time (SMD = -0.42 (-1.32 to 0.49)) with VSP, as well as differences in horizontal (SMD = -0.39 (-0.73 to 0.05)) and vertical measurements (SMD = -0.20 (-0.54 to 0.13)), and in accuracy indicators (SNA0: SMD = -0.15 (-0.46 to 0.16); SNB0: SMD = 0.53 (-0.82 to 1.87)). SNA0 represents the angle formed by sella (S), nasion (N), and point A (A), and SNB0 represents the angle formed by sella (S), nasion (N), and point B (B). The funnel plot showed no evidence of publication bias. VSP reduced planning and surgical times and predicted facial outcomes more accurately than TSP. These findings suggest that VSP can be an effective alternative to TSP in orthognathic surgeries.

Analysis of the implementation of a circuit for intra-operative superposition and comparison of the surgical outcomes using ICBCT in maxillofacial surgery

PURPOSE

This paper describes a novel circuit for intraoperative analysis with ICBCT in maxillofacial surgery. The aim is to establish guidelines, define indications, and conduct an analysis of the implementation of the circuit for intraoperative comparison of surgical outcomes in relation to 3D virtual planning in maxillofacial surgery.

METHODS

The study included 150 maxillofacial surgical procedures. Intraoperative actions involved fluoroscopy localization, intraoperative CBCT acquisition, segmentation, and superimposition, among other steps. Surgical times due to intraoperative superposition were measured, including time required for ICBCT positioning and acquisition, image segmentation, and comparison of 3D surfaces from the surgical planning.

RESULTS

Successful intraoperative comparison was achieved in all 150 cases, enabling surgeons to detect and address modifications before concluding the surgery. Out of the total, 26 patients (17.33%) required intraoperative revisions, with 11 cases (7.33%) needing major surgical revisions. On average, the additional surgical time with this circuit implementation was 10.66 ± 3.03 min (n = 22).

CONCLUSION

The results of our research demonstrate the potential for performing intraoperative surgical revision, allowing for immediate evaluation, enhancing surgical outcomes, and reducing the need for re-interventions.

Virtual surgical plan with custom surgical guide for orthognathic surgery: systematic review and meta-analysis

BACKGROUND

The shift from traditional two-dimensional (2D) planning to three-dimensional (3D) virtual surgical planning (VSP) has revolutionized orthognathic surgery, offering new levels of precision and control. VSP, combined with computer-aided design/computer-aided manufacturing (CAD/CAM) technology, enables the creation of patient-specific surgical guides and implants that translate preoperative plans into more precise surgical outcomes. This review examines the comparative accuracy and operative efficiency of VSP, especially when used with custom surgical guides, against conventional 2D planning in orthognathic surgery.

MAIN TEXT

The study systematically reviewed and analyzed published literature comparing the accuracy and operative time between VSP and conventional planning methods. The meta-analysis included clinical trials, controlled trials, and observational studies on patients undergoing orthognathic surgery, focusing on the degree of alignment between planned and postoperative bone positions and total surgery time. Results indicate that VSP consistently reduces discrepancies between planned and actual surgical outcomes, particularly when integrated with custom surgical guides. Additionally, while VSP demonstrated potential time-saving advantages over conventional planning, these differences were not statistically significant across studies, likely due to high variability among study protocols and designs.

CONCLUSIONS

VSP with custom surgical guides enhances surgical accuracy in orthognathic procedures, marking a significant advancement over traditional methods. However, the reduction in operative time was not conclusively significant, underscoring the need for further studies to evaluate time efficiency. These findings emphasize VSP's role in improving surgical precision, which holds substantial implications for future orthognathic surgical practices.

Accuracy of 3D Virtual Surgical Planning Compared to the Traditional Two-Dimensional Method in Orthognathic Surgery: A Literature Review

With the innovation of three-dimensional imaging and printing techniques, computer-aided surgical planning, also known as virtual surgical planning (VSP), has revolutionized orthognathic surgery. Designing and manufacturing patient-specific surgical guides using three-dimensional printing techniques to improve surgical outcomes is now possible. This article presents an overview of VSP in orthognathic surgery and discusses the advantages and accuracy of this technique compared to traditional surgical planning (TSP). A PubMed and Google Scholar search was conducted to find relevant articles published over the past 10 years. The search revealed 2,581 articles, of which 36 full-text articles specifically addressed the topic of this study. The review concludes that VSP in orthognathic surgery provides optimal functional and aesthetic results, enhances patient satisfaction, ensures precise translation of the treatment plan, and facilitates intraoperative manipulation.

Evaluation of a Fully Digital, In-House Virtual Surgical Planning Workflow for Bimaxillary Orthognathic Surgery

BACKGROUND

The advantages of virtual surgical planning (VSP) for orthognathic surgery are clear. Previous studies have evaluated in-house VSP; however, few fully digital, in-house protocols for orthognathic surgery have been studied.

PURPOSE

The purpose of this study was to evaluate the difference between the virtual surgical plan and actual surgical outcome for orthognathic surgery using a fully digital, in-house VSP workflow.

STUDY DESIGN, SETTING, SAMPLE

This is a prospective cohort study from September 2020 to November 2022 of patients at the Victoria General Hospital in Halifax, NS, Canada who underwent bimaxillary orthognathic surgery. Patients were excluded if they had previously undergone orthognathic surgery or were diagnosed with a craniofacial syndrome.

MAIN OUTCOME VARIABLES

The primary outcome variables were the mean 3-dimensional (3D) (Euclidean) distance error, as well as mean error and mean absolute error in the transverse (x axis), vertical (y axis), and anterior-posterior (z axis) dimensions.

COVARIATES

Covariates included age, sex, and surgical sequence (mandible-first or maxilla-first).

ANALYSES

The primary outcome was tested using Z and t critical value confidence intervals. The P value was set at .05. The 3D distance error for mandible-first and maxilla-first groups was compared using a 2-sample t-test as well as analysis of variance.

RESULTS

The study sample included 52 subjects (24 males and 28 females) with a mean age of 27.7 (± 12.1) years. Forty three subjects underwent mandible-first surgery and 9 maxilla-first surgery. The mean absolute distance error was largest in the anterior-posterior dimension for all landmarks (except posterior nasal spine, left condyle, and gonion) and exceeded the threshold for clinical acceptability (2 mm) in 16 of 23 landmarks. Additionally, mean distance error in the anterior-posterior dimension was negative for all landmarks, indicating deficient movement in that direction. The effect of surgical sequence on 3D distance error was not statistically significant (P = .37).

CONCLUSION AND RELEVANCE

In general, the largest contributor to mean 3D distance error was deficient movement in the anterior-posterior direction. Otherwise, mean absolute distance error in the vertical and transverse dimensions was clinically acceptable (< 2 mm). These findings were felt to be valuable for treatment planning purposes when using a fully digital, in-house VSP workflow.

A New Method to Design and Manufacture a Low-Cost Custom-Made Template for Mandible Cut and Repositioning Using Standard Plates in BSSO Surgery

In this study, a new methodology for designing and creating a custom-made template for maxillofacial surgery has been developed. The custom-made template can be used both for cutting and repositioning of the mandible arches for executing a BSSO (bilateral sagittal split osteotomy) treatment. The idea was developed in order to give the possibility of using a custom-made template with standard plates, thus reducing long times, high costs and low availability of custom-made plates; this represents the proof of novelty of the proposed template, based on a well-established methodology. The methodology was completely developed in the CAD virtual environment and, after the surgeons' assessment, an in-vitro experiment by a maxillofacial surgeon was performed in order to check the usability and the versatility of the system, thanks to the use of additive manufacturing technologies. When computer-aided technologies are used for orthognathic surgery, there are significant time and cost savings that can be realised, as well as improved performance. The cost of the whole operation is lower than the standard one, thanks to the use of standard plates. To carry out the procedures, the proposed methodology allows for inexpensive physical mock-ups that enable the BSSO procedure to be performed.

Enhancing Surgical Outcomes via Three-Dimensional-Assisted Techniques Combined with Orthognathic Treatment: A Case Series Study of Skeletal Class III Malocclusions

(•) Orthognathic surgery is a necessary procedure for the correction of severe skeletal discrepancies, among which are skeletal Class III malocclusions. Currently, both conventional fixed braces and clear aligners can be used in orthognathic surgery. However, the use of clear aligners remains a little-chosen option. The present study aimed to evaluate the skeletal and aesthetic improvements in adults with Class III malocclusion after surgical treatment and compare the results achieved by fixed appliances versus clear aligners. The study sample included four patients (three males and one female, aged 18 to 34 years) with skeletal Class III malocclusion, three of whom underwent a bimaxillary surgery and one of whom underwent only a bilateral sagittal split osteotomy. Two patients were treated with fixed appliances and two with clear aligners. The pre- and post-surgical hard and soft tissue cephalometric measurements were performed and compared for each patient and between fixed appliances and clear aligners. One year after surgery, all patients showed an essential modification of the face’s middle and lower third with an increase in the convexity of the profile and the Wits index and a reduction in the FH^NB angle. No differences were noted between fixed appliances and aligners. Therefore, thanks to the 3D-assisted surgery associated with orthodontics, every participant achieved proper occlusal function and an improved facial aesthetics. In addition, the clear aligners can be considered a valid alternative for pre- and post-surgical orthodontic treatment.

On the use of intraoperative 3D-RX C-arm imaging in orthognathic surgery: a prospective non-consecutive case series study

CONTEXT

Segment and osteosynthesis malposition resulting in patients' complaints (mainly about asymmetries) are encountered in orthofacial/orthognathic surgery.

OBJECTIVE, DESIGN, AND SETTING

We planned to investigate the usefulness of intraoperative three-dimensional (3D) imaging concerning positioning and fixation of bone segments and osteosynthesis in orthognathic/orthofacial surgery. We performed a prospective study of non-consecutive cases. All patients receiving a bimaxillary osteotomy, genioplasty, and their combinations were included in the study from May 2016 to May 2020. Unilateral and bilateral sagittal split osteotomies were excluded. There were no gender and age limitations. All were intraoperatively examined using the BV Pulsera 3D-RX System (Philips Medical, Eindhoven, The Netherlands). The outcome variables were the percentage of revisions of segment positioning and osteosynthesis. Predictor variables were age, gender, type of surgery, timing (pre- and post-imaging), and surgeon experience (senior vs assistant).

RESULTS

Forty female and twenty-two male patients were included (mean age 25.25 years ± 7.52 and 29.1 years ± 12.6 respectively). We evaluated 27 genioplasties and 34 Le Fort "type-I" osteotomies. Indications for segment repositioning and redo-osteosynthesis increased after intraoperative imaging as compared to operator's clinical judgment before intraoperative imaging (95% confidence interval; p < .001 and p = .002 respectively).

CONCLUSION

Suboptimal positioning and fixation of bone segments or osteosynthesis were more apparent with 3D imaging. In addition, some satisfactory cases were also revised for an optimal outcome. As a result, surgeons were prompted to more revisions than judged necessary without intraoperative imaging.

Machine learning-based decision support system for orthognathic diagnosis and treatment planning

BACKGROUND

Dento-maxillofacial deformities are common problems. Orthodontic-orthognathic surgery is the primary treatment but accurate diagnosis and careful surgical planning are essential for optimum outcomes. This study aimed to establish and verify a machine learning-based decision support system for treatment of dento-maxillofacial malformations.

METHODS

Patients (n = 574) with dento-maxillofacial deformities undergoing spiral CT during January 2015 to August 2020 were enrolled to train diagnostic models based on five different machine learning algorithms; the diagnostic performances were compared with expert diagnoses. Accuracy, sensitivity, specificity, and area under the curve (AUC) were calculated. The adaptive artificial bee colony algorithm was employed to formulate the orthognathic surgical plan, and subsequently evaluated by maxillofacial surgeons in a cohort of 50 patients. The objective evaluation included the difference in bone position between the artificial intelligence (AI) generated and actual surgical plans for the patient, along with discrepancies in postoperative cephalometric analysis outcomes.

RESULTS

The binary relevance extreme gradient boosting model performed best, with diagnostic success rates > 90% for six different kinds of dento-maxillofacial deformities; the exception was maxillary overdevelopment (89.27%). AUC was > 0.88 for all diagnostic types. Median score for the surgical plans was 9, and was improved after human-computer interaction. There was no statistically significant difference between the actual and AI- groups.

CONCLUSIONS

Machine learning algorithms are effective for diagnosis and surgical planning of dento-maxillofacial deformities and help improve diagnostic efficiency, especially in lower medical centers.

DIGITAL DENTISTRY AND ITS IMPACT ON ORAL HEALTH-RELATED QUALITY OF LIFE

Over the past 50 years, digitization has gradually taken root in dentistry, starting with computer tomography in the 1970s. The most disruptive events in digital dentistry were the introduction of digital workflow and computer-aided manufacturing, which made new procedures and materials available for dental use. While the conventional lab-based workflow requires light or chemical curing under inconsistent and suboptimal conditions, computer-aided manufacturing allows for industrial-grade material, ensuring consistently high material quality. In addition, many other innovative, less disruptive, but relevant approaches have been developed in digital dentistry. These will have or already impact prevention, diagnosis, and therapy, thus impacting patients' oral health and, consequently, their oral health-related quality of life. Both software and hardware approaches attempt to maintain, restore, or optimize a patient's perceived oral health. This article outlines innovations in dentistry and their potential impact on patients' oral health-related quality of life in prevention and therapy. Furthermore, possible future developments and their potential implications are characterized.

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.

Computer-assisted planning and patient-specific plates in orthognathic surgery: a global study

OBJECTIVE

Using computer-assisted surgery (CAS) and patient-specific plates (PSP) in orthognathic surgery has shown improved accuracy and efficiency compared with traditional techniques. This study analyzed current global trends in planning and investigated the reasons for CAS and PSP use.

STUDY DESIGN

A survey of 29 multiple choice questions was distributed to AO Foundation Craniomaxillofacial e-mail subscribers biweekly between July 14, 2021 and September 2, 2021. Questions focused on specifics of respondents' preoperative workup, methods of data collection, and the use of cutting guides and patient-specific plates. Objective clinical outcomes and subjective surgeon reasons for use were also investigated.

RESULTS

Of the 557 responses, 420 (75.4%) participant responses were eligible for analyses. Most (302/420, 71.9%) respondents used CAS when performing orthognathic surgery, although regional differences were observed. Almost all respondents in North America implemented CAS in their surgery plan (44/46, 95.7%) compared with only 47.4% (18/38) in the Middle East/North Africa. Surgeons with 10 to 15 years of experience were far more likely to incorporate CAS. More than half (175/301, 58.1%) of CAS users also used PSP, of which 43% (68/158) did so for maxillary-only cases, 3.2% (5/158) used PSP for mandible-only surgeries, and 42.4% (67/158) used PSP for both. Surgeons' primary reasons for using CAS and PSP were accuracy (200/253, 79.1%), efficiency (196/253, 77.5%), and ease of preoperative planning (150/253, 59.3%). Most (77.9%) surgeons perceived that CAS was equal to or faster than traditional surgery.

CONCLUSIONS

Our study shows differences in use regionally and with surgeon experience. Surgeons primarily use CAS and PSP in orthognathic surgery to increase accuracy and efficiency, minimize intraoperative deviations from the surgical plan, and reduce total surgical time.

Virtual surgical planning in craniomaxillofacial surgery: a structured review

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.

Accuracy of hard and soft tissue prediction using three-dimensional simulation software in bimaxillary osteotomies: A systematic review

INTRODUCTION

Orthognathic surgery is considered nowadays as a revolutionary treatment option for treating skeletal discrepancies and severe malocclusions in the sagittal, vertical and transverse dimensions. This surgery allows both the restoration of facial harmony and the achievement of satisfactory dental occlusion. The technology of computer-assisted surgeries including virtual surgical simulation programs and planning software greatly contributes to providing a three-dimensional simulation and precise mobilization of the maxilla and/or mandible, thus allowing the prediction of the final outcome in soft tissues. This study aims to systematically review the available scientific literature about the accuracy of the hard and soft tissue predictions delivered by the many promoted three-dimensional simulation software.

MATERIAL AND METHODS

An electronic search was conducted on various databases: Medline via PubMed, The Cochrane Library, EBSCO-host, and Web of Science. The search was established on a well-defined research question following PICO principle: population, intervention, comparator and outcome. Search evaluation and the assessment of risk of bias were undertaken in each study following its type and design.

RESULTS

Fifteen studies were included for qualitative analysis. Seven studies evaluated the accuracy of soft tissue prediction, seven focused more on the accuracy of hard tissue and one study assessed both hard and soft tissue prediction accuracy delivered by the simulation software. Moreover, three studies were judged to be low risk and four were classified as high risk. Included studies revealed that hard tissue prediction is highly accurate and reliable, leading to clinically acceptable results. Yet, soft tissue prediction is unclear due to various factors that bias its results. Caution should therefore be taken when providing information about the soft tissue planning to patients.

CONCLUSIONS

Computer assisted 3D simulation protocols allow for more precise repositioning of the maxilla and/or mandible compared to conventional 2D methods. However, 3D soft tissue prediction using simulation software remains less accurate, especially in the labial region.

Surgical accuracy of CAD/CAM splints using virtual surgical planning in orthognathic surgery: policy implications for healthcare in Australia

BACKGROUND

This study examines post-surgical outcomes of maxillary position using virtual surgical planning (VSP) with computer designed and manufactured surgical splints, without the use of costly patient specific implants (PSI), in the treatment of routine nonsyndromic orthognathic patients. The cost of these personalized medical devices and their impact in the setting of cranio-maxillofacial surgery is currently under review by The Department of Health and Aged Care in Australia.

METHODS

This is a single-centre retrospective analysis of 49 patients who underwent bimaxillary orthognathic surgery by a single surgeon at Epworth Richmond Hospital (Victoria, Australia) over a period spanning 2016 to 2020. Patients were included in the study provided their surgery was facilitated using VSP with manufacture of computer designed occlusal splints.

RESULTS

Use of computer designed and manufactured splints were highly reliable in reproducing the virtual surgical plan, when using palatal plane, upper incisor angulation, and anterior upper facial height.

CONCLUSION

Use of computer designed and manufactured splints provide a method of leveraging the accuracy of VSP methods, without the additional costs associated with PSI. These findings may assist in appropriate resource allocation and case stratification in patients undergoing orthognathic surgery.

Latest Evidence on Orthognathic Surgery Techniques and Potential Changes in Oral Microbiota related to Intermaxillary Fixation in Orthodontic Patients: A Systematic Review

Background:

Orthognathic surgery is often applied for the correction of facial dysmorphia, and different findings were highlighted regarding the techniques applied. After surgical treatment, intermaxillary fixation is placed, which compromises oral hygiene and, consequently, can lead to increased plaque accumulation and microbiological changes, promoting the proliferation of periodontopathogenic bacteria. Therefore, the aims of the present review are to describe the main evidence from the last 20 years of clinical studies concerning surgical techniques applied to orthognathic surgery and, finally, to analyze potential changes in the oral microbiota.

Materials and Methods:

An electronic search was conducted in the PubMed (MEDLINE) and Scopus databases; the MeSH (Medical Subject Heading) terms are bacteria, dental plaque, evidence-based practice, maxillomandibular fixation, microbiota, operative procedures, and orthognathic surgery.

Results:

At the end of the search process, 31 relevant articles were finally included and analyzed in this systematic review, which has a low risk of bias. Clinical studies on humans have been considered in this review. Based on the studies included it would be preferable to use piezoelectric technology in osteotomies because of its many advantages, “surgery-first” technique allows for results comparable to the standard technique in Class III malocclusions while improving quality of life more rapidly, the “mandible-first” technique seems to have more advantages than the “maxilla-first” technique, Computer-Aided Design and Manufacturing (CAD/CAM) could provide more accurate and precise results, and finally, Laser can be applied with different advantages. Regarding intermaxillary fixation, no long-term increase in the concentration of periodontal bacteria was recorded.

Conclusion:

Several findings still need to be confirmed with reference to the best suturing technique to reconstitute the nasal wing base, the real effectiveness of “surgery-first,” “maxilla-first,” and “mandible-first” approaches in patients with Class III malocclusion, the use of CAD/CAM and Laser, more studies should be conducted to evaluate quantitative and qualitative changes in other microorganisms following intermaxillary fixation.

Virtual Surgical Planning for Patients with Skeletal-Dental and Obstructive Sleep Apnea Syndrome

The integration of virtual surgical planning (VSP) for the treatment of skeletal, dental, and facial abnormalities and obstructive sleep apnea (OSA) with maxillofacial surgery has catapulted surgical planning. Although reported for treating skeletal-dental abnormalities and dental implant surgery, a paucity of knowledge existed reporting the feasibility and resultant outcome measures when VSP was employed for planning maxillary and mandibular surgery for OSA patients. The surgery-first approach is at the forefront of advancing maxillofacial surgery. Case series reporting success with the surgery-first approach for patients with skeletal-dental and sleep apnea patients have been reported. In sleep apnea patients, clinically significant reductions in apnea-hypopnea index and improvement of low oxyhemoglobin saturation have been achieved. More so, significant improvement in the posterior airway space at the occlusal and mandibular planes were achieved, while preserving aesthetic norms as measured by tooth to lip measurements. VSP is a feasible tool used for predicting surgical outcome measures in maxillomandibular advancement surgery for patients with skeletal, dental, facial, and OSA derangements.

Dual Application of Patient-Specific Occlusion-Based Positioning Guide and Fibular Cutting Guide for Accurate Reconstruction of Segmental Mandibular Defect

In this study, the authors introduced a dual application of patient-specific occlusion-based positioning guide and fibular cutting guide to obtain ideal occlusal relationship and mandibular contour in patients undergoing mandibular reconstruction. A retrospective review was performed in 21 patients who underwent mandibular reconstruction with a fibular osteocutaneous free flap. Using computed tomography and intraoral scanning data, fibular cutting guide and occlusion-based positioning guide were simulated in a modeling software and 3-dimensionally printed. Both guides were applied in 9 patients, defined as dual guide group, while the fibular cutting guide was solely used in the remaining patients, defined as single guide group. Functional outcomes including occlusion status, trismus, presence of osseointegrated implant were assessed at 1-year postoperative period. To evaluate the accuracy of the reconstruction, the discrepancy between the planned simulation and actual surgical result was quantified by measuring mandibular deviation angle and volume conformity. Regarding the functional outcomes, all patients in dual guide group showed satisfactory occlusion and intact oral capacity at postoperative 1-year assessment, while 3 patients in single guide group had prolonged malocclusion. The dual guide group showed significantly decreased deviation angle in coronal (right side, 2.93°±1.98° vs. 7.02°±2.81°, P =0.003) and axial plane (right side, 3.20°±2.04° vs. 7.63°±3.40°, P =0.006). The mean volume conformity between the simulation and actual fibular object was significantly higher in the dual guide group (75.27%±6.12% vs. 59.06%±8.57%, P =0.001). In conclusion, the use of occlusion-based positioning guide combined with the fibular cutting guide can enhance the accuracy of mandible reconstruction and functional 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.

The Efficacy of 3D Virtual Surgery, CAD/CAM, and 3D Printing Technology for Maxillomandibular Advancement in Obstructive Sleep Apnea Patients

OBJECTIVE

Maxillomandibular advancement (MMA) is the most effective surgical method for treating obstructive sleep apnea, and it moves the maxillomandibular complex forward to increase the entire upper airway volume. By using 3-dimensional (D) virtual surgery, computer-aided design/computer-aided manufacturing, and 3D printing technologies, it is possible to overcome all the limitations of conventional methods.

MATERIALS AND METHODS

In this study, (modified) MMA was performed by applying 3D technologies to obstructive sleep apnea patients. Virtual surgery was done as surgical plan, cutting guides, and customized plates were made by computer-aided design/computer-aided manufacturing and 3D printing technologies for surgical procedures.

RESULTS

After surgery, all patients improved their appearance, quality of sleep, and sleep apnea level were dramatically improved. Through these results, it was found that there are many advantages in using 3D technologies for preparing and implementing MMA.

CONCLUSIONS

It was confirmed that the accuracy and efficiency of surgery were increased by applying 3D technologies. This suggests that 3D technologies are very useful tools in surgical area.

Computer guided maxillo-malar piezoelectric osteotomies for midface augmentation

PURPOSE

Despite maxillo-malar osteotomies having been discarded in the most recent literature, in the setting of orthognathic surgery they provide several advantages for middle third augmentation. This paper reintroduces maxillo-malar osteotomies as an effective method to increase volume of midfacial region in combination with contemporary technology, including piezosurgery, virtual surgical planning, and navigation.

MATERIAL AND METHODS

Eighteen patients with midface hypoplasia were included in this study and underwent orthognathic surgery with maxillo-malar osteotomies. All patients underwent the same workflow: virtual design of maxillo-malar osteotomies, surgery with navigation-assisted piezoelectric osteotomies, and computerized morphometric analysis.

RESULTS

Simulated maxillo-malar osteotomies were successfully replicated in the operating room, as shown by accuracy evaluation performed using three-dimensional analysis. In long-term follow-up period, no permanent complications were assessed. Superimposition between postoperative and preoperative CBCTs revealed that the soft tissue area influenced by the underlying skeletal movement was comparable for all cases.

CONCLUSIONS

Virtual surgical planning, navigation, and piezosurgery are today indispensable tools to perform maxillo-malar osteotomies safely and accurately. We suggest incorporating such osteotomies in the surgeon's armamentarium for patients with severe midfacial hypoplasia as they offer an integrated solution to restore functionality and aesthetics.

Accuracy of Orthognathic Surgical Planning using Three-dimensional Virtual Techniques compared with Conventional Two-dimensional Techniques: a Systematic Review

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 2^nd, 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.

A Full Computerized Workflow for Planning Surgically Assisted Rapid Palatal Expansion and Orthognathic Surgery in a Skeletal Class III Patient

In the present case report, we present and discuss the digital workflow involved in the orthodontic/orthognathic combined treatment of a skeletal malocclusion correction in a 17-year-old male patient affected by a skeletal class III, facial asymmetry, sagittal and transversal deficiency of the medium third of the skull, dental crowding, and bilateral cross-bite. The first stage of the treatment involved surgically assisted rapid palatal expansion and occlusal decompensation, using fixed self-ligating appliance. An orthodontic software package (i.e., Dolphin 3D Surgery module) was used to perform virtual treatment objective evaluation by integrating data from cone beam computer tomography acquisition, intraoral scan, and extraoral photographs. The software allowed a comprehensive evaluation of skeletal, dento-alveolar, and soft-tissue disharmonies, qualitative and quantitative simulation of surgical procedure according to skeletal and aesthetic objectives, and, consequently, the treatment of the malocclusion. Using a specific function of the software, the surgical splint was designed according to the pre-programmed skeletal movements, and subsequently, the physical splint was generated with a three-dimensional (3D) printing technology. Once a proper occlusal decompensation was reached, a Le Fort I osteotomy of the maxilla and a bilateral sagittal surgical osteotomy of the mandible were executed to restore proper skeletal relations. The whole treatment time was 8 months. The orthodontic/orthognathic combined treatment allowed to correct the skeletal and the dental imbalance, as well as the improvement of facial aesthetics. Accordingly, the treatment objectives planned in the virtual environment were achieved. Virtual planning offers new possibilities for visualizing the relationship between dental arches and surrounding bone and soft structures in a single virtual 3D model, allowing the specialists to simulate different surgical and orthodontic procedures to achieve the best possible result for the patient and providing an accurate and predictable outcome in the treatment of challenging malocclusions.

Deep convolutional neural network-based automated segmentation and classification of teeth with orthodontic brackets on cone-beam computed-tomographic images: a validation study

OBJECTIVE

Tooth segmentation and classification from cone-beam computed tomography (CBCT) is a prerequisite for diagnosis and treatment planning in the majority of digital dental workflows. However, an accurate and efficient segmentation of teeth in the presence of metal artefacts still remains a challenge. Therefore, the following study aimed to validate an automated deep convolutional neural network (CNN)-based tool for the segmentation and classification of teeth with orthodontic brackets on CBCT images.

METHODS

A total of 215 CBCT scans (1780 teeth) were retrospectively collected, consisting of pre- and post-operative images of the patients who underwent combined orthodontic and orthognathic surgical treatment. All the scans were acquired with NewTom CBCT device. A complete dentition with orthodontic brackets and high-quality images were included. The dataset were randomly divided into three subsets with random allocation of all 32 tooth classes: training set (140 CBCT scans-400 teeth), validation set (35 CBCT scans-100 teeth), and test set (pre-operative: 25, post-operative: 15 = 40 CBCT scans-1280 teeth). A multiclass CNN-based tool was developed and its performance was assessed for automated segmentation and classification of teeth with brackets by comparison with a ground truth.

RESULTS

The CNN model took 13.7 ± 1.2 s for the segmentation and classification of all the teeth on a single CBCT image. Overall, the segmentation performance was excellent with a high intersection over union (IoU) of 0.99. Anterior teeth showed a significantly lower IoU (P < 0.05) compared to premolar and molar teeth. The dice similarity coefficient score of anterior (0.99 ± 0.02) and premolar teeth (0.99 ± 0.10) in the pre-operative group was comparable to the post-operative group. The classification of teeth to the correct 32 classes had a high recall rate (99.9%) and precision (99%).

CONCLUSIONS

The proposed CNN model outperformed other state-of-the-art algorithms in terms of accuracy and efficiency. It could act as a viable alternative for automatic segmentation and classification of teeth with brackets.

CLINICAL SIGNIFICANCE

The proposed method could simplify the existing digital workflows of orthodontics, orthognathic surgery, restorative dentistry, and dental implantology by offering an accurate and efficient automated segmentation approach to clinicians, hence further enhancing the treatment predictability and outcomes.

Custom made cutting guides and osteosynthesis plates versus CAD/CAM occlusal splints in positioning and fixation of the maxilla in orthognathic surgery: A prospective randomized study

The aim of this study is to compare the accuracy of maxilla positioning in orthognathic surgery with the use of custom-made devices (cutting guides and patient-fitted osteosynthesis plates) comparing to CAD/CAM splints. A prospective randomized study was performed. Patients with dentofacial deformities undergoing orthognathic surgery were compared, using customized guides (experimental group) vs. CAD/CAM surgical splints (control group) for the repositioning of the upper maxilla. Preoperative and postoperative CT scans were used to compare positioning and fixation of the maxilla in the three planes of space. A total of 30 patients were included in the study (15 patients in each study group). The mean error obtained with customized guides was 0.8 mm (range 0.1-1.9) in the anterior-posterior axis, 0.4 mm (range 0-1.4) in the vertical axis and 0.2 mm (range 0-1.1) in the horizontal axis. There were statistically significant differences in the anterior-posterior and vertical axes in favour of the customized implants, whereas there were no differences in the horizontal plane. Furthermore, there was a mean reduction of the operative time of 36.5 min in the experimental group. Within the limitations of the study it seems that patient specific surgical guides should be preferred when accuracy of repositioning of the maxilla and saving operative time are the priority.

Current and Novel Treatment Options for OSA

Obstructive sleep apnoea is a challenging medical problem due to its prevalence, its impact on quality of life and performance in school and professionally, the implications for risk of accidents, and comorbidities and mortality. Current research has carved out a broad spectrum of clinical phenotypes and defined major pathophysiological components. These findings point to the concept of personalised therapy, oriented on both the distinct clinical presentation and the most relevant pathophysiology in the individual patient. This leads to questions of whether sufficient therapeutic options other than positive airway pressure (PAP) alone are available, for which patients they may be useful, if there are specific indications for single or combined treatment, and whether there is solid scientific evidence for recommendations. This review describes our knowledge on PAP and non-PAP therapies to address upper airway collapsibility, muscle responsiveness, arousability and respiratory drive. The spectrum is broad and heterogeneous, including technical and pharmaceutical options already in clinical use or at an advanced experimental stage. Although there is an obvious need for more research on single or combined therapies, the available data demonstrate the variety of effective options, which should replace the unidirectional focus on PAP therapy.

The analysis of individual pathophysiological composition opens new directions towards personalised treatment of OSA, focusing not only on pharyngeal dilation, but also on technical or pharmaceutical interventions on muscle function or breathing regulationhttps://bit.ly/3sayhkd

The Effect of Zirconium Dioxide (ZrO2) Nanoparticles Addition on the Mechanical Parameters of Polymethyl Methacrylate (PMMA): A Systematic Review and Meta-Analysis of Experimental Studies

The number of studies on the subject of effects of zirconium dioxide (ZrO2) nanoparticles addition on the mechanical parameters of polymethyl methacrylate (PMMA) is still very limited. Therefore, in this research, the authors wanted to assess PMMA modified with the nano-ZrO2 additive in terms of changes in flexural, impact and tensile strength values in relation to PMMA without such component. A systematic review and meta-analysis were performed to evaluate the effect of incorporating nano-ZrO2 into PMMA on individual types of material strength. The obtained numerical data were tabulated and analyzed in the search for percentage changes in those parameters. It was then calculated for each set and the procured model was examined using residual sum of squares (RSS) to assess the discrepancy between the data and the estimation model whilst mean absolute deviation (MAD) was employed to determine robustness. The results of the systematic review were composed of data obtained from individual studies presented in eight independent articles. Overall, the addition of nano-ZrO2 increases the flexural strength of the composite with the PMMA matrix depending on the size of the ZrO2 grains administered. Unfortunately, these conclusions are based on a very limited amount of research and require further verification, especially regarding tensile strength.

Computer-Aided Autogenous Coronoid Process Graft Combined With Median and Unilateral Sagittal Split Osteotomy for Late Reconstruction of Condylar Fracture and Occlusion after Trauma

PURPOSE

This study proposes a high-precision surgical technique that combines both computer-aided design/computer-aided manufacturing (CAD/CAM) and the screw-track transfer technique for condylar and occlusal reconstruction.

MATERIALS AND METHODS

A 43-year-old male patient with facial asymmetry, limited mouth opening, and malocclusion underwent condylar and occlusal reconstruction surgery. An autogenous coronoid process graft was performed by combining CAD/CAM and the screw-track transfer technique.

RESULTS

The surgical plan was transformed successfully from preoperative virtual surgical planning to actual surgery; this was confirmed by merging the postoperative computed tomography images with the preoperative three-dimensional surgical design. The patient recovered well and had better occlusion and facial symmetry, as well as an increased degree of mouth opening post-surgery. No complications were observed.

CONCLUSIONS

CAD/CAM combined with the screw-track transfer technique is a precise and feasible method that can be applied to autogenous coronoid process grafts. This approach can be used to reconstruct the condylar process and achieve a good occlusal relationship.

One-splint versus two-splint technique in orthognathic surgery for class III asymmetry: comparison of patient-centred outcomes

OBJECTIVES

Two-jaw orthognathic surgery (OGS) is done using either the one-splint technique with free-hand positioning of the maxillomandibular complex or the two-splint technique with intermediate splints to position the maxilla. It is uncertain which technique achieves better outcomes. This study compares frontal soft tissue symmetry and subjective patient QoL between one-splint and two-splint techniques in skeletal Class III asymmetry patients undergoing OGS with three-dimensional surgical planning.

MATERIALS AND METHODS

This retrospective case-control study comprised 34 one-splint and 46 two-splint OGS patients. Frontal photographs and Orthognathic Quality of Life Questionnaire (OQLQ) were done pre- and post-treatment. Frontal soft tissue symmetry was analysed with the anthropometric Facial Symmetry Index. Measurements were compared with t-tests and chi-squared tests with p-value set at 0.05.

RESULTS

The groups differed in pre-treatment ANB and OQLQ scores. The two-splint group showed significant improvement in all symmetry measures. The one-splint group showed significant improvement in all symmetry measures except midface deviation, upper contour deviation and the Facial Contour Symmetry Index. Both groups showed significant improvement in OQLQ scores. There were no significant differences in post-treatment symmetry measurements and OQLQ scores between groups.

CONCLUSIONS

Although two-splint technique may better improve contour symmetry, there were no significant differences in frontal soft tissue symmetry and QoL after OGS in skeletal Class III asymmetry with either one-splint or two-splint technique, with both techniques resulting in significant improvement.

CLINICAL RELEVANCE

One-splint and two-splint surgical techniques produce similar patient-centred outcomes in Class III asymmetry patients.

Accuracy of virtual surgical planning in segmental osteotomy in combination with bimaxillary orthognathic surgery with surgery first approach

Background

This study aimed to assess the accuracy of virtual surgical planning (VSP) in segmental osteotomy in combination with bimaxillary orthognathic surgery with surgery first approach (SFA) by means of three-dimensional (3D) measuring and superimposition, so as to promote the application of digital technology in combined orthodontic-orthognathic treatment.

Methods

20 patients treated with segmental osteotomy in combination with bimaxillary orthognathic surgery with SFA from 2018 to 2020 were included. All of them acquired VSP performed by ProPlan CMF 3.0 software (Materialise Corporation, Belgium). The preoperative (T0) 3D model of VSP and the postoperative (T1) 3D model, reconstructed by the cone-beam computed tomography (CBCT) data acquired one week after surgery, were compared by measuring the 3D coordinates of the landmarks as well as 3D model superimposition for deviation analysis. The deviation analysis was achieved by Geomagic Studio 2013 (3D Systems Corporation, USA). The differences which represented the accuracy of VSP were evaluated by the root mean square deviation (RMSD) and the Bland–Altman method.

Results

There was no statistically significant difference between the 3D coordinates of T1 and T0 (P > 0.05), and the mean overall RMSD was 1.37 mm, within the clinical relevance of 2 mm. The RMSD of sagittal direction (1.76 mm) was greater than that of coronal and vertical directions (1.09 mm and 1.24 mm), and the RMSD of maxillary and mandibular aspects were basically equal (1.30 mm and 1.45 mm). The Bland–Altman method showed the T0 and T1 measurements were in good agreement. The mean RMSD obtained from the deviation analysis was 1.85 mm, within the clinical relevance.

Conclusions

VSP in segmental osteotomy in combination with bimaxillary orthognathic surgery with SFA proved to acquire accurate outcome in this study.

Evaluation of the accuracy of virtual planning in bimaxillary orthognathic surgery: Systematic review

The purpose of this research was to evaluate the accuracy of virtual planning in bimaxillary orthognathic surgery in bone by comparing the mean linear and angular measurements of the surgical plan with the actual surgical result. Electronic databases, MEDLINE via PubMed, Web of Science, SCOPUS, the Cochrane Library, grey literature, and the American clinical trials registry (www.ClinicalTrials.gov), were accessed as search engines. The studies consisted of publications on the assessment of accuracy in virtual planning in bimaxillary orthognathic surgery between 2010 and 2020. After application of the eligibility criteria, 26 articles were included, and their quality was evaluated using the methodological index for non-randomised studies (MINORS) tool and Cohen's kappa statistic in the MedCalc program (MedCalc Software Ltd). Evidence obtained by comparing the planning and surgical results, both in the maxilla and mandible, showed that there is great accuracy in virtual planning in bimaxillary orthognathic surgery.

Relapse and temporomandibular joint dysfunction (TMD) as postoperative complication in skeletal class III patients undergoing bimaxillary orthognathic surgery: A systematic review

Objectives

The aim of this study was to determine Relapse and TMD as postoperative complication in skeletal class III patients undergoing bimaxillary orthognathic surgery.

Materials and methods

Data was obtained by database searching using The Cochrane Central Register of Controlled Trials (central), PUBMED, SCOPUS, EMBASE, Google scholar, National Medical library, New Delhi. The titles and abstracts of the electronic search results were screened and evaluated by two observers for eligibility according to the inclusion and exclusion criteria.

Results

5261 articles were retrieved for the review. Among these, 3474 duplicate articles were removed. 418 studies were selected based on the eligibility criteria. For the present review, 30 articles were included after elimination according to the inclusion criteria. The Prisma diagram flowchart demonstrates our selection scheme. Quality assessment criteria to evaluate the studies were decided by two review authors in accordance with CONSORT guidelines. Each study was assessed using the evaluation method described in the Cochrane Handbook for Systematic Reviews. Among the 30 studies included in the review, marked degree of relapse in the mandible was noted from 3 months - 1 year postoperatively in 8 studies, 5 studies reported both TMD prevalence and relapse, whereas only 4 studies reported TMD disorder alone.

Conclusion

Complications of relapse and TMD are associated with bimaxillary orthognathic surgery procedures. More RCTs and CCTs are needed in this regard to get better quality evidence. This review was registered with PROSPERO: CRD42020211342.

Imaging in Oral and Maxillofacial Surgery

The scope of oral and maxillofacial surgery treatment and care is very broad, from dentoalveolar surgery, to pathology and reconstruction, to treatment of craniofacial deformities. The effective surgical treatment of patients requires appropriate and accurate diagnostic imaging. The various imaging modalities used in oral and maxillofacial surgery are typically for diagnostic and treatment planning purposes. With the improvements of three-dimensional imaging and software programs, surgical treatment and care have been enhanced with patient-specific guides, hardware, and implants. This article discusses the various imaging modalities used for a variety of typical oral and maxillofacial surgery procedures.

Three-Dimensional Computer-Assisted Orthognathic Surgery: Traditional Hybrid Versus Full Digital Planning Models

PURPOSE

Three-dimensional (3D) computer-aided planning has truly revolutionized orthognathic surgery (OGS) treatment, but no study has compared the traditional hybrid and full 3D digital planning models. This study compared these virtual planning models in the treatment of asymmetric maxillomandibular disharmony.

METHODS

Young adult patients with an asymmetric skeletal class III deformity who underwent 3D computer-aided 2-jaw OGS using hybrid (alginate dental impression, 2D cephalometric tracings, manual-guided stone model surgery, occlusion setup, and splint fabrication; n = 30) or full digital (laser-scanned dentition, 3D cephalometric tracings, virtual-based occlusion setup and surgery, and computer-generated surgical splint; n = 30) planning models were consecutively recruited. Preoperative and postoperative 3D cephalometric analyses (dental relation, skeletal assessments based on sagittal and frontal views, and soft tissue evaluations) were adopted for intragroup and intergroup comparisons. Postoperative patient-perceived satisfaction with facial appearance was also recorded.

RESULTS

Both hybrid and full digital planning groups had significant (all P < 0.05) improvements after surgery with respect to facial convexity, incisor overjet, and frontal symmetry parameters. The full 3D digital planning-based OGS treatment had similar (all P > 0.05) 3D cephalometric-derived outcomes (preoperative, postoperative, and treatment-induced change data) and patient-perceived outcomes compared with the traditional hybrid 3D planning method.

CONCLUSIONS

For the decision-making process in selecting the planning model, multidisciplinary teams could consider additional parameters such as patient comfort, storage needs, convenience for data reuse, overall planning time, availability, and costs.

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.

Comparison of feasibility, time consumption and costs of three virtual planning systems for surgical correction of midfacial deficiency

Background

Today virtual surgical planning (VSP) is a standard method in maxillofacial corrective surgery and is the key to reach satisfactory esthetic outcomes. The purpose of this study was to evaluate usability of three established virtual surgical planning software applications by comparing feasibility, time consumption, and costs in a standardized workflow for a modified intraoral quadrangular Le Fort II osteotomy (IQLFIIO).

Results

A cross-sectional study was performed based on retrospective and re-planned data of patients with midfacial deficiency treated by modified IQLFIIO, using three software applications: IPS Case Designer ®, Dolphin Imaging ®, and ProPlan CMF ®. Feasibility: All evaluated steps of the VSP procedure could be successfully performed in all three evaluated applications. In all software packages, it was possible to design the surgical splints with CAD/CAM technology. Working time: The mean value of time needed was IPS Case Designer ®, 36.5 min; Dolphin Imaging ®, 33.6 min; ProPlan CMF ®, 45.5 min. We found statistical significant difference between ProPlan CMF ® and Dolphin Imaging ® (p value, 0.02). Costs: Asset costs for acquiring the software, license fee, license possibilities, paying for support services, and service contracts were evaluated and are found in similar ranges.

Conclusion

All three tested software applications are usable for virtual planning of an IQLFIIO and splint production by CAD/CAM technology. Successful movement of bone segments and overlaying soft tissues proved feasibility. Time consumption and costs were found in similar ranges.

Accuracy of custom temporomandibular joint replacement surgery using a virtual surgical planning protocol

BACKGROUND

Accurate placement of TMJ implant components may be facilitated by virtual surgical planning (VSP) technologies. The aim of this study was to assess the accuracy of a typical VSP protocol and describe the pattern of surgical error associated with total alloplastic TMJ replacement.

METHODS

A retrospective analysis was undertaken on 40 adult patients who were implanted with a fully customised, 3D printed TMJ prosthesis due to end-stage TMJ disease. Planned TMJ implant position based on preoperative CBCT images was compared with final position on postoperative OPGs using a previously validated linear rescaling method. Translational discrepancy was described in the anterior-posterior direction and superior-inferior direction. Rotational discrepancy was described as anterior or posterior.

RESULTS

Lin's concordance between preoperative and postoperative position was 0.97, with no significant differences (p > 0.05). The Bland-Altman analysis showed a 95% limit of agreement between planned and final position of - 5.9 to 5.4 mm. Overall, final implant position was more anterior (0.4 mm), superior (0.4 mm) and posteriorly rotated (2.4°) compared with planned position.

CONCLUSION

The use of VSP in TMJ replacement surgery results in accurate implant placement with good agreement between planned and final implant position. Discrepancies in planned and final implant position tended to result in the mandibular component of the implant being translated anterior superiorly and rotated posteriorly, with potential implications for the biomechanical performance of the implant and overall device longevity. These results should be used to assist TMJ surgeons pre- and intraoperatively to facilitating accurate implant positioning and optimal surgical rehabilitation.