Soft-tissue sound-speed-aware ultrasound-CT registration method for computer-assisted orthopedic surgery.

Ultrasound (US) has been introduced to computer-assisted orthopedic surgery for bone registration owing to its advantages of nonionizing radiation, low cost, and noninvasiveness. However, the registration accuracy is limited by US image distortion caused by variations in the acoustic properties of soft tissues. This paper proposes a soft-tissue sound-speed-aware registration method to overcome the above challenge. First, the feature enhancement strategy of multi-channel overlay is proposed for U2-net to improve bone segmentation performance. Secondly, the sound speed of soft tissue is estimated by simulating the bone surface distance map for the update of US-derived points. Finally, an iterative registration strategy is adopted to optimize the registration result. A phantom experiment was conducted using different registration methods for the femur and tibia/fibula. The fiducial registration error (femur, 0.98 ± 0.08 mm (mean ± SD); tibia/fibula, 1.29 ± 0.19 mm) and the target registration error (less than 2.11 mm) showed the high accuracy of the proposed method. The experimental results suggest that the proposed method can be integrated into navigation systems that provide surgeons with accurate 3D navigation information.

Accuracy of dynamic navigation compared to static surgical guides and the freehand approach in implant placement: a prospective clinical study.

BACKGROUND: Computer-guided implant surgery has improved the quality of implant treatment by facilitating the placement of implants in a more accurate manner. This study aimed to assess the accuracy of implant placement in a clinical setting using three techniques: dynamic navigation, static surgical guides, and freehand placement. We also investigated potential factors influencing accuracy to provide a comprehensive evaluation of each technique's advantages and disadvantages. MATERIALS AND METHODS: Ninety-four implants in 65 patients were included in this prospective study. Patients were randomly assigned to one of three groups: dynamic navigation, static surgical guides, or freehand placement. Implants were placed using a prosthetically oriented digital implant planning approach, and postoperative CBCT scans were superimposed on preoperative plans to measure accuracy. Seven deviation values were calculated, including angular, platform, and apical deviations. Demographic and consistency analyses were performed, along with one-way ANOVA and post-hoc tests for deviation values. RESULTS: The mean global platform, global apical, and angular deviations were 0.99 mm (SD 0.52), 1.14 mm (SD 0.56), and 3.66° (SD 1.64°) for the dynamic navigation group; 0.92 mm (SD 0.36), 1.06 mm (SD 0.47), and 2.52° (SD 1.18°) for the surgical guide group; and 1.36 mm (SD 0.62), 1.73 mm (SD 0.66), and 5.82° (SD 2.79°) for the freehand group. Both the dynamic navigation and surgical guide groups exhibited statistically significant differences in all values except depth deviations compared to the freehand group (p < 0.05), whereas only the angular deviation showed a significant difference between the dynamic navigation and surgical guide groups (p = 0.002). CONCLUSION: Our findings highlight the superior accuracy and consistency of dynamic navigation and static surgical guides compared to freehand placement in implant surgery. Dynamic navigation offers precision and flexibility. However, it comes with cost and convenience considerations. Future research should focus on improving its practicality. TRIAL REGISTRATION: This study was retrospectively registered at the Thai Clinical Trials Register-Medical Research Foundation of Thailand (MRF) with the TCTR identification number TCTR20230804001 on 04/08/2023. It was also conducted in accordance with the Declaration of Helsinki and approved by the institutional ethics committee at the Xian Jiaotong University Hospital of Stomatology, Xian, China (xjkqII[2021] No: 043). Written informed consent was obtained from all participants.

Mouth opening limitation and influence of age and surgical location for static fully guided dental implant placement: an observational, cross-sectional clinical study.

The influence of age and region of the mouth was assessed in regard to mouth opening in fully guided implant placement. Ninety patients were included in this study, 30 in each of three age groups (20-34, 35-55, and >55 years). Maximum passive mouth opening was recorded in three locations: incisal, canine, and molar. The minimum distance required to allow the bone drilling sequence through a static fully guided approach was analysed for four implant systems: Straumann, MIS Dentsply, Astra Tech Dentsply, and Dentium. The mean ± standard deviation maximum mouth opening (all 90 patients) was 46.34 ± 7.70 mm, 36.82 ± 5.92 mm, and 30.99 ± 5.40 mm in the incisal, premolar, and molar region, respectively. No significant difference in mouth opening at any of the three locations was found between the age groups (all P > 0.05). However, a correlation was found between increasing age and decreasing average mouth opening in all three mouth regions; each additional 1 year resulted in a mean reduction of 0.13 mm, 0.09 mm, and 0.08 mm in the incisal, premolar, and molar region, respectively. The minimum required mouth opening was most likely to be met for implant placement in the incisal region (98.9% of all patients) and least likely to be met for placement in the molar region, particularly for older patients (as low as 30% of patients). Mouth opening remains a major limitation in fully guided implant surgery, especially in posterior areas and in older patients. The use of some implant systems in the posterior area may be limited to only one in three patients.

OrthoCalc: The six degrees of freedom measurement workflow of rotational and displacement changes for maxilla positioning evaluation.

BACKGROUND: This study is undertaken to establish the accuracy and reliability of OrthoCalc, a 3D application designed for the evaluation of maxillary positioning. METHODS: We registered target virtual planned models, maxillary models from pre-operative and post-operative CT scans, and post-operative intra-oral scans to a common reference system, allowing for digital evaluation. To assess rotational changes, we introduced a novel measurement method based on virtual cuboid models. Displacement errors were calculated based on proposed registration matrices. We also compared OrthoCalc to established commercial medical software as a benchmark. RESULTS: Statistical significance calculated showed no significant differences between OrthoCalc and commercial software. the biggest error of 0.04 degree in rotation change was found in the yaw. A maximum displacement change of 0.75 mm was found in the X direction. CONCLUSIONS: Our study validates OrthoCalc as a precise and reliable tool for assessing maxillary position changes with six degrees of freedom in orthognathic surgery, endorsing its clinical utility.

Dynamic navigation-assisted bone ring technique for partially edentulous patients with severe vertical ridge defects.

The autogenous bone ring technique is among the approaches for vertical alveolar ridge augmentation, and this technique can enable simultaneous implantation. However, the outcomes can be compromised due to donor site morbidity, shifting of the bone ring graft positioning, and inaccurate implant placement. In recent decades, dynamic navigation systems have been introduced into the field of implantology, allowing the accuracy of outcomes to be improved. This Technical Note describes the use of dynamic navigation to guide bone ring surgery, which is expected to enable more precise and predictable bone augmentation and implantation procedures, reduce the risk of injuries to the adjacent anatomical structures, and achieve better treatment outcomes.

Automated Identification of Key Steps in Robotic-Assisted Radical Prostatectomy Using Artificial Intelligence.

PURPOSE: The widespread use of minimally invasive surgery generates vast amounts of potentially useful data in the form of surgical video. However, raw video footage is often unstructured and unlabeled, thereby limiting its use. We developed a novel computer-vision algorithm for automated identification and labeling of surgical steps during robotic-assisted radical prostatectomy (RARP). MATERIALS AND METHODS: Surgical videos from RARP were manually annotated by a team of image annotators under the supervision of 2 urologic oncologists. Full-length surgical videos were labeled to identify all steps of surgery. These manually annotated videos were then utilized to train a computer vision algorithm to perform automated video annotation of RARP surgical video. Accuracy of automated video annotation was determined by comparing to manual human annotations as the reference standard. RESULTS: A total of 474 full-length RARP videos (median 149 minutes; IQR 81 minutes) were manually annotated with surgical steps. Of these, 292 cases served as a training dataset for algorithm development, 69 cases were used for internal validation, and 113 were used as a separate testing cohort for evaluating algorithm accuracy. Concordance between artificial intelligence‒enabled automated video analysis and manual human video annotation was 92.8%. Algorithm accuracy was highest for the vesicourethral anastomosis step (97.3%) and lowest for the final inspection and extraction step (76.8%). CONCLUSIONS: We developed a fully automated artificial intelligence tool for annotation of RARP surgical video. Automated surgical video analysis has immediate practical applications in surgeon video review, surgical training and education, quality and safety benchmarking, medical billing and documentation, and operating room logistics.

A robotic system for transthoracic puncture of pulmonary nodules based on gated respiratory compensation.

BACKGROUND AND OBJECTIVE: With the urgent demands for rapid and precise localization of pulmonary nodules in procedures such as transthoracic puncture biopsy and thoracoscopic surgery, many surgical navigation and robotic systems are applied in the clinical practice of thoracic operation. However, current available positioning methods have certain limitations, including high radiation exposure, large errors from respiratory, complicated and time-consuming procedures, etc. METHODS: To address these issues, a preoperative computed tomography (CT) image-guided robotic system for transthoracic puncture was proposed in this study. Firstly, an algorithm for puncture path planning based on constraints from clinical knowledge was developed. This algorithm enables the calculation of Pareto optimal solutions for multiple clinical targets concerning puncture angle, puncture length, and distance from hazardous areas. Secondly, to eradicate intraoperative radiation exposure, a fast registration method based on preoperative CT and gated respiration compensation was proposed. The registration process could be completed by the direct selection of points on the skin near the sternum using a hand-held probe. Gating detection and joint optimization algorithms are then performed on the collected point cloud data to compensate for errors from respiratory motion. Thirdly, to enhance accuracy and intraoperative safety, the puncture guide was utilized as an end effector to restrict the movement of the optically tracked needle, then risky actions with patient contact would be strictly limited. RESULTS: The proposed system was evaluated through phantom experiments on our custom-designed simulation test platform for patient respiratory motion to assess its accuracy and feasibility. The results demonstrated an average target point error (TPE) of 2.46 ± 0.68 mm and an angle error (AE) of 1.49 ± 0.45° for the robotic system. CONCLUSIONS: In conclusion, our proposed system ensures accuracy, surgical efficiency, and safety while also reducing needle insertions and radiation exposure in transthoracic puncture procedures, thus offering substantial potential for clinical application.

Computer assisted skull base surgery: a contemporary review.

Skull base surgery has evolved significantly since Harvey Cushing's first descriptions in the early 1900s. Computer aided surgery (CAS) applications continue to expand; they include virtual surgical planning, augmented and virtual reality, 3D printing of models/cutting guides/implants, surgical navigation, and intraoperative imaging. The authors will review the current skull base CAS literature and propose a computer aided surgical workflow categorizing these applications into 3 phases: 1) Virtual planning, 2) Surgical execution, 3) Intraoperative verification.

Prosthetic rehabilitation in patients with jaw reconstruction by fibula free flap: A systematic review.

This systematic review aimed to evaluate the dental prosthetic rehabilitation (DPR) in patients after jaw reconstruction with fibula free flap. Four databases were searched from January 2000 to January 2023. Of the 2507 studies identified, 36 observational studies were included. Cancer was the most common surgical indications for jawbone resection with 58.3 % of cases followed by benign tumours which representing 24 %. The DPR rate was estimated at 51.6 % across the studies (ranging from 38 % to 55 % depending on the benign or malignant nature of the tumors). Implant-supported prostheses represented 58.9 % of cases of which 66.9 % were fixed and 33.1 % were implant-stabilized overdentures. Virtual surgical planning (VSP) was used in 20 % of studies and aimed to improve the position of the grafted fibula, quality, and aesthetics of DPR and to decrease ischemia and the operating time. One in two authors performed DPR 12 months after jaw reconstruction. If implant survival rate reached 93 % in non-irradiated fibula, it fell to 38 %, 55 %, and 77 % if implantation occurred in the 12, 17, and 24 months after radiotherapy, respectively. Various parameters should be better investigated in further studies including the typology of the prostheses (implant-supported vs removable), the use of VSP, and the optimal time for DPR taking into account the characteristics of the tumor, the size of bone defect, and the need for external irradiation therapy.

Persistent myogenic temporomandibular disorders: Are navigation-guided botulinum toxin-A injections into the lateral pterygoid muscles effective?

BACKGROUND: Botulinum toxin has proven effective in treating persistent myogenous temporomandibular disorders (M-TMDs) unresponsive to conservative therapies. While the usual injection sites are the masseter and temporalis muscles, the deeper lateral pterygoid muscle (LPM) is often overlooked due to its difficulty of access and the risk of local complications. This study aims to evaluate the effectiveness of botulinum toxin-A injections (BTX-A) in the LPM with MR-guided navigation of patients with persistent M-TMDs. METHODS: This retrospective study enrolled 34 patients suffering from M-TMDs despite conservative therapies with a total of 51 injection sessions. All of them were treated by BTX-A injections in the LPM using MR-guided navigation, masseter and temporalis with clinical guidance. The effectiveness of the treatment was evaluated with measures of maximum pain-intensity scores of breakthrough and background pain, maximal interincisal mouth opening (MIO), and the presence of joint sounds. The assessment was conducted before injections, and subsequently, at 1 and 3 months postoperatively. Adverse events and perception of improvement with the treatment were also reported for each injection sessions. RESULTS: BTX-A injections in the LPM significantly improved pain scores intensity with a reduction of 65 % and 49 % respectively at the 1- and 3-month follow-ups, with peak effectiveness at 1 month. This study showed also a statistically significant improvement in mean MIO at 3 months post-injection and a decrease in joint sounds with persistence in 9,7 % of cases at 3-month follow-up compared to 41,2 % at baseline. No significant adverse events were observed. Patients treated with BTX-A injections in the LPM had a subjective complete improvement in their perception of treatment efficacy in 63 % of cases at the end of the follow-up period. CONCLUSIONS: This study reports clinical experience on the use of MR-guided navigation to perform accurate, reliable, and safe BTX-A injections in the LPM. Although our results appear to be encouraging regarding symptom improvement of patients suffering from persistent M-TMDs, this approach may not be feasible as a primary standard procedure for managing M-TMDs. Further research is necessary to explore potential reproducible, safe, and cost-effective alternatives to enhance the accessibility of the LPM in clinical practice.

AUTONOMOUS ROBOTIC SURGERY SEEMS PROMISING AS AN ACCURATE TECHNOLOGY FOR SINGLE-TOOTH IMPLANT PLACEMENT IN THE ESTHETIC ZONE.

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Yang S, Chen J, Li A, Deng K, Li P, Xu S. Accuracy of autonomous robotic surgery for single-tooth implant placement: a case series. J Dent. 2023;132:104451. doi:10.1016/j.jdent.2023.104451. Epub 2023 Feb 11. PMID: 36781099. SOURCE OF FUNDING: This case series study was supported by grants from the Guangdong Basic and Applied Basic Research Foundation, Science and Technology Projects in Guangzhou, Science Research Cultivation Program, and Clinical Research Initiation Plan of the Stomatological Hospital, Southern Medical University, China. TYPE OF STUDY/DESIGN: Case series. No a priori power calculation or pilot data. Nonconsecutive participant recruitment.

The Accuracy of Zygomatic Implant Placement Assisted by Dynamic Computer-Aided Surgery: A Systematic Review and Meta-Analysis.

PURPOSE: The present systematic review aimed to investigate the accuracy of zygomatic implant (ZI) placement using dynamic computer-aided surgery (d-CAIS), static computer-aided surgery (s-CAIS), and a free-hand approach in patients with severe atrophic edentulous maxilla and/or deficient maxilla. METHODS: Electronic and manual literature searches until May 2023 were performed in the PubMed/Medline, Scopus, Cochrane Library, and Web of Science databases. Clinical trials and cadaver studies were selected. The primary outcome was planned/placed deviation. Secondary outcomes were to evaluate the survival of ZI and surgical complications. Random-effects meta-analyses were conducted and meta-regression was utilized to compare fiducial registration amounts for d-CAIS and the different designs of s-CAIS. RESULTS: A total of 14 studies with 511 ZIs were included (Nobel Biocare: 274, Southern Implant: 42, SIN Implant: 16, non-mentioned: 179). The pooled mean ZI deviations from the d-CAIS group were 1.81 mm (95% CI: 1.34-2.29) at the entry point and 2.95 mm (95% CI: 1.66-4.24) at the apex point, and angular deviations were 3.49 degrees (95% CI: 2.04-4.93). The pooled mean ZI deviations from the s-CAIS group were 1.19 mm (95% CI: 0.83-1.54) at the entry point and 1.80 mm (95% CI: 1.10-2.50) at the apex point, and angular deviations were 2.15 degrees (95% CI: 1.43-2.88). The pooled mean ZI deviations from the free-hand group were 2.04 mm (95% CI: 1.69-2.39) at the entry point and 3.23 mm (95% CI: 2.34-4.12) at the apex point, and angular deviations were 4.92 degrees (95% CI: 3.86-5.98). There was strong evidence of differences in the average entry, apex, and angular deviation between the navigation, surgical guide, and free-hand groups (p < 0.01). A significant inverse correlation was observed between the number of fiducial screws and the planned/placed deviation regarding entry, apex, and angular measurements. CONCLUSION: Using d-CAIS and modified s-CAIS for ZI surgery has shown clinically acceptable outcomes regarding average entry, apex, and angular deviations. The maximal deviation values were predominantly observed in the conventional s-CAIS. Surgeons should be mindful of potential deviations and complications regardless of the decision making in different guide approaches.

Accuracy Analysis of Computer-Assisted and Guided Dental Implantology by Comparing 3D Planning Data and Actual Implant Placement in a Mandibular Training Model: A Monocentric Comparison between Dental Students and Trained Implantologists.

The aim of this study was to investigate how precisely implantation can be realized by participants on a phantom head according to preliminary planning. Of particular interest here was the influence of participants' previous knowledge and surgical experience on the precision of the implant placement. The placed implants were scanned using an intraoral scanner, saved as STL files, and superimposed with the 3D-planned implant placement. Deviations from the planning were indicated in millimeters and degrees. We were able to show that on average, the deviations from computer-assisted 3D planning were less than 1 mm for implantologists, and the students also did not deviate more than 1.78 mm on average from 3D planning. This study shows that guided implantology provides predictable and reproducible results in dental implantology. Incorrect positioning, injuries to anatomical structures, and implant positions that cannot be prosthetically restored can thus be avoided.

Use of intraoperative 3D imaging in the maxillofacial operating room: A French national survey.

PURPOSE: To gain a comprehensive understanding of the utilization of intraoperative 3D imaging among maxillofacial surgeons practicing in France through a web-based questionnaire. METHODS: An 18-point multiple-choice questionnaire was developed and distributed to participants. The questionnaire was divided into two sections, with the first section gathering general information about the respondents and the second section providing an overview of the utilization of 3D imaging techniques, such as cone-beam computed tomography (CBCT), computed tomography (CT) scan, and magnetic resonance imaging (MRI), including the conditions, frequencies, and indications for use, with a particular focus on the number of acquisitions per procedure and the other departments with whom the equipment is shared. RESULTS: A total of 75 participants completed the survey, with 30% of university hospital departments and 0% of private clinics currently utilizing intraoperative 3D imaging systems. The main indications for 50% of the users were for temporomandibular joint surgery and orbital fractures. CONCLUSION: The results of this survey indicate that the utilization of intraoperative 3D imaging in French maxillofacial surgery is limited to university centers, with poor utilization and a lack of standardization in indications for use.

Dynamic Implant Surgery-An Accurate Alternative to Stereolithographic Guides-Systematic Review and Meta-Analysis.

(1) Background: Dynamic guided surgery is a computer-guided freehand technology that allows highly accurate procedures to be carried out in real time through motion-tracking instruments. The aim of this research was to compare the accuracy between dynamic guided surgery (DGS) and alternative implant guidance methods, namely, static guided surgery (SGS) and freehand (FH). (2) Methods: Searches were conducted in the Cochrane and Medline databases to identify randomized controlled clinical trials (RCTs) and prospective and retrospective case series and to answer the following focused question: "What implant guidance tool is more accurate and secure with regard to implant placement surgery?" The implant deviation coefficient was calculated for four different parameters: coronal and apical horizontal, angular, and vertical deviations. Statistical significance was set at a p-value of 0.05 following application of the eligibility criteria. (3) Results: Twenty-five publications were included in this systematic review. The results show a non-significant weighted mean difference (WMD) between the DGS and the SGS in all of the assessed parameters: coronal (n = 4 WMD = 0.02 mm; p = 0.903), angular (n = 4 WMD = -0.62°; p = 0.085), and apical (n = 3 WMD = 0.08 mm; p = 0.401). In terms of vertical deviation, not enough data were available for a meta-analysis. However, no significant differences were found among the techniques (p = 0.820). The WMD between DGS and FH demonstrated significant differences favoring DGS in three parameters as follows: coronal (n = 3 WMD = -0.66 mm; p =< 0.001), angular (n = 3 WMD = -3.52°; p < 0.001), and apical (n = 2 WMD = -0.73 mm; p =< 0.001). No WMD was observed regarding the vertical deviation analysis, but significant differences were seen among the different techniques (p = 0.038). (4) Conclusions: DGS is a valid alternative treatment achieving similar accuracy to SGS. DGS is also more accurate, secure, and precise than the FH method when transferring the presurgical virtual implant plan to the patient.

Stability of maxillary expansion osteotomy using patient-specific fixation implants without necessitating removable appliances: a retrospective analysis.

OBJECTIVE: This study aimed to evaluate the long-term stability of surgical maxillary expansion using patient-specific fixation implants (PSFIs) without intraoral retention. MATERIALS AND METHODS: Fifteen patients who had undergone segmented Le Fort I osteotomy and PSFIs with available preoperative (t0) early (t1) and 1-year follow-up computed tomography (CT) scans (t2) were evaluated. The early and 1-year 3D models were superimposed to transfer the bony landmarks; the distances between each pair of landmarks at the different time points were then measured. The distances between the canines and second molars were also measured directly on the CT scans. RESULTS: The achieved maxillary expansions ranged from a median of 4.39 (2.00-6.27) mm at the greater palatine foramina to a median of 2.14 (1.56-2 > 83) mm at the canine level of the palatal bone. One year postoperatively, the changes in skeletal diameters ranged from a median of - 0.53 (- 1.65 to 0.41) mm at the greater palatine foramina (p = 0.12) to 0.17 (- 0.09 to 0.32) mm at the canine level of the palatal bone (p = 0.56). Changes in dental arch diameters ranged from a median of - 0.6 (- 2 to 0.00) mm between the second molars to - 1.3 (- 1.8 to - 0.25) mm between the canines (P < 0.05). CONCLUSION: This study showed the stability of maxillary expansion osteotomy using PSFIs, even without postoperative intraoral retention. CLINICAL RELEVANCE: PSFIs are a reliable method for the surgical treatment of transverse maxillary discrepancy. PFSIs are easy-to-use and improve surgical accuracy.

Surgical navigation in maxillofacial surgery: A French national survey.

PURPOSE: to gain a national understanding of the utilization of surgical navigation among maxillofacial surgeons in France through a web-based questionnaire. METHODS: A 14-point multiple-choice questionnaire was created and distributed to the participants, divided into two sections. The first section gathered general information about the respondents, and the second section provided an overview of the use of surgical navigation. RESULT: A total of 75 participants completed the survey. The results showed that a majority of university hospital departments (65%) utilize an intra-operative 3D imaging system, while very few private clinics and general hospitals use this technology. CONCLUSION: The survey suggests that surgical navigation is primarily used in university centers in French maxillofacial surgery, with limited utilization and non-standardized indications for use.

Virtual Resection Specimen Interaction Using Augmented Reality Holograms to Guide Margin Communication and Flap Sizing.

Head and neck surgeons often have difficulty in relocating sites of positive margins due to the complex 3-dimensional (3D) anatomy of the head and neck. We introduce a new technique where resection specimens are 3D scanned with a smartphone, annotated in computer-assisted design software, and immediately visualized on augmented reality (AR) glasses. The 3D virtual specimen can be accurately superimposed onto surgical sites for orientation and sizing applications. During an operative workshop, a surgeon using AR glasses projected virtual, annotated specimen models back into the resection bed onto a cadaver within approximately 10 minutes. Colored annotations can correspond with pathologic annotations and guide the orientation of the virtual 3D specimen. The model was also overlayed onto a flap harvest site to aid in reconstructive planning. We present a new technique allowing interactive, sterile inspection of tissue specimens in AR that could facilitate communication among surgeons and pathologists and assist with reconstructive surgery.

The Flipping-Wedge Osteotomy: How 3D Virtual Surgical Planning (VSP) Suggested a Simple and Promising Type of Osteotomy in Pediatric Post-Traumatic Forearm Deformity.

(1) Background: The application of computer-aided planning in the surgical treatment of post-traumatic forearm deformities has been increasingly widening the range of techniques over the last two decades. We present the "flipping-wedge osteotomy", a promising geometrical approach to correct uniapical deformities defined during our experience with virtual surgical planning (VSP); (2) Methods: a case of post-traumatic distal radius deformity (magnitude 43°) treated with a flipping-wedge osteotomy in an 11-year-old girl is reported, presenting the planning rationale, its geometrical demonstration, and the outcome of the procedure; (3) Results: surgery achieved correction of both the angular and rotational deformities with a neutral ulnar variance; (4) Conclusions: flipping-wedge osteotomy may be a viable option to achieve correction in forearm deformities, and it deserves further clinical investigation.

Implant rehabilitation of the esthetic area: A five-year retrospective study comparing conventional and fully guided surgery.

INTRODUCTION: To compare the clinical outcomes of anterior single maxillary implants placed using conventional or guided implant surgery. METHODS: In this retrospective clinical study 44 patients rehabilitated with a single anterior implant in the maxillary arch were included. Twenty-four implants were inserted applying a guided surgery approach (GS), and 20 applying a conventional freehand approach (CS). Outcome measures were: implant survival rate and complications; mean bone level (MBL) evaluated at surgery (T0), after 6 weeks (6 W), and after 1 year (1Y), 2 years (2Y), 3 years (3Y), 4 years (4Y), and 5 years (5Y); patients' satisfaction evaluated through a questionnaire filled out before surgery (BS) and at 1 week, 6 W, 2Y and 5Y; Pink esthetic score (PES) and white esthetic score (WES) evaluated at 1Y, 3Y and 5 Y. Significance of differences between groups were tested by Fisher's exact test, Mann-Whitney U test, and Wilcoxon's signed rank test. RESULTS: During the 5-year follow-up there were no drop-outs and no implant failed. No significant differences between groups were found in MBL. A significant difference between groups was found in VAS scores regarding speech at 2 years, aesthetics at 6 weeks, confidence at 1 week and 6 weeks, satisfaction at T0 and at 1 W, pain/comfort at 1 W and at 6 W; all VAS scores resulted significantly improved compared to baseline. No significant differences in WES were found, while significant differences in PES scores between CS and GS groups were found at 3 and 5 years (p value = 0.023 and 0.004 respectively) with better outcomes for GS. A significant difference over time was found in PES between 5-year and one-year values. CONCLUSIONS: Guided surgery and conventional surgery implants did not show any difference in MBL during the 5-year observation period. Guided surgical procedure guarantee optimal esthetic outcome and seems able to guarantee better soft tissue result over time, even though more long-term studies are necessary to confirm this data.