UNASSIGNED: Asian women prefer a smooth and narrowed mandibular appearance. The purpose of the retrospective cohort study is to evaluate guide plate-assisted mandibular angle ostectomy (MAO) in improving mandibular symmetry for Asian female patients with mandibular angle hypertrophy (MAH) with normal occlusal relationship.
UNASSIGNED: We retrospectively examined 11 patients with asymmetry MAH with normal occlusal relationship who received MAO at Shanghai Ninth People\'s Hospital between September, 2020, and January, 2022. Preoperative plans were designed based on CT data and executed using metal guide plate during the operation. Preoperative and one-week postoperative CT scans were used to assess measurements including Height_Go, Divergence_Go, ∠ZyZy-GoGo, and osteotomy volume, to evaluate symmetry. For precision, compare the postoperative CT with the preoperative design, assessing osteotomy distance, angle, and volume error. Patient satisfacation was evaluated with Likert Scale in 6-month follow-up. Secondary lipofilling procedures were given as appropriate. Statistical analysis was performed using paired t-tests in SPSS.
UNASSIGNED: The mean age of the 11 patients was 28.5 years (range 23-34 years). 2 of these underwent lipofilling procedures. No complications were observed during the following-up. Postoperative results were not statistically different from the design, demonstrating a precision of within 2 mm. Height_Go disparity within 5 mm get corrected notably, reducing asymmetry from 15.09% preoperatively to 2.74% postoperatively. Patients satisfaction was rated at 4.5 out of 5 in 6 month follow-up.
UNASSIGNED: Guide plate-assisted mandibular angle osteotomies achieve effective and precise surgery. This approach demonstrates a safe option for correction for mandibular asymmetry, achieving patient satisfaction.

Genioplasty is a widely used surgical approach to address chin deformities by performing an osteotomy on the inferior border of the mandible to allow for comprehensive repositioning of the chin. This study aimed to compare the accuracy of freehand chin repositioning with a guided technique that employed specialised surgical guides. For this retrospective study, data from 30 adult patients who underwent orthognathic surgery to correct dentofacial deformities were analysed. All patients underwent virtual planning before surgery, with half of them treated using freehand chin repositioning and the other half using the guided technique. The surgical outcomes were measured and compared with the virtual plan to assess the positional and rotational accuracy of the techniques. In terms of translational assessment, noteworthy values that exceeded clinically acceptable limits were observed only in sagittal movement in the freehand group (0.97 mm, interquartile range (IQR) 0.73-2.29 mm). Regarding rotational accuracy, both groups exhibited an IQR that surpassed acceptable limits for pitch (3.26°, IQR 2.06-5.20 for the guided group and 2.57°, IQR 1.63-4.24° for the freehand group). The Mann-Whitney test indicated no statistical differences between the groups in any translational or rotational assessment. In conclusion, although there was no statistical difference, the guided technique proved effective in achieving clinically acceptable accuracy in all positions and almost all rotations, displaying superior results in sagittal positioning compared with the freehand technique. To fully harness the advantages of guides and to guarantee accuracy in all rotations, we recommend further research involving guides made of more rigid materials, and customised implants.

OBJECTIVE: To compare miniscrew versus bone tracing registration methods on dental implant placement accuracy and time efficiency in edentulous jaws using a dynamic computer-assisted implant surgery (d-CAIS) system.
METHODS: Twelve fully edentulous maxillary models were allocated into two groups: miniscrew tracing (MST) group, where registration was performed by tracing four miniscrews; and bone tracing (BT) group, where registration was conducted by tracing maxillary bone fiducial landmarks. Six implants were placed on each model using the X-Guide® d-CAIS system. Pre- and postoperative cone-beam computed tomography (CBCT) scans were superimposed to evaluate implant placement accuracy. The time required for registration and the overall surgery time were also recorded.
RESULTS: Thirty-six implants were placed in each group. The MST group showed significantly lower mean angulation deviations (mean difference (MD): -3.33°; 95% confidence interval (CI): -6.56 to -0.09); p = 0.044), 3D platform deviations (MD: -1.01 mm; 95%CI: -1.74 to -0.29; p = 0.006), 2D platform deviations (MD: -0.97 mm; 95%CI: -1.71 to -0.23; p = 0.010), and 3D apex deviations (MD: -1.18 mm; 95%CI: -1.92 to -0.44; p = 0.002) versus the BT group. The overall surgery time was similar for both groups (MD: 6.10 min.; 95%CI: -0.31 to 12.51; p = 0.06), though bone tracing required significantly more time compared with miniscrew registration (MD: 4.79 min.; 95%CI: 2.96 to 6.62; p < 0.05).
CONCLUSIONS: Registration with MST increases the accuracy of implant placement with a d-CAIS system in edentulous jaws compared with the BT method, and slightly reduces the overall surgery time.
CONCLUSIONS: Miniscrew tracing registration improves implant placement accuracy in comparison with bone tracing registration.

BACKGROUND: This study introduced an Augmented Reality (AR) navigation system to address limitations in conventional high tibial osteotomy (HTO). The objective was to enhance precision and efficiency in HTO procedures, overcoming challenges such as inconsistent postoperative alignment and potential neurovascular damage.
METHODS: The AR-MR (Mixed Reality) navigation system, comprising HoloLens, Unity Engine, and Vuforia software, was employed for pre-clinical trials using tibial sawbone models. CT images generated 3D anatomical models, projected via HoloLens, allowing surgeons to interact through intuitive hand gestures. The critical procedure of target tracking, essential for aligning virtual and real objects, was facilitated by Vuforia\'s feature detection algorithm.
RESULTS: In trials, the AR-MR system demonstrated significant reductions in both preoperative planning and intraoperative times compared to conventional navigation and metal 3D-printed surgical guides. The AR system, while exhibiting lower accuracy, exhibited efficiency, making it a promising option for HTO procedures. The preoperative planning time for the AR system was notably shorter (4 min) compared to conventional navigation (30.5 min) and metal guides (75.5 min). Intraoperative time for AR lasted 8.5 min, considerably faster than that of conventional navigation (31.5 min) and metal guides (10.5 min).
CONCLUSIONS: The AR navigation system presents a transformative approach to HTO, offering a trade-off between accuracy and efficiency. Ongoing improvements, such as the incorporation of two-stage registration and pointing devices, could further enhance precision. While the system may be less accurate, its efficiency renders it a potential breakthrough in orthopedic surgery, particularly for reducing unnecessary harm and streamlining surgical procedures.

OBJECTIVE: Acute acromioclavicular (AC) joint dislocation is a common orthopedic injury that can significantly impair shoulder function and reduce quality of life. Effective treatment methods are essential to restore function and alleviate pain. To investigate the short-term clinical efficacy of the minimally invasive closed-loop double endobutton fixation assisted by orthopaedic surgery robot positioning system (TiRobot) in the treatment of AC joint dislocation, and to evaluate its feasibility and safety.
METHODS: The clinical data of 19 patients with AC joint dislocation who underwent treatment with closed-loop double Endobutton fixation assisted by TiRobot between May 2020 and December 2022 were retrospectively analyzed. Visual Analog Scale (VAS) pain scores, the Constant Murley Score (CMS), and shoulder abduction range of motion were assessed and compared preoperatively and at the last follow-up. Computed tomography (CT) parameters of the acromioclavicular joint, including acromioclavicular distance (ACD), the distance between the upper and lower Endobutton (DED), the horizontal distance between the anterior edge of the distal clavicle and the anterior edge of the acromion (DACC), the diameter of the clavicular tunnel (DCT), and coracoid tunnel diameter (DC), were compared at 2 days, and 1 month after surgery, as well as at the last follow-up, along with the evaluation of intraoperative and postoperative complications.
RESULTS: The postoperative VAS, CMS, and shoulder-abduction range of motion were significantly improved compared with the preoperative (all, P<0.05). The statistical analysis showed no significant difference in the CT image parameters of the acromioclavicular joint at 2 days and 1 month after surgery(all, P>0.05). Comparisons of DCT and DC revealed statistically significant differences between the last follow-up and 1 month after surgery (P<0.05), and no statistically significant difference was found in ACD, DED, and DACC(all, P>0.05). There were no complications such as infection or vascular or neurological damage, no cases of rostral or clavicle fractures, loss of reduction, heterotopic ossification, shoulder stiffness, and no loosening or breaking of internal fixations.
CONCLUSIONS: Closed-loop double endobutton internal fixation assisted by TiRobot is an ideal method for the treatment of acute acromioclavicular (AC) joint dislocation. This method has the advantages of relatively simple operation, more accurate localization of bone tunnel during operation, less surgical trauma, and good recovery of shoulder function.

暂无摘要。

Computer-assisted implant planning allows for a comprehensive treatment plan by combining radiographic data provided by a Cone Beam Computed Tomography (CBCT) with surface optical scan (IOs) data that includes patient intraoral situation and the intended restorative planning. Integrating a tailored restorative design with the patient\'s anatomical conditions through virtual implant planning allows for an ideal bio-restorative treatment planning to maximize biological, functional, and esthetic outcomes. This article discusses dataset registration techniques that combine radiographic CBCT data with restorative information as the main path to create a virtual patient. The described techniques include the use of removable radiographic templates with radiopaque markers, dual scan technique, and direct digital file registration of intra-oral scans using anatomical references. Depending on the individual clinical situation, different factors must be considered to appropriately select methods that achieve an optimal registration of diverse datasets. An inherent challenge lies in the presence of scattering artifacts in CBCT scans. Two approaches are proposed for these situations - the use of chairside-fabricated composite resin markers or adhesive spot-markers fabricated for the use with CBCT scans. Both techniques exhibit limitations that need to be taken into consideration. Further approaches should be developed for situations involving scattering in CBCT.

UNASSIGNED: Proximal femoral fractures (PFF) are a significant health concern among the elderly, often leading to complications and high mortality rates. Intramedullary nailing is widely considered the most effective treatment for lateral proximal femoral fractures (LPFF), with the Tip Apex Distance (TAD) being a crucial predictor of surgical success. This study aimed to compare outcomes between patients treated with and without the ADAPT (ADAptive Positioning Technology) system, which aids in the precise placement of the cephalic screw.
UNASSIGNED: A retrospective analysis was conducted on 97 patients with intertrochanteric fractures treated in 2022. Patients were divided into two groups: those treated with the ADAPT system (group I, n=34) and those treated without it (group II, n=63). Fractures were classified according to AO/OTA classification. The primary outcomes measured were operative time, cephalic screw angle, TAD, and incidence of lag screw cut-out. Statistical analyses included chi-square tests and t-tests, with significance set at P < 0.05.
UNASSIGNED: The ADAPT system did not significantly reduce TAD (18.21 mm in the ADAPT group vs. 19.94 mm in the control group, p=0.149). Operative times were similar between the groups. The incidence of lag screw cut-out was low in both groups, with no significant differences. The study confirmed a strong correlation between higher TAD and increased risk of screw cut-out, underscoring the importance of precise screw placement.
UNASSIGNED: Computer-assisted surgery, such as the ADAPT system, aims to enhance the accuracy of cephalic screw placement. In this study, the ADAPT system didn\'t demonstrate a statistically significant advantage in reducing TAD or preventing screw cut-out. Nevertheless, the critical role of TAD in preventing fixation failure was reaffirmed, emphasising the need for precise surgical techniques.
UNASSIGNED: While the ADAPT system did not show a significant advantage in reducing TAD or preventing screw cut-out in this study, the importance of achieving optimal TAD in cephalomedullary nailing was reinforced. Future research should continue to explore the role of computer-assisted systems in enhancing surgical accuracy and improving outcomes for patients with LPFF.

Objective  The aim of this work was the development of an augmented reality system including the functionality of conventional surgical navigation systems. Methods  An application software for the Augmented Reality System HoloLens 2 from Microsoft was developed. It detects the position of the patient as well as position of surgical instruments in real time and displays it within the two-dimensional (2D) magnetic resonance imaging or computed tomography (CT) images. The surgical pointer instrument, including a pattern that is recognized by the HoloLens 2 sensors, was created with three-dimensional (3D) printing. The technical concept was demonstrated at a cadaver skull to identify anatomical landmarks. Results  With the help of the HoloLens 2 and its sensors, the real-time position of the surgical pointer instrument could be shown. The position of the 3D-printed pointer with colored pattern could be recognized within 2D-CT images when stationary and in motion at a cadaver skull. Feasibility could be demonstrated for the clinical application of transsphenoidal pituitary surgery. Conclusion  The HoloLens 2 has a high potential for use as a surgical navigation system. With subsequent studies, a further accuracy evaluation will be performed receiving valid data for comparison with conventional surgical navigation systems. In addition to transsphenoidal pituitary surgery, it could be also applied for other surgical disciplines.

OBJECTIVE: Digital protocols and bioactive materials may reduce complications and improve tooth autotransplantation (ATT) success and survival rates. This prospective study assesses the performance of a fully digital autotransplantation protocol of close-apex molars with the adjunctive application of Enamel Matrix Derivatives (EMD).
METHODS: Twelve adult patients with 13 hopeless molar teeth were replaced with autotransplantation of closed apex third molars. Outcomes, including success and survival rates, clinical, endodontic, radiographic, patient-reported outcome measures (PROMs), and digital image assessments, were conducted over a two-year follow-up period.
RESULTS: Survival and success rates were 100% and 91.2%, respectively, with no progressive inflammatory or replacement root resorption (ankylosis) except for one tooth presenting radiographic furcation involvement. A significant probing depth reduction of 2.4 ± 2.58 mm and CAL gains of 2.8 ± 3.03 mm were observed in transplanted teeth compared to the hopeless receptor teeth. Radiographic bone levels remained stable throughout the study period (-0.37 ± 0.66 mm), and digital image assessments showed minimal alveolar ridge width changes (-0.32 to -0.7 mm) and gingival margin changes (-0.95 to -1.27 mm) from baseline to last visit. PROMs indicated very high patient satisfaction.
CONCLUSIONS: The use of a digital ATT protocol with adjunctive use of EMD in closed-apex third molars demonstrated promising short-term high success and survival rates. Additionally, this type of therapy adequately preserves the dimensions of the alveolar ridge in the receptor site.
CONCLUSIONS: This is the first prospective clinical study examining the effect of a digital tooth autotransplantation protocol combined with the application of EMD. It demonstrates that this approach is an effective treatment for replacing hopeless teeth and also validates the digital assessment of ATT alveolar ridge preservation at the recipient site.