We have reported that the cytokines and chemokines contained in conditioned medium of human mesenchymal stem cells (MSC-CM), which were derived from bone marrow, promote bone regeneration. We recently reported macrophage phenotype polarization towards the anti-inflammatory M2 phenotype induced by MSC-CM and its potential to establish regenerative condition and assist subsequent bone regeneration. However, the specific factors in the MSC-CM responsible for this process remain unclear. Monocyte chemoattractant protein (MCP) -1, present in MSC-CM, promotes cell migration and activation of the monocyte-macrophage lineage; therefore, we hypothesized that MCP-1 is one of the key factors in MSC-CM-induced macrophage phenotype polarization. The effect of MCP-1 on MSC-CM-induced macrophage phenotype polarization and subsequent bone regeneration was investigated in this study. MCP-1 was depleted from MSC-CM (depMSC-CM) and used in subsequent experiments. Rat bone marrow macrophages were incubated in MSC-CM or depMSC-CM and expression of macrophage markers was examined in vitro. In addition, the effect of MSC-CM and depMSC-CM on bone regeneration and macrophage phenotype polarization were evaluated using rat calvaria defect model in vivo. MSC-CM enhanced M2 macrophage marker expression in rat bone marrow macrophages compared to those treated with depMSC-CM in vitro. In addition, MSC-CM increased the number of M2 macrophage marker-positive cells in bone defects and enhanced subsequent bone regeneration in a rat calvaria bone defect model. MCP-1 seemed to be a one of the most contributing factors in MSC-CM-induced macrophage phenotypic polarization and subsequent bone regeneration.

Lingual nerve injury following dental procedures, such as lower third molar extractions, can cause significant sensory deficits. For patients with persistent severe symptoms, surgical reconstruction using a nerve conduit is often considered. However, the degree of recovery varies, and the optimal timing of intervention and the significance of the nerve gap distance remain subjects of clinical debate. Using the Medical Research Council Scale (MRCS) as a standardized measure of sensory function, this study aims to determine the independent effects of the timing of surgery, nerve gap length, and other potential prognostic factors on nerve functional recovery, specifically defining success as MRCS S3+ or higher. This study retrospectively analyzed a cohort of 49 patients who underwent lingual nerve repair surgery. The success of nerve recovery was evaluated using two established criteria: the standard Functional Sensory Recovery (FSR), MRCS S3 or higher, and the strict MRCS S3+ or higher criteria based on American Society of Plastic Surgeons (ASPS) criteria. The MRCS S3+ or higher criteria was designated as the primary outcome for all multivariate analyses. The time to surgery variable was logarithmically transformed, Log (Time to Surgery, months), to account for the highly skewed distribution. Statistical analysis used univariate and multivariate logistic regression to assess the association between each predictor and postoperative MRCS score. A secondary analysis examined predictors for allodynia resolution. The logarithmically transformed time to surgery, Log (Time to Surgery, months), was the sole statistically significant independent predictor for achieving MRCS S3+ (Odds Ratio OR = 0.236, 95% CI: 0.063-0.887, P = 0.032). This indicates that earlier intervention significantly increases the odds of functional recovery. Nerve gap length was not a significant predictor (OR = 0.941, P = 0.518). Furthermore, no variable was found to be a significant predictor for allodynia resolution (P > 0.05). Earlier surgical intervention, quantified by Log (Time to Surgery), is an independent and critical factor for achieving MRCS S3+ functional sensory recovery after lingual nerve repair. The distance of the nerve gap did not show an independent predictive effect on the final sensory outcome.

BackgroundSeveral treatment modalities have been reported in the management of mandibular fractures using an alternative computer-guided approach through the utilization of different designs of guiding devices. However, these computer-guided methods do not always guarantee accurate anatomical bone reduction. This study aimed to assess the reduction precision of the computer-guided mandibular fracture and internal fixation using screw holes locating surgical guide, as presented earlier in the orthognathic surgery field in various studies to be applied in the field of mandibular traumatology, comparing it with the conventional approach.MethodsTwenty-six patients with Brown Class III mandibular fracture, defined by a single fracture line involving the body, parasymphysis or symphysis regions, were randomly assigned to two groups for open reduction and internal fixation. The study group underwent reduction and fixation using patient-specific screw-hole locating guide and pre-bent titanium miniplates, whereas the control group received conventional reduction and fixation with intraoperatively adapted titanium miniplates. Virtual reduction of the fractured mandible was performed in all cases of both groups utilizing CT scan and mimics software. Then, the actual postoperative mandibular model was superimposed over the virtually operated mandibular model based on predefined reference points and plans to obtain dental and bony linear measurements. The recorded measures were statistically analysed.ResultsThe actual postoperative mandibular model in the computer-guided group showed minimal deviation from the virtual mandibular model. While the deviation of the actual post operative model in the conventional group from the virtual model was higher, the difference in deviation between the two groups was statistically significant. The mean bony deviation was 0.09 ± 0.29 mm in the computer-guided group, versus 0.70 ± 0.33 mm in the control group p < 0.001. The mean dental deviation was 0.05 ± 0.16 mm in the computer-guided group versus 0.56 ± 0.32 mm in the control group p < 0.001.The mean operative time of the computer-guided group(1.49 ± 0.19)(hours) was significantly shorter than the mean operative time of control group (1.82 ± 0.37)(hours) which is statistically significant p < 0.001.ConclusionsThe use of screw-hole locating guide and pre-bent plates enhanced surgical accuracy and efficiency. It also highlighted how patient-specific design can reduce dependence on surgeon experience and standardized outcomes in complex mandibular fractures.Trial registrationThe study is registered at ClinicalTrials.gov Protocol Registration and Results System Receipt, ID: NCT05444829.

BackgroundIn recent years, the use of facial soft tissue fillers via cosmetic injections has steadily increased, along with the incidence of adverse events caused by injection vascular occlusion. We aimed to three-dimensionally visualize the anastomosis between facial soft tissue and the vascular system to enhance the safety and effectiveness of facial injections. A cadaver model was used to visualize facial anatomy. A red gelatin–lead oxide contrast agent was perfused to visualize the blood vessels, while 3.75% iodine-potassium iodide was used to stain the soft tissues. Micro-computed tomography scanning was then performed to capture detailed imaging results.ResultsWe successfully visualized both facial soft tissues and blood vessels simultaneously, including the two-dimensional distribution of vascular tissues and the three-dimensional hierarchical structure of the soft tissue. This allowed accurate assessment of the vascular flow and interconnections in the facial region.ConclusionsThis study provides a detailed three-dimensional representation of the facial vascular anatomy, particularly in the periocular area. By clarifying facial vascular anastomoses, this technique offers a valuable reference for promoting safer and more effective filler injections and reducing the risk of injection-related complications. Providing an interactive, high-resolution vascular dataset of a specific developmental stage. Promoting safe and effective injection of fillers provides a more reliable reference for reducing complications caused by injections.Supplementary InformationThe online version contains supplementary material available at 10.1186/s40902-025-00492-7.

Background and aimFacial nerve injury is a critical complication of rhytidectomy, affecting patient outcomes and satisfaction. Despite its importance, standardized management strategies remain limited. This systematic review evaluates current evidence on the management, outcomes, and prevention of facial nerve injuries in rhytidectomy, with stratification by injury severity to enhance clinical applicability.MethodsIn this study, PubMed, Embase, and the Cochrane Library were searched from inception to July 2025, identifying 20 studies that met the inclusion criteria. The quality of the studies was assessed using AMSTAR 2 and the Newcastle–Ottawa Scale. Additionally, the review was conducted in accordance with the PRISMA guidelines to ensure transparency and accuracy in reporting the results.ResultsThe incidence of facial nerve injury ranged from 0.5% to 5%, with 70% of patients achieving full recovery within six months through conservative treatments (corticosteroids, physiotherapy). Management and outcomes varied by injury severity: neuropraxia (80–90% of cases) typically resolved conservatively, while axonotmesis or neurotmesis required surgical interventions (e.g., nerve repair) or adjunct therapies (e.g., botulinum toxin). Preventive measures, such as meticulous surgical techniques and awareness of facial danger zones, were effective. Intraoperative nerve monitoring showed potential but needs further validation.ConclusionsConservative management suffices for most cases, particularly neuropraxia, yet 10% of patients experience persistent deficits, underscoring the need for severity-stratified approaches. Prospective multicenter registries with standardized outcome measures, individual patient data meta-analyses, and Bayesian hierarchical modeling are essential to address evidence gaps and enhance clinical practice.Graphical abstract