华西口腔医学杂志最新文献

Objectives: This study aimed to build a surgical navigation system based on mixed reality (MR) and optical positioning technique and evaluate its clinical applicability in craniomaxillofacial trauma bone reconstruction. Me-thods We first integrated the software and hardware platforms of the MR-based surgical navigation system and explored the system workflow. The systematic error, target registration error, and osteotomy application error of the system were then analyzed via 3D printed skull model experiment. The feasibility of the MR-based surgical navigation system in craniomaxillofacial trauma bone reconstruction was verified via zygomatico-maxillary complex (ZMC) reduction experiment of the skull model and preliminary clinical study.

Results: The system error of this MR-based surgical navigation system was 1.23 mm±0.52 mm, the target registration error was 2.83 mm±1.18 mm, and the osteotomy application error was 3.13 mm±1.66 mm. Virtual surgical planning and the reduction of the ZMC model were successfully conducted. In addition, with the guidance of the MR-based navigation system, the frontal bone defect was successfully reconstructed, and the clinical outcome was satisfactory.

Conclusions: The MR-based surgical navigation system has its advantages in virtual reality fusion effect and dynamic navigation stability. It provides a new method for doctor-patient communications, education, preoperative planning, and intraoperative navigation in craniomaxillofacial surgery.

Objectives: This work aimed to construct N6-methyladenosine (m⁶A) regulator-based prognostic signature and evaluate the prognostic value and the intervention on tumor immune microenvironment of this m⁶A risk signature.

Methods: Using transcriptome and clinical data of head and neck squamous cell carcinoma (HNSCC) from The Cancer Genome Atlas (TCGA), we profiled m⁶A regulators and constructed an m⁶A risk signature. The relationship between m⁶A modulation and immune function was studied by differential gene expression, cell type enrichment, and correlation analyses.

Results: Fifteen m⁶A regulators had aberrant expression in HNSCC. A three-gene m⁶A prognostic signature (i.e., YTHDC2, IGF2BP2, and HNRNPC) was constructed and identified as an independent prognostic indicator for HNSCC. The m⁶A regulator signature-based high-risk group revealed pro-tumoral immune microenvironment due to the dysregulation of immune-related gene expression, abnormal enrichment of multiple immunocytes, and production of immunoregulatory factors.

Conclusions: This comprehensive analysis of m⁶A regulators and tumor immune landscape in HNSCC revealed that the m⁶A signature of YTHDC2, IGF2BP2, and HNRNPC could serve as a promising biomarker for monitoring HNSCC development and may be a potential target for tumor therapy in the future.

Dens invaginatus (DI) is a developmental anomaly as a result of a deepening or invagination of the enamel organ into the dental papilla during tooth development. In addition, DI is a malformation with varying anatomical features, which poses numerous challenges to treatment. Endodontic treatment of dens in dente is one of the most complica-ted cases of DI. Herein, an immature lateral incisor that employed regenerative endodontic treatment was presented. The mentioned tooth was diagnosed with DI, pulp necrosis, and chronic apical periodontitis. Hence, a favorable prognosis has been shown by a 2-year review with cone beam computed tomography. The tooth was functional with normal periodontal parameters and exhibited a normal response to the electric pulp sensibility test. Thus, regenerative endodontic treatment can also be recommended to endodontists for teeth with DI.

Objectives: This study aimed to investigate whether the microglia in the spinal trigeminal nucleus caudal part (Sp5C) were activated in a rat model of trigeminal neuralgia and to explore whether the activation level of microglia is consistent with maxillofacial pain level.

Methods: Chronic constriction injury of trigeminal nerve (CCI) was induced by partial ligation of infraorbital nerve (IoN) in rats. The behavioral change of rats observed at D1, D5, D10, D15, and D30 days post-surgery and the change of pain threshold were detected with electronic Von Frey filaments served as an evaluation index of maxillofacial pain. Weight change was measured by weighing. Ionized calcium binding adaptor molecule-1 (Iba-1) expression level of Sp5C at each time point was detected, and three microglia morphological categories were analyzed by immunohistochemical staining.

Results: The changes of behavioral and pain threshold suggested the maxillofacial pain level first increased and then decreased post-surgery in the IoN-CCI group. Both the expressions of Iba-1 and proportion of ameboid morphology in ipsilateral Sp5C increased from D1 and reached their peaks in D10 and D5, respectively. Then, they recovered nearly to the same level with contralateral Sp5C on D30. This trend was consistent with the maxillofacial change.

Conclusions: The model of trigeminal neuralgia in rats constructed by partial ligation of infraorbital nerve can induce the activation of microglia in Sp5C, and the activation level is consistent with maxillofacial pain, which reached its peak at around D10 post-surgery.

Radiation-induced oral mucositis is an oral mucosal injury caused by radiation ionizing radiation, which often manifests as oral mucosal congestion, erosion, and ulcers. Radiation-induced oral mucositis manifesting as vascular proliferative changes in the oral mucosa has not been reported. We report a case of oral mucosal atypical vascular proliferation after radiotherapy for a malignant maxillofacial tumor. We discussed the mechanism and treatment of aty-pical vascular proliferation in the oral mucosa secondary to radiotherapy, including diagnosis, treatment, and previous literature.

External apical root resorption is among the most common risks of orthodontic treatment, and it cannot be completely avoided and predicted. Risk factors causing orthodontic root resorption can generally be divided into patient- and treatment-related factors. Root resorption that occurs during orthodontic treatment is usually detected by radiographical examination. Mild or moderate root absorption usually does no obvious harm, but close attention is required. When severe root resorption occurs, it is generally recommended to suspend the treatment for 3 months for the cementum to be restored. To unify the risk factors of orthodontic root resorption and its clinical suggestions, we summarized the theoretical knowledge and clinical experience of more than 20 authoritative experts in orthodontics and related fields in China. After discussion and summarization, this consensus was made to provide reference for orthodontic clinical practice.

Immune checkpoint inhibitors (ICIs) present significant efficacy in the treatment of malignant tumors, and they have been approved as the first-line of treatment for various cancers. Pembrolizumab monotherapy or combined with chemotherapy has been recommended by domestic and foreign guidelines for the first-line treatment of recurrent/metastatic head and neck squamous cell carcinoma. Although ICIs represent a milestone in the treatment of head and neck squamous cell carcinoma, potential problems still need to be addressed, such as the selection of the efficacy predictors for ICIs, the evaluation of the tumor response to ICIs, and the treatment of immune hyperprogression and immune-related adverse events. Therefore, to form a relatively unified understanding of ICIs treatment for head and neck squamous cell carcinoma, we integrated the clinical experience of multi-disciplinary experts of head and neck cancers on the basis of current clinical hot issues and finally developed this consensus.

Objectives: This study aimed to investigate the accuracy of model superimposition and automatic analysis for upper and lower dentition widths in iTero Progress Assessment during the clear aligner process.

Methods: Nineteen cases were included in this retrospective case control study. Pretreatment dental cast (T0) and post treatment dental cast after staged treatment (T1) were available for three-dimensional (3D) model superimposition. The movements of maxillary teeth in the horizontal plane (cross section) after staged treatment and the widths of upper and lower dentitions were measured by 3D model superimposition in real world and iTero Progress Assessment. The data collected from the two methods were compared.

Results: The movements [Median (upper and lower quartiles)] of maxillary teeth in the horizontal plane after staged treatment were 2.31 (1.59, 3.22) and 1.79 (1.21, 3.03) mm in iTero Progress Assessment and 3D model analysis, respectively. Significant difference was observed between the two groups (P<0.05). In the measurement of upper and lower dentition width, four indicators were measured, including intercanine width upper, intermolar width upper, intercanine width lower, and intermolar width lower. Before treatment, the measurement of iTero Progress Assessment were (35.78±2.49), (56.21±2.51), (27.43±1.38), (52.26±2.91) mm, respectively, and actual measurement were (35.77±2.53), (56.17±2.47), (27.40±1.41), (52.30±2.86) mm, respectively, without significant difference (P>0.05). After stage treatment, the measurement of iTero Progress Assessment were (37.37±2.86), (57.76±2.56), (28.89±2.00), (54.16±2.19) mm, respectively, and actual measurement were (37.29±2.94), (57.71±2.63), (28.88±2.05), (54.01±2.15) mm, respectively, and there was no significant difference (P>0.05).

Conclusions: The data from iTero Progress Assessment did not coincide with the model superimposition results with palate as reference. The accuracy of model superimposition in iTero Progress Assessment needs further investigation, whereas the arch width analysis is accurate. Therefore, iTero Progress Assessment results should be interpreted with caution by orthodontists in clinical applications.

Objectives: This work aimed to synthesize a novel injectable alginate impression material and evaluate its accuracy.

Methods: Certain proportions of sodium alginate, trisodium phosphate dodecahydrate, potassium fluorotitanate, diatomaceous earth, and other ingredients were dissolved in water and mixed evenly with a planetary centrifugal mixer to obtain a certain viscosity base paste. Certain proportions of calcium sulfate hemihydrate, magnesium oxide, glycerin, and polyethylene glycol (PEG) 400 were mixed evenly with a planetary centrifugal mixer to obtain the reactor paste with the same viscosity as the base paste. The base and reactor pastes were poured into a two-cylinder cartridge at a 2∶1 volume ratio. A gun device was used to accomplish mixing by compressing materials into a mixing tip. The samples were divided into three groups: injectable alginate impression materials (IA group) as the experimental group, and Jeltrate alginate impression materials (JA group) and Silagum-putty/light addition silicone rubber impression materials (SI group) as the two control groups.

Results: Scanning electron microscopy (SEM) showed that the injectable alginate impression materials had a denser structure and fewer bubbles than the commercial alginate impression material. The accuracy of the three kinds of impression materials was evaluated by 3D image superposition. The deviations between the three test group models and the standard model (trueness) were 49.58 μm±1.453 μm (IA group), 54.75 μm±7.264 μm (JA group), and 30.92 μm±1.013 μm (SI group). The deviations of the models within each test group (precision) were 85.79 μm±8.191 μm (IA group), 97.65 μm±11.060 μm (JA group), and 56.51 μm±4.995 μm (SI group). Significant differences in trueness and precision were found among the three kinds of impression materials (P<0.05).

Conclusions: The accuracy of the new injectable alginate impression material was better than that of the traditional powder-type alginate impression material but worse than that of the addition silicone rubber impression materials. The novel injec-table alginate impression material demonstrated good operation performance and impression accuracy, showing broad application prospect.

Objectives: This study aimed to explore the specific mechanism, mediated by the reactive oxygen species (ROS) and PINK1/Parkin pathway, of the mitochondrial autophagy of human periodontal ligament cells (hPDLCs) under starvation conditions.

Methods: hPDLCs were isolated and cultured from normal periodontal tissues. Earle's balanced salt solution (EBSS) was used to simulated a starvation environment and thus stimulate hPDLCs mitochondrial autophagy. N-Acetyl-L-cysteine (NAC) was used to inhibit ROS production to explore the role of ROS in hPDLC mitochondrial autophagy. Cyclosporin A was used to inhibit the PINK1/Parkin pathway to study the role of ROS and the PINK1/Parkin pathway in hPDLCs activation under starvation. The mitochondrial membrane potential was detected by flow cytometry with a JC-1 mitochondrial membrane potential detection kit. The morphological structure of mitochondria and the formation of mitochondrial autophagosome were observed by transmission electron microscopy. Mito tracker red cmxros and lyso tracker green staining were used to observe the localization of mitochondria and lysosomes. The formation intensity of ROS was detected with a DCFH-DA ROS fluorescent probe. The expression levels of mitochondrial autophagy genes (Tomm20 and Timm23) and the PINK1/Parkin pathway were detected by real-time quantitative polymerase chain reaction (RT-qPCR). The expression levels of mitochondrial autophagy proteins (Tomm20 and Timm23) and PINK1/Parkin protein were detected by Western blot.

Results: EBSS starvation for 30 min induced the strongest activation of hPDLCs mitochondrial autophagy, increased the expression of ROS, downregulated the expression of mitochondrial autophagy-related genes (Tomm20 and Timm23) (P<0.001), and upregulated the PINK1/Parkin pathway (P<0.001). After NACinhibited ROS production, mitochondrial autophagy was also inhibited. Meanwhile, the expression of Tomm20 and Timm23 was upregulated (P<0.001 and P<0.05), and the expression of the PINK1/parkin pathway (P<0.001 and P<0.05) was down regulated. When cyclosporin A inhibited the expression of the PINK1/Parkin pathway (P<0.05 and P<0.05), it reversed the mitochondrial autophagy of hPDLCs (P<0.001 and P<0.01) and also upregulated the expression of Tomm20 and Timm23 (P<0.001 and P<0.01).

Conclusions: ROS enhanced the mitochondrial autophagy of hPDLCs primarily through the PINK1/Parkin pathway under starvation conditions.