Thromboembolic diseases, which comprise venous thromboembolic diseases and arterial thromboembolic diseases, have become the number one cause of death worldwide. To prevent or treat thrombosis, patients with thromboembolic diseases need to take antithrombotic drugs, which would increase the risk of bleeding during and after surgery. Tooth extraction is the most common operation in oral and maxillofacial surgery clinics. Although patients given oral antithrombotic drugs do not need to undergo drug withdrawal, the perioperative management of such patients remains confusing to most clinicians. Moreover, the potential risk factors for bleeding warrant further study. To improve the clinicians’ knowledge of perioperative management for patients subjected to tooth extractions with oral antithrombotic drugs, experts have drafted this consensus focusing on preoperative bleeding risk assessment, intraoperative operating norms, and postoperative care to summarize the points needing attention.

The mixed dentition stage is the period between primary and permanent dentition. The following biological processes are complicated and variable: jaw growth, development of inherited permanent teeth embryo, physiological absorption of primary teeth, restoration of surrounding alveolar bones, and growth and function establishment of soft tissues. For the normal development of the jaw, the establishment of the good occlusion relationship, development, and function of soft tissue is very important, whether or not the primary teeth are normally replaced by the permanent teeth in the mixed dentition stage. The eruption space is linked to the normal replacement of primary and permanent teeth. The presence of a mixed dentition space results in the incidence and progression of malocclusion and impacts the normal growth and development of the occlusion, jaw, and face. Space management in the mixed dentition stage is a crucial means to prevent and reduce malocclusion. The following were discussed and analyzed: the possible space problems, why the size of the space was affected, the content that needs to be assessed, and the methods of space management in the mixed dentition that can be used to unify and standardize the management of mixed dentition. This paper was developed to serve as a guide for regulated space management during the mixed dentition period.

The quality of vessel anastomosis is a key element for the success of free flap reconstruction. When adopting free flaps for oral and maxillofacial defect reconstruction, skills in selecting vessels, determining the clinical manifestations of the recipient vessel, and anastomosis technique are needed. Key points on postoperative flap observation were also required. We are experienced on this subject given that we have accomplished more than 1 000 free flaps for patients with oral and maxillofacial defects in the last 5 years. In this article, we summarize the skills and key points in free flap reconstruction of oral and maxillofacial defects, including vessel anastomosis skills, vessel selection, and vessel crisis diagnosis.

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.

Oral mucosal administration is extensively used to treat systemic diseases and oral mucosal diseases owing to unique oral mucosal structure and convenient administration. However, the special microenvironment of the oral cavity being open, moving, and humid causes oral mucosal drug delivery to face great challenges. To address this dilemma, local adhesive agents have been widely studied for sustained drug delivery and improved bioavailability, showing broad prospects. Recently, the author has performed studies on oral mucosal adhesive agents. In this paper, the progress of research on oral mucosal adhesive materials is reviewed.

Early childhood caries (ECC) is the most prevalent chronic oral disease and one of the worldwide public health problems of great urgency for children. ECC can affect children's teeth, dentition, craniomaxillofacial, and general health and development. Therefore, through dental caries etiologies and caries risk assessment, patient-centered, personalized planning and a combination of prevention and treatment should be implemented in the clinical management for ECC. Periodic and continuous cycle management can only be accomplished with the cooperation of medical staff, children, and their guardians. This expert consensus will expound the clinical management of ECC in the following aspects: caries risk assessment, early clinical prevention, treatment strategies, and postoperative management.

Although the current technical systems of orthodontic tooth movement are practically mature, a noticeable gap still exists between the overall treatment results and the expectations. According to literature review, orthodontic tooth movement involves three core scientific issues, i.e., position objective, efficiency, and accuracy. Research concerning these three issues is the key to further improve orthodontic treatment outcomes and promote progress of the subject orthodontics.

Obtaining optimal enamel bonding is a common recommendation to ensure the retention, edge closure, and clinical service life of porcelain veneers. Bonding surface is determined after tooth preparation. More or less dentin exposure often occurs due to the uneven thickness of the enamel. Identifying the enamel or dentin on the bonding surface and adopting the “selective etching” technique are useful to obtain the maximal bonding strength. Naked eye recognition in “selective etching” has uncertain results and is experience-based, whereas the proposed technique controls the preparation depth through the first target restoration space template to obtain the accurate enamel and dentin subarea. It is mapped to the second bonding template, depending on the treatment carried out on the enamel and dentin surface, to accurately predict the adhesion of porcelain veneers.

Sagittal split ramus osteotomy (SSRO) is a versatile orthognathic procedure for correcting mandibular deformities. Various complications can possibly occur when performing SSRO, and it can even cause serious adverse consequences because of the complexity of anatomy and operative procedures. The types of complications and their accompanying clinical manifestations are closely related to the choice of diagnosis and treatment strategies and clinical outcomes. To discuss the causes, prevention, and treatment measures of various common complications of SSRO, domestic orthognathic surgery experts prepared this consensus to increase the awareness of SSRO complications, thereby ensuring safe surgical procedure and good results.

Objective This study aimed to evaluate the efficacy of three methods in root canal retreatment to remove the filling material in the root canals. Methods Ninety tooth roots filled by gutta percha or plasticized material (n=45, each) were randomly divided into three groups (n=15). WaveOne (WaveOne group), 1^#P drill+WaveOne (1^#P+WaveOne group), and ultrasound P5 working end ET25+ProTaper Universal (P5+ProTaper Universal group) were used to remove the root canal filling material and prepare for root canal. The operating time of each canal was recorded and the percentage of residual filling material area was measured on the root canal wall of the mesial and distal dissected root section. The degree of deviation of the root canal after operation was measured for the root samples filled by gutta percha. Results The type of root filling material and the method of root canal retreatment had no significant effect on the percentage of residual area of the filling material (P>0.05). However, the remaining filling material area of apical 1/3 of the root canal was significantly higher than that of cervical 1/3 of the root canal (P<0.05). The average operating times for removing gutta-percha or plasticized material in the W and 1^#P+WaveOne groups were significantly less than that in the P5+ProTaper Universal group (P=0.000). The root canal retreatment methods had no significant effect on the curvature of the root canal (P=0.650). Conclusion WaveOne single file's cleaning ability and center positioning ability were similar to those of ProTaper Universal. Moreover, WaveOne can be independently used for most root canals without a pathway when removing the root canal fillings, thereby simplifying the process of root canal retreatment.

Abutment is an important component serving as a connecting link between the implant and the implant-supported prosthesis. In accordance with mechanical, biological, and other conventional norms, it can compensate the deviation between the implant and the prosthesis, which plays a significant role in maintaining the health of peri-implant tissue and the longevity, stability, and effectivity of prosthesis. However, choosing an anterior implant abutment correctly and conveniently is challenging, given the great variety of anterior abutment in clinical practice. Through virtual implant design, the correct implant site was compared and selected, and the supra-target prosthesis was coordinated before and after the operation. The implant level vertical of height of target restoration space (I) was measured to predict the availability and the retentive method of the implant restoration. After implantation, the primary selection of abutment type was selected according to the implant system (S), screw access position, and retentive method of the prosthesis. The final selection of abutment is accomplished by combining the measured values of peri-implant soft tissue thickness (T), gingival height (GH), and long axis of implant (L). Furthermore, the concepts and the classified applications of custom abutment were discussed in detail in this paper. The plan's main control variables L, I, GH, T, and S compose the words Lights, so this plan can be abbreviated as the anterior abutment decision tree. The decision tree has good decision-making efficiency and high clinical accessibility.

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.

Objective In this study, TeeTester digital occlusal analysis system was used to analyse the occlusal characteristics of chewing side preference (CSP) and non-CSP patients with TMD symptoms. Methods According to the questionnaire and oral examination, 80 subjects were screened and divided into four groups: 20 CSP patients with TMD symptoms, 20 CSP patients without TMD symptoms, 20 non-CSP patients with TMD symptoms, 20 non-CSP patients without TMD symptoms. TeeTester digital occlusal system was applied to measure the occlusal characteristics in all four groups, including total contect area (TCA), total occlution force (TOF), distribution of occlusal force (DOF), asymmetric index of occlusal force (AOF), occlusal time (OT), disclusion time (DT) and center of occlusal force(COF). SPSS 25.0 was used to analyze the statistical data. Results At intercuspal position, the data reveals significant differences in the maximum TOF and TCA among the four groups (P<0.05). There was significant difference in the distribution of occlusal force between the preferred side and the other side of CSP patients with or without TMD symptoms (P<0.05). Among the four groups, there were statistically significant difference in the position of the center point of occlusal force, the direction of the center point of occlusal force, and the vertical distance between the center point of occlusal force and the center line (P<0.05). The COF, maximum TOF and TCA of the preferred side of dentition were significantly positive correla⁃ted with CSP (P<0.05), according to Spearman correlation analysis. However, the maximum TOF and TCA of the both side of dentition were significantly negative correlated with TMD symptoms (P<0.05). Conclusion 1) The occlusal characteristics of CSP patients and non-CSP patients with TMD symptoms are different. TeeTester digital occlusal analysis system provides objective parameters for the dynamic evaluation of occlusion. 2) Among all the occlusal cha⁃racteristics, maximum TOF, TCA and COF of the preferred side of dentition were positively correlated with CSP. The abnormal occlusal characteristics (maximum TOF and TCA of the whole dentition) caused by CSP are related to TMD symptoms.

Objective This work aimed to study the effects of loupes and microscopes on a dental technician’s working posture during practical operation from ergonomic aspects. The technician's working postures under the conditions of the naked eye, loupes, and microscopes were compared. The practical value of loupes and microscopes was assessed based on the evaluation index of working posture from ergonomic aspects. Methods Three dental technicians who were skilled in using loupes and microscopes from West China Stomatology Technology Department of Sichuan University were involved in this prospective rando-mized controlled trial. Before the operation, cameras were installed in the sagittal position, top-view position, and dorsal position of the operation. Each technician made five porcelain veneers of the right maxillary central incisor following the standard process. A chairside computer-aided design and computer-aided manufacturing (CAD/CAM) system was used to mill and layer the ceramic block under the naked eye (A: control group), 3.5× headwear loupes (B: loupe group), and 9× desktop microscopes (C: microscope group). The working posture was recorded by videos throughout the entire process. After each operation, the investigator used OpenPose to recognize the working posture. The joint angles of the arm, elbow, wrist, neck, and trunk, as well as their corresponding rapid upper limb assessment (RULA) scores, were calcula-ted by MATLAB. The working posture was assessed from ergonomic aspects based on the joint angles, RULA scores, and operation time. Statistical analysis was performed using SPSS 26.0. Results The RULA score of upper limb joint angles showed that the angles of the arm, elbow, wrist, neck, and trunk under the naked eye were 14.93°±9.44°, 120.19°±2.99°, 23.97°±2.84°, 47.27°±5.72°, and 7.76°±2.30°, respectively. All of the joint angles were significantly different among the three groups (P<0.05). Compared with the control group, the angles of the neck and trunk in the loupe group were reduced by 29.09% and 42.53%, respectively, whereas those in the microscope group were significantly reduced by 43.99% and 87.11%, respectively. Multiple comparisons by LSD for the angles of neck and trunk revealed that the loupe group and the microscope group were significantly different from the control group (P<0.05), and they were also significantly different from each other (P<0.05). The mean RULA scores were 6.24±0.34 in the control group, 5.53±0.35 in the loupe group, and 3.31±0.19 in the microscope group. Compared with the control group, the mean RULA score in the loupe group was lower, and that in the microscope group was significantly lower. The differences between every two groups were statistically significant (P<0.05). The mean RULA score in the microscope group was significantly lower than that in the loupe group (P<0.05). The average operation times of the control group, loupe group, and microscope group were (50.69±36.78), (52.01±34.65), and (59.44±35.81) min, respectively. No significant difference was found among the three groups (P>0.05). Conclusion Use of loupes and microscopes showed an improvement in ergonomics and working posture of dental technicians. Microscopes had a better effect in the ergonomic convenience of the technician than loupes.

Objective This study aimed to summarize the clinical outcomes of surgical treatment for severe medication-related osteonecrosis of the jaw (MRONJ, stages 2 and 3). Methods A retrospective cohort study was conducted to review the patients with severe MRONJ from July 2013 to May 2021. All patients were treated surgically. The characteristics and clinical variables were recorded and analyzed. Results A total of 104 patients (123 MRONJ lesions) were included, including 42 males and 62 females, aged 64.6±9.1 years. The primary disease was malignant in 91 cases and benign in 13 cases. Forty-three cases (35.0%) were stage 2 lesions, and 80 (65.0%) were stage 3 lesions. Thirty-nine (31.7%) lesions were located in the maxilla, and 84 (68.3%) lesions were located in the mandible. The most commonly used bisphosphonates were zoledronic acid (n=89; 85.6%), followed by alendronate (n=10; 9.6%), and pamidronate (n=10; 9.6%). Antiangiogenic agents were administered in 62 (59.6%) patients. The mean duration of bisphosphonate therapy was 34.7±25.8 months, and the mean duration of drug holiday was 10.1±10.7 months. All operations were performed under general anesthesia. For stage 2 lesions, debridement and saucerization were performed to completely resect the lesions, and the wounds were closed without tension through local mucoperiosteum flaps. For stage 3 lesions, after the lesions were completely resected, the bone defect was covered by reconstruction plate fixation and ipsilateral submandibular gland translocation, iodoform gauze, and buccal fat pad accordingly. The follow-up period ranged from 3 months to 6 years; 81.3% (100/123) of the lesions reached mucosal healing at the last follow-up, whereas wound infection and dehiscence occurred in 18.7% (23/123) of the lesions postoperatively. Conclusion Severe MRONJ lesions could be surgically treated to achieve mucosal healing. Vascularized flap reconstruction could be considered if the patient’s general condition could tolerate it.

Quantitative grinding of abutment teeth is needed in crown and bridge restoration. Accurate quantitative preparation of teeth is one of the goals of minimally invasive restoration. In this paper, a case of congenital loss of upper and lower incisors was reported. Guided by the target restoration space (TRS), a personalized digital guide plate for tooth preparation was built to assist precise tooth preparation after the multidisciplinary combination therapy of orthodontic and periodontal teeth. Finally, the fixed bridge was prepared to meet the integrity, beauty, and function of the maxillary for the patient. In this case, the results suggest that the digital guide plate built under the guidance of TRS can be used to improve the accuracy of dental preparation.

Objective This study aimed to investigate the clinical application effect of double eyelid incision in the internal fixation of suturae zygomatico-frontalis fracture. Methods A total of 12 patients with zygomatic complex fracture and evident fracture segment displacement, accompanied by facial collapse or mouth opening limitation and other functional disorders, were selected for open reduction and internal fixation. The suturae zygomatico-frontalis fracture was fixed using a double eyelid approach. Postoperative evaluation was performed on fracture reduction and fixation to evaluate the improvement of function and deformity, postoperative scar, and other conditions. Results All fractures had convenient reduction and fixation, and all patients had satisfactory facial appearance, evident functional improvement, and hidden postoperative scar. Conclusion As a surgical approach to reduce and internally fix zygomatic complex fracture, double eyelid incision can reduce not only the fracture, but also the trauma, thereby indicating its certain clinical value.

Objective This study aimed to present a method for multi-modal medical data fusion that could be used for increased vertical dimension of occlusion (VDO) and occlusal rehabilitation in a digital manner, thus facilitating the process of clinical diagnosis and restoration. Methods With the aid of a computer software, a visual and operable four-dimensional virtual dental patient was created by data fusion of intraoral scan, extra-oral face scan, cone-beam computed tomography, and dynamic occlusal movement trace to conduct a systematical review of the occlusion and temporomandibular joint of the virtual patient. This approach could be used for increased VDO on the basis of the aesthetics of anterior teeth and the restoration space of posterior teeth. It allowed jaw reconstruction and occlusal rehabilitation with fixed prosthesis by using computer-aided design and manufacturing (CAD/CAM) devices. Results A visual and operable four-dimensional virtual dental patient was created by integrating the method for multimodal medical data fusion with CAD/CAM devices, thus making the process of occlusal rehabilitation with fixed prosthesis safer and more convenient than before. Conclusion With the method for multimodal medical data fusion, the presented application enables the fusion of different data sources of the patient at the same time and space by creating a virtual patient. It is useful for showing the function and anatomical structure of the patient’s oral and maxillofacial system in a visual and convenient manner, thus providing a powerful tool in the process of clinical diagnosis and restoration.

Objective This study aimed to investigate the feasibility of gelatin methacryloyl (GelMA) hydrogel loa-ded with minocycline-chitosan-nanoparticles (MCN) for the treatment of periodontitis in vitro and vivo. Methods MCN were synthesized by ionic gel method. GelMA/MCN composite hydrogels were prepared by compounding MCN with GelMA hydrogel. The materials were characterized by transmission electron microscope, scanning electron microscopy, and Fourier transform infrared spectroscopy. The degradation behavior and drug release rates of hydrogels were evaluated. The antibacterial activity of GelMA/MCN hydrogel against Porphyromonas gingivalis was detected, and the minimum antibacterial concentration was determined. Biocompatibility and osteogenic experiments were conducted under a simulated periodontitis environment. A rat model of periodontitis was constructed to observe the therapeutic effects of GelMA/MCN hydrogel. Results MCN was successfully synthesized with a particle size of about 80 nm, while the structures of GelMA/MCN had no significant differences from GelMA. MCN and GelMA/MCN released minocycline slowly and steadily. Bacterial growth was completely inhibited when the MCN concentration was higher than or equal to 0.2 mg·mL^-1. GelMA/MCN hydrogels exhibited good biocompatibility at effective antimicrobial concentrations under the simulated periodontitis environment with the enzyme. The in vivo results showed that GelMA/MCN prevented the progression of periodontitis and promoted the repair of bone defects. Conclusion GelMA/MCN composite hydrogel can release minocycline slowly and steadily and has good antibacterial activity and biocompatibility to promote the repair of periodontitis bone defects.

Objective This study aimed to compare the capabilities of sonic, ultrasonic, and laser-activated irrigation for debris removal in the root canal isthmus. Methods A total of 32 human maxillary first premolars with root canal isthmus were prepared by Reciproc Blue, and were randomly divided into four groups (n=8, each group). The groups were subsequently subjected to different regimens as follows: the conventional syringe group (control group) was irrigated by No.27 side opening syringe, the sonic group with EDDY connected pneumatic motor, the ultrasonic group with IRRI Safe connected to a ultrasonic P5 handle, and the laser group with Er:YAG laser device connected to a 9 mm fiber tip for 20 s in each root canal. The first and last four samples in each group were irrigated for 80 and 120 s, respectively. All samples were fixed, decalcified, embedded, sectioned, and stained with hematoxylin-eosin. Image J software was used for measurement analysis of the isthmus and canal debridement efficacy, and SPSS 25.0 was utilized for statistical analysis of all data. Results The isthmus debridement efficacy of conventional syringe irrigation, sonic, ultrasonic, and laser groups after 80 s irrigation were 30.91%±3.14%, 52.22%±0.31%, 83.77%±5.64%, and 77.97%±7.97%, respectively. The isthmus debridement efficacy of the three experimental groups were better than the conventional syringe irrigation group (P<0.05). The isthmus debridement efficacies of ultrasonic and laser groups after 80 s were better than that of the sonic group (P<0.01, P<0.05). However, no significant difference was observed between the ultrasonic and laser groups. The isthmus debridement efficacy of conventional syringe irrigation, sonic, ultrasonic, and laser groups after 120 s were 75.72%±2.38%, 85.66%±4.42%, 88.07%±4.09%, and 89.12%±3.63%, respectively. The isthmus debridement efficacies of the three experimental groups were better than that of the conventional syringe irrigation group (P<0.05), but no significant difference was observed among the groups (P>0.05). The root canal debridement efficacy among the four groups also exhibited no significant difference (P>0.05). The debridement efficacies of the root canal and isthmus after 120 s irrigation were better than those after 80 s irrigation (P<0.01, P<0.001). Conclusion Ultrasonic, sonic, and laser-activated irrigation have better results in removing debris from the isthmus than conventional syringe irrigation. The isthmus debridement efficacy of sonic- and laser-activated irrigation are slightly better than that of ultrasonic activated irrigation. The debridement efficacies of 120 s irrigation are better than those of 80 s irrigaion.

Objective To study and analyze the clinical patterns of lower-level lymph node (Ⅳ and Ⅴ) metastasis in primary tongue squamous cell carcinoma, and establish a reference for the decision-making of the lower-level neck dissection in tongue squamous cell carcinoma. Methods A total of 203 patients with primary tongue squamous cell carcinoma were recruited. These patients underwent simultaneous/secondary comprehensive neck (level Ⅰ-Ⅴ) dissection in Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine from January 2010 to December 2015. Their clinicopathological and follow-up data were obtained and analyzed to reveal the prognosis and risk factors of primary tongue squamous cell carcinoma with lower-level lymph node metastasis. Results Among the 203 patients, the metastasis rates of levels Ⅳ and Ⅴ are 14.78% and 4.93%, respectively. Level Ⅳ metastasis is more prevalent in males than females (P=0.04); non-smokers are more likely to have level Ⅴ metastasis than smokers (P=0.046). Lymph node status in levels Ⅲ and Ⅳ are significantly associated with the risk of metastasis in level Ⅴ (P=0.001). Patients with extracapsular invasion in level Ⅲ have a significantly increased risk of metastasis in levels Ⅳ (P=0.014) and Ⅴ (P=0.026). The 5-year survival rate of patients with lower lymph node (Ⅳ/Ⅴ) metastasis is only 14.70%, which is an independent poor prognostic factor for patients with primary tongue squamous cell carcinoma (P<0.000 1). Conclusion Most primary tongue squamous cell carcinoma metastases occur in levels Ⅰ-Ⅲ. However, the rate of lower-level lymph node metastasis is rather low. For the cN0 and cN+ patients with levels Ⅰ-Ⅱ lymph node metastases without extracapsular invasion, the strategy for level Ⅴ management may be observation rather than dissection.

Objective 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). Conclusion 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.

Objective This study aimed to systematically evaluate the safety and clinical efficacy of 4 mm-extra-short implant (ESI) placement in severely atrophic posterior areas. Methods Databases of PubMed, Embase, Cochrane Library, Web of Science, CNKI, and Wanfang from January 1, 2010, until August 31, 2022, were searched to identify randomized controlled trials or controlled clinical trials related to ESI and standard implants (SI). An additional hand search of the references of included articles was also conducted. Meta-analyses were carried out with RevMan 5.4 software. Results A total of 11 studies were included, involving six randomized controlled trials and five controlled clinical trials. The meta-analyses indicated that when implants were placed in the posterior area, the implant survival rate between ESI and SI did not significantly differ [RR=1.23, 95%CI (0.66, 2.27), P=0.52]. ESI resulted in significantly stable marginal bone level [MD=-0.16, 95%CI (-0.25,-0.07), P=0.000 7] and less biological complications [RR=0.34, 95%CI (0.19, 0.62), P=0.000 4] but more mechanical complications [RR=2.89, 95%CI (1.05, 7.92), P=0.04]. Conclusion Based on the limited evidence, ESI could achieve clinical outcomes similar to those of SI when the height of the posterior alveolar bone is less than 5 mm, with lower technical sensitivity and fewer postoperative clinical complications than SI. Due to insufficient evidence and limited sample size, further clinical trials are needed to verify the long-term efficacy of ESI.

Objective 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. Conclusion 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.

Salivary low-grade intraductal carcinoma (LGIDC) is a rare tumor that mainly occurs in the parotid. Thus far, LGIDC originating from the accessory parotid gland has been rarely reported in domestic and foreign literature. This study reports a case of LGIDC of the accessory parotid gland and a brief summary of its clinical features, diagnostic points, and treatment by reviewing the literature, with the aim of providing a reference for clinical practice and further research.

Objective To analyze the association between sagittal temporomandibular joint (TMJ) disc position of patients with anterior disc displacement evaluated by magnetic resonance imaging (MRI) and bone morphology of the TMJ evaluated by cone-beam computed tomography (CBCT). Methods One hundred and seventy-eight TMJs of 97 patients were retrospectively analyzed. The TMJ disc position was evaluated using MRI and classified into four types: control group (without disc displacement), slight group (disc slightly anteriorly displaced), moderate group (disc moderately anteriorly displaced), and severe group (disc severely anteriorly displaced). The measurements of TMJ bone morphology among four groups were evaluated by CBCT through Mimics software including condyle linear dimensions (condyle length, width, and height), condylar volume and surface area, and the depth and length of the glenoid fossa, joint anterior space, joint superior space, and joint posterior space. The sagittal plane position of the condyle was also assessed. The differences in all the morphologic measurement parameters among the four groups were detected using the one-way analysis of variance or the Kruskal Wallis test, and Chi-square tests. The correlations between disc sagittal position and all the morphologic measurements were also analyzed. Results There were significant differences in measurements of condyle linear dimensions, condylar volume and surface area, depth of the glenoid fossa, joint spaces, and distribution of the condyle sagittal positions among the four groups. By contrast, there were no statistical differences in terms of the length of the glenoid fossa among the four groups. Correlation analysis revealed that there is a statistically significant negative correlation among condyle linear dimensions, condylar volume and surface area, the depth of the glenoid fossa, joint superior space, and disc position. However, joint posterior space was positively correlated with disc position. Conclusion A statistically significant correlation was determined between TMJ bone morphology and different sagittal disc positions. Degenerative changes in TMJ bone morphology clinically diagnosed should be altered, which can be the patients' marker of anterior disc displacement.

Objective This study aims to evaluate the color stability and related properties including water sorption and solubility of ten light-cured composite resins in different solutions. Methods A total of 10 composite resins were BeautifilⅡ(B2) and Ceram. X One Universal (CXU), Charisma (CS), Charisma Diamond (CD), Denfil (DF), DX. Universal (DXU), Filtek Z250 (Z250), Filtek Z350 XT (Z350), FS-1 (FS), and Magnafill Putty (MP). Meanwhile, a total of 20 disk-shaped samples were fabricated and randomly divided into four groups (n=5), which were immersed in distilled water (control group), curry, coffee, and red wine for 28 days. The color (CIE L∗a∗b∗) was measured by a spectrophotometer at baseline and 1, 7, 14, 21, and 28 days after immersion, and the color differences were calculated. Water sorption and solubility values were measured ba-sed on ISO 4049: 2019. In addition, three-way ANOVA was used to evaluate the influence of resin materials, solutions, and immersion time on discoloration results, meanwhile, one-way ANOVA was used to compare the water sorption values and solubility values of different materials. Results All samples showed a certain degree of color change with time. Color differences were significantly influenced by materials, solutions, and immersion time (P<0.001). The color changes of the measured materials at any time point: curry>red wine>coffee>distilled water. Thus, all materials showed clinically unacceptable discoloration (ΔE>3.3) after immersing in staining curry, coffee, and red wine for 7 days. Therefore, when immersed in curry for 28 days, CS and DXU had the smallest and the largest color difference. In addition, when immersed in coffee for 28 days, FS showed the smallest color change and DXU showed the largest. Moreover, when immersed in red wine for 28 days, FS showed the smallest color change and Z350 showed the largest. Furthermore, MP and CXU had small color differences in all solutions. Meanwhile, Z350 had the highest water sorption and MP had the lowest. The solubility values of CS and CD were significantly higher than those of other materials. Conclusion The color stability of light-cured composite resin is materials-depended and affected by pigment types and immersion time. Thus, MP and CXU have better color stability. MP has low water sorption.

Objective To evaluate the size and shape of sella turcica and cranial base in patients with different degrees of congenital absence of teeth. Methods The subjects comprised 322 patients from the Department of Orthodontics, West China Hospital of Stomatology, Sichuan University from 2020 to 2021. Based on the number of congenital absence of teeth, the patients were divided into three groups: control group (without loss of teeth, n=112), group Ⅰ (loss of 1-2 teeth, n=104), and group Ⅱ (loss of 3 or more teeth, n=106). Uceph cephalometric software was used to measure the linear and angular parameters of cranial base. The length, depth, and diameter of sella turcica were also calculated. The shape of sella turcica was described as normal or with aberrations. Analysis of variance, Kruskal-Wallis H test, chi-square test, and Fisher’s exact test were conducted with SPSS 21.0. Results No statistical differences were observed in the length, depth, and diameter of sella turcica and parameters related to the cranial base among the three groups (P>0.05). The incidence of sella turcica bridge among the three groups was statistically significant (P=0.013). The incidence was higher in the study group compared with the control group (P<0.05), and no significant difference was observed between groups Ⅰ and Ⅱ (P>0.05). Conclusion Although the linear size of sella turcica and parameters related to the cranial base was not statistically different between normal subjects and patients with congenital absence of teeth, the incidence of sella turcica bridge was higher in patients with congenital absence of teeth, suggesting the possibly abnormal anatomical morphology of sella turcica in this population.

Objective This study aimed to analyze the effect of core and veneer porcelain thickness and resin cement on the opalescence property (OP) of glass-ceramic veneers, which were used to restore discolored teeth. Methods IPS e.max CAD LT A3 ceramic specimens were fabricated by computer aided design and computer aided manufacturing (CAD/CAM). The thickness values of core porcelain groups were 0.25 and 0.50 mm, and those of the core/veneer porcelain groups were 0.25 mm core/0.25 mm dentin, 0.50 mm core/0.25 mm dentin, 0.50 mm core/0.50 mm dentin, and 0.50 mm core/0.25 mm dentin/0.25 mm incisal. To simulate the clinical bonding procedure of porcelain veneer, resin cement Variolink N Bleach XL was coated at the bottom of CAD/CAM porcelain veneer specimens to make composite specimens of CAD/CAM porcelain veneer and resin cement. The L*a*b* values of specimens in the reflection and transmission pattern were measured by a spectrophotometer. Then, the OP was calculated. Results The OP values of 0.25 and 0.50 mm core porcelain groups, and 0.25 mm core/0.25 mm dentin, 0.50 mm core/0.25 mm dentin, 0.50 mm core/0.50 mm dentin, and 0.50 mm core/0.25 mm dentin/0.25 mm incisal core/veneer porcelain groups were 6.10±0.50, 7.00±0.24, 6.40±0.24, 7.08±0.28, 7.16±0.21, and 7.86±0.11 respectively. With increasing thickness of core porcelain, the OP values increased significantly (P<0.05). When 0.25 mm-thick dentin porcelain was added, no significant difference was found in the OP values of specimens with the same core porcelain thickness (P>0.05). For the 0.50 mm core porcelain group, no significant difference was found between 0.25 and 0.50 mm-thick dentin porcelain groups (P>0.05), but the OP values increased significantly after increasing the 0.25 mm incisal porcelain (P<0.05). The OP values of 0.25 mm core/0.25 mm dentin, 0.50 mm core/0.25 mm dentin, 0.50 mm core/0.50 mm dentin, and 0.50 mm core/0.25 mm dentin/0.25 mm incisal CAD/CAM porcelain veneer-resin cement composite specimens were 6.29±0.31, 7.56±0.36, 7.67±0.30, and 8.65±0.53. The OP values increased with increasing thickness of the porcelain layer (P<0.05), but no statistically signi-ficant difference was found between the groups of 0.50 mm core/0.25 mm dentin and 0.50 mm core/0.50 mm dentin (P=0.733). The influence of porcelain layer thickness and resin cement on the OP value was statistically different (P<0.05), and no interaction was found between the total thickness and the presence of resin cement (P>0.05). Conclusion When using glass-ceramic veneers for discolored teeth, the following are recommended to improve the OP and obtain a natural and realistic effect: adopt the design of direct sintering incisal porcelain with core porcelain; appropriately increase the thickness of core porcelain; and select resin cement with opaque effect.

Objective The purpose of the study was to evaluate the effect of hydroxyapatite (HA)-based desensiti-zing agents and determine their influence on the bonding performance of mild universal adhesives. Methods Mid-coronal dentin samples were sectioned from human third molars and prepared for a dentin-sensitive model. According to desensitizing applications, they were randomly divided into four groups for the following treatments: no desensitizing treatment (control), Biorepair toothpaste (HA-based desensitizing toothpaste) treatment, Dontodent toothpaste (HA-based desensitizing toothpaste) treatment, and HA paste treatment. Dentin tubular occlusion and occluded area ratios were evaluated by scanning electron microscopy (SEM). Furthermore, All-Bond Universal, Single Bond Universal, and Clearfil Universal Bond were applied to the desensitized dentin in self-etch mode. The wettability and surface free energy (SFE) of desensitized dentin were evaluated by contact angle measurements. Bonded specimens were sectioned into beams and tested for micro-tensile bond strength to analyze the effect of desensitizing treatment on the bond strength to dentin of universal adhesives. Results SEM revealed that the dentin tubule was occluded by HA-based desensitizing agents, and the area ratios for the occluded dentin tubules were in the following order: HA group>Biorepair group>Dontodent group (P<0.05). Contact angle analysis demonstrated that HA-based desensitizing agents had no statistically significant influence on the wettability of the universal adhesives (P>0.05). The SFE of dentin significantly increased after treatment by HA-based desensitizing agents (P<0.05). The micro-tensile bond strength test showed that HA-based desensitizing toothpastes always decreased the μTBS values (P<0.05), whereas the HA paste group presented similar bond strength to the control group (P>0.05), irrespective of universal adhesive types. Conclusion HA-based desensitizing agents can occlude the exposed dentinal tubules on sensitive dentin. When mild and ultra-mild universal adhesives were used for subsequent resin restoration, the bond strength was reduced by HA-based desensitizing toothpastes, whereas the pure HA paste had no adverse effect on bond strength.

Objective This study aims to investigate the diagnostic application of an artificial intelligence (AI) computer-aided diagnostic system based on a convolutional neural network algorithm in detecting chronic apical periodontitis in cone beam computed tomography (CBCT) images. Methods CBCT raw data of 55 single root chronic apical pe-riodontitis taken in 2nd Dental Center of Peking University School and Hospital from 49 patients from January 2017 to December 2021 were collected, and the chronic apical periodontitis areas were identified by experienced clinicians ma-nually and segmented layer by layer in Materialise Mimics Medical Software. Deep learning of lesion characterization was conducted via AI 3D U-Net, and the network segmentation results were compared manually with the test sets in terms of intersection over union (IOU), Dice coefficient, and pixel accuracy (PA). Results In our deep learning algorithm, the IOU for all actual true lesions in test set samples was 92.18%, and the Dice coefficient and the PA index were 95.93% and 99.27%, respectively. Lesion segmentation and volume measurements performed by humans and AI systems showed excellent agreement. Conclusion AI systems based on deep learning methods can be applied for detecting chronic apical periodontitis on CBCT images in clinical applications.

Cleidocranial dysplasia is a rare autosomal dominant hereditary disease that mainly affects the skeletal and dental development and has an incidence rate of about 1∶1 000 000. In this study, a case of cranio-clavicular dysplasia was reported, and related literature was reviewed. RUNX2 6p21.1 NM_001024630.3 Exon4 c.534dupAp.(Val179fs) was identified to be a new frameshift mutation by gene analysis.

Objective Pathological bone resorption is common in chronic periodontitis. However, the effect of exosomes (Exo) secreted by periodontal ligament stem cells (PDLSCs) on bone resorption is unclear. This study explored the Exo of inflammatory PDLSCs, their protein components, and their effects on osteoclast differentiation. Methods PDLSCs were isolated from the periodontal ligament tissues of orthodontic patients and those with chronic periodontitis. The surface markers of PDLSCs were detected by flow cytometry. Exo were characterized by Western blot, transmission electron microscope (TEM), bicinchoninic acid assay (BCA), nanosight tracking analysis (NTA). The protein components of Exo were detected by protein profiling. The expression levels of differentially expressed proteins tumor necrosis factor-α (TNF-α), receptor activator of nuclear factor-κB ligand (RANKL), interleukin (IL)-1α, transforming growth factor β (TGF-β), and bone morphogenetic protein 2 (BMP-2) were verified by enzyme linked immunosorbent assay (ELISA). Then, 10, 100, and 1 000 μg·mL^-1 of Exo-CP or Exo-WT were added to RAW264.7 medium, and the expression levels of osteoclast-related indicators were detected by real time quantitative polymerase chain reaction (RT-qPCR), Western blot, and tartrate resistant acid phosphatase (TRAP) staining at 5 days. Experimental data were statistically analyzed using SPSS 24.0 software. Results The differentially expressed proteins enriched in Exo-CP were mainly related to the tumor necrosis factor (TNF) signaling, osteoclast differentiation, and nuclear transcription factor κB (NF-κB) signaling pathways. ELISA experiments confirmed Exo-CP had high expression of TNF-α, RANKL, and IL-1α and low expression of TGF-β1 and BMP-2 (P<0.05). Adding Exo-CP to RAW264.7 significantly increased the expression of mRNA and proteins related to osteoclast differentiation of cells. In a concentration-dependent manner, the effect of Exo-CP on osteoclast differentiation at concentrations of 100 and 1 000 μg·mL^-1 was significantly higher than that on the 10 μg·mL^-1 concentration group (P<0.05). Conclusion Pathological bone resorption of chronic periodontitis may be caused by the activation of Exo-CP to promote osteoclast differentiation. The main protein in Exo may be RANKL and TNF-α. This research provides a new perspective on pathological bone resorption in chronic periodontitis.

Objective To evaluate the effectiveness of an acellular dermal matrix or a connective tissue autograft in the treatment of multiple adjacent gingival recessions through Meta-analysis. Methods Randomized controlled trials were screened in four electronic databases in English according to the inclusion and exclusion criteria until April 20, 2022. The main outcome indicators were keratinized gingival tissue width, recession depth, probing depth, clinical attachment level, complete root coverage, and root coverage esthetic score. Results Seven randomized controlled trials were included. After 12 months, the connective tissue graft in the control group could increase the keratinized gingival tissue width [mean difference (MD)=-0.28 (-0.47, -0.08), P=0.006], reduce the gingival recession depth [MD=0.23 (0.12, 0.35), P<0.000 1], and improve the complete root coverage [risk ratio=0.80, 95% confidence interval (0.69, 0.93), P=0.003] compared with the acellular dermal matrix in the experimental group. No significant difference was found in probing depth, clinical attachment level, and root coverage esthetic score between groups. Conclusion Connective tissue grafts have advantages in increasing the keratinized gingival tissue width, reducing the gingival recession depth, and improving the complete root coverage in surgeries for treating multiple adjacent gingival recessions. Acellular dermal matrices also have some clinical value in terms of operation simplicity and similar effectiveness.