To investigate the impact of spatial positions of the transfer fork registration markers on the accuracy of generating a virtual dentofacial patient. An in vitro study was conducted using a mannequin head with a standard maxillary dentition model. Radiopaque gauge markers were fixed on the face and dentition of the mannequin head. CBCT was performed and the distance and angle between the dentition and facial markers were measured in the CBCT as reference values. Intraoral scanners were used to obtain 3D morphological data of the maxilla. Two types of transfer fork were designed and fabricated. The registration markers on transfer fork A were positioned in the midline area, while those on transfer fork B were located at the corners of the mouth on both sides. The transfer forks were digitised and connected to the maxillary dentition within the mannequin head, and facial scanning was performed using a facial scanner five times in each group. A virtual dentofacial patient was built through matching and integration of digital dentition, face and transfer fork data using 3D reverse engineering software (Geomagic Wrap 2021, 3D Systems, Rock Hill, SC, USA). Measurement values including feature lengths and feature angles between six facial gauge markers and three dentition gauge markers were obtained in the virtual patients. The mean trueness and precision of linear difference for virtual patients established using transfer fork A were -1.00 ± 0.11 mm and 0.27 ± 0.02 mm and the angle deviation was -1.88 ± 0.27 degrees, whereas for transfer fork B, the mean trueness and precision of linear difference were 2.66 ± 0.25 mm and 0.83 ± 0.06 mm, and the angle deviation was 3.74 ± 0.87 degrees. There is an overall significant difference in the trueness values of feature lengths (t = -13.963, P = 0.000) and angles (t = -5.985, P = 0.004) between transfer fork groups A and B, with group A showing better trueness and precision. Linear and angular errors will be introduced in the process of building up a virtual dentofacial patient using a transfer fork. The trueness and precision of the transfer fork with the matching markers at the centre of the lips are more precise than the transfer fork, with matching markers on both sides of the mouth.
To examine the increased use of chairside CAD/CAM among Chinese dental practitioners, and to explore the existing barriers influencing its further application and satisfaction levels. A semi-structured questionnaire was developed to gather respondents' demographic information, as well as their experiences and behaviours regarding the implementation of chairside CAD/CAM. A specialised web-based survey system and WeChat were used to display and distribute the final questionnaire. Then, the data were analysed with Chi-square tests and regression analyses to determine the effects of various demographic variables on chairside CAD/ CAM applications. A total of 1,969 questionnaire responses were included in the analyses. Chairside CAD/ CAM systems were used by 36.9% of participants, with a higher usage rate observed among prosthodontists (60.0%) and dental practitioners holding a PhD degree (57.7%). Chairside CAD/ CAM-fabricated prostheses were most commonly used in the posterior maxilla (83.3%) and mandible (86.0%), followed by the anterior maxilla and mandible (63.8% and 48.6%, respectively). Major barriers to further application included high initial investment, frequent updates of equipment and software programs, and a lack of expertise in chairside CAD/CAM usage. Most dental practitioners did not use chairside CAD/CAM systems. The application rate was significantly influenced by sex, location, educational background, department and type of healthcare facility. Chairside CAD/CAM users showed limited satisfaction with the aesthetic performance of the fabricated prostheses. To improve the popularity of chairside CAD/CAM systems, especially among dental practitioners lacking advanced academic degrees, it is highly advisable to optimise CAD software programs and offer comprehensive training opportunities.
To establish an animal model of oral squamous cell carcinoma invading the mandible through multi-sample experiments that verified the stability, repeatability, tumorigenicity and mandible destruction rate of the model. Oral squamous cell carcinoma cell suspension was injected into the outer side of the mandible through the anterior edge of the masseter muscle of naked mice to observe the tumourforming process. Then, the anatomical, histological and imaging examinations were carried out to determine whether the tumour had invaded the mandible. By comparing the tumour growth of multiple groups of various squamous cell carcinoma cells (CAL27, HN6 and HN30 cells), the changes in body weight and characteristics of tumour formation were compared, and the experience was summarised to further verify the stability, repeatability, tumour formation rate and arch damage rate of the model. The subsequent specimens of tumour-bearing nude mice were validated once the model had been established. In vitro, tumour tissue wrapped around the mandible's tumour-bearing side, and the local texture was tough with no resistance to acupuncture. Haematoxylin and eosin staining revealed that squamous cells were infiltrating the mandible in both the horizontal and sagittal planes. Microcomputed tomography results showed that the mandible on the tumour-bearing side displayed obvious erosion damage. Cell lines with various passage rates clearly had diverse tumour-bearing life cycles. This study successfully established an animal model of oral squamous cell carcinoma invasion of the mandible. The model has excellent biological stability, repeatability, tumorigenesis rate and mandible destruction rate.
To determine whether the targeting age should be adjusted for the National Children's Pit and Fissure Sealant (PFS) Programme. Statistical analysis was conducted on the results of oral health examination results of school-aged children in regions covered by the National Children's Oral Disease Comprehensive Intervention Programme (NCODCIP) in 2018. We analysed the eruption status and dental caries condition of the children's four first permanent molars (FPMs) and performed statistical tests for the data. Data analysis from 811,855 children aged 6 to 9 years showed that the complete eruption rate (CER) of the FPMs in Chinese children aged 6 years was 67.2%, and reached 94.1% by age 9. Before the implementation of the PFS Programme, the prevalence of dental caries in 6-year-olds was 11.0%, and 23.2% by age 9. Caries prevalence was higher in girls than boys. The growth rate of caries prevalence slowed with age. Our study indicated that the eruption time of FPMs in Chinese children has been earlier than predicted, and the caries prevalence was more severe than expected. Therefore, it is recommended that the targeting age for the National PFS Programme be lowered from 7 years old to 6 years old.
To establish precise positional references for orthognathic surgery by examining the relative positioning of the infraorbital foramen (IOF) in relation to the anterior nasal spine (ANS) and the mental foramen (MF) in relation to the pogonion (Pog). A cohort of 115 patients with CBCT images was randomly selected for analysis. Distances and positional relationships between the IOF and ANS, as well as the MF and Pog, were measured using 3D reconstruction images. On average, the ANS was situated 21.40 mm below the IOF, with a horizontal distance of 26.42 mm. The horizontal and vertical distances between the MF and Pog were 23.57 and 9.71 mm, respectively. Scatter plots centred on the ANS indicated that 83% (191/230) of the IOF were distributed in a 30- to 45-degree fan shape, the radius of which ranged from 30 to 40 mm. Similarly, 98% (226/230) of the MF occupied a 45-degree fan shape within a 20 to 30 mm radius in the bilateral superior quadrant centred on the Pog. During maxillary osteotomy, there is a potential risk of damaging the infraorbital neurovascular bundle located 21.40 mm above the ANS. To mitigate the risk of IOF injury, caution is advised, particularly when retracting the flap below a 30-degree fan shape within a 30 to 40 mm radius centred on the ANS and a 45-degree fan shape within a 20 to 30 mm radius centred on the Pog. Special attention is warranted during flap elevation in this specified area.
To analyze and summarize the clinical efficacy of mucoperiosteal flap combined with perforation technique for tooth extraction in medication-related osteonecrosis of the jaw risk (MRONJ) population, and to provide clinical treatment options for such patients. This study included 51 patients receiving antiresorptive drug (ARD) treatment who underwent tooth extraction at the Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology between November 2016 and February 2024. Preoperative clinical data were collected and analyzed. Based on their drug history, patients were categorized into two groups: (1) low-dose ARD group for patients with non-neoplastic lesion like osteoporosis (LDA), (2) high-dose ARD group for patients with bone metastatic lesions like breast cancer (HDA). All patients underwent tooth extraction using mucoperiosteal flap combined with perforation technique. Follow-up assessments were conducted at 1 week, 2 weeks, 1 month, 3 month and 6 months postoperatively. The primary evaluation outcome was whether the patient had developed MRONJ at the extraction site at 6 months. The secondary evaluation outcome was whether the extraction socket mucosa healed completely within 1 month. Statistical analysis included Chi-square, Fisher's exact, Mann-Whitney U/t tests and survival analysis to contrast between LDA and HDA group. Significance was set at p ≤ 0.05. A total of 82 extraction sites in 51 patients (31 females in LDA group with a mean age of 66.58 ± 13.29 years. 14 females and 6 males in HDA group with a mean age of 58.24 ± 11.63 years) were included in the study. Of these, 47 extraction sites in the LDA group, 35 extraction sites in the HDA group. During postoperative follow-up, MRONJ only occurred in 2 extraction sites in HDA group in two patients, resulting in a postoperative clinical healing rate of 100% (47/47) in LDA group and 94.3% (33/35) in HDA group. A significant difference in the time to extraction socket mucosal healing was observed between the LDA and HDA groups (p ≤ 0.05). This study demonstrated that in patients with potential risks of MRONJ, the application of mucoperiosteal flap combined with perforation technique based teeth extraction method could safely and effectively alleviate the dental inflammation in the oral cavity, and mitigates the risk of MRONJ development.
To explore and visualise how different degrees of labio-lingual inclination of the maxillary incisors affect the aesthetic assessment of smiling profiles in people with various chin positions. Different perceptions from professionals and non-professionals are outlined in this study. A profile photograph with a clear facial contour and a full smile was captured and then edited into a series of 49 smiling profile pictures, with seven variations in both chin position and maxillary incisor inclination. A MaxDiff survey was conducted to rank the photos according to the aesthetic preference of orthodontists and laypeople. The data were then evaluated using count analysis and hierarchical Bayes estimation. Upright and mild lingual inclination (0 to 5 degrees) of the maxillary incisors generally gained higher acceptance in both groups when chin protrusion was not taken into consideration, whereas the opposite was true for labial inclination. The acceptance of excessive lingual inclination (10 to 15 degrees) of the central incisor in laypeople was significantly higher than in orthodontists. Both groups suggested that as chin retrusion increases (6 mm), increasing maxillary incisor lingual inclination (10 degrees) is preferred. When chin retrusion was greater (6 mm), upright or mild lingual inclination (0 to 5 degrees) was considered acceptable by orthodontists, but greater lingual inclination (5 to 15 degrees) was also acceptable by laypeople. Both labio-lingual inclination of maxillary incisors and chin position play an essential role in the aesthetic assessment of smile profiles. The ideal value for maxillary incisor inclination varies with chin position.
To elucidate the genetic aetiology of basal cell nevus syndrome (BCNS) within a Chinese cohort featuring an affected family. The patient's and their parents' peripheral venous blood was collected for high-throughput exon sequencing. Tools such as Mutation Taster2 and SIFT were used to predict mutation harmfulness and obtain the most suspected pathogenic mutation. GeneMANIA was employed to construct the protein interaction network between the gene and Hedgehog pathway. SWISS-MODEL was used to simulate the bioinformatics structure changes of the mutant gene and HDOCK was utilised to simulate molecular docking. Finally, the function of this gene mutation was verified by q-PCR. A novel pathogenic mutation of PTCHD3 was identified. CCDC57 in the Hedgehog pathway was found to interact with PTCHD3 through GeneMANIA. SWISS-MODEL predicted that PTCHD3 mutation would lead to changes in the 3D structure of the protein. HDOCK showed that the binding between PTCHD3 and CCDC57 was significantly reduced. The mutation of PTCHD3 may result in decreased binding ability of PTCHD3 to CCDC57, activate the Hedgehog pathway and lead to the occurrence of the disease. The diagnosis and treatment pathway for clinical discovery of OKC was provided. A novel pathogenic mutation of PTCHD3 was identified in Chinese BCNS patients. PTCHD3 may play a role in various biological processes mediated by the Hedgehog signalling pathway and is expected to be a new potential therapeutic target.
To assess the canalis sinuosus (CS) in pathological lesions located in the anterior maxilla using CBCT. In total, 104 lesions in the anterior maxilla were assessed. The localisation of CS termination points on the alveolar crest was evaluated. Subsequently, the consistency of the CS and CS-lesion relationships were determined based on the maximal diameter of the lesion and the presence of a cortical perforation. Of the 104 lesions, 82 (78.8%) exhibited at least one CS. The presence of CS was statistically significantly different based on the diameter of the lesion (P 0.001). When the presence of CS was investigated in relation to cortical perforation status, a significant difference was observed (P 0.05). Anatomically, CS was most common in the central incisor and ended most frequently near the crest apex vertically and in the palatal region horizontally. Among the instances of CS, 55.3% were lesion-related, 22.3% were in contact and 23 (22.3%) were unrelated to the lesion. The incidence of CS was high in anterior maxillary pathological lesions and even higher in small-sized pathological lesions. Most CSs were located within or next to the surgical margin of the pathological lesion.
To evaluate the effects of a novel software developed to assist dental students in mak-ing tooth ground sections and gaining knowledge of dental hard tissues. Students were divided into three groups (class-use group, after-class-use group and control group) and taught how to make real sections or allowed to use the aforementioned software to make virtual tooth ground sections on the computer. The present authors then assessed the efficiency of making the first tooth ground sections, the quality of ground sections and performance skills. The sectioning time for the class-use group was less than that for the after-class-use group and control group (P = 0.027), and the quality of sections for the class-use group was higher (P = 0.036). In the objective test 1 week later, the after-class-use group performed better than the control group (P = 0.019). Users agreed that the software stimulated their interest and improved their learning results. This software is an efficient tool to help students to make tooth ground sections and study the histology of dental hard tissues in a simple and functional way.
To assess the clinical efficacy of 5-aminolaevulinic acid photodynamic therapy (5-ALA-PDT) in treating oral potentially malignant disorders (OPMDs) and investigate the utility of toluidine blue staining and autofluorescence examination for monitoring the efficacy of 5-ALA-PDT. A prospective cohort study was conducted, including 75 OPMDs patients who underwent 5-ALA-PDT and follow-up observation. The patients' lesion size and clinical presentation were recorded to evaluate the clinical efficacy of 5-ALA-PDT. Toluidine blue staining and autofluorescence examination were performed as auxiliary monitoring methods, aiming to assess their diagnostic capabilities as non-invasive examinations for detecting pathological oral epithelial dysplasia (OED) and explore their monitoring value for the clinical efficacy of 5-ALA-PDT. Toluidine blue staining showed a sensitivity of 62.2% and a specificity of 42.9% for diagnosing OED, whereas autofluorescence examination showed a sensitivity of 67.2% and a specificity of 64.3%. The parallel combination of both examinations increased the sensitivity to 77.0%, whereas the series combination increased the specificity to 71.4%. After 5-ALA-PDT, 38.7% of patients with OPMDs achieved complete remission, with an overall response rate of 92%. Persistent positive toluidine blue staining after 5-ALA-PDT treatment was significantly associated with treatment failure. The clinical efficacy of 5-ALA-PDT gradually decreased in patients with aggravation, stable or improved lesions from non-invasive examinations both before and after treatment. 5-ALA-PDT demonstrates significant efficacy in treating OPMDs by effectively eliminating lesions. Toluidine blue staining and autofluorescence examination have certain diagnostic capabilities for OED and can be used for monitoring efficacy during 5-ALA-PDT treatment.
To compare the marginal fit and mechanical performance of three-unit implant-supported fixed dental prostheses (ISFDPs) fabricated using fully digital and conventional workflows. Three-unit ISFDP specimens in this study simulated the restoration of three consecu-tively missing teeth in the mandibular posterior region. Twenty-four specimens were divided into three groups: the zirconia fully digital (ZFD) group received zirconia ISFDPs fabricated using a fully digital workflow; the polyetherketoneketone fully digital (PFD) group received polyetherketoneketone (PEKK) ISFDPs fabricated using a fully digital workflow; and the zir-conia control (ZC) group received zirconia ISFDPs fabricated using a conventional workflow. Marginal gaps between restorations and abutments during passive and active fit were meas-ured, and initial screw loosening torque values of restorations were recorded. After undergoing 1,200,000 cycles of vertical loading, the restorations were reassessed for marginal gaps and loosening torque values. Marginal fit under passive and active fit in the ZFD group showed no significant dif-ference in relation to the ZC group. Marginal gaps in the PFD group (134.39 ± 41.13 µm) under passive fit were significantly larger than in the ZFD group, and decreased significantly under active fit (22.28 ± 10.45 µm). No significant difference in marginal fit was observed before and after cyclic loading in all groups. No significant difference was found in loosening torque change between the ZFD and ZC groups, whereas the change in the PFD group (median -2.13%, Q25 -3.30%/Q75 0.28%) was significantly lower than in the ZC group (median -5.83%, Q25 -8.46%/Q75 -3.75%). Three-unit ISFDPs fabricated using fully digital and conventional workflows exhibit similar marginal fit and mechanical performance. Additionally, PEKK ISFDPs demonstrate clinically acceptable marginal fit and mechanical performance.
Cystic lesions in the jaws are frequently associated with impacted teeth, and include dentigerous cysts, odontogenic keratocysts, unicystic ameloblastoma and adenoid odontogenic tumours. The most common treatment modality is enucleation of cysts with removal of the impacted tooth. Marsupialisation is a more conservative treatment modality than enucleation and is considered the first-line treatment, especially in the initial management of benign cystic lesions during the mixed dentition period. Depending on the size of the lesion, the position of the impacted tooth and the available space, the majority of teeth can erupt spontaneously after marsupialisation. A multidisciplinary approach has been used in recent years for management of these lesions. Orthodontic traction is sometimes performed on the impacted tooth to guide tooth eruption postoperatively. When an impacted tooth or teeth within cystic lesions are preserved and functional occlusion is obtained, the patient's quality of life can improve significantly. Prospective clinical trials with a larger patient cohort are necessary to determine the clinical benefit of the conservative approach with marsupialisation or surgical-orthodontic treatment of impacted teeth in cystic lesions since only studies of small groups of patients or case reports have been published to date.
To investigate the prevalence and characteristics of taurodontism in patients with cleft lip and palate (CLP) and clarify the relationship between CLP and the frequency and severity of taurodontism. CBCT scans of 30 patients with bilateral CLP (BCLP), 70 with unilateral CLP (UCLP) and 70 healthy individuals were taken for investigation. In each group, the first and second molars were assessed for the presence of taurodontism. In taurodontic teeth, the severity of taurodontism was measured and classified based on the taurodontic index (TI). The frequency and severity of taurodontism were compared between the three groups. Taurodontism was significantly higher in patients with CLP (P < 0.001), and its prevalence was significantly higher in patients with BCLP than those with UCLP (P = 0.003) and the control group (P < 0.001). There was no difference among the three groups regarding the severity of taurodontism. Additionally, the frequency of taurodontism in the second molars was significantly higher than that in the first molars in the control group (P = 0.019). Based on this investigation, clinicians should be aware of the possible complications that may occur when performing dental procedures on patients with BCLP and UCLP due to the higher incidence of taurodontism in these patients.
To establish cephalometric normative reference values based on the subjective consensus of Chinese orthodontic experts regarding the evaluation of lateral cephalometric radiographs. This study included 120 patients in the permanent dentition stage who visited the Department of Orthodontics at Peking University School and Hospital of Stomatology between 2022 and 2025. The participants were divided into two groups: an adolescent group (n = 60, aged 14.40 ± 1.70 years, 30 boys and 30 girls) and an adult group (n = 60, aged 24.33 ± 5.65 years, 30 men and 30 women). Lateral cephalometric radiographs were analysed by two PhD students and one postdoctoral researcher from the Department of Orthodontics. Through statistical analysis, cephalometric normative values were established for Tweed, Downs, Steiner and Peking University analysis methods as well as for soft tissue measurements, and comparisons were made between the two age groups. A reference standard for cephalometric normative values was developed, reflecting the consensus of Chinese orthodontic experts in assessing profile harmony. Significant differences (P 0.05) were identified between the adolescent and adult groups in the normative values of FMA (MPA), GoGN/SN, SE and G-Sn-Pos. Expert consensus evaluation of lateral cephalometric radiographs provides a more objective basis for identifying harmonious samples. This enables the derivation of more accurate cephalometric normative values for sagittal skeletal measurements and soft tissue parameters.
To evaluate the precision and efficiency of dynamic navigation-assisted trephines and fissure drills at varying depths utilising a 3D printed model. A computer-designed in vitro standardised model was 3D printed using photosensitive resin, with hemispherical cavities reserved at depths of 5, 10 and 15 mm from the outer surface of the model. CBCT scans were taken before the procedure, and the data were imported into dynamic navigation software. Navigation paths were planned and executed using a trephine with a diameter of 4 mm and a fissure drill with a diameter of 1.2 mm guided by the dynamic navigation system. Ten procedures were performed at each depth. Postoperative CBCT scans were taken to reconstruct the navigated trajectories, and the platform deviations, end deviations and angular deviations were calculated by comparing the actual paths with the planned paths. The operating time was recorded. Under the guidance of the dynamic navigation system, the mean platform, end and angular deviations for trephines were 0.34 ± 0.17 mm, 0.25 ± 0.15 mm and 1.02 ± 0.49 degrees, respectively. For fissure drills, the mean deviations were 0.29 ± 0.13 mm, 0.31 ± 0.18 mm, and 1.33 ± 0.98 degrees, respectively. No significant differences were found with different depths or instrument types (P > 0.05). High-speed handpieces with fissure drills showed superior efficiency to low-speed handpieces with trephines (P < 0.001). Dynamic navigation technology achieved good accuracy within a 15-mm depth range. The use of a trephine or fissure drill did not affect the accuracy of the dynamic navigation technique. High-speed handpieces with fissure drills showed superior efficiency.
Denosumab is a humanized monoclonal antibody targeting receptor activator of nuclear factor-κB ligand (RANKL) and is commonly used in the treatment of osteoporosis and cancer-related bone metastases. However, the persistent use of denosumab has been associated with an increasing incidence of denosumab-related osteonecrosis of the jaw (DRONJ), particularly following tooth extraction. This expert consensus aims to develop clinical management guidelines for the perioperative period of tooth extraction in patients who are currently receiving or have previously received denosumab therapy. The consensus covers the definition, etiology, epidemiology, staging, and risk factors of DRONJ, focusing on preoperative assessment, risk-based prevention strategies, minimally invasive surgical techniques, and postoperative follow-up protocols. The core management strategy for DRONJ emphasizes individualized decision-making based on a comprehensive preoperative assessment of medication history, local infection, and systemic conditions. The main risk factors for DRONJ include high-dose and long-term denosumab therapy, preexisting oral infections, such as periodontitis and periapical periodontitis, and invasive dental procedures, including tooth extraction, diabetes, and concomitant use of glucocorticoids or antiangiogenic agents. Core preventive measures include strict perioperative oral care, risk assessment-based antibiotic prophylaxis, long-term drug holidays, which were developed by dentists and physicians prio-ritizing the primary disease, and minimally invasive surgical techniques for managing trauma, preserving local blood supply, thoroughly removing infected tissues, and ensuring tight wound closure. This consensus highlights the importance of multidisciplinary collaboration between dental and clinical medicine experts in managing DRONJ. High-quality research is necessary to provide an evidence-based foundation for optimizing DRONJ prevention and treatment strategies. 地舒单抗是一种靶向核因子κB受体活化因子配体（RANKL）的人源化单克隆抗体，常用于治疗骨质疏松症和癌症相关骨转移。然而，随着地舒单抗在临床患者中应用越来越多，地舒单抗相关颌骨坏死（DRONJ）的病例也随之增加，尤其是在拔牙后。本专家共识旨在为正在或曾接受地舒单抗治疗的患者，制定拔牙围手术期的临床管理指南。共识内容涉及DRONJ的定义、病因、流行病学、分期、风险因素，并重点阐述了术前评估、基于风险的预防策略、微创手术技术及术后随访方案。DRONJ的核心管理策略强调基于术前全面评估用药史、局部感染及全身状况的个体化决策，DRONJ主要风险因素包括大剂量长疗程的地舒单抗治疗、牙周炎或根尖周炎等既存口腔感染、拔牙等口腔侵入性操作、糖尿病以及合并使用糖皮质激素或抗血管生成药物等。核心预防措施包括严格的围手术期口腔护理、基于风险评估的抗生素预防、以优先保障原发病治疗为前提的由口腔医生与内科医生共同制定的长期药物假期以及控制创伤、保障局部血供、彻底清除感染灶并实现创口严密闭合的微创外科技术。该共识强调了口腔和临床医学专家在处理DRONJ时进行多学科合作的重要性。未来有必要开展更多高质量研究，为优化DRONJ的防治策略提供循证依据。.
To compare the prevalence and morphological characteristics of canalis sinuosus (CS) between unilateral cleft lip and palate (UCLP), bilateral cleft lip and palate (BCLP) and control groups. The sample consisted of 238 CBCT images (476 sides) from 98 UCLP subjects (196 sides), 36 BCLP subjects (72 sides) and 104 healthy controls (208 sides). Recorded parameters included prevalence of CS, diameter, location of the teeth and adjacent structures. Afterwards, the recorded parameters were compared between the UCLP, BCLP and control groups. The prevalence of CS in the control, UCLP and BCLP groups showed significant differences. The BCLP group revealed a significantly lower prevalence of CS than the UCLP and control groups. There was a considerable increase in CS diameter in the CLP groups compared with the control group. The terminal location of CS was in the canine region for the CLP groups and in the lateral incisor region for the control group. CLP had a significant impact on the location of the end of the CS. CEJB (cementoenamel junction buccal) and CEJL (cementoenamel junction lingual) measurements showed significant differences between the CLP cases and control groups. Different characteristics was revealed between the control, UCLP and BCLP groups. Assessment of CS in patients with CLP with CBCT images is crucial before performing surgical procedures.
To investigate the regulatory role of proenkephalin (PENK) on the osteogenic differentiation process of human bone marrow mesenchymal stem cells (hBMMSCs). PENK knockdown and overexpression in hBMMSCs were performed by using lentivirus containing the specific short hairpin RNA or whole coding region for PENK in vitro. The alkaline phosphatase level and mineralised nodule formation were observed by alkaline phosphatase (ALP) and Alizarin Red S (ARS) staining and quantification. Meanwhile, the expression levels of osteogenic-related mRNA and protein were detected by qRT-PCR and Western blot. Transfection of lentivirus in hBMMSCs was effectively confirmed by the green fluorescent protein-positive cells under fluorescence microscopy, and qRT-PCR and Western blot analyses verified the successful establishment of PENK knockdown and overexpression hBMMSCs. The results showed that knockdown of PENK effectively promoted the osteogenic differentiation of hBMMSCs, with enhanced ALP and ARS staining, and increased expression levels of osteogenic-related genes and proteins. Conversely, the overexpression of PENK inhibited the osteogenic differentiation of hBMMSCs. This finding identified PENK as a potential therapeutic target for bone regeneration of oral and maxillofacial bone defects.
To assess the impact of incorporating various weight fractions of nanometre-sized particulate fillers on specific properties of microfilled composite resin. Microfilled composite resin was prepared by mixing 29 wt.% of resin matrix (BisGMA/TEGDMA) with the 71 wt.% of silane treated particulate fillers (Ø 0.4 µm). Then, various fractions of nanometre-sized (180 nm) fillers (0, 5, 10, 15, 20, 25, 30 and 35 wt.%) were added gradually using a high-speed mixing machine. For each composite resin, flexural properties (n = 8) were evaluated using a three-point bending test on a universal testing machine (ISO standard 4049). Fourier transform infrared (FTIR)-spectrometry was used to calculate the degree of monomer conversion (DC%). Surface microhardess (Vickers) was also determined. Surface gloss was measured before and after polishing (4,000-grit paper). A two-body wear test was performed in a ball-on-flat configuration using a chewing simulator with 15,000 cycles. A non-contact 3D optical profilometer was utilised to measure wear depth. An analysis of variance (ANOVA) was applied to interpret the results statistically, then a post hoc Tukey analysis was performed. ANOVA revealed that the fraction of nanofillers had a significant effect (P 0.05) on flexural modulus, DC%, microhardness, gloss and wear depth. The group without nanofillers showed the highest DC% (56.6%), gloss after polishing (76.2 GU) and wear resistance (24.2 µm) values, whereas the group with 35 wt.% of nanofillers had the highest flexural modulus (9 GPa) and microhardness (70 VH). It is beneficial to add nanofillers to microfilled composite resin; however, it is essential to assess the proportion ratio carefully. Optimising all the properties of composite resin at once with just one formulation is challenging.