Porphyromonas gingivalis OMVs promoting endothelial dysfunction via the STING pathway in periodontitis.

OBJECTIVE: This study aimed to assess the effects of Porphyromonas gingivalis outer membrane vesicles (Pg-OMVs) in chronic periodontitis and explore the underlying mechanism involved. METHODS: In vitro, Pg-OMVs were incubated with Ea.hy926 (vessel endothelial cells, ECs) to evaluate their effects on endothelial functions and to investigate the underlying mechanism. The effects of endothelial dysfunction on MG63 osteoblast-like cells were verified using an indirect co-culture method. For in vivo studies, micro-CT was conducted to identify alveolar bone mass. Immunofluorescence staining was conducted to confirm the levels of stimulator of interferon genes (STING) in the blood vessel and the number of Runx2+ cells around the alveolar bone. RESULTS: Pg-OMVs were endocytosed by ECs, leading to endothelial dysfunction. The cGAS-STING-TBK1 pathway was activated in ECs, which subsequently inhibited MG63 migration and early osteogenesis differentiation. In vivo, Pg-OMVs promoted alveolar bone resorption, increased STING levels in the blood vessel, and decreased Runx2+ cells around the alveolar bone. CONCLUSIONS: Pg-OMVs caused endothelial dysfunction and activated the cGAS-STING-TBK1 signal cascade in ECs, thereby impairing ECs-mediated osteogenesis. Furthermore, Pg-OMVs aggregated alveolar bone loss and altered the blood vessel-mediated osteogenesis with elevated STING.

Investigating oral microbiome profiles in patients with cleft lip and palate compared with the healthy control.

BACKGROUND: Patients with cleft lip and palate (CLP) have an oronasal communication differed from the closed state in healthy individuals, leading to a unique oral microbiome. This study aimed to determine if variances in the oral microbiota persist among CLP patients who have received treatments for the closure of these fistulas compared to the microbiota of healthy individuals. METHODS: Saliva samples were collected from a cohort comprising 28 CLP patients (CLP group) and 30 healthy controls (HC group). Utilizing 16S rRNA sequencing on the Illumina NovaSeq platform, we conducted a comprehensive analysis of the diversity and composition of the oral microbiota. RESULTS: The analysis of the microbiota in the saliva samples revealed a total of 23 microbial phyla, 38 classes, 111 orders, 184 families, 327 genera and 612 species. The alpha diversity with microbial abundance and evenness indicated the significant difference between the CLP and HC groups. Principal coordinate analysis (PCoA) and the ADONIS test further supported the presence of distinct microorganisms between the two groups. The CLP group displayed elevated abundances of Neisseria, Haemophilus, Porphyromonas, and Granulicatella, as indicated by LefSe analysis. Conversely, Rothia, Veillonella, and Pauljensenia exhibited significant reductions in abundance in the CLP group. The results of the PICRUSt analysis indicated significant differences in the relative abundance of 25 KEGG pathways within the CLP group. Through Spearman correlation analysis, strong associations between Rothia, Veillonella, and Pauljensenia and 25 functional pathways linked to CLP were identified. CONCLUSION: Findings of this study offer a thorough comprehension of the microbiome profiles of CLP patients after the restoration of oronasal structure and are anticipated to present innovative concepts for the treatment of CLP.

Effect of socioeconomic and malocclusion-related factors on duration of orthodontic treatment by fixed appliance: A retrospective study.

OBJECTIVES: The aims of this study were to evaluate the effect of related factors that influence orthodontic treatment time and to identify the predictors of orthodontic treatment duration in a Chinese population. MATERIALS AND METHODS: Information for 29 sociodemographic, malocclusion and orthodontic treatment characteristics was collected. Patients were divided into two groups: the duration ≤24 months group and duration >24 months group. The treatment dates of the initial visit and end of orthodontic treatment were obtained to calculate duration. The data were subjected to univariate and multivariate logistic regression modelling to quantify the association between characteristics and the treatment duration; odds ratios (ORs) and 95% confidence intervals (95% CIs) are reported. RESULTS: Of 2120 patients, 704 patients (mean age, 15.9 ± 6.0 years) were included. Age, extraction, Bolton ratio (overall), rotated teeth, overjet and crowding (lower arch) were predictors for duration. The nomogram based on predictive factors exhibited strong discrimination ability, with concordance indices of 0.755 (95% CI = 0.712-0.798) in the training cohort model and 0.717 (95% CI = 0.647-0.787) in the validation cohort model. The calibration curves for the training and validation cohorts showed that the probabilities of the nomogram agreed well with actual probabilities. CONCLUSIONS: Young age, non-extraction and severe crowding (lower arch) can increase the chance of durations of ≤24 months. Rotated teeth, excessive overjet and Bolton ratio (overall) can increase the chance of durations of >24 months.

Changes of maxillary central incisor and alveolar bone in Class II Division 2 nonextraction treatment with a fixed appliance or clear aligner: A pilot cone-beam computed tomography study.

INTRODUCTION: This retrospective clinical study investigated the clinical changes of maxillary central incisor and alveolar bone in Class II Division 2 nonextraction treatment with fixed appliances or clear aligners on the basis of cone-beam computed tomography. METHODS: Fifty-nine Chinese Han patients with similar demographic characteristics were collected from a conventional bracket group, a self-ligating bracket group, and a clear aligner group. All measurements about root resorption and alveolar bone thickness on the cone-beam computed tomography images were tested. Changes between pretreatment and posttreatment were evaluated by paired-sample t test. The variation among the 3 groups was compared by 1-way analysis of variance. RESULTS: The resistance center of the maxillary central incisor showed upward or forward movement, and the axial inclination was increased in 3 groups (P <0.0001). Root volume loss in the clear aligner group (23.68 ± 4.82 mm3) was significantly less than that in the fixed appliances group (28.24 ± 6.44 mm3 in the conventional bracket group, 28.17 ± 6.07 mm3 in the self-ligating bracket group) (P <0.05). All 3 groups showed a significant decrease in palatal alveolar bone and total bone thickness at all 3 levels at posttreatment. In contrast, labial bone thickness significantly increased except for crestal level l. Among the 3 groups, the clear aligner group had a prominent increase in labial bone thickness at the apical level (P = 0.0235). CONCLUSIONS: Clear aligner treatment for Class II Division 2 malocclusions could effectively reduce the incidence of fenestration and root resorption. Our findings will be beneficial to comprehensively understand the effectiveness of different appliances for Class II Division 2 malocclusions treatment.

Evaluating the accuracy of automated cephalometric analysis based on artificial intelligence.

BACKGROUND: The purpose of this study was to evaluate the accuracy of automatic cephalometric landmark localization and measurements using cephalometric analysis via artificial intelligence (AI) compared with computer-assisted manual analysis. METHODS: Reconstructed lateral cephalograms (RLCs) from cone-beam computed tomography (CBCT) in 85 patients were selected. Computer-assisted manual analysis (Dolphin Imaging 11.9) and AI automatic analysis (Planmeca Romexis 6.2) were used to locate 19 landmarks and obtain 23 measurements. Mean radial error (MRE) and successful detection rate (SDR) values were calculated to assess the accuracy of automatic landmark digitization. Paired t tests and Bland‒Altman plots were used to compare the differences and consistencies in cephalometric measurements between manual and automatic analysis programs. RESULTS: The MRE for 19 cephalometric landmarks was 2.07 ± 1.35 mm with the automatic program. The average SDR within 1 mm, 2 mm, 2.5 mm, 3 and 4 mm were 18.82%, 58.58%, 71.70%, 82.04% and 91.39%, respectively. Soft tissue landmarks (1.54 ± 0.85 mm) had the most consistency, while dental landmarks (2.37 ± 1.55 mm) had the most variation. In total, 15 out of 23 measurements were within the clinically acceptable level of accuracy, 2 mm or 2°. The rates of consistency within the 95% limits of agreement were all above 90% for all measurement parameters. CONCLUSION: Automatic analysis software collects cephalometric measurements almost effectively enough to be acceptable in clinical work. Nevertheless, automatic cephalometry is not capable of completely replacing manual tracing. Additional manual supervision and adjustment for automatic programs can increase accuracy and efficiency.

Dynamic Change in Oral Microbiota of Children With Cleft Lip and Palate After Alveolar Bone Grafting.

To investigate the longitudinal influence of alveolar bone grafting on the oral microbiota of children with cleft lip and palate (CLP).Twenty-eight children with nonsyndromic CLP were recruited and underwent secondary alveolar bone grafting at the first time. Unstimulated saliva and plaque samples were collected from the subjects preoperatively and at 2 days, 1 month, and 3 months postoperatively. The v3-v4 hypervariable regions of the 16S rRNA gene from bacterial DNA were sequenced using the Illumina MiSeq sequencing platform.The alpha diversity of the saliva and plaque microbiota was significantly decreased at 2 days postoperatively and then increased at 1 and 3 months postoperatively. The saliva and plaque microbiota compositions at 2 days postoperatively differed from those at the other time points, and the microbiota compositions at 1 and 3 months postoperatively showed a gradual shift toward the preoperative composition. The saliva, but not plaque, microbiota composition 3 months postoperatively was similar to that preoperatively.The effect of secondary alveolar bone grafting on the plaque microbiota in children with CLP lasted longer than the saliva microbiota. Alveolar bone grafting altered the saliva microbiota in children with CLP within 3 months postoperatively.

Simulation training for ceramic crown preparation in the dental setting using a virtual educational system.

OBJECTIVES: The aim was to evaluate the effectiveness of a pre-clinical training of ceramic crown preparation using the Virtual Educational System for Dentistry. MATERIAL AND METHODS: Fifty-seven dental students were recruited to prepare a ceramic crown under the guidance of the Real-time Dental Training and Evaluation System (RDTES) in order to collect pre-learning data. They participated in the online virtual learning course independently on the Virtual Learning Network Platform (VLNP). One week later, the students were invited to complete their post-learning crown preparation with the RDTES. A questionnaire survey explored students' perceived benefits or drawbacks of the virtual educational system. Students were allocated into Group A (n = 15), B (n = 24) and C (n = 18) based on their pre-learning performance. Differences of assessment results amongst different groups were evaluated by ANOVA and Kruskal-Wallis tests. The pre- and post-learning assessment results in all groups were compared using paired t tests or Wilcoxon signed rank tests. RESULTS: The error scores for four assessment items (instrument selection, preparation section, preparation reduction, preparation surface and profile) and total score of outcome assessment after the virtual learning were significantly different with those before the virtual learning (P < 0.05). There were significant interactions between time and student group in the mean scores of process and outcome assessments (P < 0.001), except for the assessment item "damage of adjacent teeth." CONCLUSION: The application of a Virtual Educational System for Dentistry with the VLNP and RDTES in pre-clinical operative training helps students improve their clinical skills.

Assessing the Interdental Septal Thickness in Alveolar Bone Grafting Using Cone Beam Computed Tomography.

OBJECTIVE: To assess the interdental septal thickness of grafted bone bridges using cone beam computed tomography (CBCT). PATIENTS: Of 71 patients with cleft lip and/or palate having undergone alveolar bone grafting for the first time at least 6 months previously, 52 patients with 57 grafted sites rated type I or II based on the Bergland scale using occlusal radiographs were selected. INTERVENTIONS: CBCT was performed for each bone-grafted alveolar cleft within 1 week after the occlusal radiographs were taken. MAIN OUTCOME MEASURES: The thickness of the grafted bone bridge was evaluated using CBCT according to the relationship between crest thickness and the root width of cleft-adjacent teeth, and the results were classified into four categories, with scores of 1 to 4 indicating that the thickness of the bony bridge was ≥100%, ≥75%, ≥50%, and <50% of the root width of the cleft-adjacent teeth, respectively. RESULTS: Of the 34 grafted sites rated type I on the Bergland scale, 15 (44.12%), 10 (29.41%), 4 (11.76%), and 5 (14.71%) clefts were scored 1 to 4 on interdental septal thickness using CBCT, respectively. Of the 23 cases of type II, 3 (13.04%), 9 (39.13%), 1 (3.45%), and 10 (43.48%) clefts were scored 1 to 4, respectively. CONCLUSIONS: The interdental septal thickness of grafted bone bridges with clinically successful heights based on the Bergland scale (type I or II) using occlusal radiographs varied significantly in the evaluation using CBCT.

Development and assessment of an online virtual orthodontic curriculum.

INTRODUCTION: Due to break space and time limits, an entirely new online curriculum of orthodontic education with online evaluation system has been structured and developed in the dental school, based on virtual reality simulation. CURRICULUM: At Nanjing Medical University, a new online orthodontic curriculum with programmatic assessment process was constructed and implemented based on competency-based education (CBE). It was consisted of the online orthodontic theoretical lectures based on the National Open Online Course "Orthodontics," the online journal club via the online "flipped classroom," and the online orthodontic pre-clinical training via the virtual learning network platform. In order to evaluate this curriculum, 94 Year 4 dental students took part to complete the online orthodontic curriculum. The mean total score of all the students was 91.99, and the element scores of the online theoretical lectures, journal club, virtual pre-clinical training, and online final examination were respectively 96.83, 79.49, 96.00, and 87.02, which showed a good performance. According to the student feedback toward this curriculum via the online questionnaire, nearly 98% of the students showed agreement or strong agreement that the online orthodontic curriculum has enhanced their orthodontic theoretical understanding and orthodontic practical ability. CONCLUSION: As a student-centered CBE, this online orthodontic curriculum with online evaluation system could provide both orthodontic theory and practice teaching for all the dental students at all times and places based on the online virtual mode, which enriched learners' critical thinking, problem solving, and assessment skills.

Investigating Oral Microbiome Profiles in Children with Cleft Lip and Palate for Prognosis of Alveolar Bone Grafting.

In this study, we sought to investigate the oral microbiota structure of children with cleft lip and palate (CLP) and explore the pre-operative oral bacterial composition related to the prognosis of alveolar bone grafting. In total, 28 patients (19 boys, 9 girls) with CLP who were scheduled to undergo alveolar bone grafting for the first time were recruited. According to the clinical examination of operative sites at the third month after the operation, the individuals were divided into a non-inflammation group (n = 15) and an inflammation group (n = 13). In all, 56 unstimulated saliva samples were collected before and after the operation. The v3-v4 hypervariable regions of the 16S rRNA gene were sequenced using an Illumina MiSeq sequencing platform. Based on the beta diversity of the operational taxonomic units (OTUs) in the inflammation and non-inflammation samples, the microbial variation in the oral cavity differed significantly between the two groups before and after the operation (P < 0.05). Analysis of the relative abundances of pre-operative OTUs revealed 26 OTUs with a relative abundance higher than 0.01%, reflecting a significant difference of the relative abundance between groups (P < 0.05). According to a principal component analysis of the pre-operative samples, the inflammation-related OTUs included Tannerella sp., Porphyromonas sp., Gemella sp., Moraxella sp., Prevotella nigrescens, and Prevotella intermedia, most of which were enriched in the inflammation group and showed a significant positive correlation. A cross-validated random forest model based on the 26 different OTUs before the operation was able to fit the post-operative status of grafted sites and yielded a good classification result. The sensitivity and specificity of this classified model were 76.9% and 86.7%, respectively. These findings show that the oral microbiota profile before alveolar bone grafting may be related to the risk of post-operative inflammation at grafted sites.

[A new three-dimensional scale in the evaluation of the secondary alveolar bone grafting].

OBJECTIVE: To propose a new three-dimensional method or grading scale in the evaluation of the secondary alveolar bone grafting, thus modifying the Bergland grading scale. METHODS: A total of 40 patients (26 male, 14 female) with unilateral cleft lip and palate (UCLP), who underwent secondary alveolar bone grafting at least 3 months ago, were enrolled. Regional cone-beam CT (CBCT) scans were taken to evaluate the height and thickness of the postoperative bone bridges. A new three-dimensional grafting scale was established, including four grades respectively in alveolar height and thickness. RESULTS: According to the new three-dimensional scale in this study, 15 grafted sites were rated grade T-I or T-II in the alveolar thickness among 18 sites of grade H-I in height, and 10 among 15 of grade H-II in height. Therefore, 25 grafted sites were considered as clinical success in the alveolar thickness (grade T-I or T-II) among 33 sites with clinical success in alveolar height (grade H-I and H-II). There were 24% of 33 sites with clinical success in height, which were considered as clinical failure in the alveolar thickness. CONCLUSIONS: It is necessary to establish a new three-dimensional method or grading scale for evaluating the secondary alveolar bone grafting. The three-dimensional scale can take comprehensive view of the bone-grafted alveolar clefts and thus modify the Bergland grading scale.