Characterization and functional prediction of the dental plaque microbiome in patients with alveolar clefts.

Introduction: Alveolar cleft (AC) is a common congenital defect in people with cleft lip and palate (CLP). Alveolar bone grafting (ABG) is typically performed during adolescence, resulting in the fissure remaining in the mouth for a longer length of time. Patients with AC have a greater rate of oral diseases such as dental caries than the normal population, and the precise characteristics of the bacterial alterations caused by AC are unknown. Methods: We recruited a total of 87 subjects and collected dental plaque samples from AC adolescents (AAP), post-operative ABG adolescents (PAP), healthy control adolescents (CAP), AC young adults (AYP), post-operative ABG young adults (PYP), and healthy control young adults (CYP). The sequencing of 16S rRNA genes was performed. Results: The microbial composition of plaque from alveolar cleft patients differed significantly from age-matched healthy controls. Linear discriminant analysis effect size (LEfSe) analysis revealed that AAP was enriched for Neisseria, Haemophilus, Fusobacterium, Rhodococcus, Aggregatibacter, Gemella, and Porphyromonas, whereas AYP was enriched for Capnocytophaga, Rhodococcus, and Actinomyces-f0332. There were phenotypic differences in facultatively anaerobic, Gram-negative, Gram-positive, and oxidative stress tolerance between the AYP group with longer alveolar cleft and the healthy control group according to Bugbase phenotypic predictions. Alveolar bone grafting did not alter the functional phenotype of alveolar cleft patients but reduced the number of differential genera between alveolar cleft patients and healthy controls at both ages. Conclusions: Our study systematically characterized the supragingival plaque microbiota of alveolar cleft patients, post-alveolar bone grafting patients, and matched healthy controls in two ages to gain a better understanding of plaque ecology and microbiology associated with alveolar clefts.

Predicting chronological age of 14 or 18 in adolescents: integrating dental assessments with machine learning.

AIM: Age estimation plays a critical role in personal identification, especially when determining compliance with the age of consent for adolescents. The age of consent refers to the minimum age at which an individual is legally considered capable of providing informed consent for sexual activities. The purpose of this study is to determine whether adolescents meet the age of 14 or 18 by using dental development combined with machine learning. METHODS: This study combines dental assessment and machine learning techniques to predict whether adolescents have reached the consent age of 14 or 18. Factors such as the staging of the third molar, the third molar index, and the visibility of the periodontal ligament of the second molar are evaluated. RESULTS: Differences in performance metrics indicate that the posterior probabilities achieved by machine learning exceed 93% for the age of 14 and slightly lower for the age of 18. CONCLUSION: This study provides valuable insights for forensic identification for adolescents in personal identification, emphasizing the potential to improve the accuracy of age determination within this population by combining traditional methods with machine learning. It underscores the importance of protecting and respecting the dignity of all individuals involved.

Using machine learning to determine age over 16 based on development of third molar and periodontal ligament of second molar.

BACKGROUND: Having a reliable and feasible method to estimate whether an individual has reached 16 years of age would greatly benefit forensic analysis. The study of age using dental information has matured recently. In addition, machine learning (ML) is gradually being applied for dental age estimation. AIM: The purpose of this study was to evaluate the development of the third molar using the Demirjian method (Demirjian3M), measure the development index of the third molar (I3M) using the method by Cameriere, and assess the periodontal ligament development of the second molar (PL2M). This study aimed to predict whether Chinese adolescents have reached the age of criminal responsibility (16 years) by combining the above measurements with ML techniques. SUBJECTS & METHODS: A total of 665 Chinese adolescents aged between 12 and 20 years were recruited for this study. The development of the second and third molars was evaluated by taking orthopantomographs. ML algorithms, including random forests (RF), decision trees (DT), support vector machines (SVM), K-nearest neighbours (KNN), Bernoulli Naive Bayes (BNB), and logistic regression (LR), were used for training and testing to determine the dental age. This is the first study to combine ML with an evaluation of periodontal ligament and tooth development to predict whether individuals are over 16 years of age. RESULTS AND CONCLUSIONS: The study showed that SVM had the highest Bayesian posterior probability at 0.917 and a Youden index of 0.752. This finding provides an important reference for forensic identification, and the combination of traditional methods and ML is expected to improve the accuracy of age determination for this population, which is of substantial significance for criminal litigation.

Psychological Impact of the COVID-19 Pandemic on Emergency Dental Care Providers on the Front Lines in China.

Coronavirus disease 2019 (COVID-19) is an infectious disease that emerged at the end of 2019. On 30 January 2020, the World Health Organization (WHO) classified it as a pandemic. To examine the psychological effects on dental care providers in China in the midst of the COVID-19 outbreak and factors closely associated with those effects, we conducted a cross-sectional study online with 4 widely used self-administered questionnaires: the Patient Health Questionnaire-9, the General Anxiety Disorder-7, the Perceived Stress Scale-10, and the Acute Stress Disorder Scale. Univariate and multivariate analyses were performed to evaluate the variables that potentially affected the mental health of emergency dental care providers. As a result, 969 out of 1035 questionnaires were included in the analysis, with 642 respondents reporting more than 1 symptom (66.3%). The symptom of perceived stress was reported by the largest proportion of the respondents (66.2%, n = 641), and anxiety the least (7.1%, n = 69). After adjustment for confounders, it was found that dental practitioners with preexisting physical health conditions were at higher risk of depression (odds ratio [OR], 1.972; 95% CI, 1.128-3.448; P = .017), and perceived stress (odds ratio, 2.397 95% CI, 1.283-4.478; P = .006). Additionally, feelings of fear, helplessness, or terror resulting from the possibility of contracting COVID-19 were significantly associated with the prevalence of all the 4 psychological symptoms observed (P < .05). In the present study, we found that dental care providers suffered psychological depression, stress, anxiety, and posttraumatic stress disorder (PTSD) during COVID-19, which indicates the importance of psychological support at times of major epidemic outbreaks. Chinese Clinical Trial Registry number: ChiCTR2000031538.

[Clinical management of calcified root canal with Mtwo NiTi files].

PURPOSE: To evaluate the effect of Mtwo NiTi files in the management of calcified root canals. METHODS: Thirty-five calcified root canals from 21 cases unsuccessfully prepared with C-Pilot files and EDTA were treated with Mtwo NiTi files and EDTA. The data was analyzed with SAS 9.4 software package. RESULTS: Twenty-three calcified root canals were successfully prepared. The success rate was 65.71%. Instrument separation occurred in 4 root canals, and ledge occurred in 3 root canals. Categorized by calcified position, the success rate of three groups had no significant differences (P>0.05). CONCLUSION: Mtwo NiTi files can effectively process calcified root canals.

Effects of deferoxamine on the repair ability of dental pulp cells in vitro.

INTRODUCTION: In previous studies, we found that hypoxia promoted the mineralization of dental pulp cells (DPCs). However, the clinical application of hypoxia as a therapy is questionable or unfeasible. Deferoxamine (DFO), a medication for iron overload, has also been shown to induce hypoxia. The purpose of this study was to investigate the effects of DFO on the repair ability of DPCs. METHODS: DPCs were obtained by using a tissue explant technique in vitro and were treated with different concentrations of DFO or hypoxia culture for 2 days. The viability, proliferation, migration, and odontogenic differentiation of DPCs were assayed and analyzed. The expression of hypoxia-inducible factor 1-alpha (HIF-1α) was assessed through Western blotting. RESULTS: Ten micromolars of DFO enhanced the expression of HIF-1α similarly to hypoxia and did not affect the viability of DPCs for 2 days. Furthermore, the proliferation, migration, and odontogenic differentiation of DPCs were promoted by DFO. CONCLUSIONS: These results suggest that DFO might improve the repair ability of DPCs by HIF-1α.

RECQL1 plays an important role in the development of tongue squamous cell carcinoma.

BACKGROUND/AIMS: RECQL1, a member of the human RECQ helicase family, participates in DNA repair. Recent reports showed that RECQL1 silencing in cancer cells resulted in mitotic catastrophe, which prevented tumor growth in murine models. However, its therapeutic potential has never been examined in tongue squamous cell carcinoma (SCC). METHODS: To explore the role of RECQL1 in the development of tongue SCC, we used RNA interference technology to silence RECQL1 in SCC-9 and SCC-15 human tongue SCC cell lines, and to subsequently evaluate its effects both in vitro and in vivo. RESULTS: After RECQL1 was silenced in SCC cells by siRNA, we observed downregulation of RECQL1 mRNA and protein in cancer cells. RECQL1 is one of the predicted miR-203 targets, and we found that miR-203 downregulated the expression of RECQL1 at the post-transcriptional level. RECQL1-shRNA or miR-203 overexpression inhibited SCC-9 cell growth. In addition, there was accumulation of cells in the sub-G1 fraction and increased apoptosis 72 h post-transfection. In addition, knockdown of RECQL1 led to a strong anticancer effect, as the tumorigenicity of SCC-9 cells was inhibited in vivo. Moreover, we found that two immunosuppressive factors were also significantly downregulated upon RECQL1 knockdown or miR-203 overexpression in vitro. CONCLUSION: Collectively, these results indicate that RECQL1 plays an important regulatory role in cancer cell proliferation and tumor progression.

[Clinical study on the effects of single visit root canal treatment of chronic periapical periodontitis by two kinds of root canal preparation instruments system].

PURPOSE: To investigate the different incidence of postoperative pain and long-term follow-up curative effects in patients with chronic periapical periodontitis undergoing single visit root canal treatment by two kinds of canal preparation instruments system. METHODS: Ninety-eight permanent teeth with chronic periapical periodontitis were divided into two groups randomly. One group was prepared with nickel-titanium instruments, the other group was prepared with K files. After canal preparation, all the teeth underwent canal filling immediately. The different incidence of postoperative pain and long-term follow-up curative effects were recorded. Statistical analysis was carried out using SPSS13.0 software package. RESULTS: One week after treatment, the rate of serious symptom of periapical periodontitis in the Ni-Ti group was less than that in the K file group (P<0.05 ). 18 months after treatment, the curative effect of two groups had no significant difference (P>0.05 ). CONCLUSIONS: Nickel-titanium instrument used in treatment of chronic periapical periodontitis lead to less serious postoperative reaction than K file instruments, but the same long-term follow-up curative effects as K file instruments. Nickel-titanium instruments system is worthy of wide application in patients with chronic periapical periodontitis undergoing single visit root canal treatment.