The Chinese journal of dental research : the official journal of the Scientific Section of the Chinese Stomatological Association (CSA)最新文献

Objective: To determine whether the targeting age should be adjusted for the National Children's Pit and Fissure Sealant (PFS) Programme.

Methods: 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.

Results: 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.

Conclusion: 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.

Objective: To investigate the role of the biosynthetic gene cluster BGC3 of Streptococcus mutans (S. mutans) in the process of dental caries.

Methods: BGC3 and ∆BGC3 S. mutans strains were constructed and their growth curves were evaluated. Acid production capacity was assessed by evaluating pH reduction levels over identical culture periods. The survival of bacteria in phosphate citrate buffer solution (pH 3.0) was quantified. The expression levels of virulence genes (atpF, gtfC, gtfD, spaP, vicR and ftf) were analysed using the qPCR. Co-culture experiments were conducted to evaluate bacterial adaptability. Bacterial viability was determined by microscopical examination of live/dead staining.

Results: Deletion of BGC3 did not significantly impact S. mutans growth or acid production in biofilms. The ∆BGC3 strain exhibited enhanced acid resistance and higher expression levels of virulence genes compared to the wild type. In addition, ∆BGC3 exhibited superior bacterial viability in the co-culture system.

Conclusion: BGC3 affected the acid resistance and expression of caries-related genes in S. mutans. The BGC3 knockout strain exhibited a more robust survival capability than the wild-type strain.

Objective: To establish a rapid and high-throughput clinical matrix-assisted laser desorption ionisation-time of flight mass spectrometry (CLIN-MALDI-TOF-MS) method for identifying oral microorganisms and to determine the distinct representative species across various oral sites.

Methods: Samples were collected from 54 volunteers from four oral sites: saliva, supragingival plaque, oral mucosa and dorsum of the tongue. Microorganisms were cultured on brain heart infusion (BHI) plates and identified using CLIN-MALDI-TOF-MS after processing with specific reagents for mass spectrometry.

Results: The method identified 15 species and 12 genera of microorganisms, revealing significant differences in microbial composition among the oral sites, and different oral cavity sites harboured distinct relatively representative species.

Conclusion: The CLIN-MALDI-TOF-MS method offers a rapid and efficient approach for large-scale microbial identification in the oral cavity, providing a suitable approach for future experimental teaching and highlighting the importance of site-specific microbial communities in oral health research.

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.

Objective: To explore the differential translation profiles and coding products of human jaw bone marrow mesenchymal stem cells (h-JBMMSCs) during osteogenic differentiation.

Methods: Ribo-seq was used to examine the differential translated genes (DEGs), open reading frames (ORFs) and genes associated with the osteogenic differentiation phase of h-JBMMSCs. Western blotting (WB) was performed to detect the expression of osteocalcin (OCN) and bone sialoprotein (BSP). Alkaline phosphatase (ALP) activity and alizarin red staining (ARS) were used to detect osteogenic differentiation. A lentivirus containing 5'UTR-ORF-GFPmut was designed to transfect h-JBMMSCs, and fluorescence and green fluorescent protein (GFP) expression were analysed. The SNHG1 peptide was synthesised for osteogenic induction and to detect osteogenic markers.

Results: A total of 53,432 ORFs were detected and 199 candidate translation sORFs, including lncRNA SNHG1, were identified after removing the annotated protein-coding genes. In addition, the 5'UTR-ORF-GFPmut showed green fluorescence and expressed GFP. Knockdown of the lncRNA SNHG1 increased the ALP activity of h-JBMMSCs, promoted the expression of OCN and BSP, and enhanced the intensity of ARS and calcium ion content. However, overexpression of lncRNA SNHG1 and the SNHG1 polypeptide inhibited the osteogenic differentiation of h-JBMMSCs.

Conclusion: LncRNA SNHG1 inhibited the osteogenic differentiation of h-JBMMSCs. LncRNA SNHG1 can encode a peptide of 19-amino acid and inhibit the osteogenic differentiation of h-JBMMSCs.

Objective: 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.

Methods: 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.

Results: 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.

Conclusion: 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.

Objective: To compare accuracy, duration of drilling and accumulation of bone chips between low-speed drilling and conventional drilling in freehand implant placement surgery.

Methods: The implant surgery procedures were performed using identical drill bits on pig ribs in the low-speed drilling group and the conventional drilling group. CBCT images of the preoperative implant design and postoperative implant positions were compared by using the space vector formula to calculate the angular deviation of the implants between the two groups, as well as the horizontal and vertical deviations of the implant necks and roots. The duration of the procedure was recorded, and the bone chips were collected and compared using a screening method and scanning electron microscopy.

Results: There were no significant differences in any of the four primary outcome variables relating to accuracy between the low-speed and conventional drilling methods. However, the results revealed that the length of the procedure differed significantly between the two groups and more large bone fragments could be collected when performing low-speed drilling.

Conclusion: Low-speed drilling does not affect the accuracy of implant nest preparation, but it can harvest large bone chips which may have better osteogenic activity. Low-speed drilling could be an alternative to conventional drilling.

Objective: 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).

Methods: 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.

Results: 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.

Conclusion: 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.

Objective: 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.

Methods: 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.

Results: 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).

Conclusion: 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.

Oral diseases not only greatly impact patients' daily lives, but also pose a severe threat to their overall health. Due to the constant exposure of saliva to oral diseases, the former plays a vital role in their diagnosis and monitoring. Exosomes, nanosized bilayer lipid encapsulated nanovesicles, are widely present in saliva and can be released by any type of cell. Exosomes inherit features from their mother cells in both physiological and pathological conditions. The molecular characteristics and expression levels of exosomes depend on their cellular origin, and they can directly reflect the physiological state of the body and cells. This makes salivary exosomes a promising source for early detection and monitoring of oral diseases. As a result, researchers have been exploring the potential use of exosomes as biomarkers for diagnosing and predicting various oral diseases. This review provides an overview of the composition, separation and function of salivary exosomes. It also discusses their potential as diagnostic and prognostic markers for several oral diseases, including periodontitis, primary Sjögren's syndrome, oral mucosal diseases, hand-foot-mouth disease and oral squamous cell carcinoma. By studying salivary exosomes, researchers hope to improve the early detection and monitoring of oral diseases, leading to better outcomes for patients.