[A novel periodontal endoscopy-aided non-incisional periodontal regeneration technique：a case series study].

PURPOSE: To investigate the effect of endoscopy-aided non-incisional periodontal regeneration technique (NIT) in the treatment of alveolar bone angular resorption. METHODS: Thirteen patients with severe periodontitis(13 diseased teeth) were selected. All patients had alveolar bone angular resorption on adjacent surface. The patients received NIT treatment 6 weeks after periodontal primary therapy. The visualization of subgingival environment was acquired by the periodontal endoscopy. Following the removal of the subgingival plaque, calculus and intra-bony granulation tissue, bone grafting materials were placed into the intra-bony defects with the assistance of a delicate gingival protector. No flap was elevated and no sutures were applied. Probing depth (PD), gingival recession (GR), clinical attachment level (CAL), as well as radiographic parameters were evaluated at baseline and 2 years after treatment. SPSS 22.0 software package was used for data analysis. RESULTS: At 2-years follow-up, an average CAL gain of (3.65±2.10) mm (P＜0.001), PD reduction of (4.42±1.66) mm (P＜0.001), and minimal increase in GR of (0.38±0.87) mm (P=0.25) were observed. Alveolar bone was significantly improved at 2-years follow-up on radiographs (P＜0.001). CONCLUSIONS: For angular resorption site of alveolar bone, NIT treatment can obtain good periodontal regeneration results without flap inversion.

Influence of alveolar bone thickness and bucco-palatal inclination on root resorption of lateral incisors in unilateral maxillary impacted canines: a retrospective observational study.

BACKGROUND: This study aimed to investigate the potential associations between alveolar bone thickness, bucco-palatal inclination of maxillary lateral incisors, and lateral incisor root resorption in patients with unilateral maxillary impacted canines (UMICs). METHODS: A total of three hundred and five subjects (120 males, 185 females; mean age, 16.39 years; standard deviation, 4.04) with UMICs were included. Canine position and root resorption were assessed using CBCT. UMICs were divided into palatal, buccal and mid-alveolus groups (PICs, BICs and MAICs), with 117, 137 and 51 subjects, respectively. Alveolar bone thickness and bucco-palatal inclination of lateral incisors were measured using the Dolphin software. RESULTS: The prevalence of lateral incisor root resorption was significantly lower in the BICs (13.9%) than MAICs (29.4%) and PICs (29.1%). Alveolar bone thickness of the apical area was smaller in UMICs with lateral incisor root resorption than no resorption in both PICs (8.33 ± 1.64 vs 10.53 ± 2.55 mm) and BICs (8.94 ± 1.85 vs 10.76 ± 2.28 mm). Furthermore, lateral incisors on the impacted side were more buccally inclined in PICs with lateral incisor root resorption than no resorption, while in both BICs and MAICs, there was no statistical difference between lateral incisor root resorption than no resorption. Moreover, alveolar bone thickness of the apical area, rather than bucco-palatal inclination of lateral incisors, was significantly correlated with lateral incisor root resorption both in PICs and BICs. CONCLUSIONS: Lateral incisor root resorption is less common in BICs. Thinner alveolar bone thickness at the apical area of lateral incisors can be considered as a potential risk factor for lateral incisor root resorption in UMICs.

Facial asymmetry of the hard and soft tissues in skeletal Class I, II, and III patients.

To investigate and compare the facial asymmetry (hard and soft tissues) among skeletal Class I, II, and III patients. A total of 221 subjects, including skeletal Class I (n = 80), skeletal Class II (n = 75), and skeletal Class III (n = 66), were included in the study. CBCT, 22 skeletal landmarks, and 10 soft tissue landmarks were used for the measurements and the asymmetry index was calculated to assess the facial asymmetry. Statistical analyses included one-way ANOVA, Kruskal-Wallis test, and Spearman correlation analysis. The skeletal Class III patients presented greater asymmetry than Class II patients for 10 hard tissue landmarks and 3 soft tissue landmarks (p < 0.05). High correlation of asymmetry was found between four soft tissue landmarks and their corresponding skeletal landmarks (rs ≥ 0.71), as well as Me and ANS (r > 0.86). The ANS and Me in 21.3% patients deviated to contralateral sides. The skeletal Class III patients had more facial asymmetry than the Class II patients. Soft tissues showed similar asymmetry as the underlying hard tissues rather than a compensation of the hard tissue asymmetry. The inconsistency in the deviation of Me and ANS may exacerbate facial asymmetry.

Clinical and radiographic evaluation of Bio-Oss granules and Bio-Oss Collagen in the treatment of periodontal intrabony defects: a retrospective cohort study.

OBJECTIVE: This retrospective study aimed to analyze the clinical efficacy of two regenerative surgical methods - Bio-Oss granules combined with barrier membranes and Bio-Oss Collagen alone - and to help clinicians achieve better periodontal regeneration outcomes in the specific periodontal condition. METHODOLOGY: Patients who underwent periodontal regeneration surgery from January 2018 to April 2022 were retrospectively screened, and their clinical and radiographic outcomes at 6 months postoperatively were analyzed. The probing depth (PD), clinical attachment level (CAL), bleeding on probing (BOP), gingival recession (GR), distance from the cemento-enamel junction to the bottom of the bone defect (CEJ-BD), and depth of intrabony defects (INFRA) were recorded before the operation (T0) and 6 months after it (T1), and subsequently compared. RESULTS: In total, 143 patients were included - 77 were placed in the Bio-Oss group and 66 were placed in the Bio-Oss Collagen group. All indicators, including PD and CAL at T1, showed significant differences compared to baseline, for both groups (P<0.001). PD reduction was greater in the group receiving the Bio-Oss Collagen treatment (P=0.042). Furthermore, in cases when the baseline PD range was 7-11 mm and the age range was 35-50 years, PD reduction was more significant for patients receiving the Bio-Oss Collagen treatment (P=0.031, 0.023). A linear regression analysis indicated that postoperative PD and CAL were positively correlated with baseline values, and that the efficacy tended to decrease with increasing age. CONCLUSION: Both the use of Bio-Oss Collagen alone and the use of Bio-Oss granules combined with barrier membranes resulted in significant effects in the treatment of periodontal intrabony defects. The Bio-Oss Collagen treatment generated more improvements in PD than the Bio-Oss granules combined with barrier membranes, particularly within the baseline PD range of 7-11 mm and the 35-50 years age group. Additionally, age was the main factor influencing the effectiveness of regenerative surgery for intrabony defects: older individuals exhibited fewer improvements.

Uprighting horizontally impacted third molars by super-elastic nickel-titanium wire in patients with an extracted first molar.

Protracting lower second molars and uprighting horizontally impacted third molars is a significant orthodontic challenge in patients who require the extraction of severely decayed first molars. Here, we describe the use of biomechanics to upright 90°-tilted lower third molars following second molar protraction. Herein, we introduce a technique for uprighting the lower third molars by (1) the placement of superelastic nickel titanium archwires, (2) bonding, and (3) repositioning of a buccal tube in a tilted position to compensate for the efficiency of Ni-Ti (nickel-titanium) wire. The treatment mechanics used for our two cases showed that even severely impacted third molars can be uprighted by routine continuous straight-wire techniques. This technique proved to be a simple, efficient and reliable treatment option for uprighting horizontally impacted third molars.

Advancing chronic toxicity risk assessment in freshwater ecology by molecular characterization-based machine learning.

The continuously increased production of various chemicals and their release into environments have raised potential negative effects on ecological health. However, traditional labor-intensive assessment methods cannot effectively and rapidly evaluate these hazards, especially for chronic risk. In this study, machine learning (ML) was employed to construct quantitative structure-activity relationship (QSAR) models, enabling the prediction of chronic toxicity to aquatic organisms by leveraging the molecular characteristics of pollutants, namely, the molecular descriptors, fingerprints, and graphs. The limited dataset size hindered the notable advantages of the graph attention network (GAT) model for the molecular graphs. Considering computational efficiency and performance (R2 = 0.78; RMSE = 0.77), XGBoost (XGB) was used for reliable QSAR-ML models predicting chronic toxicity using small- or medium-sized tabular data and the molecular descriptors. Further kernel density estimation analysis confirmed the high accuracy of the model for pollutant concentrations ranging from 10-3 to 102 mg/L, effectively aligning with most environmental scenarios. Model interpretation showed SlogP and exposure duration as the primary influential factors. SlogP, representing the distribution coefficient of a molecule between lipophilic and hydrophilic environments, had a negative effect on the toxicity outcomes. Additionally, the exposure duration played a crucial role in determining the chronic toxicity. Finally, the chronic toxicity data of bisphenol A validated the robustness and reliability of the model established in this research. Our study provided a robust and feasible methodology for chronic ecological risk evaluation of various types of pollutants and could facilitate and increase the use of ML applications in environmental fields.

Clinical and radiographic evaluation of Bio-Oss granules and Bio-Oss Collagen in the treatment of periodontal intrabony defects: a retrospective cohort study

Abstract Objective This retrospective study aimed to analyze the clinical efficacy of two regenerative surgical methods — Bio-Oss granules combined with barrier membranes and Bio-Oss Collagen alone — and to help clinicians achieve better periodontal regeneration outcomes in the specific periodontal condition. Methodology Patients who underwent periodontal regeneration surgery from January 2018 to April 2022 were retrospectively screened, and their clinical and radiographic outcomes at 6 months postoperatively were analyzed. The probing depth (PD), clinical attachment level (CAL), bleeding on probing (BOP), gingival recession (GR), distance from the cemento-enamel junction to the bottom of the bone defect (CEJ-BD), and depth of intrabony defects (INFRA) were recorded before the operation (T0) and 6 months after it (T1), and subsequently compared. Results In total, 143 patients were included — 77 were placed in the Bio-Oss group and 66 were placed in the Bio-Oss Collagen group. All indicators, including PD and CAL at T1, showed significant differences compared to baseline, for both groups (P<0.001). PD reduction was greater in the group receiving the Bio-Oss Collagen treatment (P=0.042). Furthermore, in cases when the baseline PD range was 7-11 mm and the age range was 35-50 years, PD reduction was more significant for patients receiving the Bio-Oss Collagen treatment (P=0.031, 0.023). A linear regression analysis indicated that postoperative PD and CAL were positively correlated with baseline values, and that the efficacy tended to decrease with increasing age. Conclusion Both the use of Bio-Oss Collagen alone and the use of Bio-Oss granules combined with barrier membranes resulted in significant effects in the treatment of periodontal intrabony defects. The Bio-Oss Collagen treatment generated more improvements in PD than the Bio-Oss granules combined with barrier membranes, particularly within the baseline PD range of 7-11 mm and the 35-50 years age group. Additionally, age was the main factor influencing the effectiveness of regenerative surgery for intrabony defects: older individuals exhibited fewer improvements.

MAT2A inhibition suppresses inflammation in Porphyromonas gingivalis-infected human gingival fibroblasts.

Background: Methionine adenosyl transferase II alpha (MAT2A) is the key enzyme to transform methionine into S-adenosylmethionine (SAM), the main methylgroup donor involved in the methylation. The purpose of our study wasto explore whether MAT2A-mediated methionine metabolism affected theexpression of inflammatory cytokines in human gingival fibroblasts(hGFs). Methods: Both healthy and inflamed human gingiva were collected. HGFs werecultured and treated with P. gingivalis, with or without MAT2Ainhibitor (PF9366), small interference RNA (siRNA), or extrinsic SAMpretreatment. The levels of inflammatory cytokines were detected byreal-time PCR, western blotting, and ELISA. SAM levels were detectedby ELISA. The nuclear factor-kappa B (NF-κB) and mitogen-activatedprotein kinase (MAPK) pathway was explored by western blotting. Results: The expression of MAT2A was increased in the inflamed tissues. P.gingivalis infection promoted the expression of MAT2A and SAM inhGFs. Meanwhile, PF9366 and MAT2A-knockdown significantly decreasedexpression of inflammatory cytokines and SAM production. PF9366inhibited activation of NF-κB/MAPK pathway in P. gingivalis-treatedhGFs. Conclusions: MAT2A-mediated methionine metabolism promoted P. gingivalis-inducedinflammation in hGFs. Targeting MAT2A may provide a novel therapeuticmethod for modulating periodontitis.

A novel periodontal endoscopy-aided non-incisional periodontal regeneration technique in the treatment of intrabony defects: a retrospective cohort study.

BACKGROUND: Gingival recession and post-operation discomfort are still a problem for patients receiving the periodontal regeneration surgery for intra-bony defects. To further reduce the trauma and the post-operation gingival recession, a novel periodontal endoscopy-aided non-incisional regeneration technique (NIT) was proposed in the treatment of intra-bony defects. METHODS: Retrospective analysis of 21 subjects treated with NIT and 21 subjects with periodontal endoscopy-aided scaling and root planing (PSRP) at baseline and 1-year evaluation was conducted. After removing the subgingival calculus and granulation tissue, bone grafting materials were placed into intrabony defects with the assistance of a gingival retractor in the NIT group. Probing depth (PD), gingival recession (GR), clinical attachment level (CAL), as well as the distance between bone crest (BC) level and base of the defect (BD) (intrabony defect depth, IBD) were evaluated at baseline and 1 year after treatment. RESULTS: At 1-year follow-up, the value of CAL, PD and IBD were statistically significant different compared with baseline in both two groups (p<0.001). CAL gain (p = 0.012) and PD reduction (p = 0.004) was greater in the NIT than PSRP. However, no difference in the IBD reduction was found between the NIT group and PSRP. Better CAL gain and PD reduction was achieved in the 1-year term in the NIT when compared with PSRP. CONCLUSION: NIT have resulted in significant gains in both clinical and radiographic parameters. NIT might be utilized as an alternative of the surgical treatment for periodontal intrabony defects. TRIAL REGISTRATION: This clinical trial registration was registered retrospectively (August 3, 2023) and the number is ChiCTR2300074317.

Diagnostic accuracy of severe periodontitis for Ramfjord teeth based on different classifications.

OBJECTIVE: To evaluate the accuracy of Ramfjord teeth (RT) protocol for the diagnosis of severe periodontitis based on different classifications and explore the misclassification bias such as teeth loss. METHODS: Patients (n = 435) receiving full-mouth periodontal examination (FMPE) were included. Patients were classified as severe (stage III/IV) periodontitis and no/mild/moderate (no/stage I/II) periodontitis according to the case definition proposed by the Centers for Disease Control and Prevention (CDC) and the American Academy of Periodontology (AAP)-(CDC/AAP), a new classification introduced by AAP and the European Federation of Periodontology (EFP)-(AAP/EFP), and consensus of Chinese experts (CCE). Sensitivity, specificity, positive predictive value, negative predictive value, Youden's index, and area under the receiver operating characteristic curve (AUROC) compared with FMPE were evaluated. RESULTS: The specificity of RT was 86.8%, 92.2%, and 77.1% when compared with FMPE protocol based on CDC/AAP, AAP/EFP, and CCE classifications, while the AUROC value was 0.934, 0.961, and 0.886 specifically. The loss of the first molar leads to the greatest reduction in the detection rate of severe periodontitis. CONCLUSIONS: RT showed the highest specificity based on the new AAP/EFP classification. The loss of the first molar leads to the greatest reduction in the detection rate of severe periodontitis.

The incidence and severity of open gingival embrasures in adults treated with clear aligners and fixed appliances: a retrospective cohort study.

BACKGROUND: To evaluate the incidence and severity of open gingival embrasures (OGEs) in adult patients treated with clear aligners and fixed appliances. METHODS: Two hundred non-extraction adult subjects with less than 5 mm of crowding (mean age, 24.6 ± 3.8 years) were enrolled in this retrospective study. The subjects were divided into the clear aligner (n = 100) and fixed appliance group (n = 100). The intraoral photographs were utilized to determine the incidence of OGEs in the upper arch between maxillary central incisors, as well as the lower arch between mandibular central incisors. Crown overlap, crown shape, posttreatment root angulation, the distance from the interproximal contact point (ICP) to the alveolar bone crest (ABC) after treatment and interproximal enamel reduction (IPR) were determined in the two groups. RESULTS: The incidence of OGEs between maxillary and mandibular central incisors after orthodontic treatment was 35.0% and 38.0% in the clear aligner group, respectively, significantly higher than that (18.0% and 24.0%) in the fixed appliance group (P < 0.05). The average area of an OGE after clear aligner treatment was larger both in the maxilla (0.16 ± 0.12mm2) and mandible (0.21 ± 0.24mm2) compared with that (0.05 ± 0.03mm2 and 0.05 ± 0.06mm2) after fixed appliance treatment (P < 0.05). No difference was found regarding pretreatment crown overlap, crown shape, treatment duration, posttreatment root angulation, amount and distribution of IPR and the distance from ICP to ABC. CONCLUSIONS: The incidence and severity of OGEs were higher in adults treated with clear aligners. Clinicians should be aware of the risk of OGEs during treatment with clear aligners.

Self-reported oral health habits, knowledge and conditions of schoolchildren and adolescents in mainland China.

To determine the oral health habits, knowledge and conditions of students in China and investigate the impact of associated factors. A self-reported online questionnaire was distributed through social networks in mainland China to assess the oral health habits, knowledge, and conditions of students aged 6-20 years attending primary, middle, and high schools. Factors potentially associated with oral health, such as oral health habits of their parents, family education level, and economic regions, were analyzed using McNemar's and Chi-square tests. Within one month, 5561 valid questionnaires were retrieved from all 31 provinces or equivalent regions in mainland China. The results showed that 46.9% of students suffered from bleeding when brushing their teeth, while only 11.8% reported professional teeth cleaning at a dental clinic. Soda beverages were widely consumed among them (75.4%). A significant minority of students brushed their teeth less than twice daily (22.8%) and for about 2 minutes each time (19.3%). Only 21.9% of the students had preventive oral health care. Students' toothbrushing habits and knowledge about interdental cleaning tools were associated with parental habits (p < 0.001). Overall, students from families with higher educational backgrounds and eastern China had better oral health habits, knowledge, and conditions. There is a need to pay more attention to gingival health and caries prevention among schoolchildren and adolescents in mainland China. Improving parental oral hygiene habits could have a positive impact on the oral health of students. Further research on oral health among students is needed in the middle and western regions of China.

Hexokinase 2-mediated glycolysis supports inflammatory responses to Porphyromonas gingivalis in gingival fibroblasts.

BACKGROUND: When infected with Porphyromonas gingivalis, gingival fibroblasts undergo metabolic reprogramming, and rely on aerobic glycolysis rather than oxidative phosphorylation for rapid energy replenishment. Hexokinases (HKs) are catalysts for glucose metabolism, and HK2 constitutes the major HK inducible isoform. The objective of this study is to determine whether HK2-mediated glycolysis promotes inflammatory responses in inflamed gingiva. METHODS: Levels of glycolysis-related genes were assessed in normal and inflamed gingiva. Human gingival fibroblasts were harvested and infected with Porphyromonas gingivalis in order to mimic periodontal inflammation. 2-deoxy-d-glucose, an analogue of glucose, was used to block HK2-mediated glycolysis, while small interfering RNA was used to knock down HK2 expression. The mRNA and protein levels of genes were analyzed by real-time quantitative PCR and western blotting, respectively. HK2 activity and lactate production were assessed by ELISA. Cell proliferation was assessed by confocal microscopy. The generation of reactive oxygen species was assessed by flow cytometry. RESULTS: Elevated expression of HK2 and 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 was observed in the inflamed gingiva. P. gingivalis infection was shown to promote glycolysis in human gingival fibroblasts, as evidenced by increased gene transcription of HK2 and 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3, cell glucose consumption, and HK2 activity. Inhibition and knockdown of HK2 resulted in reduced cytokine production, cell proliferation, and reactive oxygen species generation. Furthermore, P. gingivalis infection activated the hypoxia-inducible factor-1α signaling pathway, thus promoting HK2-mediated glycolysis and proinflammatory responses. CONCLUSIONS: HK2-mediated glycolysis promotes inflammatory responses in gingival tissues, and therefore glycolysis can be targeted in order to inhibit the progression of periodontal inflammation.

The role of pretreatments in handling antibiotic resistance genes in anaerobic sludge digestion - A review.

Sludge is among the most important reservoirs of antibiotic resistance genes (ARGs), which would cause potential environmental risks with the sludge utilization. Currently, anaerobic digestion (AD) is effective to simultaneously realize the resource recovery and pollutants removal, including antibiotic resistance genes (ARGs), and various pretreatments are used to enhance the performance. Recently, plentiful publications have focused on the effects of pretreatment on ARGs removal, but the contradictory results are often obtained, and a comprehensive understanding of the research progress and mechanisms is essential. This study summarizes various pretreatment techniques for improving AD efficiency and ARGs reduction, investigates promising performance in ARGs removal when pretreatments combined with AD, and analyzes the potential mechanisms accounting for ARGs fates. The results showed that although thermal hydrolysis pretreatment showed the best performance in ARGs reduction during the pretreatment process, the significant rebound of ARGs would occur in the subsequent AD process. Conversely, ozone pretreatment and alkali pretreatment had no significant effect on ARGs abundance in the pretreatment stage, but could enhance ARGs removal by 15.6-24.3 % in the subsequent AD. Considering the efficiency and economic effectiveness, free nitrous acid pretreatment would be a promising and feasible option, which could enhance methane yield and ARGs removal by up to 27 % and 74.5 %, respectively. Currently, the factors determining ARGs fates during pretreatment and AD processes included the shift of microbial community, mobile genetic elements (MGEs), and environmental factors. A comprehensive understanding of the relationship between the fate of ARGs and pretreatment technologies could be helpful for systematically evaluating various pretreatments and facilitating the development of emerging and effective pretreatment techniques. Moreover, given the effectiveness, economic efficiency and environmental safety, we called for the applications of modern analysis approaches such as metagenomic and machine learning on the optimization of pretreatment conditions and revealing underlying mechanisms.

PINK1-mediated mitophagy reduced inflammatory responses to Porphyromonas gingivalis in macrophages.

OBJECTIVE: Mitochondria are strained by microbial stimuli in the periodontal niche. Damaged mitochondria are cleared by mitophagy. The purpose of the study was to explore whether mitophagy participated in the progress of periodontitis and whether activation of mitophagy can inhibit inflammatory responses to bacterial infection in macrophages. METHODS: Mitophagy-related genes were measured in the healthy and inflamed human gingiva. Bone marrow-derived macrophages (BMDMs) were infected with Porphyromonas gingivalis. Dexmedetomidine, urolithin A, and resveratrol were used to activate mitophagy, while small interference RNA was utilized to knock down PTEN-induced putative protein kinase 1 (PINK1). Activation of mitophagy-related genes and colocalization of them were detected by Western blot and confocal imaging. Damages of mitochondria, accumulation of mitochondrial reactive oxygen species (mtROS), and production of IL-1ß, IL-6, and TNF-α were measured. RESULTS: Levels of mitophagy-related genes were decreased in inflamed periodontal tissues and P. gingivalis-infected BMDMs. Dexmedetomidine, urolithin A, and resveratrol activated mitophagy, leading to reduced mitochondria damages, decreased mtROS generation, and inhibited IL-1ß, IL-6, and TNF-α production. PINK1 knockdown reduced dexmedetomidine, urolithin A, and resveratrol-induced anti-inflammatory effect. CONCLUSION: Inhibited mitophagy participated in the progress of periodontitis. Activation of mitophagy may become a therapeutic target during the progress of periodontitis by reducing mtROS.

Periodontal-orthodontic interdisciplinary management of a "periodontally hopeless" maxillary central incisor with severe mobility: A case report and review of literature.

BACKGROUND: Treating periodontally hopeless teeth with advanced bone resorption and severe tooth mobility is a great challenge for both orthodontists and periodontists. Biofilm-induced periodontal inflammation and occlusal trauma-related inflammation may synergistically aggravate tooth mobility. This case report illustrates that even periodontally hopeless teeth can be saved and have long-term stability with comprehensive periodontal treatment to control periodontal inflammation and promote periodontal bone regeneration and intricate orthodontic mechanical control to correct cross bite and occlusal trauma. CASE SUMMARY: A 27-year-old female patient whose chief complaint was severe tooth mobility and discomfort of the maxillary incisor was diagnosed with severe aggressive periodontitis by clinical and radiographic examinations. To reduce tooth mobility and establish stable occlusion, we combined orthodontic treatment with periodontal therapy to preserve the tooth. Orthodontic treatment was performed after basic periodontal therapy and periodontal surgery. The loosened upper right central incisor was successfully retained, and the periodontal tissue remained stable during follow-up. CONCLUSION: Teeth with severe mobility and bone loss can be saved through interdisciplinary treatment when periodontal inflammation is strictly controlled.

Difference in the alveolar bone remodeling between the adolescents and adults during upper incisor retraction: a retrospective study.

The purpose of this study was to compare the difference of alveolar bone remodeling between the adolescents and adults in the maxillary incisor area during retraction. This retrospective study included 72 female patients who needed moderate anchorage to correct the bimaxillary protrusion. Subjects were further divided into the minor group (n = 36, 11-16 years old) and adult group (n = 36, 18-35 years old). Digital lateral cephalography and cone beam CT scanning were taken in each patient before (T0) and after treatment (T1). Cephalometry was conducted to assess incisor retraction, while alveolar bone thickness (ABT), alveolar bone distance (ABD), and alveolar bone area (ABA) were detected to assess changes in the alveolar bone. No difference in the inclination of upper incisors was observed at both T0 and T1 between two groups. Changes in the alveolar bone showed a similar tendency with bone apposition on the labial side and bone resorption on the palatal side in both groups. Less increase in the labial ABT (T1-T0) and more decrease in the palatal ABT (T1-T0) was found in the adult group, leading to less total ABT in the adult group. Higher reduction in ABD (T1-T0) was found in the adult group. Moreover, more decrease in the ABA (T1-T0) was found in the adult group. Adult patients have less alveolar bone support after treatment when compared with young adolescents. Orthodontists should take the age into consideration to reduce the potential periodontal risks during the treatment planning.

Dietary Restriction Attenuates Inflammation and Protects Mouse Skin from High-Dose Ultraviolet B Irradiation.

Ultraviolet B (UVB) radiation may influence the occurrence or even worsen cutaneous disorders from inflammatory to neoplastic disorders. Dietary restriction (DR) is a well-known regimen that can retard aging-associated pathologies, and is shown by us and others that it can significantly inhibit inflammation under various conditions, including in both undisturbed and stressed settings. It is unknown whether DR could act as a nonpharmacological factor to protect skin against UVB-induced damage. In this study, we performed 30% DR to mice 1 week before UVB irradiation (798.6 mJ/cm2). Remarkably, continuous DR significantly ameliorated UVB-induced skin damage and histological changes, associated with a great reduction in the inflammatory responses in the skin. Intriguingly, refed DR mice with ad libitum diet even 24 hours postirradiation reinflamed the inflammatory responses and induced significantly strong damage to the skin. Together, this study provides the first experimental evidence that DR greatly protects mouse skin from high dose of UVB irradiation, which if translatable could have great implications in human beings.

Microtubule affinity regulating kinase 4 promoted activation of the NLRP3 inflammasome-mediated pyroptosis in periodontitis.

BACKGROUND: Microtubule dynamics plays a crucial role in the spatial arrangement of cell organelles and activation of the NLRP3 inflammasome. PURPOSE: This study aimed to explore whether microtubule affinity regulating kinase 4 (MARK4) can be a therapeutic target of periodontitis by affecting microtubule dynamics and NLRP3 inflammasome-mediated pyroptosis in macrophages. MATERIALS AND METHODS: The NLRP3 inflammasome-related genes and MARK4 were measured in the healthy and inflamed human gingival tissues. Bone marrow-derived macrophages (BMDMs) were infected with Porphyromonas gingivalis, while the MARK4 inhibitors (OTSSP167 and Compound 50) and small interference RNA were utilized to restrain MARK4. Apoptosis-associated speck-like protein (ASC) speck was detected by confocal, and levels of interleukin-1ß (IL-1ß), as well as IL-18, were assessed by ELISA. RESULTS: Increased staining and transcription of MARK4, NLRP3, ASC, and Caspase-1 were observed in the inflamed gingiva. P. gingivalis infection promoted MARK4 expression and the NLRP3 inflammasome in BMDMs. Inhibition of MARK4 decreased LDH release, IL-1ß and IL-18 production, ASC speck formation, and the pyroptosis-related genes transcription. Furthermore, MARK4 inhibition reduced microtubule polymerization and acetylation in P. gingivalis-infected BMDMs. CONCLUSIONS: MARK4 promoted NLRP3 inflammasome activation and pyroptosis in P. gingivalis-infected BMDMs by affecting microtubule dynamics. MARK4 inhibition might be a potential target in regulating the NLRP3 inflammasome during periodontitis progress.

Hexokinase 2-mediated glycolysis promotes receptor activator of NF-κB ligand expression in Porphyromonas gingivalis lipopolysaccharide-treated osteoblasts.

BACKGROUND: Glucose metabolism plays a pivotal role in sustaining the inflammatory response to microbial stimulation by providing sufficient energy in immune cells. The main purpose of our study was to explore whether hexokinase 2 (HK2)-mediated glycolysis affected the expression of receptor activator of NF-κB Ligand (RANKL) in Porphyromonas gingivalis lipopolysaccharide (P. gingivalis-LPS)-treated osteoblasts and evaluate the potential involvement of the AKT/PI3K pathway activation during HK2-mediated glycolysis. METHODS: Primary mice osteoblasts were treated with P. gingivalis-LPS, whereas the HK2 inhibitor (Lonidamine, LND) and small interference RNA were used to restrain HK2 expression. Conditioned medium from osteoblasts was utilized for culturing osteoclast precursors. The mRNA and protein levels of genes involved in glycolysis and bone metabolism including RANKL and osteoprotegerin (OPG) were detected by real-time PCR and western blotting. HK2 and lactate levels were detected by ELISA. Tartrate-resistant acid phosphatase (TRAP) staining was utilized to assess osteoclast formation. The involvement of the AKT/PI3K pathway in osteoblasts was explored by Western blotting. RESULTS: P. gingivalis-LPS enhanced HK2 expression along with rising glycolysis in osteoblasts. LND and HK2-knockdown decreased RANKL expression and the RANKL/OPG ratio in osteoblasts, leading to less osteoclast formation from osteoclast precursors as evidenced by TRAP staining, while the osteogenic potential and proliferation of osteoblasts were not affected by HK2-knockdown. Moreover, P. gingivalis-LPS activated the AKT/PI3K pathway, which could regulate HK2 and RANKL expression in osteoblasts. CONCLUSIONS: HK2-mediated glycolysis promoted RANKL in osteoblasts and enhanced osteoclast differentiation. Targeting glycolysis may provide novel therapeutic methods for reducing alveolar bone loss.