Periodontitis causally affects the brain cortical structure: A Mendelian randomization study.

OBJECTIVE: To estimate whether genetically proxied periodontitis causally impacts the brain cortical structure using Mendelian randomization (MR). BACKGROUND: Periodontitis is one of the most prevalent inflammatory conditions globally, and emerging evidence has indicated its influences on distal organs, including the brain, whose disorders are always accompanied by magnetic resonance imaging (MRI)-identified brain cortical changes. However, to date, no available evidence has revealed the association between periodontitis and brain cortical structures. METHODS: The instrumental variables (IVs) were adopted from previous genome-wide association study (GWAS) studies and meta-analyses of GWAS studies of periodontitis from 1844 to 5266 cases and 8255 to 12 515 controls. IVs were linked to GWAS summary data of 51 665 patients from the ENIGMA Consortium, assessing the impacts of genetically proxied periodontitis on the surficial area (SA) or the cortical thickness (TH) of the global and 34 MRI-identified functional regions of the brain. Inverse-variance weighted was used as the primary estimate; the MR pleiotropy residual sum and outlier (MR-PRESSO), the MR-Egger intercept test, and leave-one-out analyses were used to examine the potential horizontal pleiotropy. RESULTS: Genetically proxied periodontitis affects the SA of the medial orbitofrontal cortex, the lateral orbitofrontal cortex, the inferior temporal cortex, the entorhinal cortex, and the temporal pole, as well as the TH of the entorhinal. No pleiotropy was detected. CONCLUSIONS: Periodontitis causally influences the brain cortical structures, implying the existence of a periodontal tissue-brain axis.

Periodontitis is associated with altered brain structure and function in normal cognition middle-aged and elderly individuals.

BACKGROUND: Numerous studies have proposed that periodontitis is a potential risk factor for Alzheimer's disease. However, the association between periodontitis and brain normal cognition in aged and elderly individuals (NCs) is unclear. Such a link could provide clues to Alzheimer's disease development and strategies for early prevention. OBJECTIVE: To explore the associations between periodontal condition and metrics of both brain structure and function among NCs with the help of multimodal magnetic resonance imaging (MRI). METHODS: High-resolution T1-weighted structural data, resting-state functional-MRI data, and measures of periodontal condition were collected from 40 NCs. Cortical volume, thickness, and area as well as regional homogeneity were calculated with the aid of DPABISurf software. Correlation analyses were then conducted between each imaging metric and periodontal index. RESULTS: Consistent negative correlations were observed between severity of periodontitis (mild, moderate, severe) and cortical volume, area, and thickness, not only in brain regions that took charge of primary function but also in brain regions associated with advanced cognition behavior. Among participants with mild attachment loss (AL) and a shallow periodontal pocket depth (PPD), periodontal index was positively correlated with most measures of brain structure and function, while among participants with severe AL and deep PPD, periodontal index was negatively correlated with measures of brain structure and function (all p < .005 for each hemisphere). CONCLUSIONS: Our results demonstrate that periodontitis is associated with widespread changes in brain structure and function among middle-aged and elderly adults without signs of cognitive decline, which might be a potential risk factor for brain damage.

Nuclear imaging to visualize periodontal inflammation: Findings of a randomized controlled trial.

OBJECTIVE: To investigate non-surgical periodontal therapy by 18F-fluorodeoxyglucose (2-[18F]FDG) uptake using positron emission tomography (PET) integrated with computed tomography (CT). SUBJECTS: Eighty-five patients with peripheral artery disease and severe periodontitis-randomized into three groups receiving therapy with (PT1; n = 29) or without (PT2; n = 28) systemic antibiotics or no treatment (controls: n = 28)-underwent nuclear imaging at baseline and at 3 months. RESULTS: Clinical inflammation (periodontal inflamed surface area; PISA) did not significantly differ across the groups at baseline (p = 0.395) but was significantly reduced at 3 months (p < 0.001), and significantly more so in the PT1/PT2 groups than in the control group (p < 0.001/=0.025) and in the PT1 than in the P2 group (p = 0.001). Radiotracer uptake was measured in both jaws using maximum and mean 'standardized uptake values' (SUVmax, SUVmean) and 'target-to-background ratios' (TBRmax, TBRmean). At 3 months, reductions were relatively small in absolute numbers and fell short of revealing correlations with PISA or significant differences across the groups. Still, they were very consistent in both treatment groups, whereas reductions were not consistently seen in the control group. CONCLUSIONS: 2-[18F]FDG PET/CT scans did reflect the clinical effects of periodontal treatment very consistently but, for reasons yet to be clarified, less closely than expected.

ADGRU: Adaptive DenseNet with gated recurrent unit for automatic diagnosis of periodontal bone loss and stage periodontitis with tooth segmentation mechanism.

BACKGROUND: Periodontics and gingivitis are two of the most widely prevalent illnesses that affect people nowadays. The sixth most common disease in the world is periodontitis, and detecting periodontal bone loss is essential in the earlier condition and is crucial for the development of the proper diagnosis. Early bone loss detection can be assisted by using computer-assisted radiography examination. Understanding disease progression helps to select the most effective treatment action. OBJECTIVES: An effective deep model is suggested to detect periodontal bone loss at an earlier stage for preventing the progression of Periodontics bone loss. METHODS: This work is intimated by collecting images from online resources. Further, the images gathered from the dataset are preceded by the tooth segmentation which is done using DenseUNet + + . Further, the segmented images are given to the Adaptive DenseNet with Gated Recurrent Unit (AD-GRU) for detecting periodontal bone loss and this diagnosis is used for the periodontitis stage, where the ADGRU performance is augmented by optimizing the attributes using the Refined Red Kite Optimization Algorithm (RRKOA). RESULTS: The offered approach attained an accuracy of 94.45% which is higher than the88.63%, 90.58%, 89.54%, and 92.96% attained by the LSTM, DenseNet, GRU, DenseNet-GRU. DATA CONCLUSION: The findings of the simulation proved the designed framework outperformed the traditional model with high accuracy. CLINICAL RELEVANCE: The developed effectual deep model-based periodontal bone loss and stage periodontitis diagnosis structure is used in healthcare applications.

Periodontitis and brain magnetic resonance imaging markers of Alzheimer's disease and cognitive aging.

INTRODUCTION: We examined the association of clinical, microbiological, and host response features of periodontitis with MRI markers of atrophy/cerebrovascular disease in the Washington Heights Inwood Columbia Aging Project (WHICAP) Ancillary Study of Oral Health. METHODS: We analyzed 468 participants with clinical periodontal data, microbial plaque and serum samples, and brain MRIs. We tested the association of periodontitis features with MRI features, after adjusting for multiple risk factors for Alzheimer's disease/Alzheimer's disease-related dementia (AD/ADRD). RESULTS: In fully adjusted models, having more teeth was associated with lower odds for infarcts, lower white matter hyperintensity (WMH) volume, higher entorhinal cortex volume, and higher cortical thickness. Higher extent of periodontitis was associated with lower entorhinal cortex volume and lower cortical thickness. Differential associations emerged between colonization by specific bacteria/serum antibacterial IgG responses and MRI outcomes. DISCUSSION: In an elderly cohort, clinical, microbiological, and serological features of periodontitis were associated with MRI findings related to ADRD risk. Further investigation of causal associations is warranted.

A cascading learning method with SegFormer for radiographic measurement of periodontal bone loss.

OBJECTIVE: Marginal alveolar bone loss is one of the key features of periodontitis and can be observed via panoramic radiographs. This study aimed to establish a cascading learning method with deep learning (DL) for precise radiographic bone loss (RBL) measurements at specific tooth positions. MATERIALS AND METHODS: Through the design of two tasks for tooth position recognition and tooth semantic segmentation using the SegFormer model, specific tooth's crown, intrabony portion, and suprabony portion of the roots were obtained. The RBL was subsequently measured by length through these three areas using the principal component analysis (PCA) principal axis. RESULTS: The average intersection over union (IoU) for the tooth position recognition task was 0.8906, with an F1-score of 0.9338. The average IoU for the tooth semantic segmentation task was 0.8465, with an F1-score of 0.9138. When the two tasks were combined, the average IoU was 0.7889, with an F1-score of 0.8674. The correlation coefficient between the RBL prediction results based on the PCA principal axis and the clinicians' measurements exceeded 0.85. Compared to those of the other two methods, the average precision of the predicted RBL was 0.7722, the average sensitivity was 0.7416, and the average F1-score was 0.7444. CONCLUSIONS: The method for predicting RBL using DL and PCA produced promising results, offering rapid and reliable auxiliary information for future periodontal disease diagnosis. CLINICAL RELEVANCE: Precise RBL measurements are important for periodontal diagnosis. The proposed RBL-SF can measure RBL at specific tooth positions and assign the bone loss stage. The ability of the RBL-SF to measure RBL at specific tooth positions can guide clinicians to a certain extent in the accurate diagnosis of periodontitis.

Correlation between the presence of tonsilloliths and the bone defects by periodontitis on imaging analysis: a pilot study.

BACKGROUND: Very recently, a significant relationship between tonsilloliths and dental plaque-related pathologies was reported using digital panoramic radiographs. Their dynamics over time suggest that tonsilloliths may be in a permanently active phase that functions to remove foreign matter. The aim of the study was to evaluate the relationship between the occurrence of tonsilloliths and the extent of periodontitis. METHODS: A total of 608 patients who underwent both CT and panoramic radiographs were included in the study. Both of two imaging were retrospectively and independently assessed with respect to the presence of tonsilloliths detected on CT and panoramic radiographs, and bone defects caused by periodontitis detected on panoramic radiographs. The type of retrospective study is case-control. Then, the differences between age groups were evaluated with respect to the degree of bone resorption and its correlation with the presence of tonsilloliths. The relationships between categorical variables were assessed using Pearson's correlation coefficient or Spearman's correlation coefficient. RESULTS: There was a significant relationship between tonsilloliths on CT and the extent of the bone defect on panoramic radiographs (Spearman's correlation coefficient, r = 0.648, p = 0.043). In addition, there was a significant difference in the extent of the bone defect caused by periodontitis between subjects with and without tonsilloliths in the 60 to 69-year-old group (Mann-Whitney U test, p = 0.025), 70 to 79-year-old group (Mann-Whitney U test, p = 0.002), and 80 to 89-year-old group (Mann-Whitney U test, p = 0.022), but not in other age groups (Mann-Whitney U test: under 9-year-old group, p = 1.000; 10 to 19-year-old group, p = 1.000; 20 to 29-year-old group, p = 0.854; 30 to 39-year-old group, p = 0.191, 40 to 49-year-old group, p = 0.749; 50 to 59-year-old group, p = 0.627; ≥90-year-old group, p = 1.000). CONCLUSIONS: The presence of tonsilloliths was related to the extent of periodontitis because the structures were responding dynamically.

Men with HIV have increased alveolar bone loss.

BACKGROUND: Periodontal health in men with HIV remains understudied, despite suggestions of associations between HIV infection and gingival pocketing, periodontal attachment loss, and gingival inflammation. As antiretroviral therapy (ART) has improved the quality of life for people living with HIV (PLWH), aging-related risk factors and comorbidities, including periodontitis, have emerged. This study aims to assess alveolar bone height, gingival crevicular fluid (GCF) cytokines, and periodontal disease activity in men with and without HIV. METHODS: Ninety-three men (50 HIV+, 43 HIV-) aged 35-70 years were recruited from Columbia University Irving Medical Center clinics. Periodontal examination, GCF collection, and intraoral radiographs were collected. Statistical analysis was conducted with t-tests for continuous variables and chi-squared tests for categorical variables. RESULTS: While no significant differences were observed in bleeding on probing, clinical attachment loss and pocket depths, men with HIV exhibited significantly greater alveolar crestal height on radiographs compared to men without HIV (HIV + 3.41+/-1.35 mm, HIV- 2.64+/-1.01 mm; p = 0.004), reflecting greater alveolar bone loss. CONCLUSIONS: Men living with HIV demonstrate increased alveolar bone loss compared to those without HIV, possibly mediated by elevated IL6 levels. These results underscore the importance of comprehensive oral health management in PLWH and highlight the need for further research understanding the mechanisms linking HIV infection, cytokine dysregulation, and periodontal health.

Effect of osteoarthritis on alveolar bone loss in experimental periodontitis in rats.

BACKGROUND: There is scarce information about the relationship between periodontal disease and osteoarthritis. This study investigated the effect of surgically induced osteoarthritis on alveolar bone loss in experimental periodontitis in rats. METHODS: 12 rats were divided into test and control groups. On day 1, the animals were anaesthetized, and silk ligatures were ligated around 6 maxillary posterior teeth in each animal from both groups. Surgical induction of osteoarthritis was performed on the left knees in the test group. No knee surgeries were performed in the control group. The ligatures were kept in place for 30 days, at which time the animals were euthanatized, and the maxillae and knee joints were harvested and processed for histological analysis. The alveolar bone loss was assessed using a zoom stereomicroscope. RESULTS: The knee joint histologic sections of the control group showed normal joint features, whereas in the test group there were substantial changes typical of osteoarthritis, including wide joint spaces, prominent monocytic infiltration of the synovium, invasion of periarticular bone, and decreased chondrocyte density. Comparison of the bone height between the groups showed a significantly higher bone loss in the test than in the control group The marginal mean bone height, adjusted for covariates and the intraclass correlation between sites, was 1.19 and 0.78 mm in the test and control groups, respectively (p < .0001). CONCLUSIONS: Surgically induced osteoarthritis leads to greater alveolar bone loss in the experimental periodontitis model in rats.

The tree shrew as a new animal model for the study of periodontitis.

AIM: Periodontitis is an inflammatory, infectious disease of polymicrobial origin that can damage tooth-supporting bone and tissue. Tree shrews, evolutionarily closer to humans than commonly used rodent models, have been increasingly used as biomedical models. However, a tree shrew periodontitis model has not yet been established. MATERIALS AND METHODS: Periodontitis was induced in male tree shrews/Sprague-Dawley rats by nylon thread ligature placement around the lower first molars. Thereafter, morphometric and histological analyses were performed. The distance from the cemento-enamel junction to the alveolar bone crest was measured using micro-computed tomography. Periodontal pathological tissue damage, inflammation and osteoclastogenesis were assessed using haematoxylin and eosin staining and quantitative immunohistochemistry, respectively. RESULTS: Post-operatively, gingival swelling, redness and spontaneous bleeding were observed in tree shrews but not in rats. After peaking, bone resorption decreased gradually until plateauing in tree shrews. Contrastingly, rapid and near-complete bone loss was observed in rats. Inflammatory infiltrates were observed 1 week post operation in both models. However, only the tree shrew model transitioned from acute to chronic inflammation. CONCLUSIONS: Our study revealed that a ligature-induced tree shrew model of periodontitis partly reproduced the pathological features of human periodontitis and provided theoretical support for using tree shrews as a potential model for human periodontitis.

Five-year radiological findings from a randomized controlled trial of four periodontitis treatment strategies.

Radiographic findings from long-term studies of periodontitis treatment have rarely been reported. Although bone destruction is a prominent feature of periodontitis, the long-term effect on alveolar bone levels of different treatment strategies, with or without adjunctive metronidazole (MTZ), has not been reported. We investigated the 5-year radiographic outcome of therapy in patient groups treated with conventional scaling and root planing (SRP) or same-day full-mouth disinfection (FDIS), with or without adjunctive MTZ. Following a 3-month oral hygiene phase, 184 periodontitis patients were randomly allocated to one of four treatment regimens: (i) FDIS+MTZ; (ii) FDIS+placebo; (iii) SRP+MTZ; or (iv) SRP+placebo. Following active treatment, patients received biannual maintenance. In total, 161 patients (87.5%) completed the 5-year follow-up examination, at which the radiographic bone level (RBL), clinical attachment level, probing pocket depth, presence of plaque, and bleeding were recorded again. At the 5-year follow up examination, minor radiological bone loss was observed in the intervention groups FDIS+placebo, SRP+MTZ, and SRP+placebo; by contrast, the FDIS+MTZ group did not show any change in RBL. Full-mouth disinfection did not generally perform better than conventional SRP performed over a period of 2 to 4 weeks.

Accuracy of clinical and radiographic recording protocols for diagnosing periodontitis.

OBJECTIVE: To compare the accuracy of periodontal examination at 6-sites full-mouth protocol with clinical and radiographic partial-mouth recording protocols (PRPs) to diagnose periodontitis considering new 2018 case definition. METHODS: Periodontitis was diagnosed by full-mouth assessment of clinical attachment level (CAL) at 6-sites (n = 8529) according to 2018 case definition (standard reference). Three clinical and radiographic PRPs were considered: (i) 4 interproximal sites of all teeth (4-sites, full-mouth); (ii) 6-sites on Community Periodontal Index of Treatment Needs (CPITN) teeth (6-sites, CPITN teeth); (iii) 4-sites on CPITN teeth (4-sites, CPITN teeth); (iv) radiographic examination on interproximal sites of all teeth (rM-D, full-mouth); and (v) radiographic examination on interproximal sites of CPITN teeth (rM-D, CPITN teeth) using Image J®. Sensitivity, specificity, Positive Predictive Value (PPV) and Negative Predictive Value (NPV), accuracy, and Κappa (k) were estimated (α = 0.05). RESULTS: The 4-sites, full-mouth protocol showed 100% sensitivity and NPV, 79.87% PPV, low specificity (38.32%), 69.30% accuracy, and poor agreement (k = 0.468). 6-sites and 4-sites CPITN teeth protocols showed 100% PPV and specificity, sensitivity and NPV of >60%, accuracy of >80%, and good agreement (k > 0.65). All clinical PRPs outperformed radiographic protocols. CONCLUSION: Clinical PRPs using index teeth are highly accurate in diagnosing periodontitis considering 2018 case definition.

Effect of telmisartan on an experimental model of periodontitis in mice.

OBJECTIVE: This study was performed to explore the impact of telmisartan on experimental periodontitis in mice, in terms of alveolar bone destruction, by using micro-computed tomography analysis. MATERIALS AND METHODS: Male BALB/c mice were divided into four groups of 7 to 9 mice each: control (C) group; experimental periodontitis (E) group; experimental periodontitis-plus-telmisartan 5 mg/kg (ET5) group; and experimental periodontitis-plus-telmisartan 10 mg/kg (ET10) group. The mice in Group C were not subjected to experimental periodontitis. The other mice from Groups E, ET5 and ET10 were exposed to periodontitis. Periodontitis was induced by inoculation with Porphyromonas gingivalis. RESULTS: Telmisartan significantly suppressed both the reduction in alveolar bone height and increase of root exposure caused by P. gingivalis infection. When mice were treated with telmisartan, the decrease in the bone volume fraction induced by the infection was notably recovered. In addition, telmisartan reversed P. gingivalis-induced alterations in the microstructural parameters of trabecular bone, except trabecular thickness.No significant difference was evident between Groups ET5 and ET10 in both the extent of alveolar bone loss and microstructural parameters assessed, except bone volume fraction and trabecular number. CONCLUSION: Telmisartan may have potential benefits as a host modulation agent for the therapy of periodontitis.

Clinical, radiographic characterizations and complications of maxillary molar in a periodontitis population: a retrospective study based on CBCT radiography.

OBJECTIVE: This study was aimed to delineate the clinical, CBCT radiographic characteristics, and complications of maxillary molar in a periodontitis population. MATERIALS AND METHODS: Medical records and CBCT images were utilized to identify adult patients with periodontitis in a tertiary referral dental hospital between June 2019 and December 2020. CBCT scan images were used to characterize the detailed bone thickness, absorbing height, and position of maxillary molar as well as their associated conditions. All relevant descriptive epidemiological data, clinical information, radiographic details, and associated complications were recorded and statistically analyzed. RESULTS: According to the above criteria, 577 eligible periodontitis patients were enrolled and defined as research cohort here with mean age 45 ± 4.8 years. Male patients outnumbered females with a gender ratio of 1.23:1. Our results demonstrated that the bone loss of maxillary first molar was more serious than that of second molar with tooth position symmetry. The occurrence of various complications (periodontal abscess, pulp lesions, furcation lesion, and mucosal thickening) was significantly correlated to periodontal-related clinical parameters of maxillary molar. CONCLUSIONS: Our results demonstrated the more serious bone loss of maxillary first molar with tooth position symmetry. The occurrence of various complications was significantly correlated to periodontal-related clinical parameters. Our findings offer valuable information concerning the clinical, radiographic characteristics, and complications of maxillary molar in a periodontitis population. CLINICAL RELEVANCE: These findings are beneficial for clinicians to comprehensively understand the bone status, pathogenesis, and clinical management of maxillary molar in periodontitis.

Cone beam computed tomography assessment of the prevalence and association of pulp calcification with periodontitis.

Periodontitis has a known association with pathological calcification in the cardiovascular system. Considering the close anatomic and circulatory association between dental pulp and the periodontium, this study aimed to evaluate the prevalence of pulp calcification (PC) under different periodontal conditions, as well as the associations of PC with the degree of periodontal damage, via cone beam computed tomography (CBCT) examination. In this study, 55 patients were categorized into three groups according to periodontal condition: group 1 (healthy controls), group 2 (periodontitis stage I-II), and group 3 (periodontitis stage III-IV). PC and radiographic bone loss (RBL) was assessed by CBCT in sagittal, axial, and coronal views, and statistical analyses were conducted. PC was identified in 378 of 1170 teeth (32.3%). The prevalence significantly differed among the three groups (P < 0.001). Group 2 had a 2.43-fold (P < 0.001, 95% confidence interval [CI] 1.64-3.61) higher risk of PC than group 1; and the risk of PC was 3.04-fold (P < 0.001, 95% CI 2.06-4.48) higher in group 3 than group 1. Teeth with more severe RBL exhibited a higher prevalence of PC (P < 0.001). Molar teeth had a higher risk of PC than incisors and premolars. In conclusion, the occurrence of PC is related to the periodontal state, and the prevalence of PC is higher in teeth with periodontitis; tooth type and periodontitis status are important risk factors for PC.

Medication-related osteonecrosis of the jaw using periodontitis-induced rat before tooth extraction.

OBJECTIVE: This study aimed to investigate the occurrence of medication-related osteonecrosis of the jaw (MRONJ) after tooth extraction due to periodontitis in ovariectomized rats. METHODS: Twenty-four osteoporosis-induced rats were administered with zoledronic acid (ZA; ZA group) or saline (CONT group). In both groups, tooth extraction was performed after inducing periodontitis, and all animals were sacrificed 8-week after tooth extraction. RESULTS: Micro-CT of the tibia showed that the bone volume fraction, bone surface density, trabecular number, and bone mineral density were significantly higher in the ZA group than in the CONT group. Histologically, the proliferative zone on the growth plate was thicker in the ZA group than in the CONT group. Micro-CT of the extraction sites revealed that the bone volume fraction was significantly higher in the ZA group than in the CONT group. Radiologically, the ZA group showed partial healing and delayed healing. Histological analysis revealed normal bone healing status with completely healed epithelium in the extraction sites of the CONT group, whereas abnormal empty osteocytes in the necrotic bone and inflammatory infiltration were observed in the ZA group. CONCLUSION: The incidence of MRONJ increased in the rats administered with ZA.

Clinical And Radiographic Assessment Of Autogenous Dentin Nanoparticles In Treatment Of Stage Iii Periodontitis: A Split-Mouth Clinical Study.

Objectives: To compare autogenous dentin nanoparticles with allograft bone grafts in the treatment of stage III periodontitis. Method: The randomised study was conducted at the Department of Oral Medicine and Periodontology, Faculty of Oral and Dental Medicine, Kafrelsheikh University Hospital, Egypt, from January 2021 to January 2022, and comprised adult patients of either gender with stage III periodontitis. Each patient's bilateral intrabony defect was randomly treated with an allograft on one side and a graft made of dentin nanoparticles on the testside. Each patient'sremoved tooth was ground into these nanoparticles. Both groups had their probing pocket depth and clinical attachment loss evaluated at baseline and six months aftersurgery. Additionally, digital periapical films were collected in both groups at baseline and six months after therapy to assess vertical bone loss. Data was analysed using SPSS 20. RESULTS: Of the 20 patients, 8(40%) were males and 12(60%) were females with overall mean age 31.00±4.06 years(range: 18-50 years). Of the 40 sites, 20(50%) each were in test and control groups. Compared to baseline values, both groups showed significant improvement in probing pocket depth, clinical attachment loss and vertical bone loss post intervention (p<0.05). There was no significant difference between the postoperative outcomes of the two groups(p>0.05). CONCLUSIONS: Autogenous dentin nanoparticles were found to be an effective and promising biomaterial for bone regeneration in intrabony defects. Clinical Trial: NCT05258006 link: https://clinicaltrials.gov/ct2/show/NCT05258006, Registration date of the Trial 10/2/2022.

Dec2 negatively regulates bone resorption in periodontitis.

BACKGROUND AND OBJECTIVES: The potential role of the transcription factor Differentiated embryo-chondrocyte 2 (Dec2) in the progression of inflammatory diseases such as periodontitis has been unclear. Here, the effect of Dec2 on the expression of RANKL and on osteoclastogenesis was determined. MATERIAL AND METHODS: Wild-type (WT) and Dec2 knockout (KO) mice as a model for periodontitis were used to assess alveolar bone resorption by microcomputed tomography (CT). Western blot, flow cytometry, quantitative real-time PCR, and immunohistochemical analyses were utilized to detect inflammation and osteoclasts. Luciferase reporter and Chromatin immunoprecipitation (ChIP) assays examined the interaction between Dec2 and RANKL. RESULTS: Micro-CT showed that the alveolar bone resorption of Dec2KO mice was more severe than WT mice after treatment with P. gingivalis. Immunohistochemistry and Tartrate-resistant acid phosphatase staining showed active osteoclast differentiation in Dec2KO mice. There was an increase in CD11b+ F4/80+ and CD4+ RANKL+ T cells in Dec2KO mice treated with P. gingivalis. Moreover, inflammatory and immune markers were expressed at significantly higher levels in gingival mononuclear cells in Dec2KO mice. Furthermore, luciferase reporter and ChIP assays confirmed the direct binding of Dec2 protein to the RANKL gene. CONCLUSION: Dec2 has an immune regulation ability that modulates P. gingivalis-induced periodontitis via RANKL.

Comparison of the efficacy of periodontal prognostic systems in predicting tooth loss.

AIM: The aim of this analysis was to assess how different tooth-prognosis systems could predict tooth loss in a cohort of periodontitis patients followed up prospectively during supportive periodontal care (SPC). MATERIALS AND METHODS: Clinical and radiographic data of 97 patients undergoing regular SPC for 5 years were used to assign tooth prognosis using four different systems (McGuire & Nunn, 1996; Kwok & Caton, 2007; Graetz et al., 2011; Nibali et al., 2017). Three independent examiners assigned tooth prognosis using all four systems, following a calibration exercise. The association between prognostic categories and tooth loss was tested for each prognostic system separately and across prognostic systems. RESULTS: All four systems showed good reproducibility and could identify teeth at higher risk of being lost during 5 years of SPC; the risk of tooth loss increased with the worsening of tooth-prognosis category (p < .0001). Although specificity and negative predictive values were good, low sensitivity and positive predictive values were detected for all systems. CONCLUSIONS: Previously published periodontal prognostic systems exhibited good reproducibility and predictive ability for tooth retention. However, low sensitivity was detected, with several teeth in the worst prognosis category being retained at 5 years. Some modifications in the number of categories and their definitions are suggested.

Assessment of periodontitis grade in epidemiological studies using interdental attachment loss instead of radiographic bone loss.

AIM: Comparison of grading according to radiographic bone loss (BL) or according to interdental clinical attachment loss (CAL). MATERIALS AND METHODS: In 100 periodontitis patients at the Department of Periodontology of Goethe-University Frankfurt, Germany, periodontitis grade was assigned by (i) indirect evidence using BL at the most affected tooth divided by root length and (ii) CAL at the most affected tooth divided by root length of the respective tooth type according to root length in German and Swedish cohorts. The resulting quotients were divided by age. RESULTS: Patients (age: 53.5 ± 10.4 years; 57 females; 16 smokers; no diabetes; stage: 78 III, 22 IV) were by either method assigned to grade B or C (BL: 35 B, 65 C; CAL [German]: 23 B, 77 C; [Swedish]: 29 B, 71 C). Using root length (German cohort), agreement was 76% (kappa: 0.427; fair to good/moderate agreement) and 72% (Swedish cohort; kappa: 0.359; poor/fair agreement). Molars were most frequently chosen (BL: 64%; CAL: 71%). CONCLUSIONS: Assignment of periodontitis grade by indirect evidence using BL or CAL using standard root length of the German cohort showed fair to good/moderate agreement. Thus, grade assignment by CAL may be used in epidemiologic studies where radiographs are not available.