Periodontitis and alveolar resorption in human skeletal remains: The relationship between quantitative alveolar bone loss, occlusal wear, antemortem tooth loss, dental calculus and age at death in a low socioeconomic status, modern forensic human collection from Yucatan.

OBJECTIVE: This paper assesses the relationship between the distance between the cemento-enamel junction and alveolar crest and risk factors commonly associated with periodontitis. MATERIALS: Eighty individuals between 28 and 92 years old with known biological sex and age were analyzed from a 20th century forensic human collection from Merida, Yucatan (Mexico). METHODS: Macroscopic assessment, along with metric analysis, was employed using a probe. RESULTS: Ante-mortem tooth loss was positively correlated with the distance between the cemento-enamel junction and alveolar crest, as was the presence of root calculus in females. CONCLUSIONS: Cemento-enamel junction to alveolar crest distance is not a reliable indicator of periodontitis since it is not directly related to periodontitis-causing infectious pathogens, and since ante-mortem tooth loss can affect root exposure. SIGNIFICANCE: This study demonstrates that a purely quantitative approach to diagnosing periodontitis in archaeological and forensic human remains can be misleading. LIMITATIONS: The skeletal collection is only representative of the low socioeconomic class of Merida, and its female cohort is underrepresented. In addition, because the Xoclan collection is modern, limitations (particularly with respect to tooth wear) of the applicability of these interpretations to older archaeological remains exist. SUGGESTION FOR FURTHER RESEARCH: A combination of quantitative and qualitative characteristics of alveolar bone is needed to reliably diagnose periodontitis in skeletal populations.

Clinical status and assessment of caries on first permanent molars in a group of 6- to 13-year-old Tunisian school children.

AIM: The present survey aimed to highlight the clinical status of first permanent molars (FPMs) among a group of children aged between 6 and 13 years in public primary schools in Tunisia and to determine the association between FPMs' dental caries, gingival bleeding, malocclusion, dental fluorosis, and enamel defects. MATERIALS AND METHODS: The survey involved a cross-sectional study based on a dental examination conducted in public primary schools in Monastir Tunisia. A dental caries assessment was performed on FPMs using the International Caries Detection and Assessment System classification; the number of carious lesions in permanent and temporary dentition was established using the decayed/missing/filled teeth (DMFT) index. The Gingival Index and the Dental Aesthetic Index were used to determine the occurrence of gingival bleeding and malocclusions. Dean's index and the modified Development Defects of Enamel index were used to define the enamel defects. The χ2 test was used to assess the difference between more than two groups, and the level of statistical significance was set at .05%. RESULTS: A total of 545 children and 2080 FPMs were examined. The prevalence of dental caries in FPMs was recorded to be 35.8%. The overall mean DMFT index of the study population was 1.62 and the mean DMFT index was 1.41. The proportion of carious FPMs increased significantly with the age of the children (p < .05). The mandibular first permanent molar presented higher caries prevalence than its maxillary counterpart (p < .05). The presence of surfaces affected by molar incisor hypomineralization was recorded in 4.3% and the presence of surfaces affected by fluorosis was recorded in 4.6% of FPMs. No association was reported between FPMs' dental caries, gingival bleeding, malocclusion, and enamel defects (p > .05). CONCLUSION: Although the prevalence of caries in FPMs was considered moderate, health promotion programs should be implemented on a large scale to decrease the prevalence of dental caries among school children.

Prevalence of premature loss of deciduous teeth and its relationship with gender among children from Acapulco, Guerrero: a cross-sectional study.

BACKGROUND: Premature loss of deciduous teeth is the exfoliation or extraction before physiological replacement with < 50% or < 75% of the root of the substitute tooth formed or if there is > 1 mm of alveolar bone covering the permanent successor tooth organ. This study aimed to estimate the prevalence of premature tooth loss in children and identify associated factors in a health center in Acapulco, Guerrero. METHODS: We conducted a cross-sectional study in which we collected information from 109 clinical records of children examined from January 2019 to August 2021. Sociodemographic data of the children and parents were collected: socioeconomic level, non-pathological personal history, and the history of premature deciduous tooth loss. Multivariate analysis to identify factors associated with premature deciduous tooth loss was performed with CIETmap statistical software. Odds ratio (OR) and 95% confidence interval (CI) were calculated to estimate the strength of the association. RESULTS: The prevalence of premature loss of primary teeth was 40% (43/109). The leading cause was caries (84%, 36/43). The tooth organ with the highest loss occurrence was the lower right second molar (33%, 14/43). Gender was identified as an associated factor, with males having a higher risk of loss (ORa = 2.97; CI95% = 1.33-6.65). CONCLUSIONS: Our results were similar to those reported in other studies. Strategies aimed at health promotion directed at parents and children should be reinforced.

INTRODUCCIÓN: Se considera como pérdida prematura de dientes deciduos a la exfoliación o extracción antes del recambio fisiológico con < 50% o < 75% de la raíz del diente sustituto formado, o si existe > 1 mm de hueso alveolar cubriendo al órgano dentario sucesor permanente. El objetivo de este trabajo fue estimar la prevalencia de pérdida prematura dental en niños e identificar factores asociados en un centro de salud de Acapulco, Guerrero. MÉTODOS: Se llevó a cabo un estudio transversal en el que se recopiló información de 109 expedientes clínicos de niños atendidos de enero de 2019 a agosto de 2021. Se recolectaron datos sociodemográficos de los niños y los padres: nivel socioeconómico, antecedentes personales no patológicos y el antecedente de la pérdida prematura del diente deciduo. Se realizó un análisis multivariado para identificar factores asociados con la pérdida prematura de dientes deciduos con el software estadístico CIETmap. Se calcularon la razón de momios (OR) y el intervalo de confianza (IC) del 95% para estimar el grado de la asociación. RESULTADOS: La prevalencia de pérdida prematura de dientes primarios fue del 40% (43/109). La principal causa fue por caries (84%, 36/43). El órgano dentario con más ocurrencia de pérdida fue el segundo molar inferior derecho (33%, 14/43). Se identificó el sexo como factor asociado, y se observó que el sexo masculino presenta mayor riesgo de pérdida (ORa = 2.97; IC95% = 1.33-6.65). CONCLUSIONES: Nuestros resultados fueron similares a lo reportado en otros estudios. Deben reforzarse las estrategias de promoción de la salud dirigidas a los padres de familia y a sus hijos.

Differences in Brain Volume by Tooth Loss and Cognitive Function in Older Japanese Adults.

BACKGROUND: We investigated the association between tooth loss and structural brain volume and its mediating effect on the association between tooth loss and cognitive function in older Japanese. METHODS: A cross-sectional study was conducted by using the data of 494 randomly sampled community-dwelling individuals aged 65-84 years living in Tokamachi City, Japan. Total brain volume (TBV), gray matter volume (GMV), white matter volume (WMV), and hippocampal volume (HV) were measured with magnetic resonance imaging. The association of self-reported number of teeth (≥20, 1-19, and 0) with cognitive function assessed with the Japanese version of the Quick Mild Cognitive Impairment screen and structural brain volume was examined. Causal mediation analysis was performed to evaluate the mediating effect of structural brain volume. Age, sex, socioeconomic status, health behavior, comorbid conditions, and total intracranial volume were adjusted. RESULTS: Respondents with no teeth showed lower cognitive function (coefficient = -4.01; 95% confidence interval [CI]: -7.19, -0.82), lower TBV (coefficient = -10.34; 95% CI: -22.84, 2.17), and lower GMV (coefficient = -6.92; 95% CI: -14.84, 0.99) than those with ≥20 teeth (P for trends were 0.003, 0.035, and 0.047, respectively). The number of teeth was not significantly associated with WMV or HV. GMV showed a significant mediating effect on the association between the number of teeth and cognitive function (coefficient = -0.38; 95% CI: -1.14, -0.002, corresponding to 9.0% of the total effect), whereas TBV did not. CONCLUSIONS: GMV was suggested to mediate the relationship between tooth loss and lower cognitive function.

Tooth Loss, Sociodemographic Conditions and Oral Health-Related Quality of Life in the Elderly

Abstract Objective: To verify the association between impacts produced by tooth loss and sociodemographic variables in the oral health-related quality of life (OHRQoL) in the elderly. Material and Methods: This is an analytical cross-sectional study carried out in the municipality of Vitória/ES, Brazil, which sample was composed of 402 older adults. The Oral Health Impact Profile (OHIP-14) was used to measure the individuals' OHRQoL. For data analysis, descriptive and bivariate analyses were performed using the Fisher's exact test and the Mantel-Haenzsel test to assess the effects of combined dimensions. The significance level adopted was 5%. To assess the strength of association between independent variables and dimensions, Odds-Ratio (OR) with 95% confidence interval (CI) was calculated. Results: The prevalence of negative impact on OHRQoL in the elderly was 32.6%. The greatest impact perception was found in individuals with up to 10 years of schooling (p=0.021 and OR=1.602), with need for removable partial dentures (p=0.000 and OR=2.873) and those who did not accept the loss of dental elements (p=0.000 and OR=3.064). Conclusion: Older female adults with socioeconomic class C/D-E, with up to 10 years of schooling, who lost 11 or more teeth, who declared the need for removable partial dentures, suffered greater impacts caused by tooth loss on OHRQoL.

Periodontal diseases and potential risk factors in Egyptian adult population-Results from a national cross-sectional study.

BACKGROUND: Despite the interdependence of general and periodontal health, there is paucity of national representative data on the prevalence of periodontal diseases and their associated risk factors in Egyptian population. This cross-sectional study, thus, aimed to assess the prevalence of periodontitis and tooth loss among Egyptian adults and investigate the association between potential risk factors and periodontal diseases. METHODS: A total of 5,954 adults aged ≥ 20 years were included in this study as a subsample from Egypt's national oral health survey. Periodontitis was diagnosed with Community Periodontal Index 'CPI' scores ≥3 and tooth loss not due to caries was included in the analysis. Socio-demographic data and information on behavioral factors and history of diabetes were gathered in a face-to-face interview. Logistic regression was done to interpret the impact of potential predictors on the incidence of the two selected outcome variables. RESULTS: The overall prevalence of periodontitis was 26% and regression analysis revealed that higher odds of periodontitis existed among illiterate participants (OR = 1.74; 95% CI: 1.40-2.17), smokers (OR = 1.93; 95% CI: 1.69-2.20) and rural residents (OR = 1.16; 95% CI: 1.03-1.30). On the other hand, old age, frequency of dental attendance and history of diabetes were the main predictive factors for tooth loss. CONCLUSIONS: Among Egyptian adults, periodontal diseases were strongly associated with a multitude of modifiable and non-modifiable risk factors and inequalities in distribution of periodontal treatment needs were determined mainly by age, gender, level of education and residency location.

Tooth Loss Induces Memory Impairment and Gliosis in App Knock-In Mouse Models of Alzheimer's Disease.

BACKGROUND: Epidemiological studies have shown that tooth loss is associated with Alzheimer's disease (AD) and dementia. However, the molecular and cellular mechanisms by which tooth loss causes AD remain unclear. OBJECTIVE: We investigated the effects of tooth loss on memory impairment and AD pathogenesis in AppNL-G-F mice. METHODS: Maxillary molar teeth on both sides were extracted from 2-month-old AppNL-G-F mice, and the mice were reared for 2 months. The short- and long-term memory functions were evaluated using a novel object recognition test and a passive avoidance test. Amyloid plaques, amyloid-ß (Aß) levels, glial activity, and neuronal activity were evaluated by immunohistochemistry, Aß ELISA, immunofluorescence staining, and western blotting. The mRNA expression levels of neuroinflammatory cytokines were determined by qRT-PCR analysis. RESULTS: Tooth loss induced memory impairment via an amyloid-cascade-independent pathway, and decreased the neuronal activity, presynaptic and postsynaptic protein levels in both the cortex and hippocampus. Interestingly, we found that tooth loss induced glial activation, which in turn leads to the upregulation of the mRNA expression levels of the neuroinflammation cytokines tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and IL-1ß in the hippocampus. We also found that tooth loss activated a stress-activated protein kinase, c-Jun N-terminal kinase (JNK), and increased heat shock protein 90 (HSP90) levels in the hippocampus, which may lead to a glial activation. CONCLUSION: Our findings suggest that taking care of teeth is very important to preserve a healthy oral environment, which may reduce the risk of cognitive dysfunction.

Poor Oral Health and Inflammatory, Hemostatic, and Cardiac Biomarkers in Older Age: Results From Two Studies in the UK and USA.

BACKGROUND: We examined the association of objective and subjective oral health markers with inflammatory, hemostatic, and cardiac biomarkers in older age. METHODS: Cross-sectional analyses were based on the British Regional Heart Study (BRHS) comprising British men aged 71-92 years (n = 2,147), and the Health, Aging and Body Composition (HABC) Study comprising American men and women aged 71-80 years (n = 3,075). Oral health markers included periodontal disease, tooth count, dry mouth. Inflammatory biomarkers included C-reactive protein (CRP), interleukin-6 (IL-6) in both studies, and tissue plasminogen activator (t-PA), von Willebrand Factor (vWF), fibrin D-dimer, high-sensitivity Troponin T (hsTnT), and N-terminal pro-brain natriuretic peptide (NTproBNP) only in the BRHS. RESULTS: In both studies, tooth loss, was associated with the top tertile of CRP-odds ratios (ORs) (95% confidence interval [CI]) are 1.31 (1.02-1.68) in BRHS; and 1.40 (1.13-1.75) in the HABC Study, after adjusting for confounders. In the HABC Study, cumulative (≥3) oral health problems were associated with higher levels of CRP (OR [95% CI] =1.42 [1.01-1.99]). In the BRHS, complete and partial tooth loss was associated with hemostatic factors, in particular with the top tertile of fibrin D-dimer (OR [95% CI] = 1.64 [1.16-2.30] and 1.37 [1.05-1.77], respectively). Tooth loss and periodontal disease were associated with increased levels of hsTnT. CONCLUSIONS: Poor oral health in older age, particularly tooth loss, was consistently associated with some inflammatory, hemostatic, and cardiac biomarkers. Prospective studies and intervention trials could help understand better if poor oral health is causally linked to inflammatory, hemostatic, and cardiac biomarkers.

Elevated Coronary Artery Calcium scores are associated with tooth loss.

AIM: This study explores the association between Coronary Artery Calcium (CAC) scores and dental pathology such as missing teeth, the (peri-apical) health status and restoration grade of the teeth, and the grade of alveolar bone loss seen on a dental panoramic radiograph (Orthopantomograph-OPG). MATERIALS AND METHODS: In this retrospective cross-sectional study, data was collected from three hospitals spread in the Netherlands. Patients were included when a CAC score and an OPG were available, both recorded within a maximum period of 365 days from 2009-2017. The CAC score was measured on a CT scan, using the Agatston method. To assess dental pathology, the number of missing teeth, the number of dental implants, alveolar bone loss, caries, endodontic treatments, peri-apical radiolucencies, bone loss at implants, impacted teeth and dental cysts, were determined on the OPG. All observers were calibrated. The electronic health records provided information about: gender, age, smoking, Diabetes Mellitus, hypercholesterolemia, hypertension and Body Mass Index (BMI). RESULTS: 212 patients were included. We found a statistically significant association between the number of missing teeth and the CAC score. When modeling age, sex, and other well-known risk factors for cardiovascular disease, the significant correlation was no longer present after multivariate correction. Furthermore, the results showed a trend for more teeth with peri-apical lesions and a higher percentage of mean alveolar bone loss in the group with the highest CAC scores. CONCLUSION: This study showed that being edentulous or missing teeth is correlated to higher CAC scores however failed to be an independent predictor of atherosclerotic cardiovascular diseases. The number of (missing) teeth is an easily accessible marker and could be used as a marker for atherosclerotic cardiovascular disease (ACVD) risk by almost any healthcare worker. The current study needs to be considered as an explorative pilot study and could contribute to the design of further (prospective) studies on the relationship between dental pathology and coronary artery calcification by adding clinical information and extra cardiovascular biomarkers.

ODONTOLOGICAL EFFECTS OF IONIZING RADIATION (review). / ODONTOLOGIChNI EFEKTY IONIZUIuChOGO VYPROMINIuVANNIa (ogliad).

BACKGROUND: Odontological effects of ionizing radiation (IR) as a result of radiotherapy, the consequences of accidents at nuclear power plants and industry, individual occupational exposure, etc. deserve significant attention interns of radiation medicine and radiation safety. OBJECTIVE: to analyze and summarize clinical and experimental data on the odontological radiation effects. OBJECT: the pathological changes in the hard tissues of teeth, pulp, periodontium, mucousmembranes of the mouth and jaws due to exposure to IR. METHOD: search in the PubMed / MEDLINE, Google Scholarabstract medical and biological databases, scientific libraries of the relevant sources of scientific information. RESULTS: Radiobiological effects of IR due to its direct and indirect action are manifested throughout the period ofodontogenesis and formation of the facial skeleton. Experimental and clinical data (in children and adults) indicatethe increased risk of dental caries, reduction of pain threshold and vascularization of tooth pulp along with its fibrosis and atrophy, periodontal dysfunction, which predispose to a high probability of tooth loss. Abnormalities in theactivity of osteoblasts and cementoblasts of dental periosteum and osteoblasts of alveolar process in combinationwith circulatory disorders due to endothelial cell death, hyalinization, thrombosis and vascular obliteration increasethe risk of jaw osteoradionecrosis. Children who have undergone a prenatal exposure to IR as a result of theChornobyl NPP accident have a premature change of teeth. Deterioration of periodontal tissues and early development of acute and complicated dental caries are typical for children and adults affected by the Chornobyl disaster. CONCLUSIONS: Summarized data on the effects of radiation exposure under different conditions on teeth primordia(i.e. immature teeth), their formation and eruption in experimental and clinical settings, as well as on the odontological radiation effects in adults are summarized. Condition of the teeth in the Chornobyl NPP accident survivorsis described. Understanding and taking into account the radiobiological odontological effects is necessary in thelight of planning, preparing, and conducting local radiation therapy and developing the standards of radiation safety and measures to protect professionals and the public in the event of possible radiation accidents at the nuclearpower plants and industry facilities.

Neurodegeneration of Trigeminal Mesencephalic Neurons by the Tooth Loss Triggers the Progression of Alzheimer's Disease in 3×Tg-AD Model Mice.

BACKGROUND: The mesencephalic trigeminal nucleus (Vmes) is not only anatomically adjacent to the locus coeruleus (LC) but is also tightly associated with the function of the LC. The LC can be the first area in which Alzheimer's disease (AD) develops, although it is unclear how LC neuronal loss occurs. OBJECTIVE: We investigated whether neuronal death in the Vmes can be spread to adjacent LC in female triple transgenic (3×Tg)-AD mice, how amyloid-ß (Aß) is involved in LC neuronal loss, and how this neurodegeneration affects cognitive function. METHODS: The molars of 3×Tg-AD mice were extracted, and the mice were reared for one week to 4 months. Immunohistochemical analysis, and spatial learning/memory assessment using the Barnes maze were carried out. RESULTS: In 4-month-old 3×Tg-AD mice, aggregated cytotoxic Aß42 was found in granules in Vmes neurons. Neuronal death in the Vmes occurred after tooth extraction, resulting in the release of cytotoxic Aß42 and an increase in CD86 immunoreactive microglia. Released Aß42 damaged the LC, in turn inducing a significant reduction in hippocampal neurons in the CA1 and CA3 regions receiving projections from the LC. Based on spatial learning/memory assessment, after the tooth extraction in the 4-month-old 3×Tg-AD mice, increased latency was observed in 5-month-old 3×Tg-AD mice 1 month after tooth extraction, which is similar increase of latency observed in control 8-month-old 3×Tg-AD mice. Measures of cognitive deficits suggested an earlier shift to dementia-like behavior after tooth extraction. CONCLUSION: These findings suggest that tooth extraction in the predementia stage can trigger the spread of neurodegeneration from the Vmes, LC, and hippocampus and accelerate the onset of dementia.

Association between tooth loss and handgrip strength in a general adult population.

Tooth loss is a prevailing condition in China due to the high prevalence of oral diseases. Since previous studies explored the association between tooth loss and handgrip strength showed incongruous results, the aim of this study was to investigate the association between tooth loss and handgrip strength in Tianjin, China. Cross-sectional data in the present study used baseline data of Tianjin Chronic Low-grade Systemic Inflammation and Health (TCLSIH) Cohort Study during 2013-2016. Eligible adults (n = 26275) were classified into four groups depending on the number of missing teeth (excluding third molars): 0, 1-2, 3-5 and ≥6. Handgrip strength was measured using a handheld type dynamometer. Analysis of covariance was used to examine the relationships between tooth loss and handgrip strength and handgrip strength per body weight according to gender. After adjustment for potential confounders, the relationships existed between increasing categories of tooth loss and handgrip strength, as well as handgrip strength per weight. The data of stratified analysis showed that there was a trending association between decreased handgrip strength and fewer retained teeth both in males and females less than 60 years of age (P for trend <0.01); whereas no significant association 60 years of age or older. Moreover, loss of more than 3 teeth was significantly associated with reduced muscle strength (P <0.01). Tooth loss is independently associated with handgrip strength in Chinese adults less than 60 years of age.

Oral pathological conditions of an Early Epipaleolithic human from Southwest Asia: Ohalo II H2 as a probable case of intentional dental ablation.

OBJECTIVE: To describe the oral pathological conditions of Ohalo II H2, an Early Epipaleolithic human from southwest Asia. MATERIALS: The dentognathic skeleton of Ohalo II H2 and relevant comparative data from similar chronological and/or geographic contexts. METHODS: Gross and x-ray observations of oral pathological conditions and occlusal wear were made following published protocols. A differential diagnosis of antemortem tooth loss is provided. RESULTS: Ohalo 2 has two carious lesions on the right M3, pulpal exposure of left M1, and mild to moderate anterior alveolar bone loss. The right I1 was lost antemortem, and there is probably agenesis of the left M3. CONCLUSIONS: The pathological conditions noted are not exceptional for a Late Upper Paleolithic forager. However, the antemortem missing right I1 is most parsimoniously explained by intentional dental ablation. SIGNIFICANCE: Ohalo 2 could represent the oldest example of dental ablation from the Late Pleistocene circum-Mediterranean world - predating the earliest examples from both North Africa and southwest Asia by several thousand years. The similarity of the Ohalo 2 ablation pattern with later Natufians provides further evidence of potential long-term behavioral trends related to the embodiment of social identities through international body modification within the Epipaleolithic of southwest Asia. LIMITATIONS: The pre-Natufian (∼23,000-14,500 cal BP) human fossil record is relatively sparse, making comparisons with the Natufian (∼14,500-11,500 cal BP) phases of the Epipaleolithic difficult. SUGGESTIONS FOR FURTHER RESEARCH: Documentation of oral pathological conditions for other pre-Natufian fossils would provide greater resolution of the temporospatial patterning of oral health and embodied social identities during the Epipaleolithic of southwest Asia.

Association between tooth loss and gray matter volume in cognitive impairment.

Previous studies have reported an association between tooth loss and gray matter volume (GMV) in healthy adults. The study aims to elucidate the link between tooth loss, brain volume differences, and cognitive impairment by investigating the total and regional differences in GMV associated with tooth loss in older people with and without cognitive impairment. Forty older participants with mild cognitive impairment or Alzheimer's disease [the cognitive impairment (CI) group] and 30 age- and sex-matched healthy participants [the control (CON) group] received T1-weighted magnetic resonance imaging scans and assessments of oral functions, including masticatory performance (MP) and the number of missing teeth (NMT). Voxel-based morphometry was used to assess the total and regional GMV, including that of the medial temporal lobe and motor-related areas. (A) When the total intracranial volume and age were controlled for, an increased MP was associated with a larger GMV in the premotor cortex in the CON group. (B) In the CI group, an increased NMT was significantly correlated with smaller regional GMV of the bilateral primary motor cortex and the premotor cortex. (C) In the CI group, but not the CON group, an increased NMT was associated with both smaller total GMV and regional GMV of the left medial temporal lobe, including the left hippocampus and parahippocampus. Tooth loss may be preferentially related to the structural differences in the medial temporal lobe in cognitively impaired older people. Further research is required to understand the mechanisms of the relationships.

Tooth Regeneration: Insights from Tooth Development and Spatial-Temporal Control of Bioactive Drug Release.

Tooth defect and tooth loss are common clinical diseases in stomatology. Compared with the traditional oral restoration treatment, tooth regeneration has unique advantages and is currently the focus of oral biomedical research. It is known that dozens of cytokines/growth factors and other bioactive factors are expressed in a spatial-temporal pattern during tooth development. On the other hand, the technology for spatial-temporal control of drug release has been intensively studied and well developed recently, making control release of these bioactive factors mimicking spatial-temporal pattern more feasible than ever for the purpose of tooth regeneration. This article reviews the research progress on the tooth development and discusses the future of tooth regeneration in the context of spatial-temporal release of developmental factors.

Periodontitis and Tooth Loss Have Negative Systemic Impact on Circulating Progenitor Cell Levels: A Clinical Study.

The aim of the present study was to investigate the association and impact of periodontitis and tooth loss on a subtype of endothelial progenitor cell (EPC) levels (CD133+/KDR+). Furthermore, the objective was to determine if the periodontal status influenced CD133+/KDR+ levels. In all, 88 patients with periodontitis and 79 healthy controls (HCs) were enrolled in the study. Enrolled patients were examined and characterized by clinical and blood sample analysis. Spearman's correlation test was applied in order to assess the interdependence between CD133+/KDR+ levels and all periodontal parameters. In order to estimate a statistically significant trend (p-trend) for ordered CD133++/KDR+ quartiles, the Jonckheere-Terpstra test was applied for all variables. Patients in the periodontitis group presented significantly lower CD133+/KDR+ levels (66.4 (45.5-269.6 cells/µL)) compared to the HC group (76.7 (24.3-313.2 cells/µL), p < 0.001). Lower CD133+/KDR+ levels negatively correlated with C-reactive protein (CRP), with the number of teeth, and with all periodontal parameters (p < 0.001). Moreover, there was a proportional increase in CD133+/KDR+ levels with a progressive increase in number of teeth (p-trend < 0.001), while there was a proportional decrease in CD133+/KDR+ levels with a proportional increase in clinical attachment level (CAL, p-trend = 0.003), probing depth (PD, p-trend = 0.007), and bleeding sites (bleeding on probing (BOP), p-trend < 0.001) as an extent measure of periodontitis. This study demonstrated that patients with periodontitis presented significantly lower CD133+/KDR+ levels compared to HCs. Moreover, all patients presented an increase in the CD133+/KDR+ EPC levels with an extended level of periodontitis and tooth loss.

A small number of residual teeth after the mandibular resection of oral cancer is associated with titanium reconstruction plate exposure.

Objective: Reconstruction plates are used to treat patients with a segmental mandibular defect after oral cancer surgery. Reconstruction plate failure analysis has rarely focused on occlusion, which conducts a mechanical force to the mandible and the plate. To determine the prognostic factors, we retrospectively evaluated patients who underwent reconstruction of a mandibular segmental defect with a reconstruction plate and assessed the number of residual paired teeth. Material and Methods: From among 390 patients with oral cancer who visited University of Tsukuba Hospital (Tsukuba, Japan) between 2007 and 2017, we selected and analyzed the data of 37 patients who underwent segmental resection of the mandible and reconstruction with reconstruction plates. Prognostic factors evaluated were patient age, sex, TNM classification, plate manufacturer, treatment with radiotherapy or chemotherapy, whether the patient had diabetes or smoked, and whether the patient had a small number of residual paired teeth, plate length, and use of a fibular-free flap. Among these 37 patients, eight reconstruction plates had intraoral or extraoral exposure and were removed in 5 years. Results: Kaplan-Meier and log-rank analyses revealed that the prognosis for the 5-year plate exposure-free rate was significantly poorer for patients with a small number of residual teeth than for patients with no teeth or those with a large number of residual teeth (.01). Univariate Cox regression analysis revealed that a small number of residual teeth was a significant prognostic factor in the loss of a reconstruction plate (hazard ratio: 5.63; 95% confidence interval [1.10, 25.85]; .04). Conclusions: A small number of residual teeth after the segmental resection of oral cancer is significantly involved in reconstruction plate survival and may be important in predicting reconstruction plate prognosis.

The concept of exposure when selecting comparison groups for determining individual susceptibility to addiction to cigarette smoking.

Smoking is a leading cause of preventable death. The effect of tobacco is even more contundent in people with mental illness and, in general, cigarette smoking addiction is influenced by genetic factors. The opioid system is involved in the mesolimbic reward system, which is of great importance in addictive behaviors, such as smoking and is influenced by genes such as the OPRM1. The aim of this study was to evaluate if selecting a comparison group that include light smokers versus people that never smoked impacts the results of genetic association studies. In addition, to evaluate the genetic association in different groups of smokers by analyzing independent covariates such as mental illness and clinical dental data. All subjects were participants of the Dental Registry and DNA Repository project. Genotyping was carried out using TaqMan chemistry for two markers in OPRM1 (rs553202 and rs7755635). Logistic regression analyses were performed as implemented in PLINK. The established value for alpha was 5%, and the Hardy-Weinberg equilibrium was evaluated by the chi-square test with one degree of freedom for each marker. 1,897 patients were included, which were allocated to eight distinct groups, according to the frequency and quantity of cigarettes smoked and mental illness status. There was no significant association between the two markers in OPRM1 and smoking. When mental illness and dental clinical data (tooth loss, dental caries, and periodontitis) were used as covariates, there were associations between heavy smoking and OPRM1, when non-smokers were used as comparison. We did not have diet or microbiome data to consider for these dental analyses and suggest that these kinds of data should be always incorporated in the future. Significant results were found only when the covariables mental illness and oral clinical data were added to the analysis.

The relationship between tooth loss and mortality from all causes, cardiovascular diseases, and coronary heart disease in the general population: systematic review and dose-response meta-analysis of prospective cohort studies.

Background: The association of tooth loss with mortality from all causes, cardiovascular diseases (CVD), and coronary heart disease (CHD) has been studied for many years; however, the results are inconsistent.Method: PubMed, Embase, Web of Knowledge, and Cochrane Oral Health Group's Trials Register databases were searched for papers published from 1966 to August 2018. We conducted dose-response meta-analysis to quantitatively evaluate the relation between tooth loss and risk of mortality from all causes, CVD, and CHD.Results: In the present study, 18 prospective studies conducted until August 2018 were considered eligible for analysis. In the analysis of linear association, the summarized relative risk (RR) values for each 10-, 20-, and 32-tooth loss for all-cause mortality were 1.15 (1.11-1.19), 1.33 (1.23-1.29), and 1.57 (1.39-1.51), respectively. Subgroup and sensitivity analyses showed consistent results. A linear relationship was found among all-cause mortality, with Pnonlinearity = 0.306. The susceptibility to all-cause mortality increased by almost 1.48 times at very high tooth loss (28-32), and slight flattening of the curve was noted. However, the summarized RR values for increment for 10-, 20-, and 32-tooth loss were not or were marginally related to increased risk of mortality from CVD/CHD. Subgroup and sensitivity analyses revealed inconsistent results. Tooth loss showed linear association with CHD mortality but not with CVD mortality. The susceptibility to all-cause mortality increased by almost 1.48 and 1.70 times for CVD and CHD, respectively, at very high tooth loss (28-32). The curve exhibited slight flattening; however, no statistical significance was detected.Conclusion: In the meta-analysis, our findings confirmed the positive relationship between tooth loss and susceptibility to all-cause mortality, but not for circulatory mortality. However, the finding that tooth loss might play a harmful role in the development of all-cause mortality remains inconclusive. Tooth loss may be a potential risk marker for all-cause mortality: however, their association must be further validated through large prospective studies.