Predicting the Next Maxima Incidents of the Seasonally Forced SEIR Epidemic Model

This paper aims at predicting the next maxima values of the state variables of the seasonal SEIR epidemic model and their in-between time intervals. Lorenz's method of analogues is applied on the attractor formed by the maxima of the corresponding state variables. It is found that both quantities are characterized by a high degree of predictability in the case of the chaotic regime of the parameter space.Comment: 6 pages, 3 figures, 2 tables, typos adde

THE ASSOCIATION BETWEEN TRAUMATIC BRAIN INJURY AND GLIOMAGENESIS AND ITS SPECIAL ROLE IN GLIOBLASTOMA MULTIFORME PATHOGENESIS: A REVIEW

Gliomas are the most common primary and aggressive intracranial tumors, represent 80% of malignant brain tumors, and despite the fact that are relatively rare tumors are responsible for significant mortality and morbidity. Glioblastoma multiforme (GBM) or diffuse astrocytoma, WHO grade IV, is the most common and aggressive primary central nervous system malignancy, represents 45% of all gliomas, shows an average incidence of 3.19/100,000 individuals, its median age of diagnosis is 64 years, and the median survival is 15 months as the 5-year relative survival is 5%. Previous studies have investigated the possible role of genetic and environmental factors in GBM pathogenesis; however, the majority of GBM cases were sporadic and certain risk factors have not been detected. GBM is divided into primary and secondary subtypes which develop through different genetic pathways, affect patients at different ages, and have differences in clinical outcomes, as show a great morphological and genetic heterogeneity. The role of traumatic brain injury (TBI) in GBM formation has been investigated in many previous reports which have hypothesized that TBI may predispose to gliomagenesis; however, the outcomes were highly controversial. Some of those researches have proposed a supposed pathogenesis model that involves a post-traumatic inflammation, stem and progenitor cell transformation, and gliomagenesis. Other similar studies have involved transcription factors associated with TBI such as p53, hypoxia-inducible factor-1a (HIF-1a), and c-Myc. On the other hand, the possibility of a pre-existing tumor rather than a trauma-induced tumor is very possible in such cases

Prevalence of Dentine Hypersensitivity in a General Dental Practice in Greece

Objectives: The aim of this study was to estimate the prevalence of dentine hypersensitivity in a sample of patients visiting a general dental practice. Study design: The study population consisted of 1,450 patients, 690 males and 760 females, aged 18-69 years. All individuals were clinically examined and answered questions regarding variables such as gender, age, educational level, occupation status, teeth affected and any factor that initiated the sensitivity. The clinical examination involved assessment of sensitive teeth per patient, while the amount of buccal gingival recession associated with the sensitive teeth was also recorded. Statistical analysis performed by using methods of descriptive statistics and chi square-test. Results: Two hundred and sixty four patients were diagnose as having dentine hypersensitivity, giving a prevalence rate 18.2% . Prevalence rate for hypersensitivity in females (19.34%) was significantly higher (p=0.0015) than males (16.95%). The mean number of sensitive teeth per patient showed a peak in the 40-49 year age group in males and in 60-69 year age group in females. The commonest teeth affected by dentine hypersensitivity were the first and second premolars, the canines and the first molars of maxilla and mandible. The majority (85.9%) of sensitive teeth had at least 1-3 mm of gingival recession while the most commonest pain-initiating stimuli was the consumption of cold drinks (56.1%). A statistically significant difference recorded between dentine hypersensitivity and educational level (p=0.00094). Conclusions: The prevalence of dentine hypersensitivity in the adult sample of the present study was 18.5%. There was also a tendency for the patients with sensitive teeth to come from higher social classe

Gingival recession: prevalence and risk indicators among young greek adults

Objectives: The aim of the current research was to assess the prevalence of gingival recession and to investigate possible associations among this condition, periodontal and epidemiological variables in a sample of young Greek adults in a general dental practice. Material and Methods: A total of 1,430 young adults was examined clinically and interviewed regarding several periodontal and epidemiological variables. Collected data included demographic variables, oral hygiene habits and smoking status. Clinical examination included the recording of dental plaque, supragingival calculus presence, gingival status and buccal gingival recession. Multivariate logistic regression analysis model was performed to access the possible association between gingival recession and several periodontal and epidemiological variables as potential risk factors. Results: The overall prevalence of gingival recession was 63.9%. The statistical analysis indicated that higher edu - cational level [OR= 2.12, 95% CI= 0.53-8.51], cigarette smoking [OR= 1.97, 95% CI= 1.48-7.91], frequent tooth brushing [OR= 0.98, 95% CI= 0.56-1.96], presence of oral piercing [OR= 0.92, 95% CI= 0.38-1.58], presence of gingival inflammation [OR= 4.54, 95% CI= 1.68-7.16], presence of dental plaque [OR= 1.67, 95% CI= 0.68-2.83] and presence of supragingival calculus [OR=1.34, 95% CI= 0.59-1.88], were the most important associated factors of gingival recession. Conclusions: The observations of the current research supported the results from previous authors that several periodontal factors, educational level and smoking were significantly associated with the presence of gingival re - cession, while presence of oral piercing was a new factor that was found to be associated with gingival recession

Prevalence of tooth erosion and associated factors in 13-16-year old adolescents in Greece

Objectives: The aim of this study was to estimate the prevalence of dental erosion and to investigate possible associations among dental erosion and medical history, dietary and lifestyle habits in a sample of adolescents in Greece. Study design: The study sample consisted of 770 adolescents, 374 boys and 396 girls aged 13 to 16 years. All individuals were clinically examined and answered questions regarding their medical history, rate and frequency of drinks and food consumption and lifestyle habits. Statistical analysis of the questionnaire items was performed by using the multiple logistic regression analysis model. Results: Two hundreds and sixty adolescents were diagnosed as having dental erosion, giving a prevalence rate 33.8%. The habit of holding drinks in the mouth before swallowing [OR=2.85, 95% CI=1.45-5.58] (p=0.002), the ingestion of acidic drinks at bedtime [OR=0.24, 95% CI=0.11-0.53] (p=0.000), the consumption of car- bonated drinks [OR=3.99, 95% CI=1.37-11.59] (p=0.011) and fruit juices [OR=0.12, 95% CI=0.04-0.38] (p=0.000) were the most important associated factors of dental erosion. Conclusions: The prevalence of dental erosion in the study sample was 33.8% while dental erosion experience was associated with frequency and habits of consumption of some dietary components

Examination of the Relation Between Periodontal Disease Indices in Patients with Systemic Diseases

Svrha: Željelo se ispitati koliki je indeks parodontne bolesti kod pacijenata upućenih na Odjel neurokirurgije te njegova povezanost s češćim sistemskim bolestima među odraslim vanjskim pacijentima u Grčkoj. Materijal i metode: Analizirana populacija sastojala se od 728 vanjskih pacijenata – 340 muškaraca i 388 žena u dobi od 40 do 70 godina. Svi su klinički pregledani i ispunili su zdravstveni upitnik. Ti su podatci raščlanjeni višestrukom logističkom regresijskom analizom za procjenu mogućih poveznica između sistemskih bolesti kao neovisnih varijabli, a kao poveznica ovisnih varijabli analizirani su parodontni džepovi od pet milimetara i više, blagi do umjereni gubitak kliničkog pričvrstka, krvarenje ili nekrvarenje nakon sondiranja te vidljive zubne naslage. Rezultati: Dubina parodontnih džepova bila je značajno i pozitivno povezana s respiratornim alergijama (P<0,001) i šećernom bolešću (P<0,001), te reumatoidnim artritisom (P=0,048). Krvarenje nakon sondiranja također je bilo povezano s respiratornim alergijama (P=0,009), kardiovaskularnim bolestima (P<0,001) i dijabetesom (P<0,001), a značajno negativno s hipertenzijom (P<0,001). Zubne naslage bile su pozitivno povezane s reumatoidnim artritisom (P=0,048). Zaključak: Pronađena je velika povezanost indeksa parodontnih bolesti, poput dubine sondiranja, gubitka kliničkog pričvrstka te zubnih naslaga i sistemskih bolesti, poput kardiovaskularnih i respiratornih, dijabetesa i reumatoidnog artritisa.Aim: The aim of the current investigation was to examine the occurrence of periodontal disease indices in out-patients referred to a specialist clinic for neurosurgery treatment and to explore possible associations between common systemic diseases and periodontal disease indices in a Greek out-patient adult population. Materials and Methods: The study population consisted of 728 out-patients, 340 males and 388 females aged 40 to 70 years. All individuals were clinically examined and filled in a health administered questionnaire. Multiple logistic regression analysis of the questionnaire items was performed to assess possible associations between systemic diseases as independent variables and the presence of periodontal pockets of 5.00 mm or more, mild/moderate or severe clinical attachment loss and the presence or absence of bleeding on probing and visible dental plaque, respectively, as dependent variables. Results: The depth of periodontal pockets was significantly and positively associated with the presence of respiratory allergy (P<0.001) and diabetes mellitus (P<0.001), whereas clinical attachment loss was significantly and positively associated with the presence of respiratory allergy (P<0.001), diabetes mellitus (P<0.001) and rheumatoid arthritis (P= 0.048). In addition, bleeding on probing was significantly and positively associated with the presence of respiratory allergy (P= 0.009), cardiovascular disease (P<0.001) and diabetes mellitus (P<0.001) and significantly and negatively associated with the presence of hypertension (P<0.001), whereas the presence of dental plaque was positively associated with the presence of rheumatoid arthritis (P= 0.048). Conclusion: Significant associations between investigated periodontal disease indices such as probing pocket depth, clinical attachment loss, bleeding on probing and dental plaque and systemic diseases such as respiratory diseases, diabetes mellitus, cardiovascular diseases and rheumatoid arthritis were recorded

Correlation between periodontal disease indices and lung cancer in Greek adults: a case — control study

Aim: The aim of the present case — control study was to examine the possible associations between periodontal disease indices and the risk of lung cancer development in a sample of Greek out-patients referred to a medical and a dental private practice. Materials and Methods: A total of 200 individuals were interviewed and underwent an oral clinical examination, and 64 of them were suffered from several histological types of lung cancer. The estimation of the possible associations between lung cancer as a dependent variable and periodontal disease indices as independent ones was carried out by using a multiple regression analysis model. Results: Probing pocket depth (odds ratio (OR) = 2.72, 95% confidence interval (CI) 1.05–7.06), clinical attachment loss (OR = 3.51, 95% CI 1.30–9.47) bleeding on probing (OR = 1.93, 95% CI 0.98–3.81) were significantly associated with the risk of developing lung cancer. Smoking (OR = 2.49, 95% CI 1.20–5.17) was significantly associated with the mentioned risk, whereas it was consisted as a confounder regarding the estimated associations between moderate/severe clinical attachment loss and presence of bleeding on probing with the risk of developing lung cancer. Conclusion: Probing pocket depth as an index for periodontal disease severity was statistically significantly associated with the risk of developing lung cancer

Reasons for Placement and Replacement of Composite Dental Restorations in an Adult Population in Greece

Svrha: Namjera je bila objasniti razloge za postavljanje i zamjenu defektnih ispuna od smolnog kompozitnog materijala te identificirati odnose između postavljenih i ponovno postavljenih ispuna prema spolu, preparaciji, vrsti zuba i dugotrajnosti. Materijali i metode: Studijski se uzorak sastojao od 700 pacijenata – 310 muškaraca i 390 žena u dobi od 18 do 58 godina koji su zatražili zbrinjavanje zubne kazuistike u privatnoj praksi u Grčkoj. Svi su bili klinički pregledani te je nakon toga izračunat broj karijesom zahvaćenih zuba (primarni karijes) i neuspjelih ispuna za svakog ispitanika. Osim toga bio je procijenjen i odnos između postavljenih i ponovljenih kompozitnih restoracija s obzirom na sljedeće parametre: dob te vrstu preparacije i zuba. Statistička analiza obavljena je hi-kvadrat testom. Rezultati: Ukupan broj prvi put postavljenih restoracija iznosio je 904 (57,7%), a ponovljenih 380 (32,3%). Primarni karijes bio je najčešći razlog za prvo postavljanje smolnih kompozitnih ispuna (63%), a slijede diskoloracije (15%) i frakture zuba (14%). Među razlozima za ponovljeno postavljanje isticali su se sekundarni karijes (42%), diskoloracija (32%) i gubitak ispuna (20%). Prosječna trajnost ponovno postavljenih kompozitnih restoracija iznosila je oko četiri godine (42%). Zaključak: Zubni karijes, primarni i sekundarni, najvažniji je razlog za postavljanje i ponavljanje ispuna od smolnog kompozita, a na drugom je mjestu diskoloracija. Dakle, kod pacijenata s visokim rizikom, kad je riječ o razvijanju karijesa, potrebne su češće stomatološke intervencije kako bi se osigurala prevencija od nastanka novih karijesnih lezija ili recidiva.Aim: The aim of the present study was to investigate the reasons for placement and replacement of defective resin-based composite (RBC) restorations and the associations between placed and replaced composite restorations by gender, type of cavity, tooth type and longevity of replaced ones. Materials and Methods: Study population consisted of 700 patients, 310 males and 390 females, aged 18 to 58 years old who sought dental treatment in a private practice in Greece. All subjects were clinically examined and the number of decayed teeth (primary caries) and failed-restored teeth was calculated for each patient. In addition the association between placed and replaced composite restorations and the following aspects was assessed: gender, cavity type and tooth type. Statistical analysis was accomplished by using chi-square test. Results: The total number of restorations placed were 904, 524 (57.7%) were placed for first time while 380 (32.3%) were replaced. Primary caries was the most frequent reason for the placement of new composite resin restorations (63%) followed by tooth discolouration (15%) and tooth fracture (14%) while the main reasons for replaced resin composite restorations were secondary caries (42%), discolouration (32%) and loss of filling (20%). The median longevity of the replaced resin composite restorations was approximately 4 years (42%). Conclusions: Dental caries, primary and secondary, was the principle reason for placed and replaced resin composite restorations followed by tooth discolouration. Therefore, patients at a high risk of developing caries may require more frequent dental care to ensure that new and recurrent carious lesions are prevented

A Survey of the Reasons for Dental Extraction in Adult Population in Greece

Svrha: Ovim se studijskim istraživanjem željelo procijeniti razloge za ekstrakcije zuba i ustanoviti njihovu povezanost s dobi i spolom odrasle populacije u Grčkoj. Materijali i metode: Uzorak se sastojao od 632 ispitanika – 340 muškaraca i 292 žene u dobi od 18 do 76 godina. Svi su se liječili u privatnoj ordinaciji u Grčkoj. Liječnik je zabilježio njihov spol, dob, broj i vrstu ekstrahiranih zuba te uzrok vađenja. Podatke je skupljao tri godine. Rezltati: Dok se radila studija ekstrahirano je, zbog različitih razloga, 1688 trajnih zuba. Rezultati su pokazali da je glavni uzrok za vađenje bila bolest parodonta (38,09 %) te karijes (36,01 %). Bolest parodonta glavni je razlog za ekstrakcije kod pacijenata iznad 50 godina (47,18 %), a karijes kod onih do 49 godina (41,39 %). Maksilarni i mandibularni centralni i lateralni incizivi te kanini najčešće su ekstrahirani zubi zbog parodontoloških razloga, a maksilarni i mandibularni prvi i drugi molari zbog karijesa. Zaključak: Bolesti parodonta i karijes i dalje su glavni razlozi za ekstrakcije zuba, bez obzira na dob pacijenta.Aim. The aim of this study was to estimate the reasons for tooth extraction and their correlations with aspects such as age and gender in adult population in Greece. Materials and Methods. The population sample consisted of 632 subjects, 340 males and 292 females, aged 18 to 76 who attended a private practice in Greece. The patients’ gender, age, number and type of extracted teeth and the reasons for tooth extraction were recorded for a period of three years. Results. One thousand six hundred and eighty eight permanent teeth were extracted for various reasons during the study period. The results showed that the main causes of extractions were periodontal disease (38.09%) and dental caries (36.01%). Periodontal disease was the main cause of extraction in patients over 50 years of age (47.18%), while dental caries was the main cause for extraction in patients up to 49 years of age (41.39%). Maxillary and mandibular central-lateral incisors and canines were the most frequently extracted teeth due to periodontal disease, while maxillary and mandibular 1st and 2nd molars, were the most frequently extracted teeth due to dental caries. Conclusions. Periodontal disease and dental caries are still the main reasons for tooth extraction regardless of the patients’ age

Reasons for Placement and Replacement of Composite Dental Restorations in an Adult Population in Greece

Svrha: Namjera je bila objasniti razloge za postavljanje i zamjenu defektnih ispuna od smolnog kompozitnog materijala te identificirati odnose između postavljenih i ponovno postavljenih ispuna prema spolu, preparaciji, vrsti zuba i dugotrajnosti. Materijali i metode: Studijski se uzorak sastojao od 700 pacijenata – 310 muškaraca i 390 žena u dobi od 18 do 58 godina koji su zatražili zbrinjavanje zubne kazuistike u privatnoj praksi u Grčkoj. Svi su bili klinički pregledani te je nakon toga izračunat broj karijesom zahvaćenih zuba (primarni karijes) i neuspjelih ispuna za svakog ispitanika. Osim toga bio je procijenjen i odnos između postavljenih i ponovljenih kompozitnih restoracija s obzirom na sljedeće parametre: dob te vrstu preparacije i zuba. Statistička analiza obavljena je hi-kvadrat testom. Rezultati: Ukupan broj prvi put postavljenih restoracija iznosio je 904 (57,7%), a ponovljenih 380 (32,3%). Primarni karijes bio je najčešći razlog za prvo postavljanje smolnih kompozitnih ispuna (63%), a slijede diskoloracije (15%) i frakture zuba (14%). Među razlozima za ponovljeno postavljanje isticali su se sekundarni karijes (42%), diskoloracija (32%) i gubitak ispuna (20%). Prosječna trajnost ponovno postavljenih kompozitnih restoracija iznosila je oko četiri godine (42%). Zaključak: Zubni karijes, primarni i sekundarni, najvažniji je razlog za postavljanje i ponavljanje ispuna od smolnog kompozita, a na drugom je mjestu diskoloracija. Dakle, kod pacijenata s visokim rizikom, kad je riječ o razvijanju karijesa, potrebne su češće stomatološke intervencije kako bi se osigurala prevencija od nastanka novih karijesnih lezija ili recidiva.Aim: The aim of the present study was to investigate the reasons for placement and replacement of defective resin-based composite (RBC) restorations and the associations between placed and replaced composite restorations by gender, type of cavity, tooth type and longevity of replaced ones. Materials and Methods: Study population consisted of 700 patients, 310 males and 390 females, aged 18 to 58 years old who sought dental treatment in a private practice in Greece. All subjects were clinically examined and the number of decayed teeth (primary caries) and failed-restored teeth was calculated for each patient. In addition the association between placed and replaced composite restorations and the following aspects was assessed: gender, cavity type and tooth type. Statistical analysis was accomplished by using chi-square test. Results: The total number of restorations placed were 904, 524 (57.7%) were placed for first time while 380 (32.3%) were replaced. Primary caries was the most frequent reason for the placement of new composite resin restorations (63%) followed by tooth discolouration (15%) and tooth fracture (14%) while the main reasons for replaced resin composite restorations were secondary caries (42%), discolouration (32%) and loss of filling (20%). The median longevity of the replaced resin composite restorations was approximately 4 years (42%). Conclusions: Dental caries, primary and secondary, was the principle reason for placed and replaced resin composite restorations followed by tooth discolouration. Therefore, patients at a high risk of developing caries may require more frequent dental care to ensure that new and recurrent carious lesions are prevented