Lokalanestetika med artikain och känselstörningar

High sensitivity receiver technology is necessary to ensure sufficient observation availability of satellite navigation in degraded signal environments. However, high sensitivity processing in the deteriorated line-of-sight conditions is susceptible to bringing about severely erroneous navigation observations. Therefore, when using a satellite navigation system, such as the Global Positioning System (GPS) or the future European Galileo in poor signal conditions, monitoring the reliability and the quality of the obtained user navigation solution is of great importance. This thesis assesses reliability testing and quality control procedures at the user-level in Global Navigation Satellite Systems (GNSS) with the aim of enhancing accuracy and reliability in poor signal conditions with failure detection and exclusion techniques. Reliability testing, namely receiver autonomous integrity monitoring (RAIM) and fault detection and exclusion (FDE), traditionally rely on statistical tests in order to isolate one erroneous measurement from position estimation. In this thesis, a slightly wider point of view is taken to the quality monitoring problem of bot

A microCT Study of Three-Dimensional Patterns of Biomineralization in Pig Molars

Domestic pig molars provide an interesting system to study the biomineralization process. The large size, thick enamel and complex crown morphology make pig molars relatively similar to human molars. However, compared to human molars, pig molars develop considerably faster. Here we use microCT to image the developing pig molars and to decipher spatial patterns of biomineralization. We used mineral grains to calibrate individual microCT-scans, which allowed an accurate measure of the electron density of the developing molars. The microCT results show that unerupted molars that are morphologically at the same stage of development, can be at markedly different stage of enamel biomineralization. Erupted molars show increased electron density, suggesting that mineralization continues in oral cavity. Yet, our comparisons show that human enamel has slightly higher electron density than pig enamel. These results support the relatively low hardness values and calcium level values that have been reported earlier in literature for pig teeth. The mineral calibration was an efficient method for the microCT-absorption models, allowing a relatively robust way to detect scanning artifacts. In conclusions, whereas thin sections remain the preferred way to analyze enamel features, such as incremental lines and crystal orientation, the microCT allows efficient and non-destructive comparisons between different teeth and species.Domestic pig molars provide an interesting system to study the biomineralization process. The large size, thick enamel and complex crown morphology make pig molars relatively similar to human molars. However, compared to human molars, pig molars develop considerably faster. Here we use microCT to image the developing pig molars and to decipher spatial patterns of biomineralization. We used mineral grains to calibrate individual microCT-scans, which allowed an accurate measure of the electron density of the developing molars. The microCT results show that unerupted molars that are morphologically at the same stage of development, can be at markedly different stage of enamel biomineralization. Erupted molars show increased electron density, suggesting that mineralization continues in oral cavity. Yet, our comparisons show that human enamel has slightly higher electron density than pig enamel. These results support the relatively low hardness values and calcium level values that have been reported earlier in literature for pig teeth. The mineral calibration was an efficient method for the microCT-absorption models, allowing a relatively robust way to detect scanning artifacts. In conclusions, whereas thin sections remain the preferred way to analyze enamel features, such as incremental lines and crystal orientation, the microCT allows efficient and non-destructive comparisons between different teeth and species.Peer reviewe

Consumption of snacks and dental caries among Finnish young men : a cross-sectional epidemiological study

The aim of this study was to investigate the frequency of consumption of snack products, as well as the association between snacking and restorative treatment need, and associated factors among a healthy Finnish male population. Approximately 8500 conscripts answered a computer-based questionnaire covering their snacking habits and other health behaviours. Restorative treatment need and history (DT, DMFT) were examined by trained and calibrated dentists. Cross-tabulations were used to investigate the associations between snacking habits and the other researched variables, and logistic regression analyses (odds ratio and 95% confidence interval) were used to investigate the variables influencing the restorative treatment need. In the present study, almost one-third of the study group consumed snack products daily, most often fizzy and energy drinks. Only 10% had received a diet counselling. The most common situations involving snacking were at the cinema and while playing computer games. According to Pearson's Chi square test, snacking was associated with smoking and snuffing and infrequent tooth brushing (p <0.001). According to the regression analyses, daily snacking, smoking, and doing exercise daily increased the odds for restorative treatment need whereas higher education level and tooth brushing twice or more often per day decreased the odds for restorative treatment need. It can be concluded that daily snacking is common among Finnish young men and is associated with restorative treatment need. Snacking is also associated with other harmful oral and general health habits. Individual dietary counselling should be routinely offered to everybody in dental clinics.Peer reviewe

Modeling enamel matrix secretion in mammalian teeth

The most mineralized tissue of the mammalian body is tooth enamel. Especially in species with thick enamel, three-dimensional (3D) tomography data has shown that the distribution of enamel varies across the occlusal surface of the tooth crown. Differences in enamel thickness among species and within the tooth crown have been used to examine taxonomic affiliations, life history, and functional properties of teeth. Before becoming fully mineralized, enamel matrix is secreted on the top of a dentine template, and it remains to be explored how matrix thickness is spatially regulated. To provide a predictive framework to examine enamel distribution, we introduce a computational model of enamel matrix secretion that maps the dentine topography to the enamel surface topography. Starting from empirical enamel-dentine junctions, enamel matrix deposition is modeled as a diffusion-limited free boundary problem. Using laboratory microCT and synchrotron tomographic data of pig molars that have markedly different dentine and enamel surface topographies, we show how diffusion-limited matrix deposition accounts for both the process of matrix secretion and the final enamel distribution. Simulations reveal how concave and convex dentine features have distinct effects on enamel surface, thereby explaining why the enamel surface is not a straightforward extrapolation of the dentine template. Human and orangutan molar simulations show that even subtle variation in dentine topography can be mapped to the enamel surface features. Mechanistic models of extracellular matrix deposition can be used to predict occlusal morphologies of teeth. Author summary Teeth of most mammals are covered by a layer of highly mineralized enamel that cannot be replaced or repaired. The enamel layer is not uniform over the underlying dentine, and spatial regulation of enamel formation is critical for making a functional tooth. To explore which kind of mechanisms could underlie the complex patterns of enamel distribution, we present a computational model. Starting from tomography-imaged teeth from which enamel has been digitally removed, enamel is restored on dentine surfaces by simulating diffusion-limited secretion of enamel matrix. Our simulations show how the combination of subtle features of dentine and diffusion-limited secretion of the enamel matrix can substantially increase the complexity of the enamel surface. We propose that the strength of the diffusion-limited process is a key factor in determining enamel distribution among mammalian species.Peer reviewe

Hammasperäinen poskiontelotulehdus

Vertaisarvioitu.Hammasperäinen poskiontelotulehdus määritellään paikalliseksi poskiontelon limakalvon paksuuntumiseksi, joka liittyy tulehtuneeseen tai laajasti hoidettuun hampaaseen tai suukirurgiseen toimenpiteeseen. Hammasperäinen syy saattaa olla taustalla 15 %:ssa poskiontelotulehduksista, erityisryhmien osalta jopa 40 %:ssa. Hampaan tukikudos- ja juurikanavatulehdukset aiheuttavat yli puolet hammasperäisistä poskiontelotulehduksista. Hammasperäiset tulehdukset ovat yleensä anaerobivoittoisia ja polymikrobisia. Tyypillisimmät oireet ovat toispuolinen märkäinen erite sekä tukkoisuus, paha maku tai haju, toispuolinen poskikipu tai -arkuus, liman valuminen nenänielusta, epämukava tunne kasvoissa tai ikenissä ja hammassärky. Kuvantamisessa käytetään panoraamakuvausta, intraoraalikuvia ja kartiokeilatietokonetomografiaa, joihin liittyy kuitenkin virhelähteitä. Hoito onnistuu, jos suun tulehdus hoidetaan. Hammashoidon lisäksi tarvitaan yleensä mikrobilääkehoito, usein poskiontelopunktio ja joskus sivuontelokirurgiaa.Peer reviewe