Swedish dental journal. Supplement最新文献

About 30% of individuals in the Swedish population will at some stage during life have treatment with orthodontic appliances. In more severe cases, when orthodontic treatment is not considered sufficient enough to correct the malocclusion, the orthodontic treatment is combined with orthognathic surgery. For these cases, a satisfying jaw relation is achieved by surgically moving the maxilla and/or the mandible into a pre-planned position. Patients due to be treated with orthognathic surgery often suffer from an impaired masticatory function, symptoms from the masticatory muscles or temporomandibular joints (temporomandibular disorders), headaches as well as dissatisfaction with their facial aesthetics. Since orthognathic treatment is expensive, in many cases arduous to the patient and not without complications, it is important to assess the treatment outcome and if this is satisfying for the patients. Previous studies that have examined the outcome after orthognathic treatment have had diverging study designs and have come to different conclusions with regard to both temporomandibular disorders and masticatory function. The overall aim of this thesis was to assess and compare the frequencies of temporomandibular disorders and the masticatory function in patients with dentofacial deformities before and after orthognathic treatment. THE THESIS IS BASED ON THE FOLLOWING STUDIES: Paper I is a systematic literature review aiming to, in an evidence-based approach, answer the question whether orthognathic treatment affects the prevalence of signs and symptoms of temporomandibular disorders. The review encompasses the period from January 1966 to April 2006 and was further extended to May 2013 in the frame story of this thesis. CONCLUSIONS IN PAPER I AND THE COMPLEMENTARY SURVEY: There is insufficient scientific evidence for a decrease of sub diagnoses of temporomandibular disorders after orthognathic treatment. There is limited scientific evidence for a reduction of masticatory muscle pain on palpation after orthognathic treatment. There is insufficient scientific evidence for an effect on temporomandibular joint pain on palpation and temporomandibular joint sounds from orthognathic surgery. Further controlled, well-designed studies assessing temporomandibular disorders before and after orthognathic treatment are needed to consolidate strong evidence considering treatment outcomes. Papers II and III are studies comparing frequencies of temporomandibular disorders in patients with dentofacial deformities with a control group. The patients were referred for a combined orthodontic and orthognathic treatment to correct their malocclusion. The control group comprised individuals with normal occlusion or minor malocclusion traits not in need of orthodontic treatment. In Paper III, temporomandibular disorders were longitudinally analysed by assessing and comparing frequencies before and after orthognathic treatment. All individuals in the studies were diag

It is widely accepted that the uptake of research findings by practitioners is unpredictable, yet until they are adopted, advances in technology and clinical research cannot improve health outcomes in patients. Despite extensive research there is limited knowledge of the processes by which changes occur and ways of measuring the effectiveness of change of practice. The overall aim of this thesis was to investigate aspects of an educational intervention in clinical endodontic routines and new instrumentation techniques in a Swedish County Public Dental Service. Special reference was made to the establishment of changed behaviour in practice, the process of change, and the clinical effects. Although a high level of competence in root canal treatment procedures is required in general dental practice, a number of Swedish studies have revealed inadequate root-fillings quality and associated periapical inflammation in general populations. It is suggested that the adoption of the nickel-titanium rotary instrumentation (NiTiR) technique would improve the cleaning and shaping of root canals and the quality of the root-filling. However, there is limited knowledge of the effectiveness of the technique when applied in general dental practice. In two of four consecutive studies, the subjects were employees of a county Public Dental Service. The aim was to investigate the rate of adoption of clinical routines and the NiTiR technique: the output, and the qualitative meaning of successful change in clinical practice. In the other two studies the aim was to investigate treatment effect and the cost-effectiveness of root canal treatment in a general population: the outcome. Four hundred employees (dentists, dental assistants, administrative assistants and clinical managers) of a Swedish County Public Dental Service were mandatorily enrolled in an educational and training program over two years. Change of practice was investigated in a post-education survey. The NiTiR technique was adopted by significantly more dentists in the intervention county compared to a control county (77% and 6% respectively). Dentists in the intervention county completed root canal instrumentation in significantly fewer sessions than the dentists in the control county. Eight in-depth interviews, two with each participant, (dentist, dental assistant, receptionist, clinical manager), were strategically selected for a phenomenological analysis. Four factors were identified as necessary for successful change: 1) disclosed motivation, 2) allowance for individual learning processes, 3) continuous professional collaboration, and 4) a facilitating educator. A random sample of 850 performed root canal treatments was used for a study of treatment outcome; 425 before and 425 after the education and adoption of the NiTiR technique. Root-filling quality, periapical status and tooth survival were assessed on radiographs taken at treatment and at follow-up, > or = 4 years later. Apical periodontiti

Background: All children in Sweden are entitled to regular, free dental care up to 20 years of age. While dental caries generally continues to decline, still there is a pronounced skewness in caries prevalence. Furthermore, the reported increase in dental erosion in young adults is cause for concern.

Aim: The aim was to study the prevalence of dental caries and dental erosion in a cohort of Swedish 20 year-olds, with special reference to the influence of previous caries experience and lifestyle as well as parental, socioeconomic and psychosocial factors.

Material and methods: The study was prospective, longitudinal and cross-sectional in design and based on registration of caries lesions, dental erosion, body adiposity status, saliva sampling, interviews, and questionnaires at 20 years of age. Data were available for the same cohort at 1, 3, 6 and 15 years of age. 499 subjects (74 percent of the original cohort) were included. Five individuals were subsequently excluded, leaving a final sample of 494.

Results: 74 percent of the subjects had initial and/or manifest caries lesions and/or restorations. The mean number of DimFS was 5.8 and the mean number of DmFS on occlusal surfaces of molars was 1.1. There was a strong relationship between caries activity at 3 and 6 years of age and approximal caries prevalence in premolars and molars at 20 years of age. Overweight/obese individuals had significantly higher caries prevalence than normal weight individuals. Parental, socioeconomic and psychosocial factors during infancy were related to approximal caries at age 20. Dental erosion was found in 75 percent of the individuals: 18 percent of these had extensive erosion. There was a significant association between caries and dental erosion. A relationship was found between dental erosion and lifestyle factors and overweight/obesity.

Conclusions: There is a strong relationship between caries prevalence at age 20 and caries experience in early childhood. Young adults show a high prevalence of dental erosion, but the severity is generally low. Overweight and obese individuals have more caries than normal weight individuals. Parental influence during the formative years has an impact on caries prevalence in young adulthood. In this cohort, dental caries and dental erosion at age 20 are related to overweight/obesity and lifestyle factors.

Surgically Assisted Rapid Maxillary Expansion (SARME) is frequently used to treat skeletal maxillary transverse deficiency (MTD) in skeletally mature and non-growing individuals. Despite previous research in the field, questions remain with respect to the long-term stability of SARME and its effects on hard and soft tissue. The overall aim of the present doctoral work was to achieve a greater understanding of SARME, using modern image technology and a multidisciplinary approach, with special reference to effects on the hard and soft tissues and respiration. A more specific aim was to evaluate the long-term stability in a retrospective sample of patients treated with SARME and orthodontic treatment and to compare the results with a matched, untreated control group. The studies in this doctoral project are thus based on two different samples and study designs. The first sample, Study I (Paper I), is a retrospective, consecutive, long-term follow-up material of study models from 31 patients (17 males and 14 females) treated with SARME and orthodontic treatment between 1991 and 2000. The mean pre-treatment age was 25.9 years (SD 9.6) with a mean follow-up time of 6.4 years (SD 3.3). Direct measurements on study models were made with a digital sliding caliper at reference points on molars and canines. To evaluate treatment outcome and long-term stability, the results were compared with study models from an untreated control group, matched for age, gender and follow-up time. The second sample, Study II (Papers II-IV), is a prospective consecutive, longitudinal material of 40 patients scheduled to undergo SARME and orthodontic treatment between 2006 and 2009. In Paper II, one patient was excluded because of a planned adenoidectomy. The final sample comprised 39 patients (16 males and 23 females). The mean age at treatment start was 19.9 years (range 15.9 - 43.9). Acoustic rhinometry, rhinomanometry and a questionnaire were used to assess the degree of nasal obstruction at three time-points; pre-treatment, three months after expansion and after completed treatment (mean 18 months). In Papers III-IV, three patients declined to participate and two had to be excluded because their CT-records were incomplete. The final sample comprised 35 patients (14 males and 21 females). The mean age at treatment start was 19.7 years (range 16.1 - 43.9). Helical CT-images were taken pre treatment and eighteen months' post-expansion. 3D models were registered and superimposed at the anterior cranial base. The automated voxel-based image registration method allows precise, accurate measurements in all areas of the maxilla. In Papers II-IV, the treatment groups constituted their own control groups. The main findings in the retrospective, long-term follow-up study were that SARME and orthodontic treatment normalized the transverse discrepancy and was stable for a mean of 6 years post-treatment. Pterygoid detachment did not entirely eliminate the side effect of buccal ti

The overall goal of this thesis was to broaden knowledge of pain mechanisms in myofascial temporomandibular disorders (M-TMD). The specific aims were to: Develop a quality assessment tool for experimental bruxism studies (study I). Investigate proprioceptive allodynia after experimental tooth clenching exercises (study II). Evaluate the release of serotonin (5-HT), glutamate, pyruvate, and lactate in healthy subjects (study III) and in patients with M-TMD (study IV), after experimental tooth clenching exercises. In (I), tool development comprised 5 steps: (i) preliminary decisions, (ii) item generation, (iii) face-validity assessment, (iv) reliability and discriminative validity testing, and (v) instrument refinement. After preliminary decisions and a literature review, a list of 52 items to be considered for inclusion in the tool was generated. Eleven experts were invited to participate on the Delphi panel, of which 10 agreed. After four Delphi rounds, 8 items remained and were included in the Quality Assessment Tool for Experimental Bruxism Studies (Qu-ATEBS). Inter-observer reliability was acceptable (k = 0.77), and discriminative validity high (phi coefficient 0.79; P < 0.01). During refinement, 1 item was removed; the final tool comprised 7 items. In (II), 16 healthy females participated in three 60-min sessions, each with 24- and 48-h follow-ups. Participants were randomly assigned to a repetitive experimental tooth clenching task with a clenching level of 10%, 20%, or 40% of maximal voluntary clenching force (MVCF). Pain intensity, fatigue, perceived intensity of vibration (PIV), perceived discomfort (PD), and pressure pain threshold (PPT) were measured throughout. A significant increase in pain intensity and fatigue but not in PD was observed over time. A significant increase in PIV was only observed at 40 min, and PPT decreased significantly over time at 50 and 60 min compared to baseline. In (III), 30 healthy subjects (16 females, and 14 males) participated in two sessions at a minimum interval of 1 wk. Microdialysis was done to collect 5-HT, glutamate, pyruvate, and lactate and to measure masseter muscle blood flow. Two hours after the start of microdialysis, participants were randomized to a 20-min repetitive experimental tooth clenching task (50% of MVCF) or a control session (no clenching). Pain intensity was measured throughout the experiment. Substance levels and blood flow were unaltered at all time points between sessions, and between genders in each session. Pain intensity was significantly higher after clenching in the clenching session compared to the same time point in the control session. In (IV), 15 patients with M-TMD and 15 healthy controls participated in one session and the methodology described above was used. M-TMD patients had significantly higher levels of 5-HT and significantly lower blood flows than healthy controls. No significant differences for any substance at any time point were observed between groups

The overall aim of this thesis was to study some aspects of the repair of the dentine barrier, especially in conjunction with dental pulp capping. Understanding the events leading to the healing of the dentine and pulp, and hence successfully preserving the vitality and functions of the tooth, would lead to a scientific basis for a less invasive treatment of pulp exposures than performing root canal treatments. The surfaces of the body have physiological barrier functions aimed at protecting the body from external noxious agents. In the tooth, the odontoblasts, which line the outermost part of the pulp and are responsible for the formation of dentine, play a central role in the barrier function and thus in the defence mechanisms of the tooth. The micro-organisms in the caries lesion can reach the pulp via the dentinal tubules. However, the barrier function helps to prevent microbial invasion and thereby avoid deleterious inflammation and subsequent necrosis of the pulp. Dentine repair is an important part of the barrier function. There are however doubts as to whether the repair also leads to restitution of the function and the ability to withstand bacterial influx over the longer term. Pulp capping is a treatment method used when the pulp has been exposed in order to stimulate healing of the pulp and dentine. The evidence for repair of the dentine after pulp capping in humans has been studied by means of a systematic review. The focus of the literature search was studies performed in humans where hard tissue formation had been studied with the aid of a microscope. We concluded, based on the limited evidence available, that calcium hydroxide based materials but not bonding agents promote formation of a hard tissue bridge. Scientific evidence was lacking as to whether MTA was better than calcium hydroxide based materials in this regard. A gel (Emdogain Gel) containing amelogenin, known to be involved in dentinogenesis, was evaluated with regard to formation of hard tissue in a clinical study. A greater amount of hard tissue was formed after application of the gel compared to the control. Characterization of the tissue concluded it to be dentine, based on its content of type 1 collagen and dentine sialoprotein, although it was not formed as a continuous bridge covering the pulp wound. Beneath a deep caries lesion an important part of the barrier function is the odontoblasts' response to bacteria with the formation of new dentine. A cell model with odontoblasts was used to study the effects of clinical isolates from a deep carious lesion on their viability and production of type 1 collagen, the major component of the dentine in the early stages of its formation. There were bacteria that negatively affected the viability of the odontoblast-like cells and different bacteria varied in their effects on type 1 collagen production, suggesting that some bacteria may have a direct influence on the odontoblasts' ability to form dentine. In summary; Emd

Unlabelled: The main functions of estrogen are associated with reproduction. However, estrogen has been shown to be of functional importance also in non-classic target organs. Previous studies, especially epidemiologic and clinical ones, have addressed estrogen's influence on periodontitis, suggesting that estrogen has a beneficial effect, but the biological mechanisms have not been identified. Estrogen exerts genomic effects in the target cells by binding to the nuclear receptors, estrogen receptor (ERs), ERalpha and ERbeta. The expression of the two subtypes of ERs varies depending on the tissue. The overall objectives of this thesis were to study the functional importance of estrogen receptors in the periodontium with special focus on inflammation, and stimulators of inflammation and their signaling pathways. The thesis is based on the following five papers. In Paper I, effects of estrogen on E. coli LPS-induced PDL cell production of interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1) and C-reactive protein (CRP) are assessed, by using ELISA. Furthermore, effects of LPS and estrogen on the normal characteristics of the PDL cell such as collagen synthesis and cell proliferation is determined by using L-[3H]proline incorporation and measurement of DNA synthesis, respectively.

Key findings: E. coli LPS stimulates PDL cell IL-6 and MCP-1 production but has no effect on the normal physiological properties of PDL cells. LPS-induced IL-6 and MCP-1 is not reversed by estrogen suggesting that estrogen has no anti-inflammatory effect in these experiments. In Paper II, we investigate the effects of ovariectomy and aging on tooth attachment in female mice by using morphometric analysis.

Key findings: Withdrawal of female sex hormone production by ovariectomy has no effect on alveolar bone height and apical termination of the junctional epithelium. In a second series of experiments these parameters are similar in mice sacrificed at 8-26 weeks of age, suggesting that tooth attachment is preserved with age in mice within a period of six months. In Paper III, the objective is to investigate the regulation of CCL2/MCP-1, CCL3/MIP-1alpha, and CCL5/RANTES chemokines by estrogen in human PDL cells by determining mRNA transcript levels (using quantitative real-time PCR) and protein levels (using ELISA).

Key findings: A physiological concentration of estrogen reduces the expression of CCL3 mRNA by about 40% compared to PDL cells treated with LPS alone. In contrast, inter-individual differences in the effects of estrogen on CCL5 mRNA expression are observed. These findings indicate that estrogen affects chemokine expression in PDL cells showing a complex pattern involving down-regulation as well as up-regulation of chemokines. Estrogen exerts both anti-inflammatory and pro-inflammatory effects through these mechanisms. In Paper IV, ER expression in human gingival b

The overall aim of this thesis was to study dentofacial morphology in Turner syndrome (TS) versus controls and the influence hereupon from karyotype. One hundred thirty two TS females (5-66 years of age), from Göteborg, Uppsala and Umeå were participating. Cephalometric analysis, cast model analysis concerning palatal height, dental arch morphology and dental crown width were performed. Eighteen primary teeth were analysed in polarized light microscopy, scanning electron microscopy, microradiography and X-ray microanalysis were performed. The TS females were divided according to karyotype into: 1 45,X; 2 45,X/46,XX; 3 isochromosome; 4 other. Compared to healthy females, TS were found to have a flattened cranial base as well as small and retrognathic jaws with a posterior inclination. The maxillary dentoalveolar arch was narrower and longer, while the mandibular dental arch was wider and longer in TS compared to controls. The palatal height did not differ comparing TS and healthy females. The dental crown width was smaller in TS for both permanent and primary teeth. Aberrant elemental composition, prism pattern and lower mineral density were found in TS primary enamel compared to enamel in primary teeth from healthy girls. Turner syndrome karyotype was found having an impact on craniofacial morphology, with the mosaic 45,X/46,XX exhibiting a milder mandibular retrognathism as well as fewer cephalometric variables differing from controls compared to other karyotypes. Also for the dentoalveolar arch morphology the 45,X/46,XX group had fewer variables differing from healthy females. The isochromosome TS group exhibited the smallest dental crown width for several teeth, while 45,X/46,XX hade the largest dental crown with for some teeth and fewer teeth than both 45,X and isochromosomes that differed from controls. Thus, the mosaic 45,X/46,XX seemed to exhibit a milder phenotype, possibly due to presence of healthy 46,XX cell lines.

During the last few decades, and especially during the 1990s, an increase in musculoskeletal pain conditions and stress-related ill-health has been observed in Sweden. At the same time, an improvement in the oral health of the population has been noted. The overall aim of this thesis was to acquire knowledge relating to possible time trends for the presence of temporomandibular disorders (TMD) in the population. A further objective was to study factors that possibly influence the presence of these disorders and the outcome of their treatment. Studies I-III are based on a series of repeated cross-sectional population-based investigations. Three independent samples of 130 individuals in the age groups of 3, 5, 10, 15, 20, 30, 40, 50, 60 and 70 years were randomly selected from the inhabitants of the city of Jönköping, Sweden in 1983, 1993 and 2003. The total participation rate was 21%, 22% and 29% respectively. The participants were examined using a questionnaire, interview and a clinical examination of the stomatognathic system regarding the presence of symptoms and signs indicative of TMD. Study IV is a retrospective survey of a clinical sample of patients referred to and treated at the Department of Stomatognathic Physiology, The Institute for Postgraduate Dental Education, Jönköping, in 1995-2002. The overall frequencies of symptoms and the rates for some clinical signs and consequently of an estimated treatment need in adults increased during the study period. In 2003, the prevalence of frequent headache in 20-year-olds, mainly females, had markedly increased. The reports of bruxism among adults increased from 1983 to 2003. Awareness of bruxism and self-perceived health impairment were associated with TMD symptoms and signs. A favourable treatment outcome was observed for the majority of patients with common TMD sub-diagnoses and no strong predictors of treatment outcome were found. In conclusion, the results suggest some time trends towards an increased prevalence in the overall symptoms and some signs indicative of TMD in the Swedish adult population during the time period 1983-2003. A profound understanding of the social determinants of health is recommended when planning public health resources.

Enamel is one of the most important structures of the tooth, both from a functional and esthetic point of view. Primary enamel carries registered information regarding metabolic and physiological events that occurred during the period around birth and the first year of life. Detailed knowledge of normal development and the structure of enamel is important for the assessment of mineralization defects. The aim of the thesis is to add more detailed information regarding the structure of primary enamel. The structural appearance of the neonatal line and the quantitative developmental enamel defect, enamel hypoplasia, was thoroughly investigated with a polarized light microscope, microradiography and scanning electron microscope. X-ray microanalysis of some elements was also performed across the enamel and the neonatal line. Postnatal mineralization of enamel at different ages and from different individuals was studied regarding the chemical content, by using secondary ion mass spectrometry. The enamel's response to demineralization was investigated in relation to the individual chemical content and the degree of mineralization of the enamel, by using polarized light microscope, microradiography, scanning electron microscope and X-ray microanalysis. The neonatal line is a hypomineralized structure seen as a step-like rupture in the enamel matrix. The neonatal line is due to disturbances in the enamel secretion stage. The enamel prisms in the postnatal enamel appeared to be smaller than the prenatal prisms. The hypoplasias showed a rough surface at the base and no aprismatic surface layer was seen in the defect. The enamel of the rounded border of hypoplasia appeared to be hypomineralized, with the bent prisms not being densely packed. Mineralization of enamel is a gradual process, still continuous at 6 months postnatally in the primary mandibular incisors. The thickness of the buccal enamel is reached at 3-4 months of age. Demineralization of enamel depends on the degree of mineralization and the chemical content of the enamel exposed. In a more porous enamel, deeper lesions will develop. The posteruptive maturation has a beneficial effect on the enamel's resistance to demineralization.