Swedish dental journal. Supplement最新文献

If tooth transplantation is to succeed, it is crucial to preserve the vitality of the cells on the root surface of the tooth transplant. Insufficient postoperative nutrition to the cells on the root surface of the tooth transplant was thought to contribute to their devitalization of these cells. Impaired nutrition may be a result of poor contact between the recipient bed and the root surface of the transplanted tooth, and development of an interposed blood clot. To improve postoperative nutrition to the root surface cells, teeth were transplanted to the recipient beds in which the tissues were regenerated during a 14 day period, i.e., using the two-stage transplantation technique. In a clinical study of this technique, a total of 95 autogenous teeth with fully developed roots were transplanted in 84 patients, and examined both clinically and radiographically for up to 13 years after the transplantation. In a dog model, a comparative experimental study was made between teeth transplanted to beds left to heal for 5 days and teeth transplanted to beds prepared immediately before the transplantation. The clinical study showed a low prevalence of tooth graft loss and root resorption even when infection of the root canal occurred. Periodontal attachment loss of less than 3 mm was found in 97% of 6 defined surfaces around the transplanted teeth. Transplanted teeth which were later extracted were often hypermobile, and signalled pain when provoked with heavy loading. Excessive extraction trauma, fixation failure, and excessive plaque accumulation after transplantation were all shown to be detrimental to tooth transplant. Transplanted teeth were used as abutments for fixed partial dentures and provided the necessary dental support for crowns and bridges even in patients with atrophic alveolar bone. The experimental histological study showed no differences between test and control teeth in terms of the prevalence of root resorption, which was suspected to be caused by traumatic injuries to the roots during extraction and non-rigid fixation of the transplanted teeth.

Unlabelled: The overall purpose behind treatment in sleep-breathing disorders is to ease breathing and thereby reduce the risk of morbidity. The mandibular protruding device (MPD) is one method of treating both obstructive sleep apnea (OSA) and snoring. The aims of the studies were to study MPD users after 2 years and evaluate the following aspects of the MPD: subjective and objective effects on sleep, influences on airway passages and hard tissues, and the incidence and types of adverse events of the masticatory system including temporomandibular disorders. Further aims were to evaluate the impact of body posture and the effects of the MPD on pharyngeal width and to validate two methods for measuring mandibular protrusion and MPD advancement.

Materials and methods: Seventy-seven subjects with OSA or snorers without OSA. were admitted to the study after a medical examination, which included a somnographic registration. The patients completed questionnaires regarding sleep quality and symptoms from the masticatory system, and underwent a clinical jaw function examination, were given an MPD, and were subjected to lateral cephalometric examination. Two follow-ups, 6 months and 2 years after MPD treatment were conducted. The study population comprised 65 patients at the 2-year follow-up.

Results: At the 2-year follow-up, a significant reduction of the subjective complaints was noted by 90% of the MPD users. In the objective evaluation, the oxygen desaturation index (ODI) of the OSA group (n = 39) decreased significantly from a mean of 14.7 to 3.1 and the mean arterial oxygen saturation (SaO2) increased significantly from 78% to 89%. The snorers maintained their initial values. In the total group, MPD treatment significantly increased most pharyngeal measures and lifted the hyoid bone. The pharyngeal area decreased significantly--by more than 50%--when the patient was supine, and the velum area increased significantly. At the 2-year follow-up, on upright cephalogram without MPD, the pharyngeal area had significantly increased and the velum area had significantly decreased. The mandible was posteriorly rotated (P < 0.01) as well as the lower incisors were proclined (P < 0.05). Mandibular advancement and vertical opening with an MPD, as measured with a ruler, compared well with measurements taken from a cephalogram. At the 2-year follow-up significant changes in the mean mandibular range of protrusion (+0.6 mm), overjet (-0.5 mm), and overbite (-0.8 mm) were registered. Nine of the 65 patients had developed a lateral open bite, and 2 were aware of the change. The reported frequency of headache was significantly reduced. At the 2-year follow-up there was a significant reduction in pain during mandibular movements.

Conclusions: MPD treatment significantly reduced subjective complaints of sleep disturbances and significantly reduced ODI values among OSA patients. A hig

The diagnostic accuracy of Tuned Aperture Computed Tomography (TACT) was evaluated for a variety of diagnostic tasks. Drawbacks of 2D radiography, lack of accessibility and high cost associated with advanced imaging modalities prompted these studies. Mechanically induced vertical/oblique radicular fractures (VRF) on unrestored and endodontically treated teeth were imaged using 2D radiography, unprocessed and TACT-IR images. The effect of iterative restoration on diagnostic accuracy was studied in association with detection tasks such as VRF and mandibular fractures, as also with quantification efforts associated with osseous healing studied in vivo. Iterative restoration deblurring of TACT produced consistently higher diagnostic quality than the other two image types. The effect of observer training and previous experience with viewing TACT indicated that observers with prior experience performed better. It was also noted that fractures extending beyond the middle third of the roots were more accurately detected. The effect of the number of basis images on diagnostic accuracy of TACT radiographs for mandibular fractures showed that reconstructions using 16 basis images that had been iteratively restored performed significantly better. In the in vivo study, quantitative evaluation of healing of osseous defects subjected to different types of grafts using TACT indicates that the most optimal healing occurred with osteoblast-polymer matrix combination. TACT-IR correlated most with histomorphometric data. Increases in gray values corresponding to bone formation were notable during the early period following surgery. These studies indicate that there is enough justification for TACT to find applications in many clinical situations where an ordinary dental x-ray source and a digital sensor/film are currently being used.

The aim of the present thesis was to investigate different aspects of temporomandibular disorders (TMD) and pain such as prevalence, diagnostics, and treatment among adolescents. The reliability of a questionnaire and the clinical examination and diagnoses according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) were assessed. Overall, we found it possible to assess and diagnose TMD in adolescents in a reliable way. The prevalence of TMD pain, gender differences, and the need for treatment were investigated among 864 adolescents from a Public Dental Service clinic. Seven percent of the subjects received a pain diagnosis according to the RDC/TMD, and the prevalence was higher among girls than boys. More subjects with TMD pain reported school absence and analgesic consumption compared to controls. Approximately every second subject who reported TMD pain also perceived a need for treatment. In an evaluation of psychosocial and dental factors, the following were found to play an important role in adolescents with TMD: stress, somatic complaints, and emotional problems. Three treatment methods were compared in a randomized controlled trial: brief information only, brief information and occlusal appliance, and brief information and relaxation therapy. In the brief information and occlusal appliance group, 60%--significantly more than in the other two groups--experienced a reduction of at least 50% in TMD pain. The influence of somatic and emotional stimuli was evaluated, and we found that adolescents with TMD pain were significantly more sensitive to not only aversive somatic but also pleasant somatic stimuli compared with healthy controls. The results suggest that not only nociceptive but also cognitive processes are implicated in chronic pain states in young TMD subjects. In conclusion, TMD pain is more common in girls than in boys and affects daily life. TMD pain in adolescents can best be improved by traditional treatment with occlusal appliance combined with brief information.

In trying to make a comprehensive caries risk profile for an individual, one faces a situation that several factors need to be considered and weighted together. Summarising these factors could be a complex process and to facilitate the practical application, a computer-based risk assessment model for caries, the Cariogram, was developed. The Cariogram program operates basically in such a way that information on a number of factors are collected about the patient, transferred to 'scores' and these scores then entered into the program. According to its built-in algorithm, the program evaluates the data and presents the summarised result expressed as one figure, a pie-diagram, illustrating the 'Chance of avoiding cavities' in the future. This thesis deals with the evaluation of the Cariogram model and, as a first step, it was important to investigate if the program was in line with how colleagues, dental students and dental hygienists would evaluate a set of cases. The first two studies (Paper I and II) confirmed that the 'opinion' on the risk profile of the risk assessment program was in line with the opinions of the majority of the responders in these groups. In the third study (Paper III), the Cariogram's assessments were tested against the "reality" for the first time. The model was used to assess risk for caries among children and to evaluate the program by comparing the caries risk assessments of the risk model with the actual caries increment of the children over a two-year period. The hypothesis was that the Cariogram should be able to sort the children into caries risk groups according to the actual caries increment and the results confirmed the theory. It was also demonstrated that the Cariogram assessed caries increment more accurately than any included single factor model. Following the evaluation of the program on the children, the aim of the fourth study (Paper IV) was to evaluate the model for risk assessment in a group of elderly individuals. Comparing the caries risk assessment of the program with the actual caries increment over a five-year period showed that the program was able to arrange this group of elderly individuals into risk groups that reflected the actual caries incidence. The aim of the fifth study was to compare the risk profiles of the children with the risk profiles of the elderly. The evaluation of caries risk among the children showed that 3% was considered having very high caries risk, while 50% appeared in the low risk group. The corresponding values for the group of elderly individuals were 26% and 2%. Overall, the risk for caries, as assessed by the Cariogram, was twice as high for the elderly as for the children (V). The present thesis also tries to explore the concept of risk, the terminology and definitions related to risk, risk management and risk assessment in dentistry.

Secular changes in the mixed dentition were studied. Permanent tooth size and dental arch dimensions were examined in Norwegian children born in the 1960s and 1980s, Swedish children born in the 1960s and 1980s, Norwegian Sami children born in the 1980s, and a sample of Norwegian skulls dating from the 14th to the 19th century. The Norwegian Sami children were nomadic in the summertime. A sample of pigs was studied before and after a maceration process to determine what dimensional changes might occur in such a process. A shrinkage of 0.3%-1.7% was found. This information was used when the skulls were compared with the modern groups. Lateral dental arch lengths were shorter in the children born in the 1960s compared with the children born in the 1980s. This was a result of the higher prevalence of caries in the second deciduous molars in the 1960s groups. Children who had lost a deciduous canine prematurely were found to have smaller dental arch perimeters. When compared with other data, this was blamed on a pre-existing crowding. Permanent tooth size was smaller in the skulls compared with the modern groups. Improved nutrition is considered to be the main reason for the difference. Relative dental arch space differed in the group born in the 1960s from that in the other groups, indicating a greater prevalence of crowding in the former. Relative dental arch space in the skulls and in the group born in the 1980s was similar. A more traditional way of living, as practised by the Sami group in this thesis, was not favorable for relative dental arch space. The transverse intermaxillary relation in boys changed from the 1960s to the 1980s, which indicated that the 1980s group ran a greater risk of developing a posterior cross-bite. Before the same conclusion could be made in the girls, the mesial drift of the first permanent molars had to be corrected for, because of a higher prevalence of caries in the 1960s group. The sex-pooled analysis of the skulls and the contemporary groups revealed that the risk for developing a posterior cross-bite in the 1980s group was greater than in the skulls. The skulls had smaller arch depths than the modern groups.

Aiming to investigate adolescents' perceptions of oral health, with a focus on gender differences, quantitative and qualitative studies were conducted in Skaraborg County, Sweden. Adolescents (13-18 years; n = 17,280) answered a school questionnaire, epidemiological indices on oral health were collected, and 17 semi-structured interviews were conducted. Most adolescents perceived their oral health as good, girls more often than boys. The oral behavior of girls was also more often healthy (floss usage: girls 31%, boys 21%), and they were consistently less satisfied with the appearance of their teeth than boys. Girls considered their own consumption of candy to be too high more often than boys. Acknowledging the importance of sound teeth was strongly associated with self-perceived oral health: boys, odds ratio (OR) 8.58 [confidence interval (CI) 7.12-10.34]; girls, OR 5.56 [CI 4.23-7.30]. Adolescents living with a single mother (13-15-yr-olds OR 1.37 [CI 1.20-1.57], 16-18-yr-olds OR 1.51 [CI 1.28-1.77]), or with neither parent, more often reported bleeding gums than those who lived with both parents, while adolescents who lived with a single father did not. Weak correlations between epidemiological indices and self-perceived oral health were found at the school level. In the interviews, adolescents perceived the possibilities to influence their own oral health as limited. Perceptions of influences on oral health were related to personal and professional care, social support, social impact, and external factors such as time and economy. Support from the mother--more than from the father--was emphasized. This thesis showed that positive oral health attitudes and parental support are of great importance if oral health is to be perceived as good. There were gender differences in all issues related to self-perceived oral health.

The aim of this thesis was to explore aspects of dental erosion by investigating its prevalence among young Saudi men and young children, develop a system for its assessment and to evaluate various tentative background factors that may be associated with its occurrence. Saudi military inductees (n = 95) were subjected to questionnaire and clinical examination, including recordings of severity of dental erosion and a number of other oral health parameters. The system applied for grading the severity of dental erosion showed an intraexaminer agreement of 78%. Around one-fourth of the maxillary anterior tooth surfaces exhibited pronounced dental erosion and the average soft drink consumption was 247 liters/year. High level of soft drink consumption and long retention time of the drink in the mouth before swallowing, intensified oral hygiene, mouth breathing and low gingival bleeding index were found to have significant correlations with the presence of dental erosion. Furthermore, less plaque on maxillary palatal tooth surfaces, increased numbers of buccal cervical defects, first permanent molar "cuppings", missing teeth, and lower salivary urea content had significant correlations with the severity of dental erosion. High intake of acidic drinks and fruits, upper respiratory tract problems and frequent taking of medication were common findings in young Saudi children (n = 16) with severe dental erosion. The clinical diagnosis of erosion in deciduous teeth was confirmed by SEM. Enamel from various healthy teeth were subjected to microhardness measurements before and after in vitro exposure to citric acid. Deciduous enamel was found to be softer and relatively more prone to erosion than permanent enamel but the potential for erosion was about the same regardless of the origin of the teeth. Six methods of drinking a sugar-free cola-type drink were assessed in two groups of healthy volunteers. Intraoral pH was measured at specific locations and at predetermined time points using the microtouch method (n = 12), and continuously by using telemetric measurement (n = 6). Of the six methods tested, those in which the drink was in contact with the tooth surface for a prolonged period of time were found to strongly affect intraoral pH. It may be concluded from this thesis that dental erosion is common among young Saudi men and that erosion is associated with many etiological, aggravating and modifying factors. Consumption of soft drinks, amount of palatal plaque on maxillary anterior teeth and salivary urea concentration are some factors related to erosion. The presence of dental erosion in children is likely to be associated with a number of general health and dietary factors but is also aggravated by the relatively more rapid progression of erosion in the deciduous teeth. Drinking method seems to be an important factor in the risk of developing dental erosion.

It has been suggested that odontoblasts are instrumental in translocating Ca2+ and inorganic phosphate (Pi) ions during the mineralization of dentin. The aim of this thesis was, therefore, to study the expression of components of the transcellular ion transport system, Na+/Ca2+ exchangers and Na(+)-Pi contransporters, in odontoblastic and osteoblastic cells. Their activity was assayed in osteoblast-like cells and in the recently developed MRPC-1 odontoblast-like cell line. To assess the relationship between ion transport and mineralization, Ca2+ and Pi uptake activities were determined in mineralizing cultures of MRPC-1 cells. Osteoblastic and odontoblastic cells showed an identical expression pattern of Na+/Ca2+ exchanger splice-variants, NCX1.3, NCX1.7 and NCX1.10, derived from the NCX1 gene, while NCX2 was not expressed. The cells showed a high sodium-dependent calcium extrusion activity. Regarding Na(+)-Pi cotransporter expression, Glvr-1, Ram-1 and the two high capacity cotransporters Npt-2a and Npt-2b were found to be expressed in odontoblasts and MRPC-1 cells. Osteoblast-like cells differed from this in expressing the Npt-1 but not the Ram-1 gene but were otherwise identical to the odontoblastic cells. Odontoblast-like cells exhibited almost twice the sodium-dependent Pi uptake activity of osteoblast-like cells. The presence of NaPi-2a and NaPi-2b, gene products of Npt-2a and Npt-2b, was verified in vivo by immunohistochemistry on mouse teeth. Both cotransporters could be detected in fully differentiated, polarized odontoblasts but not in preodontoblasts prior to dentin formation. Both cotransporters were detected in adjacent bone and in ameloblasts. Studying ion uptake in mineralizing MRPC-1 cultures, large changes were detected concomitant with the onset of mineral formation, when phosphate uptake increased by 400% while calcium uptake started to decline. The increase in Pi uptake was found to be due to activation of the NaPi-2a cotransporter. MRPC-1 cells expressed an odontoblast-like phenotype already at the onset of culture, but in order to form mineral a differentiation involving their ion transporters seems necessary. Calculating the theoretical rate of ion transport needed for dentin formation and comparing with data from the studies in this thesis showed that transcellular ion transport is both possible and sufficient to meet the phosphate and calcium demands of dentinogenesis.

Background: Dental trauma occur in childhood and adolescence with consequences in time and costs for both patient and family. The scientific knowledge of these matters is scarce. For some individuals, dental trauma will result in long, time-consuming and costly treatments in childhood which will continue into adulthood.

Aim: The thesis aimed to increase the knowledge of incidence, risk, treatment, time and costs spent on dental traumas to primary and permanent teeth in children and adolescents.

Material and method: The material for the studies emanated from the county of Västmanland, Sweden, and the municipality of Copenhagen, Denmark, and from a Swedish nation-wide material (Folksam). The material was collected from accident reports, dental files, dental trauma forms, questionnaires and telephone interviews. Descriptive, prospective and analytical methods were used. A classification of uncomplicated and complicated dental traumas was presented.

Results: The incidence of dental trauma to boys was higher, compared to girls, in the county of Västmanland in almost all age groups. For both sexes, the first years in life and the first years in school were the most accident prone periods with incidence twice as high as the average incidence for all children and adolescents in the county. Every third trauma was complicated with injuries to the pulp or periodontal ligaments. Every second patient with a dental trauma to permanent teeth suffered from multiple dental trauma episodes (MDTE) during a period of 12 years. In almost every second patient with MDTE, at least one of the affected teeth had sustained repeated trauma episodes. The risk of sustaining MDTE increased when the first trauma episode occurred in the age interval of 6-10, compared to 11-18 year olds. During a 12-year period, treatment times for complicated traumas were 2.0 and 2.7 times higher for primary and permanent teeth, respectively, compared to corresponding values for uncomplicated traumas. On average, direct time (treatment time) represented 11% and 16% of the total time, while the direct costs (health care service, transport, loss of personal property and medicine) represented 60% and 72% of the total costs of traumas to primary and permanent teeth, respectively, during a 2-year period for cases of a nation-wide material.

Conclusion: Dental traumas are frequent and some individuals are injured several times. Besides treatment time, efforts from the family are substantial in time and costs. Parameters such as degree of severity, access to treatment and place of injury are of major importance to both patient and family and should be considered when calculating time and costs of dental trauma in children and adolescents.