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- Sundell, Anna Lena, 1970-
(författare)
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Children with orofacial clefts : dental caries and health-related quality of life
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background. The current understanding on caries and enamel developmental defects prevalence and frequency, caries risk, health-related quality life (HRQoL) and stress response in young children with cleft lip and/or palate (CL/P) are sparse. In this thesis these aspects were investigated in 5- and 10- year-old children with CL/P in comparison to non-cleft children in the same ages.Design. The studies in this thesis have a cross-sectional case-control design. Participants. The study group consisted of 139 children with CL/P (80 children aged 5 years and 59 aged 10 years) and 313 non-cleft controls (144 children aged 5 years and 169 aged 10 years).Method. Caries was scored according to International Caries Detection and Assessment System (ICDAS II) and developmental enamel defects were measured as presence and frequency of hypoplasia and hypomineralization. Oral hygiene was assessed using Quigley-Hein plaque index. Stimulated saliva samples were analyzed for mutans streptococci, lactobacilli, buffering capacity and secretion rates. Information regarding children’s oral hygiene routines, dietary habits and fluoride exposure were collected with questionnaires. Caries risk was evaluated with algorithm-based software, Cariogram while HRQoL was perceived with KIDSCREEN-52. Stress response was analyzed with cortisol concentration in saliva at three different time points using a commercial competitive radioimmunoassay.Results. Caries prevalence (36% versus 18%) and caries frequency (1.2 dmfs versus 0.9 dmfs) was significantly higher in 5-year-old children with CL/P in comparison to non-cleft controls. In 10-yearolds no significant difference was found between children with CL/P and non-cleft controls in caries prevalence (47% versus 38%) or in caries frequency (0.7 DMFS versus 0.5 DMFS). Children with CL/P had significantly higher prevalence of enamel defects, higher counts of salivary lactobacilli and less good oral hygiene. The odds of being categorized with high caries risk were elevated in children with CL/P. Children with CL/P had similar HRQoL and salivary cortisol concentrations as non-cleft controls. However, 10-year-old boys with CL/P had significantly higher cortisol concentrations in the evening than non-cleft boys.Conclusions. Preschool children with CL/P seem to have more caries in the primary dentition than non-cleft controls. Children with CL/P had increased odds of being categorized as high caries risk individuals compared to controls. Some of the contributing factors seem to be higher prevalence of enamel defects, impaired oral hygiene and elevated salivary lactobacilli. Furthermore, as measured with the help of cortisol concentrations in saliva, children with CL/P were not more stressed than noncleft controls and their HRQoL was comparable to a European norm population. It appears that regular comprehensive preventive oral care in children with CL/P is effective in preventing caries development in permanent teeth. However, children with CL/P are at risk of caries development and preventive oral care should be implemented and started earlier than today.
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| 2. |
- Abtahi, Jahan, 1965-
(författare)
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Bisphosphonates and implants in the jaw bone
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Insertion of metal implants in bone is one of the commonest of all surgical procedures. The success of these operations is dependent on the fixation of the implants, which, in turn, depends on the strength of the bone that holds them. If the quality of the bone holding the implant could be improved locally, surgical procedures would become simpler and rehabilitation would become faster. Bisphosphonates are anti-resorptive drugs that act specifically on osteoclasts, thereby maintaining bone density and strength. Once released from the surface of a coated implant, bisphosphonates reduce osteoclast activity, thereby changing the balance of bone turnover in favor of bone formation, leading to a net gain in local bone density. During the last decades, the effects of bisphosphonate treatment on the stability of implants have been tested in several clinical and animal studies, but not in human jaws. This may be because it has been suggested that there is a link between the use of bisphosphonates (especially those given intravenously) and a condition called osteonecrosis of the jaw (ONJ). The pathophysiology and treatment of ONJ is controversial. The difficulty in treating ONJ has highlighted the importance of prevention.The overall aim of the present thesis was to evaluate the effect of local and systemic use of bisphosphonates on bone tissue. Could a thin, bisphosphonate-eluting fibrinogen coating improve the fixation of metal implants in the human jaw? Would it be possible to reproduce ONJ and prevent the development of this condition in an animal model?In two clinical studies, a total number of 96 implants were inserted in 21 patients. In a randomized trial with a paired design, one implant in each pair was coated with a thin fibrinogen layer containing two bisphosphonates (pamidronate and ibandronate). The bisphosphonate-coated implants showed better stability as measured by resonancefrequency analysis. Radiographic intraoral films also showed less bone loss. Three animal models were developed. In a study comparing local and systemic effects of bisphosphonates, zoledronate-coated screws inserted in rats showed better fixation in spite of a drug treatment that is known to induce ONJ-like lesions when given systemically. In another rat model, ONJ-like lesions were reproducibly induced at sites of tooth extraction whereas there were no signs of bone cell death in uninjured sites. Finally, rat experiments showed that the development of ONJ-like lesions after tooth extraction could be prevented by early mucoperiosteal coverage.In conclusion, a thin, bisphosphonate-eluting fibrinogen coating can improve the fixation of dental implants in human bone. This may lead to new possibilities in orthopaedic surgery and dentistry. The pathophysiology of ONJ is strongly linked to bone exposure in combination with drugs that reduce resorption.
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| 3. |
- Magnusson, Anders, 1957-
(författare)
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Evaluation of surgically assisted rapid maxillary expansion and orthodontic treatment : Effects on dental, skeletal and nasal structures and rhinological findings
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- 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 tipping of the posterior molars. Relapse is time-related and is most pronounced during the first 3 years after treatment. Thus the retention period should be extended and should be considered for this period. The main rhinological findings in the prospective longitudinal study were that SARME had a shortterm, favourable effect on nasal respiration, but the effect did not persist in the long-term. However, subjects with pre-treatment nasal obstruction reported a lasting sensation of improved nasal function.SARME and orthodontic treatment had a significant but non-uniform skeletal treatment effect, with significantly greater expansion posteriorly than anteriorly. The expansion was parallel anteriorly but not posteriorly. The lateral tipping of the posterior segment was significant, despite careful surgical separation. No correlation was found between tipping and the patient's age. Furthermore, SARME and orthodontic treatment significantly affected all dimensions of the external features of the nose. The most obvious changes were at the most lateral alar-bases. The difference in lateral displacement profoundly influenced the perception of a more rounded nose. There were no predictive correlations between the changes. Patients with narrow and constrained nostrils can benefit from these changes with respect to the subjective experience of nasal obstruction. It is questionable whether an alar-cinch suture will prevent widening at the alar-base.The 3D superimposition applied in Study II is a reliable method, circumventing projection and measurement errors. In conclusion, SARME and orthodontic treatment normalize the transverse deficiency, with long-term stability. SARME has a favourable effect on the subjective perception of nasal respiration. SARME significantly affects dental, skeletal and nasal structures.
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