| 941. |
- Magnusson, Anders, 1957-
(författare)
-
Evaluation of surgically assisted rapid maxillary expansion and orthodontic treatment : Effects on dental, skeletal and nasal structures and rhinological findings
- 2013
-
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.
|
|
| 942. |
- Magnusson, Anders, et al.
(författare)
-
Nasal cavity size, airway resistance, and subjective sensation after surgically assisted rapid maxillary expansion : A prospective longitudinal study
- 2011
-
Ingår i: American Journal of Orthodontics and Dentofacial Orthopedics. - : Elsevier Masson. - 0889-5406 .- 1097-6752. ; 140:5, s. 641-651
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction: The aims of this study were to measure changes in nasal minimum cross-sectional area and nasal airway resistance after surgically assisted rapid maxillary expansion and to explore a possible correlation with the subjective sensation of nasal obstruction. Methods: Minimum cross-sectional area and nasal airway resistance were measured in 39 consecutive patients treated with surgically assisted rapid maxillary expansion. Subjective nasal obstruction was assessed by a questionnaire at pretreatment and at 3 and 18 months postoperatively. Results: Subjective nasal obstruction had improved significantly by 3 months postoperatively. Minimum cross-sectional area increased and nasal airway resistance decreased. No correlations were found. In subjects with pretreatment subjective nasal obstruction and initially narrow anterior minimum cross-sectional area, there was a significant correlation between a moderate increase in anterior minimum cross-sectional area and improvement in perceived nasal obstruction. Eighteen months postoperatively, no changes were found from pretreatment values for subjective nasal obstruction, minimal cross-sectional area, or nasal airway resistance, and there were no correlations. Subjects with a sensation of nasal obstruction at treatment start reported a lasting significant subjective improvement. Conclusions: The postoperative effects of surgically assisted rapid maxillary expansion did not persist in the long term. No correlation was found between objective and subjective findings. Subjects with pretreatment nasal obstruction, however, reported a lasting sensation of improved nasal function after surgically assisted rapid maxillary expansion.
|
|
| 943. |
- Magnusson, Anders, et al.
(författare)
-
Surgically assisted rapid maxillary expansion : long-term stability
- 2009
-
Ingår i: European Journal of Orthodontics. - : Oxford University Press (OUP). - 0141-5387 .- 1460-2210. ; 31:2, s. 142-149
-
Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to evaluate treatment outcomes and long-term stability in patients treated by surgically assisted rapid maxillary expansion (SARME) and to compare the results with a matched, untreated control group. The sample comprised consecutive study models from 31 subjects (17 males and 14 females) with a mean pre-treatment age of 25.9 years [standard deviation (SD) 9.6]. The mean follow-up time was 6.4 years (SD 3.3). The transverse distances between the maxillary canines and maxillary first molars were measured with digital sliding callipers before treatment (T0), after treatment (T1), and at follow-up (T2). The data were analysed with a Mann-Whitney U, Spearman's rho, and Wilcoxon signed-rank tests. At T1, all posterior crossbites were corrected and the expansions were statistically significant. At T2, despite some reduction in the transverse measurements, the posterior crossbites remained corrected. There were no statistically significant differences between the treatment and control groups at T2 regarding transverse measurements, except for the distance between the mesio-buccal cusp tips of the maxillary first molars. In the treatment group, there was no significant difference in terms of reductions in the transverse dimensions over the short- or long-term, no significant correlations between age or gender and the decrease in transverse dimensions or between the degree of anterior and posterior expansion. There were no significant correlations between the degree of expansion and subsequent post-treatment decrease. The results indicate that SARME normalizes the transverse discrepancies and is stable a mean of 6 years post-treatment. The decreases in the transverse dimensions are most pronounced during the first 3 years post-treatment.
|
|
| 944. |
- Magnusson, Anders, et al.
(författare)
-
Three-dimensional assessment of transverse skeletal changes after surgically assisted rapid maxillary expansion and orthodontic treatment: A prospective computerized tomography study
- 2012
-
Ingår i: American Journal of Orthodontics and Dentofacial Orthopedics. - : Elsevier Masson. - 0889-5406 .- 1097-6752. ; 142:6, s. 825-833
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction: The aim of this prospective longitudinal study was to evaluate transverse skeletal changes after surgically assisted rapid maxillary expansion. The changes were registered by using a 3-dimensional computerized tomography technique based on superimposition on the anterior base of the skull. Methods: The subjects comprised 35 patients (mean age, 19.7 years; range, 16.1-43.9 years). Low-dose, helical computerized tomography images were taken at treatment start and after orthodontic treatment. The 3-dimensional models were registered and superimposed at the anterior cranial base. Results: Surgically assisted rapid maxillary expansion had a significant transverse skeletal treatment effect, significantly greater posteriorly than anteriorly. The expansion was parallel anteriorly, but posteriorly there was significant transverse tipping. Although there was no statistically significant difference between the changes at the corresponding landmarks, the range of standard deviations was marked. Conclusions: The results showed that, for registering transverse skeletal changes after surgically assisted rapid maxillary expansion, 3-dimensional superimposition is a reliable method, circumventing projection and measurement errors. Surgically assisted rapid maxillary expansion had a significant but nonuniform skeletal treatment effect. Despite careful surgical separation, pronounced posterior tipping occurred. No correlation was found between the severity of tipping and the patients age. (Am J Orthod Dentofacial Orthop 2012;142:825-33)
|
|
| 945. |
- Magnusson, Anders, et al.
(författare)
-
Three-dimensional computed tomographic analysis of changes to the external features of the nose after Surgically Assisted Rapid Maxillary Expansion and orthodontic treatment : A prospective longitudinal study
- 2013
-
Ingår i: American Journal of Orthodontics and Dentofacial Orthopedics. - : Elsevier BV. - 0889-5406.
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Introduction: The aim of this prospective, longitudinal study was toe valuate changes to the external shape and form of the nose after Surgically Assisted Rapid Maxillary Expansion (SARME) and orthodontic treatment. The changes were registered using a three-dimensional (3-D) computer tomography technique, based on superimposition on the anterior base of the skull.Method: The subjects comprised 35 patients, mean age 19.7 years (16.1-43.9). Lowdose, helical Computerized Tomography (CT) was taken at treatment start and after completed orthodontic treatment, about 18months post-surgery. The 3-D models were registered and superimposed on the anterior cranial base.Results: There was in general significant widening and overall anterior and inferior displacement of the nasal soft tissue. The changes varied in size and direction. No correlation was found between the initial and final widths of the nose, or between the initial and final widths of the nostrils.Conclusion: After SARME, the most obvious changes to the external features of the nose are at the most lateral alar-bases. The difference in lateral displacement profoundly influenced the perception of a more rounded nose. Patients with narrow and constrained nostrils can benefit from these changes. The 3-D superimposition applied in this study is a reliable method, circumventing projection and measurement errors.
|
|
| 946. |
- Magnusson, Karin, et al.
(författare)
-
An imidazole functionalized pentameric thiophene displays different staining patterns in normal and malignant cells
- 2015
-
Ingår i: Frontiers in Chemistry. - : Frontiers Media S.A.. - 2296-2646. ; 3
-
Tidskriftsartikel (refereegranskat)abstract
- Molecular tools for fluorescent imaging of cells and their components are vital for understanding the function and activity of cells. Here, we report an imidazole functionalized pentameric oligothiophene, p-HTIm, that can be utilized for fluorescent imaging of cells. p-HTIm fluorescence in normal cells appeared in a peripheral punctate pattern partially co-localized with lysosomes, whereas a one-sided perinuclear Golgi associated localization of the dye was observed in malignant cells. The uptake of p-HTIm was temperature dependent and the intracellular target was reached within 1 h after staining. The ability of p-HTIm to stain cells was reduced when the imidazole side chain was chemically altered, verifying that specific imidazole side-chain functionalities are necessary for achieving the observed cellular staining. Our findings confirm that properly functionalized oligothiophenes can be utilized as fluorescent tools for vital staining of cells and that the selectivity towards distinct intracellular targets are highly dependent on the side-chain functionalities along the conjugated thiophene backbone.
|
|
| 947. |
|
|
| 948. |
- Magnusson, Karin, et al.
(författare)
-
Differential vital staining of normal fibroblasts and melanoma cells by an anionic conjugated polyelectrolyte
- 2015
-
Ingår i: Cytometry Part A. - : Wiley: 12 months. - 1552-4922 .- 1552-4930. ; 87:3, s. 262-272
-
Tidskriftsartikel (refereegranskat)abstract
- Molecular probes for imaging of live cells are of great interest for studying biological and pathological processes. The anionic luminescent conjugated polythiophene (LCP) polythiophene acetic acid (PTAA), has previously been used for vital staining of cultured fibroblasts as well as transformed cells with results indicating differential staining due to cell phenotype. Herein, we investigated the behavior of PTAA in two normal and five transformed cells lines. PTAA fluorescence in normal cells appeared in a peripheral punctated pattern whereas the probe was more concentrated in a one-sided perinuclear localization in the five transformed cell lines. In fibroblasts, PTAA fluorescence was initially associated with fibronectin and after 24 h partially localized to lysosomes. The uptake and intracellular target in malignant melanoma cells was more ambiguous and the intracellular target of PTAA in melanoma cells is still elusive. PTAA was well tolerated by both fibroblasts and melanoma cells, and microscopic analysis as well as viability assays showed no signs of negative influence on growth. Stained cells maintained their proliferation rate for at least 12 generations. Although the probe itself was nontoxic, photoinduced cellular toxicity was observed in both cell lines upon irradiation directly after staining. However, no cytotoxicity was detected when the cells were irradiated 24 h after staining, indicating that the photoinduced toxicity is dependent on the cellular location of the probe. Overall, these studies certified PTAA as a useful agent for vital staining of cells, and that PTAA can potentially be used to study cancer-related biological and pathological processes.
|
|
| 949. |
- Magnusson, Karin, et al.
(författare)
-
Multimodal fluorescene microscopy of prion strain specific PrP deposits stained by thiophene-bassed amyloid ligands
- 2014
-
Ingår i: Prion. - : Taylor & Francis. - 1933-6896 .- 1933-690X. ; 8:4, s. 319-329
-
Tidskriftsartikel (refereegranskat)abstract
- The disease-associated prion protein (PrP) forms aggregates which vary in structural conformation yet share identical primary sequence. These variations in PrP conformation are believed to manifest in prion strains exhibiting distinctly different periods of disease incubation as well as regionally specific aggregate deposition within the brain. The anionic luminescent conjugated polythiophene (LCP), polythiophene acetic acid (PTAA) has previously been used to distinguish PrP deposits associated with distinct mouse adapted strains via distinct fluorescence emission profiles from the dye. Here we employed PTAA and 3 structurally related chemically defined luminescent conjugated oligothiophenes (LCOs) to stain brain tissue sections from mice inoculated with 2 distinct prion strains. Our results showed that in addition to emission spectra, excitation, and fluorescence lifetime imaging microscopy (FLIM) can fruitfully be assessed for optical distinction of PrP deposits associated with distinct prion strains. Our findings support the theory that alterations in LCP/LCO fluorescence are due to distinct conformational restriction of the thiophene backbone upon interaction with PrP aggregates associated with distinct prion strains. We foresee that LCP and LCO staining in combination with multimodal fluorescence microscopy might aid in detecting structural differences among discrete protein aggregates and in linking protein conformational features with disease phenotypes for a variety of neurodegenerative proteinopathies.
|
|
| 950. |
- Magnusson, Karin, 1981-
(författare)
-
Poly-and oligothiophenes : Optical probes for multimodal fluorescent assessment of biological processes
- 2015
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- One interesting class of molecules in the research field of imaging biological processes is luminescent conjugated polythiophenes, LCPs. These fluorescent probes have a flexible backbone consisting of repetitive thiophene units. Due to this backbone, the probes possess unique abilities to give rise to different spectral signatures depending on their target and environment. LCPs are a polydispersed material meaning there is an uneven distribution of lengths of the probe. Recently, monodispersed chemically well-defined material denoted luminescent conjugated oligothiophenes, LCOs, with an exact number of repetitive units and distinct sidechain functionalities along the backbone has been developed. LCOs have the advantages of being smaller which leads to higher ability to cross the blood brain barrier. The synthesis of minor chemical alterations is also more simplified due to the well-defined materials.During my doctoral studies I have used both LCPs and LCOs to study biological processes such as conformational variation of protein aggregates in prion diseases and cellular uptake in normal cells and cancer cells. The research has generally been based on the probes capability to emit light upon irradiation and the interaction with their targets has mainly been assessed through variations in fluorescence intensity, emission-and excitation profiles and fluorescence lifetime decay. These studies verified the utility of LCPs and LCOs for staining and discrimination of both prion strains and cell phenotypes. The results also demonstrated the pronounced influence minor chemical modifications have on the LCO´s staining capacity.
|
|
