| 1. |
- Cecchinato, Francesca
(författare)
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On magnesium-modified titanium coatings and magnesium alloys for oral orthopaedic applications : in vitro investigation
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In dentistry and orthopaedic surgery, research to find and developimproved biomaterials is progressing rapidly.Of specific interest is to accelerate bone formation around theimplant surface, which could improve the reliability of the implanteven in patients with compromised situations. Although the surfacemodification of the implant has been proven to certain extent topromote osseointegration, the lack of bone in the patient remains amajor issue and bone augmentation is commonly conducted priorto implant insertion. Synthetic and naturally derived resorbablematerials are commonly used. However, problems such as the lackof optimal mechanical properties or the undesirable materialresorption kinetics still exist and there still remain possibility forimprovement. Clinical approaches for orthopaedic trauma require the use ofnon-resorbable screws, plates and pins made of metallic materialssuch as titanium, cobalt-chrome and stainless steel alloys. Themajor drawback of these materials is the need of implant removalat re-entry. Therefore, the research of bioresorbable materials thatcould withstand the mechanical stresses is an ongoing topic.Based on this clinical reality, the aim of this thesis was toinvestigate the suitability of magnesium (Mg) as a biomaterial forregenerative bone applications. Namely, Mg as a doping materialfor engineered mesoporous titanium implant surfaces (Studies I, IIand III), and as a bioresorbable metal alloy for bone regenerationin bone trauma and bone defects conditions (Study IV).Study I, II, IIIMesoporous titania films produced with evaporation-induced selfassembly(EISA) technique and applied as implant surface coatingsare under investigation as a release system for the controlledadministration of several substances, such as osteoporotic drugs, toenhance early bone anchorage to the implant. Modulating the poresize of such films though the selection of EISA parameters permitsto control the adsorption of such substances into the mesoporousmatrix and their subsequent release into the peri-implant region.Studies I, II and III analysed the effect of Mg incorporation intomesoporous titania coatings towards two cellular models duringearly and later stages of cell activity.Study I characterized the morphology, chemistry, and topographyof mesoporous titania coatings and the effects of Mg-loading onsurface micro- and nano-structures. Mg release was determinedand its effect was evaluated on human foetal osteoblast populations.It was shown that mesoporous films possessed a smoothsurface with pores that faced outward. Mg adsorption did notsubstantially alter the mesoporous surface roughness both atmicro- and nano- levels. Mg was released within 24 hours ofincubation in cell culture conditions, thus its bioactive effect onlyoccurred during initial osteoblasts activity.Study II evaluated the ability of Mg-loaded mesoporous coatings tomodulate multipotent adipose-derived stromal cell differentiationtoward the osteoblast phenotype. The results demonstrated thatMg release had a strong impact on this cellular model, promotingosteoblast marker expression in standard cell culture conditions.Interestingly, Mg significantly promoted the expression of osteopontin,a protein that is essential for early biomaterial-cellosteogenic interaction.In study III, the reagents and EISA parameters in the mesoporousdeposition were varied to generate three mesoporous titaniacoatings with 2-, 6- and 7-nm average pore size, to increase Mgcontent in the interconnected porosity of the films. The effect ofvarious Mg contents released from the three mesoporous structureswas tested on human foetal osteoblasts populations with pre-designedosteogenic PCR arrays and real-time polymerase chainreaction. It was shown that Mg release affected osteogenesis andwas controlled by tuning the pore dimensions of the mesoporousfilms. Increasing pore size by 1 nm (from 6 nm to 7 nm)significantly enhanced the bioactivity of the film without alteringthe surface roughness.Study IVIn orthopaedics Mg alloys has received increasing attention asbioresorbable metals for bone regeneration. However, localizedmaterial degradation is too fast and provokes the premature loss ofmechanical properties, preventing correct cellular development andbone healing in vivo . For this reason, various alloying elements arecombined with high-purity Mg to modulate and optimize degradationbehaviour.Study IV of this thesis investigated the degradation parameters ofMg2Ag, Mg10Gd, and Mg4Y3RE alloys and how the alloysdifferently affect human umbilical cord perivascular cell adhesionand spreading. Mg4Y3RE showed the highest degradation rateand, thereby, the highest trend in increases in pH and osmolality ofthe surrounding fluid. However, both Mg4Y3RE and Mg10Gdallowed cells to better adhere and spread across their degradedsurfaces; in comparison, surface degradation of Mg2Ag was moreaggressive with weak or no visible cellular structures on it.ConclusionsIn summary, the results of the present thesis explored the potentialof Mg for its application in bone tissue regeneration. Titaniumimplant surfaces coated with mesoporous TiO2 thin films andfurther loaded with Mg enhanced bone cell activity and osteoprogenitordevelopment into mature osteoblasts. Thus, mesoporousdeposition followed by Mg loading may be a suitablealternative to existing implant surface treatments.Bioresorbable materials must degrade slowly and uniformly inorder to simulate the tissue healing process. Mg10Gd possessesreduced content of alloying element and a suitable homogenousdegradation pattern in vitro that allows proper adhesion ofundifferentiated cells. Mg10Gd thus represents a biodegradableMg-based material with promising mechanical and biologicalproperties for use in dental and orthopaedic fields.
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| 2. |
- Dimberg, Lillemor
(författare)
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Malocclusions and quality of life : cross-sectional and longitudinal studies in children
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- There are few longitudinal studies of the prevalence of malocclusionsand possible self-correction of malocclusions during the developmentof the dentition. Early intervention might be unnecessary if self-correction of the malocclusion occurs during the transition from theprimary to the permanent dentition. Most studies are cross-sectionaland in those of longitudinal design, the results are inconsistent anddifficult to interpret.Malocclusions may or may not influence the quality of life inchildren and adolescents. Thus, evaluations of the influence ofdifferent malocclusions on quality of life will certainly underpin abroader understanding and knowledge about how malocclusionsaffect the daily life of young patients. This information may also beimportant when it comes to assessing the most appropriate time forstarting orthodontic treatment, not only from a professional pointof view, but also, most importantly, from the patients’ perspective.The overall aim of this thesis was therefore to evaluate theprevalence of malocclusions, and to document changes occurringduring the development of the dentition, from the primary dentitionstage at age 3, through the mixed dentition at age 7, to the earlypermanent dentition at age 11.5 years. Further aims were to reviewthe current state of knowledge about the impact of malocclusionson oral health related quality of life (OHRQoL) and to investigatehow malocclusions affect the quality of life in a cohort of children,aged 11.5 years, whose dental care is provided by the Swedish PublicDental Service.
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| 3. |
- Halldin, Anders
(författare)
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On a biomechanical approach to analysis of stability and load bearing capacity of oral implants
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- IntroductionWhen an implant is placed in the bone the body responds to thetrauma by encapsulating the implant and its survival depends onthe ability for hard tissue encapsulation. The stability of the implantduring the healing phase is essential to achieve a good result[1]. Biological, physiological and mechanical phenomena affectimplant stability. To achieve sufficient stability during the initialhealing phase the implant has to provide sufficient static interactionwith the bone. The static interaction might affect the biologicalprocesses that in turn affect implant stability. Although, numerousstudies on the effect of dynamic interaction on implant stabilityand bone remodeling exist, the effect of static strain has yetto be clarified.As the healing progresses it may result in bone formation in closecontact with the implant (i.e osseointegration) that stabilizes theimplant. It has been found that implant surface modifications atthe micro level promote osseointegration and that moderatelyroughened implants provide rapid and strong bone response [2, 3].In addition, the application of nanostructures to an implant surfacehas been shown to elicit an initial complex gene response that mayresult in further enhancement in bone formation around the implant[4]. Furthermore the implant surface structure interlocks mechanicallywith the bone that affects the stability of the implant.The implant surface design has to take into account both biologicaland mechanical behavior of the tissues.Materials and methodsTo investigate how implant stability and the biological responseare affected by an induced static load to the bone an in vivo studywas performed. Two types of controlled static loads, excessive andmoderate, were induced by specially designed implants. Two typesof surface structure, turned and blasted, were applied on the implants.The implants were inserted in rabbits and healed for 3-84days before the stability was measured by removal torque.To simulate how the pressure changes, due to biological and mechanicalphenomena, on an implant surface that was subjected toan initial pressure, a constitutive model was developed that wascomprised of visco-elastic, visco-plastic and remodeling components.The pressure on the surface in turn affects the implant stability.To investigate how the biomechanical and the biological responsesare affected by the surface structure an in vivo study and a finiteelement analysis of the theoretical interfacial shear strength wereperformed. In the pre-clinical study, three groups of implants withdifferent nano- and microstructures were compared to an implantwith a control surface structure.The theoretical interfacial strength at different healing times wasestimated by simulating the surface structure interlocking capacityto bone using an explicit finite element method. Simulations wereperformed for different surface structures and for different pressures,simulating visco-elastic and remodeling phenomena.ResultsImplants that induced a moderate bone condensation in the bonehad a significantly higher removal torque value at the implantationtimes of 3-24 days compared to implants that did not induce condensation.The effect the induced moderate bone condensation hadon implant stability decreases over time until the pressure has vanished,which approximately occurred after 28-30 days. Turned implants,placed in tibia, that induced excessive bone condensationresulted in significant increased implant stability at implantationtimes of 3-24 days compared to implants that induced no condensation.However, when they were placed in femur it provided nosignificant difference in removal torque at an implantation time of24 days compared to implants that induced no condensation.The developed constitutive model is able to capture visco-elasticmaterial behavior and remodeling phenomena of cortical bonewhich can be used to simulate how the pressure changes on an implantsurface that is subjected to an initial pressure caused by condensation.The implant nano- and microsurface structure affects the magnitudeof the removal torque value. It was found that implants, withno significant difference in surface roughness parameters (Sa, Ssk,Sdr) on micro level, can present a significant difference in removaltorque value at 4 weeks of implantation time. In addition, it wasalso found that implants with a significant difference in surfaceroughness parameters (Sa, Ssk, Sdr) can present no significant differencein removal torque value at 4 weeks of implantation times. Thedifference may be due to various biological responses from thenano- and microstructure surfaces.The simulated interfacial strength for the different surfaces did notreach the interfacial strength that corresponds to the removaltorque obtained in the in vivo study. Comparing the two surfaces in respect of removal torque ratio, suggests that during the earlyhealing phase the difference is caused by different bone formationrates from biological processes. As the healing progresses the effectof structural interlocking capacity is more pronounced.ConclusionsThe results suggest that increased static strain in the bone not onlycreates higher implant stability at the time of insertion, but alsogenerates increased implant stability throughout the observationperiod of 3-24 days. The proposed constitutive material model consists of three differentcomponents: a visco-elastic component, a visco-plastic componentand a remodeling component. The model captures with goodagreement the experimental behavior of cortical bone during differentlongitudinal loading situations i.e. in vitro stress-strain relationship,in vivo relaxation, in vitro creep and in vivo remodeling.The results of the present study suggest that nano- and microstructurealteration on a blasted implant might enhance the initial biomechanicalperformance, while for longer healing times, the surfaceinterlocking capacity seems to be more important.Simulation of the interfacial shear strength by means of finite elementanalysis seems to be a promising method to estimate the loadbearing capacity of the bone-to-implant interface for different surfacestructures at stable healing conditions i.e. longer healing times.Furthermore, it is a promising method to estimate the implant stabilityfor different magnitudes of condensation.
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| 4. |
- Mahmood Jallal Hadi, Deyar
(författare)
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On core and bi-layered all-ceramic fixed dental prostheses, design and mechanical properties : studies on stabilized zirconiumdioxide
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Loss of teeth can affect a person’s self-esteem, social life, appearance and oral function. Reconstruction of a missing tooth has scientifically been shown to increase self-esteem and quality of life and to maintain oral function. For many patients a fixed dental prostheses (FDP) is preferred, either tooth- or implant-supported. Improvement and development of all-ceramic materials have made them preferable to other alternatives. However, despite properties of dental ceramics’ well known biocompatibility, good chemical and mechanical, the materials have their weaknesses, such as brittleness and some difficulties with the layering porcelain. Many all-ceramic materials cannot withstand minor flexure; more than 0.1 - 0.3 %, will lead to fracture. Oxide-ceramic, specifically yttria stabilized tetragonal zirconia polycrystals (Y-TZP) has become the most commonly used all-ceramic material. This material has the potential to be used for larger restorations. In addition, one of many challenges is to ensure durable zirconia-based restorations in the oral cavity. In the clinical situation, crowns and bridges are supported by a combination of different structures with differing properties, i.e. bone, dentine and enamel. The complexity of the supporting tissues in the oral cavity creates stress patterns in the prosthetic material, which need to be considered when designing a dental restoration. The durability of all-ceramic FDPs is dependent on knowledge of the material and design of the FDPs. In particular the design, shape of the connector and the radius of curvature at the gingival embrasure play a significant role in the load-bearing capacity of FDPs. The overall aim of this thesis is to evaluate design of zirconia-based restorations in relation to achieving increased fracture resistance. Another aim is related to how the choice of material used for supporting tooth analogues in the test set-up and how this influences test results relating to fracture strength of all-ceramic FDPs. Study I evaluates different radii (0.60 and 0.90 mm) of curvature in the embrasure of the connector area and different connector dimensions (2 x 2, 3 x 2 and 3 x 3 mm) and their effects on the fracture resistance of 3-unit all-ceramic FPDs made of Y-TZP. The results show that by increasing the radius of the gingival embrasure from 0.6 to 0.9 mm, the fracture strength for a Y-TZP FPD with connector dimension 3 x 3 mm will increase by 20%. Study II investigated how the choice of material (aluminium, polymer and DuraLay) used for supporting tooth analogues and support complexity influence test results concerning the fracture strength of FDPs made of a brittle material Y-TZP. The outcome of the study demonstrated that Y-TZP FDPs cemented on tooth analogues made of aluminium, with high E-modulus showed a significantly higher load at fracture and a different fracture mode than shown in clinical situations. Study III evaluates how factors as different default settings for connector design of two different CAD/CAM systems and different radii of curvature in the embrasure area of the connector will affect the fracture strength and the fracture mode of 3-unit, i.e. 4-unit allceramic FDPs made from Y-TZP and further to investigate how the number of pontics affect the fracture strength of Y-TZP. The results showed that the most crucial factor for the load-bearing capacity is the design of the radius of the gingival embrasures. Increasing the number of pontics from three to four decreases the load-bearing capacity nearly twice. Study IV investigate and compare the fracture strength and fracture mode in 11 groups of the currently most used multilayer all-ceramic systems for Y-TZP FDPs, with respect to the choice of core material, veneering material area, manufacturing technique (split-file, overpress, built-up porcelains and glass-ceramics), design of connectors and radius of curvature of FDP cores. The results show that the design of a framework is a crucial factor for the load bearing capacity of an all-ceramic FDP. The state-of-the-art designs are preferable, since the split-file designed cores call for a cross-sectional connector area, at least 42% larger, to have the same load bearing capacity as the state-of-the-art designed cores. Analyses of the fracture patterns demonstrated differences between the milled veneers and over-pressed or built-up veneers, where the milled ones showed numerically more veneer cracks whereas the other groups only showed complete connector fractures. All veneering materials/techniques tested were found, with great safety margin to be sufficient for clinical use both anteriorly and posteriorly.
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| 5. |
- Rönnbäck, Julia
(författare)
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Det är väl typiskt tjejer : om basket, kropp och femininitet
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this dissertation is to analyse how a group of female basketball players – aged 15 to 18 and located in one of Sweden’s largest cities – construct and negotiate gender and femininity through bodily and verbal practices. The study is grounded in poststructuralist theories – primarily using the theoretical work of the philosophers Judith Butler and Michel Foucault. The methods used are qualitative: participant observations, interviews and written dialogues via Facebook. The writing method used is ethnographic fiction.The first part of the analysis shows how the female basketball players frequently talk about appearance and also how they repeatedly talk about the fleshier matters of the body – such as muscles and fat. These recurrent verbal practices are parts of the processes through which the girls construct gender and femininity, and a way of exercising relational power. The girls themselves explain their frequent talk about body and appearance as something “typical” for girls and thus they use a discourse that circles them (as young women) in order to make themselves understandable.The second part of the analysis depicts how the female basketball players – in the locker room – before every game construct similar and socially recognizable female bodies. These recurrent bodily practices are further parts of the processes through which the girls construct gender and femininity. Additionally, in the second part, the analysis show how the female basketball players – through verbal and bodily practices – transform gender and convert femininity within sport and also how they, in game situations, embody two different discourses: “Girl Power” and “the insecure (sporting) girl” that encompass young (sporting) women.One conclusion in the thesis is that discourses that surround young (sporting) females appear to be central in their creation of gender identity. Furthermore, the (sporting) girls are active participants in the ongoing debate regarding what (sporting) girls are, can be and should be.
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| 6. |
- Taube, Elin
(författare)
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Loneliness : an essential aspect of the wellbeing of older people
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The overall aim of this thesis was to explore loneliness by identifying associated factors and predictors for loneliness among older people. This research was also undertaken to examine the association between loneliness and healthcare consumption. In addition, the reserach explored the experience of loneliness and evaluated the effects on loneliness, symptoms of depression and life satisfaction of a case management intervention for frail older people.Study I was a quantitative study with a longitudinal design involving persons 78 years or older and drawn from the Swedish National Study on Aging and Care. The sample comprised of 828 people at baseline (2001) who were followed-up after three years (n=511, 2004) and six years (n=317, 2007). The sample was divided into two groups, based on if the persons felt lonely or not. Factors such as personality traits, health complaints, self-reported health status and life satisfaction were included for identifying associated factors and predictors for loneliness. Studies II-IV were based on a main study with an experimental design, comprising 153 persons, 65+ years, living at home, with dependency in ADL and repeated contact with the healthcare services. Study II had a cross-sectional design drawn from the baseline assessment (n=153) of the main study. Self-reported data and register data was used to investigate the association between use of healthcare and loneliness, health status and health complaints. Study III had a qualitative design and explored the experience of loneliness by performing interviews with 12 persons (10 women), recruited from the main experimental study. The interviews were analysed by using qualitative content analysis. Study IV was a randomised controlled trial, including 153 persons randomised to an intervention (n=80) or control group (n=73) and evaluated the effect of a case management intervention after six and 12 months.Three outcomes were evaluated in regards to effectiveness; loneliness, symptoms of depression and life satisfaction.The results in Study I showed that 52 per cent of the sample at baseline felt lonely sometimes or often (mean age 84 years). The strongest associated factor for loneliness was living alone (OR=6.1, 95%, CI=3.8-9.9) and the strongest predictors for loneliness at both follow-ups, at three and six years, was feeling lonely at baseline (OR=7.2, CI=3.9-13.4 and OR=5.4, CI=2.8-10.5). Those associated factors and predictors that were identified were mainly related to psychosocial outcomes. Study II showed that 60 per cent of the frail older participants (mean age 82 years) had experienced loneliness occasionally or more often during the previous year. Those who felt lonely used significantly more outpatient services, including visits at the emergency department, compared to their peers who did not feel lonely (p=0.026). Only depressed mood was found to be independently associated with total use ofoutpatient services (B=7.4, p<0.001). In Study III, the experience of loneliness among frail older people was interpreted in the overall theme “Being in a Bubble” illustrating as being in an ongoing world but excluded because of the participants’ social surroundings and the impossibility to regain losses. The theme “Barriers” illustrated how participants had to face barriers, physical, psychological and social barriers for overcoming loneliness. The theme “Hopelessness” revealed the experience when not succeeding in overcoming the barriers and was characterised by loss of spirit and seeing loneliness as an unchangeable state. The last theme “Freedom” illustrated a positive co-existing dimension of loneliness which offered independence and time for reflection and recharging. Study IV evaluated the effect of a case management intervention for frail older people living at home in regards to loneliness, symptoms of depression and life satisfaction. At baseline, there were no significant differences between the intervention and control groups in regards to the main outcomes or sociodemographic factors. According to intention-to-treat no significant differences were found for any of the outcomes, at any time point between the two groups.When accounting for complete cases, significant differences in favour of the intervention were found at six months for loneliness (RR=0.5, p=0.028) and life satisfaction (ES=0.4, p=0.028), as well as for depressive symptoms after 12 months (ES=0.5, p=0.035).Loneliness is fairly common among older people and once the feeling is established, it is likely to stay. Factors related to psychological wellbeing appeared as the major reasons for loneliness. Frail older people tend not to differ in regards to prevalence, compared to older people in general. Frail older people who felt lonely used more outpatient services, including visits to the emergency department compared to their not lonely peers. However, it was not loneliness per se that was found to be associated with use of healthcare but rather depressed mood. The experience of loneliness among frail older people showed that it was a prevalent issue, regardless of intensity and was associated with physical and social losses. Case management for frail older people was not effective in regards to loneliness, symptoms of depression and life satisfaction. Nevertheless, there were indications that case management could be beneficial in terms of these outcomes. Loneliness is an important factor that could be associated with lower wellbeing and needs to be actively targeted. Because of the complexity, where single causes are difficult to isolate a comprehensive and individualised approach is recommended. Loneliness can be problematic regardless of intensity and is likely to be unresolved, if left unattended. This implies that appropriate assessments of loneliness and other aspects of psychological wellbeing should be undertaken.
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| 7. |
- Wiedel, Anna-Paulina
(författare)
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Fixed or removable appliance for early orthodontic treatment of functional anterior crossbite : evidence-based evaluations of success rate of interventions, treatment stability, cost-effectiveness and patients perceptions
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Anterior crossbite with functional shift also called pseudo Class III isa malocclusion in which the incisal edges of one or more maxillaryincisors occlude with the incisal edges of the mandibular incisorsin centric relationship: the mandible and mandibular incisors arethen guided anteriorly in central occlusion resulting in an anteriorcrossbite.Early correction, at the mixed dentition stage, is recommended,in order to avoid a compromising dentofacial condition whichcould result in the development of a true Class III malocclusionand temporomandibular symptoms. Various treatment options areavailable. The method of choice for orthodontic correction of thiscondition should not only be clinically effective, with long-termstability, but also cost-effective and have high patient acceptance, i.e.minimal perceived pain and discomfort. At the mixed dentition stage,the condition may be treated by fixed (FA) or removable appliance(RA). To date there is insufficient evidence to determine the preferredmethod.The overall aim of this thesis was therefore to compare andevaluate the use of FA and RA for correcting anterior crossbitewith functional shift in the mixed dentition, with special referenceto clinical effectiveness, stability, cost-effectiveness and patientperceptions. Evidence-based, randomized controlled trial (RCT)methodology was used, in order to generate a high level of evidence.The thesis is based on the following studies:The material comprised 64 patients, consecutively recruited fromthe Department of Orthodontics, Faculty of Odontology, Malmö University, Sweden and from one Public Dental Health Service Clinicin Malmö, Skane County Council, Sweden. The patients were nosyndrome and no cleft patients. The following inclusion criteria wereapplied: early to late mixed dentition, anterior crossbite affecting oneor more incisors with functional shift, moderate space deficiency inthe maxilla, no inherent skeletal Class III discrepancy, ANB angle>0º, and no previous orthodontic treatment. Sixty-two patients agreedto participate and were randomly allocated for treatment either withFA with brackets and wires, or RA, comprising acrylic plates withprotruding springs. Paper I compared and evaluated the efficiency of the two differenttreatment strategies to correct the anterior crossbite with anteriorshift in mixed dentition. Paper II compared and evaluated thestability of the results of the two treatment methods two years afterthe appliances were removed. In Paper III, the cost-effectiveness ofthe two treatment methods was compared and evaluated by costminimizationanalysis. Paper IV evaluated and compared the patient´sperceptions of the two treatment methods, in terms of perceived pain,discomfort and impairment of jaw function. The following conclusions were drawn from the results:Paper I• Anterior crossbite with functional shift in the mixed dentitioncan be successfully corrected by either fixed or removableappliance therapy in a short-term perspective.• Treatment time for correction of anterior crossbite withfunctional shift was significantly shorter for FA compared toRA but the difference had minor clinical relevance. Paper II• In the mixed dentition, anterior crossbite affecting one ormore incisors can be successfully corrected by either fixedor removable appliances, with similarly stable outcomes andequally favourable prognoses.• Either type of appliance can be recommended. Paper III• Correction of anterior crossbite with functional shift usingfixed appliance offers significant economic benefits overremovable appliances, including lower direct costs formaterials and lower indirect costs. Even when only successfuloutcomes are considered, treatment with removable applianceis more expensive. Paper IV• The general levels of pain intensity and discomfort were lowto moderate in both groups.• The level of pain and discomfort intensity was higher for thefirst three days in the fixed appliance group, and peaked onday two for both appliances.• Adverse effects on school and leisure activities as well asspeech difficulties were more pronounced in the removablethan in the fixed appliance group, whereas in the fixedappliance group, patients reported more difficulty eatingdifferent kinds of hard food.• Thus, while there were some statistically significant differences between patients´ perceptions of fixed and removableappliances but these differences were only minor and seemsto have minor clinical relevance. As fixed and removableappliances were generally well accepted by the patients, bothmethods of treatment can be recommended. Key conclusions and clinical implicationsFour outcome measures were evaluated: -success rate oftreatment, treatment stability, cost-effectiveness and patientacceptance, which is important from both patient and caregiver perspectives. It is concluded that both methods have highsuccess rates, demonstrate good long-term stability and are wellaccepted by the patients. Treatment by removable appliance isthe more expensive alternative. Thus, in the studies on whichthis thesis is based, fixed appliance emerges as the preferredapproach to correction of anterior crossbite with functionalshift in the mixed dentition.
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