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Biomedical subjects

P Axelsson

Publications and source records attributed to P Axelsson.

At least 19 recordsLinked to original sources
PubMed1999

Stability of lumbar fusion with transpedicular fixation determined by roentgen stereophotogrammetric analysis.

STUDY DESIGN: An evaluation of the intervertebral stability of transpedicular instrumentation in posterolateral lumbar fusions by roentgen stereophotogrammetric analysis. OBJECTIVES: To determine the in vivo intervertebral stability of posterolateral lumbar fusions augmented with transpedicular screws and plates. SUMMARY OF BACKGROUND DATA: Transpedicular bone screw systems have been found to be as safe and clinically effective as other types of devices in stabilizing surgery of the spine. Many experimental studies have yielded basic data on the stabilizing implant effect in vitro, but the exact in vivo stabilizing effect on human lumbar vertebrae has not been presented previously. METHODS: In 12 patients, the intervertebral stability of posterolateral fusion in the lower lumbar spine augmented with transpedicular screws and plates was evaluated by serial roentgen stereophotogrammetric analysis with the patients in supine and erect positions 1 year after surgery. RESULTS: Screws in each fused vertebra yielded stable fixation or permitted sagittal intervertebral translations smaller than 1 mm induced by the positional change. A widely decompressed and destabilized vertebra without screw fixation yielded persisting intervertebral translations. CONCLUSIONS: The current study demonstrated the adequacy of in vivo stability of lumbar fusions augmented with transpedicular screws and plates. Sagittal translation seems easier to elicit than movements along the other three-dimensional axes. A widely decompressed and destabilized vertebra without screw fixation increases the risk for persisting intervertebral translations. The roentgen stereophotogrammetric analysis technique described seems to be a good way of comparing the in vivo behavior of different implant systems.

Adult↗
PubMed1999

External pedicular fixation of the lumbar spine: outcome evaluation by functional tests.

We analyzed the pain-relieving effect and the functional outcome during external pedicular fixation of the lumbar spine. Twenty patients were included, and the diagnoses were disc degeneration with or without facet joint arthrosis in eight patients, pain after decompression in six patients, spondylolysis/olisthesis in two patients, other types of lumbar anomalies in three patients, and pseudarthrosis after prior uninstrumented fusion in one patient. Before application of the external frame, the pain level on the Visual Analogue Scale was registered at rest, as a mean level for the preceding week, and at seven different functional tests. Maximum walking capacity and walking time needed for a standardized distance were also measured. The same test procedure was repeated 1 week postoperatively with the external frame applied in locked position. With stabilization, 11 patients reported pain relief at rest and 14 when approximating the mean pain level for the week. Both these measured levels correlated to the pain level at all of the seven functional tests. Thus, the patients selected for a subsequent fusion based on pain relief during extended functional provocation would not differ from the patients selected by using only the pain-relieving effect at rest. The patients reporting pain relief tended to increase their walking distance (p = 0.06, t test) but not the speed of walking.

Adult↗
PubMed1998

Relationship between smoking and dental status in 35-, 50-, 65-, and 75-year-old individuals.

The aim of the present study was to examine the dental status and smoking habits in randomized samples of 35-, 50-, 65-, and 75-year-old subjects (n = 1093), recruited for a cross-sectional epidemiological study in the County of Värmland, Sweden. The following clinical variables were recorded by 4 well-calibrated dentists: number of edentuolous subjects, number of missing teeth, probing attachment level, furcation involvement, CPITN scores, DMF surfaces, plaque and stimulated salivary secretion rate (SSSR). In addition, the subjects reported in a questionnaire their tobacco habits, oral hygiene habits, dietary habits etc. The percentage of smokers in 35-, 50-, 65-, and 75-year-olds was 35%, 35%, 24% and 12%, respectively. In 75-year-olds, 41% of the smokers were edentulous compared to 35% of non-smokers. The difference in number of missing teeth between smokers and non-smokers was 0.6 (p=0.15), 1.5 (p=0.013), 3.5 (p=0.0007) and 5.8 (p=0.005) in the 4 age groups. Smokers had the largest mean probing attachment loss in all age groups. The differences between smokers and non-smokers in mean attachment level were 0.37 (p=0.001), 0.88 (p=0.001), 0.85 (p=0.001) and 1.33 mm (p=0.002) in the 35-, 50-, 65-, and 75-year-olds, respectively. Treatment need assessed by CPITN was in all age groups greatest among smokers. The number of intact tooth surfaces was fewer in 35-, 50-, and 75-year-old smokers than in non-smokers. The number of missing surfaces (MS) was higher in 50-, 65-, and 75-year-old smokers than in non-smokers. In addition, 35-year-old smokers exhibited a significantly larger number of decayed and filled tooth surfaces (DFS) than non-smokers. Male smokers had significantly higher SSSR than non-smoking males (p=0.012). Plaque index and oral hygiene were similar in smokers and non-smokers. Smokers reported a more frequent intake of sugar containing soft drinks (p=0.000) and snacks (p=0.003) than non-smokers. The opposite was reported for consumption of fruit (p=0.003). It was concluded that smoking is a significant risk indicator for tooth loss, probing attachment loss and dental caries.

Adult↗
PubMed1997

The spondylolytic vertebra and its adjacent segment. Mobility measured before and after posterolateral fusion.

STUDY DESIGN: By using roentgen stereophotogrammetric analysis in six patients having tantalum indicators implanted at a preoperative external fixation test, the mobility in the spondylolytic lumbosacral level and its adjacent segment could be studied before fusion and during the course of postoperative fusion consolidation. OBJECTIVE: To study the mobility effects on the segment adjacent to a lumbar fusion over time from the preoperative situation until fusion healing as defined by roentgen stereophotogrammetric analysis. SUMMARY OF BACKGROUND DATA: In vitro studies indicate that the altered biomechanical situation after lumbar fusion increases the intradiscal pressure and changes the kinematics in the juxtafused segment. METHODS: Six patients with low grade spondylolysisolisthesis were scheduled for fusion of the spondylolytic lumbosacral segment after a preoperative external fixation test. The latter procedure also included implantation of tantalum markers for spinal roentgen stereophotogrammetric analysis. Each patient was examined by roentgen stereophotogrammetric analysis at four separate occasions: before fusion (2 months after removal of the external frame) and 3, 6, and 12 months after surgery. The translatory movements of the L5 vertebra in relation to sacrum and of the L4 vertebra in relation to the L5 vertebra were calculated at each examination. RESULTS: For the juxtafused L4-L5 level, increased and decreased mobility patterns could be identified. Transformation of the preoperative mobility in the lumbosacral segment to the adjacent segment during fusion consolidation was verified in two patients but was not a general phenomenon. CONCLUSION: Fusion of the lumbosacral segment can alter the kinematics of the adjacent segment, redistributing the mobility toward relative hypermobility in the juxtafused segment.

Adult↗
PubMed1997

Posterolateral lumbar fusion using facet joint fixation with biodegradable rods: a pilot study.

Roentgen stereophotogrammetric analysis (RSA) was used to assess whether there is a potential for biodegradable rods crossing the denuded facet joints to increase the stability and healing rate of lumbar posterolateral fusions. Eleven consecutive patients with lumbosacral disc/facet joint degeneration had a posterolateral fusion augmented with 2- or 3.2-mm biodegradable rods passing perpendicularly through the center of the denuded facet joints. The patients were followed-up with RSA in supine and erect positions monthly from the 2nd to the 6th postoperative month, and again 1 year postoperatively. All seven L5-S1 fusions healed. Four cases were stable as defined by RSA within 3 months, two within 6 months, and one within 1 year. One L4-S1 fusion could not be evaluated by RSA. None of the remaining three L4-S1 fusions fully healed. In all three cases 1- to 3-mm intervertebral translations remained at 1 year. None of the 11 fusions showed any radiographic signs of osteolysis around the biodegradable rods. The promising results of this pilot study indicate that posterolateral L5-S1 fusion augmented with transarticular biodegradable rods crossing the denuded facet joints may yield rapid intervertebral stabilization and a high healing rate without any adverse rod effects. This may be due to enhanced initial fusion stabilization and/or increased ossification induced by the rods.

Adult↗
PubMed1996

Mechanics of the external fixation test in the lumbar spine. A roentgen stereophotogrammetric analysis.

STUDY DESIGN: By implanting tantalum indicators percutaneously during application of pedicular screws, lumbosacral mobility could be studied with roentgen stereophotogrammetric analysis in seven patients having a diagnostic external fixation test. OBJECTIVES: To determine the mechanical effects on the segmental mobility during an external fixation test of the lumbar spine. SUMMARY OF BACKGROUND DATA: External pedicular fixation test of the lumbar spine has been reported a valuable prognostic instrument in fusion for low back pain. METHODS: A Magerl external fixation device was applied in seven patients with low-grade spondylolysis-olisthesis. By using roentgen stereophotogrammetric technique, the intervertebral translations in the lumbosacral segment were determined. Each patient had three separate examinations; with the frame fixed, with the frame loosened, and without frame 6 weeks after screw removal. RESULTS: With the external frame fixed, the sagittal intervertebral translations were significantly reduced, in three cases to a level beneath the accuracy of the measuring method. One patient had the same immobilizing effect even with the frame loosened while for the others loosening of the frame meant regained mobility of the segment. CONCLUSION: The properties of the external fixator give an adequate mechanical basis for the prognostic external fixation test in lumbar fusion.

Adult↗
PubMed1995

Orthosis as prognostic instrument in lumbar fusion: no predictive value in 50 cases followed prospectively.

To evaluate pain relief in a lumbar orthosis as a predictor for good clinical results after solid fusion, all patients scheduled for such a surgical procedure were preoperatively encouraged to use an orthosis, soft or rigid, for 3 weeks. Grade of back pain relief as a percent using the orthosis was assessed by the patients and was registered before surgery. After surgery, at 1-year follow-up, patients with nonunion demonstrated radiographically were excluded from the series. Thus, 50 patients with solid fusion could be identified and followed for at least 2 years prospectively. At follow-up these 50 patients graded the pain relief induced by the fusion. In the preoperative corset test, 31 patients experienced significant back pain relief, meaning a reduction of at least 50%. No applicable correlation was found, however, between outcome in this corset test and the eventual clinical result expressed as improvement/no improvement after solid fusion. The two types of orthoses did not differ in this aspect. We conclude that the orthosis, rigid or soft, is not a useful instrument when selecting patients for lumbar fusion.

Adult↗
PubMed1995

Plaque formation at healthy and inflamed gingival sites in young individuals.

The present investigation was performed to evaluate the influence of gingivitis on the amount of de novo plaque that forms during a 24-h period of no oral hygiene. 292 fully dentate subjects participated in the study. The condition of the gingiva and the presence of supragingival plaque were examined at 4 surfaces of each tooth at a baseline examination. Following this examination, the participants were subjected to a comprehensive mechanical tooth cleaning and instructed to refrain from tooth cleaning measures during the subsequent 24 h. The plaque examinations were repeated at the end of the 24-h period. The results from the clinical trial revealed that during a 24-h period of no tooth cleaning, subjects with naturally occurring overt gingivitis, in general, formed more plaque than young individuals with healthy gingivae. Furthermore, plaque in all parts of the dentition, formed more frequently on tooth surfaces adjacent to sites with gingivitis than at healthy sites. It was concluded that the condition of the gingiva plays an important role for de novo plaque formation.

Adolescent↗
PubMed1995

Caries lesions and dental restorations as predisposing factors in the progression of periodontal diseases in adolescents. A 3-year longitudinal study.

The present study used a novel approach to assess the relationship between untreated caries lesions and defective and non-defective dental restorations and the incidence of gingival inflammation and the progression of chronic inflammatory periodontal diseases at the approximal surfaces of posterior teeth and at the adjacent surface of the neighboring tooth in adolescents over a period of 3 years. Two hundred-twenty-seven (227) 13-year-old schoolchildren were examined clinically and radiographically at baseline and annually at three subsequent occasions. At each site the alveolar bone height and presence of gingival bleeding were assessed. Incipient caries lesions, manifest caries, and defective and non-defective restorations were identified at the same site and also at the adjacent approximal tooth surface at all examinations, both clinically and radiographically. The data were analyzed by the multi-level logistic regression and variance components analyses. On average, 32, 8.5, 7, and 10% of the sites, respectively, were diagnosed as having incipient caries, manifest caries, and defective and non-defective restorations. There was a significant association between the presence of untreated manifest caries lesions, non-defective and defective dental restorations, and the progression of periodontal support loss. Also there was an association between presence of defective restorations and manifest caries and the incidence of gingival inflammation. Consistently, factors detected at the involved site and at the adjacent site had significant effects. The present study indicates that untreated cavities and dental restorations are predisposing factors with a significant negative effect on periodontal health in adolescents.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Lack of effect of oral hygiene training on periodontal disease progression over 3 years in adolescents.

A comprehensive new oral hygiene training program has lately been described and found effective in controlling dental plaque formation and in significantly reducing the incidence of approximal dental caries and gingivitis in adolescents. This study investigated the long-term effect of plaque control on the progression of periodontal diseases in adolescents. A group of 227 Brazilian schoolchildren were followed up over a period of 3 years. The children were divided randomly into 3 groups. The first group was given a needs-related intensive program which combined detailed information to parents and children pertaining to the etiology and prevention of dental diseases, instructions in self-diagnosis of plaque and gingivitis, and a detailed oral hygiene training based on individual needs, together with continued feedback and motivation during the entire 3 years. The second group was given a similar program, but through shorter sessions and with no motivation and feedback and no training in self-diagnosis. A control group received no motivation sessions or oral hygiene training. The 3 groups were examined radiographically at baseline and annually at 3 subsequent occasions. The data were analyzed with a multi-level variance analysis. The frequency of subjects showing sites with alveolar bone loss increased steadily during the entire period in all groups. Neither of the training programs had a significant effect on the alveolar bone level during 3 years compared to the control group. Generally, girls demonstrated higher proportions of approximal tooth surfaces showing radiographic bone loss, though not statistically significant. In this population the supragingival plaque control lacked any significant effect on periodontal disease progression.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Effect of two preventive programs on oral health knowledge and habits among Brazilian schoolchildren.

The effect upon dental health knowledge and dental health behavior of a comprehensive and a less comprehensive preventive program was compared in a 3-yr follow up study. The comprehensive program included active participation of the students and parental involvement. The study group consisted of 186 Brazilian schoolchildren 13 yr of age at the start of the program. A reference group from another school of similar socioeconomic level was included in the analyses. The data were collected from questionnaires filled in by the children under surveillance after the completion of the program. Significant differences in knowledge as well as in reported behavior were observed. The children enrolled in the comprehensive program in general scored higher in dental health knowledge than did those in the less comprehensive program. However, the latter group of children seemed to have acquired more correct knowledge during the period than had the control and reference children. Similar results were obtained concerning reported dental health behavior.

Adolescent↗
PubMed1994

The effect of a new oral hygiene training program on approximal caries in 12-15-year-old Brazilian children: results after three years.

This study evaluated the effects of a new oral hygiene training program on approximal caries in a population of 12-13-year-old Brazilian schoolchildren with a well-established habit of daily toothbrushing with a F dentifrice. Two hundred twenty-two children were randomly allocated into two test groups (I and II) and one control group (III). Group I subjects were trained to establish needs-related oral hygiene habits based on self-diagnosis and a new behavioral principle, the 'linking method', for establishment of habits. The first three visits (20 minutes each) were scheduled at two-day intervals. They were recalled for a monthly check-up during the first 4 months, and then every 3 months for reevaluation of the results based on self-diagnosis. Group II subjects were recalled at the same intervals for detailed oral hygiene instruction on how to clean every tooth surface using dental tape, toothbrush, and fluoride dentifrice. Group I developed significantly fewer (p < 0.001) new approximal manifest (dentin) caries lesions than groups II and III. The mean values (SEM) were 2.3 (0.29), 4.7 (0.59), and 5.3 (0.68), respectively. The conclusions from our study are: In a toothbrushing population using fluoride dentifrices and fluoridated drinking water, the oral hygiene training program with behavioral modification significantly reduced caries incidence on approximal surfaces. Frequent repetition of training in meticulous oral hygiene is almost redundant.

Adolescent↗
PubMed1994

Long-term effect of two preventive programs on the incidence of plaque and gingivitis in adolescents.

The efficacy of two oral hygiene training programs on the control of plaque and the prevention of gingival inflammation in adolescents was evaluated during a 3-year period. A population of 227 Brazilian schoolchildren were divided into 3 groups. The first group received a comprehensive program based on individual needs and included information sessions pertaining to the etiology and prevention of dental diseases together with extensive training in self-diagnosis and oral hygiene. In addition, an information session was arranged for parents and teachers of these children. The second group received a less comprehensive program consisting of conventional oral hygiene training. The third group (control) received no preventive program. The programs were presented through frequent initial training sessions ensued by infrequent follow-up visits. During the experimental period, the two oral hygiene training programs involved 3.5 and 1.5 hours per child, respectively. The children were examined clinically at baseline and annually over the next 3 years to assess plaque and gingival bleeding and the data were analyzed by a multi-level variance component analysis. All children showed a perpetual improvement in their oral hygiene and gingival state during the course of the study. However, the improvements observed in the comprehensive group were significantly better than that of the control group. Results from the less comprehensive group were not significantly different from the control group. Longer exposure to the programs appeared to produce more improvement; children with higher plaque and gingivitis scores prior to the program showed less favorable results; girls exhibited better results than boys.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Posterolateral lumbar fusion. Outcome of 71 consecutive operations after 4 (2-7) years.

We report the outcome of 71 consecutive posterolateral lumbar fusions without spinal instrumentation. The indication for the operation was spondylolysis-olisthesis, degenerative disc disease/facet joint arthrosis, or pain after prior laminectomy. Concerning pain relief, 29/43 patients with spondylolysis-olisthesis were classified as good. The corresponding figures in the group with degenerative disc disease and/or facet joint arthrosis were 8/16 patients and in the group with pain post-laminectomy, 6/12 patients. No surgical complications were noted. In the total material 54 patients had a solid fusion, as defined by radiographic osseous trabecular bridging at all intended levels. One-level fusions tended to heal solidly in a higher frequency than two-level fusions. For the spondylolysis-olisthesis group, healed fusion correlated with a good clinical result. Such a correlation could not be verified for the other diagnostic groups. We conclude that non-instrumented posterolateral lumbar fusion is a valid method for treating low-grade spondylolysis-olisthesis, especially when the aim is to fuse a single level. Improved patient selection methods are required in fusion for degenerative disc disease and pain after laminectomy.

Adolescent↗
PubMed1993

Lumbar orthosis with unilateral hip immobilization. Effect on intervertebral mobility determined by roentgen stereophotogrammetric analysis.

To determine the additional stabilizing effect of unilateral hip fixation on external lumbar supports, nine patients with a posterolateral lumbosacral fusion without internal fixation were examined by roentgen stereophotogrammetric analysis. The roentgen stereophotogrammetric analysis was performed with the patients in supine and erect positions 1 month after surgery, that is, before fusion consolidation. Each patient was examined without lumbar support and with a molded, rigid thoracolumbosacral orthosis with extension to one thigh, thus immobilizing one hip. The additional hip immobilization had no consistent or significant stabilizing effect on the sagittal, vertical, or transverse intervertebral translations in the lower lumbar spine. This study using roentgen stereophotogrammetric analysis gave no support for including hip immobilization when using lumbar orthoses after spinal fusion in patients adequately cooperating to minimize gross body motions.

Adult↗
PubMed1993

How Swedish dental hygienists apply their training program in the field.

The purpose of this study was to evaluate how clinical practice by Swedish dental hygienists was related to type of dental delivery system, period of training, educational institution attended and patient category. Dental hygienists from 14 different dental hygiene schools were represented. Of these schools, 11 are still in operation. A specially designed questionnaire was posted to all dental hygienists in Sweden (n = 1857). A total of 1399 questionnaire (75.3%) were completed and returned, providing data on 15,546 dental appointments. 37.2% of the Swedish dental hygienists are presently working in private practices, 45.8% in the public dental health service and 6.2% in both. Of the patients treated by hygienists, 88.7% were adults: 99.5% in private practice and 78.4% in the public dental health service. 42.0% of all dental hygienists were trained in 1980-84. The mean treatment time per appointment in private practice was 49.7 min and 45 min in the public dental health service. Scaling, root-planning and removal of overhangs took 27 min per visit in private practice and 22 min in the public dental health service. However, there were no significant differences in methods in the two delivery systems with respect to examinations, self-care training, professional mechanical toothcleaning (PMTC), topical fluoride application, or salivary and oral microbiology tests. The adult patient categories were periodontal risk (45.1%), caries risk (9.1%) and hygiene (34.6%). In periodontal risk patients, scaling, root-planning and removal of overhangs took 28 min per appointment and 14 min in caries risk patients.

Adolescent↗
PubMed1993

Integrated caries prevention: effect of a needs-related preventive program on dental caries in children. County of Värmland, Sweden: results after 12 years.

Twenty years ago the caries prevalence in Swedish children was among the highest in the world; within Sweden, it was highest in the County of Värmland. Ongoing clinical research projects were initiated to evaluate the separate and combined effects of preventive measures, and in 1978 a preventive program, based on caries risk assessment, was introduced for 3- to 19-year-olds in the county. The effects were monitored by a computerized epidemiological system. From 1979 to 1991, caries prevalence and incidence decreased by 75-90 and 75-85%, respectively. The percentage of caries-free 3-year-old children increased from 51 to 94%, and in 12-year-old children, the caries prevalence decreased from 6.5 to 1.0 DFS, the lowest in Sweden. The program is very cost-effective, and in 1990 the mean annual treatment time per child was the lowest in Sweden. Currently, new methods of caries risk prediction and integrated caries prevention are being developed, with special reference to cost-effectiveness.

Adolescent↗