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Biomedical subjects

E K Basdra

Publications and source records attributed to E K Basdra.

31 records · Page 2Linked to original sources
PubMed1997

Dentofacial changes in patients with Class III malocclusions treated by a combination of activator and chin-cup appliances.

The purpose of this study was to examine, on pre-treatment and post-treatment lateral cephalograms, the effects of combined activator/chin-cup therapy on Class III patients, and to compare mean cephalometric differences noted during treatment with untreated Class I subjects. Fourteen females and fifteen males who exhibited a Class III malocclusion were the subjects of the study. Direct comparison of the mean value changes of the cephalometric variables during treatment of Class III patients with untreated Class I subjects revealed that SNA increased more and SNB increased less in the Class III patients than in the control group, thus improving the ANB angle. At the end of treatment, all patients had a positive overjet but a more concave profile. In this study, combined activator/chin-cup therapy seemed to induce improvement in those Class III patients selected for their moderate condition and treated over a five-year period. The changes seemed to indicate growth patterns which imitate those of the untreated Class I subjects. Moreover, dentoalveolar compensations helped to improve the overjet and conceal skeletal deviations.

Activator Appliances↗
PubMed1996

Mechanical stretching of periodontal ligament fibroblasts--a study on cytoskeletal involvement.

To investigate molecular aspects of the mechanism(s) involved in orthodontic tooth movement, periodontal ligament fibroblasts (PDL) were isolated and grown on culture dishes with a flexible bottom. The cells were stimulated by stretching the bottom of the culture dishes and whole cell extracts were prepared and subjected to sodium dodecyl sulfate polyacrylamide (SDS-PAGE) electrophoresis, electrotransferred to nitrocellulose membrane and immunoprobed with antibodies specific for vimentin and alpha- and beta-tubulin. No apparent alterations in the expression profile of the above mentioned major cytoskeletal elements were evident after mechanical stretching. Moreover, immunofluorescence against the same proteins revealed no changes in their topographical organisation between stretched and unstretched cell cultures.

Blotting, Western↗
PubMed1996

A clinical report for distalizing maxillary molars by using super-elastic wires.

A class II/2 malocclusion with considerable amount of crowding was treated non-extraction by distalization. The upper molars were moved posteriorly with the use of superelastic wires. The orthodontic therapy-mode is presented and the results are discussed. This treatment approach shows another use of superelastic wires.

Adult↗
PubMed1996

Skeletal and dentoalveolar changes after extraction of the second molars in the upper jaw.

The aim of this study was to evaluate treatment results after extraction of maxillary second molars. Since this therapy was chosen in patients with class II malocclusion, deep overbite and counterclockwise growth pattern, its effects on overbite and correction of the malocclusion were examined. For this purpose pre- and post-treatment models of 25 patients with 48 extracted upper second molars were measured and lateral cephalograms were appropriately superimposed in order to determine maxillary and mandibular skeletal and dentoalveolar changes. Our results indicate an average overbite reduction from 4.7 mm to 2.7 mm. None of the patients showed a posttreatment overbite increase. Despite the considerable initial Class II relation in many cases, a Class I occlusion was achieved in 92% of the patients. Primarily, the correction was achieved by distalization of the upper first molars. Furthermore, the mesial migration of the lower first molars, skeletal changes in the lower jaw, and the growth inhibition in the upper jaw contributed to the correction of the class II malocclusion.

Adolescent↗
PubMed1996

Fluoride released from orthodontic bonding agents alters the enamel surface and inhibits enamel demineralization in vitro.

In this study, we examined two fluoride-releasing orthodontic agents in respect to fluoride release, enamel demineralization inhibition, as well as alterations observed on the enamel surface after their use. Fluoride release was found to occur in the highest concentrations within the first 24 hours for both materials examined. After this period, a dramatic decline in fluoride release was observed in both adhesives, and after 90 days no fluoride was detectable. Both fluoride-releasing materials showed significant differences on enamel demineralization around the brackets when compared with a conventional adhesive, and the agent with the initial higher amounts of fluoride release showed the best results. Scanning electron microscopy of the enamel surface revealed particle depositions of microglobular form, after the examined adhesives were used. These particles most likely represent deposition of calcium fluoride, a salt with clearly cariostatic properties. The results of this in vitro study show that certain fluoride-releasing orthodontic bonding systems may provide an additional degree of safety against caries susceptibility in patients with fixed appliances for a limited period.

Adhesives↗
PubMed1996

Extraction of maxillary second molars in the treatment of Class II malocclusion.

The results of treatment following the extraction of maxillary second molars for Class II correction were evaluated. Records (cephalograms, orthopantomograms, and models) of 32 patients treated with maxillary second molar extraction were analyzed. Cephalograms taken before and after treatment were traced and 18 variables were compared. Changes in the axial inclination of the erupted third molars relative to the occlusal plane were measured on the orthopantomograms. The form and the position (eruption in occlusion, rotations) of the maxillary third molars were evaluated on the models. The average treatment time was 26 months. The results of this study show significant changes of the angles SNA, SNB, ANB, 1/4:SN, and the distances 1-NPog, and 1-APog, as well as significant effects on the soft tissue profile. In 19 cases examined 4 years postretention, all maxillary third molars had erupted into occlusion with a mesial contact point and acceptable mesiodistal axial inclination.

Adolescent↗
PubMed1995

Rab and rho GTPases are involved in specific response of periodontal ligament fibroblasts to mechanical stretching.

To investigate the contribution of ras-related signalling molecules to the mechanotransduction process, stretch-sensing human periodontal ligament (PDL) fibroblasts were isolated and cultured in dishes with a flexible bottom. The cells were stimulated by stretching the bottom of the dishes and membrane fractions were prepared and analysed at the level of mapping small GTP-binding proteins by high resolution two-dimensional gel electrophoresis followed by renaturing transfer and an [alpha-32P]GTP-overlay procedure. This analysis revealed that mechanically-stretched PDL fibroblasts exhibit complete down-regulation of rhoA and induction of rab6, rab17 and a putative member of the rab3 subfamily in a cell type-specific manner.

Cells, Cultured↗
PubMed1995

Case report RS: guided tissue regeneration precedes tooth movement and crossbite correction.

This patient presented with a Class III malocclusion and an anterior crossbite. Although spaces were present distal to the mandibular canines, the alveolar ridges were greatly atrophied. New bone was acquired through guided tissue regeneration. The alveolar ridges were augmented, followed by successful orthodontic tooth movement and correction of the Class III relationship and the anterior crossbite.

Alveolar Process↗
PubMed1994

Mechanical loading triggers specific biochemical responses in mandibular condylar chondrocytes.

The effect of mechanical loading on the phosphorylation state of condylar cartilage proteins was investigated by high resolution electrophoretic analysis of 32P-labelled proteins from mechanically stimulated rat mandibular condylar chondrocytes. Specific dephosphorylation (and/or loss) of an acidic, 35-36 kDa protein(s) and of proteins overlapping with members of the ras superfamily of small GTP-binding proteins was observed. These responses may constitute part of a mechanically induced transduction system which establishes the differentiated phenotype.

3T3 Cells↗
PubMed1994

[The etiology of canine tooth impaction--a space analysis].

The aim of this study was to examine to what extent excess space must be taken into consideration as an etiological factor in upper canine impaction with special attention paid to the role of the adjacent laterals. To clarify this question the pre- and post-treatment models of 63 patients with a total of 84 impacted cuspids were measured and the cephalograms of 116 patients having 144 impacted cuspids were analyzed. The results of this study revealed: 84.5% of the cuspids were palatally impacted while 15.5% were labially impacted. An arch deficiency was found in only 18% of the palatally impacted cuspids, whereas there was an arch-length deficiency in 46% of the buccally impacted. In 35% of the cases there was a correlation between peg shaped laterals and palatal impaction, however, such was not present in the patients with vestibular retention. Finally the cephalometric data revealed horizontal growth characteristics in 80% of the palatally impacted canines as opposed to 23% in those labially impacted.

Adolescent↗
PubMed1994

Localized alveolar ridge augmentation before orthodontic treatment. A case report.

Extraction spaces are usually characterized by narrow, atrophic alveolar ridges, which make it difficult to move teeth orthodontically within these areas. Guided tissue regeneration is often used for alveolar ridge augmentation in implantology. In the case presented, localized alveolar ridge augmentation was performed as a preliminary procedure before orthodontic closure of an edentulous space. Guided tissue regeneration enhances the possibilities of orthodontic treatment in adult patients.

Adult↗