Direct versus indirect loading of orthodontic miniscrew implants-an FEM analysis.

OBJECTIVE: The mesialization of molars in the lower jaw represents a particularly demanding scenario for the quality of orthodontic anchorage. The use of miniscrew implants has proven particularly effective; whereby, these orthodontic implants are either directly loaded (direct anchorage) or employed indirectly to stabilize a dental anchorage block (indirect anchorage). The objective of this study was to analyze the biomechanical differences between direct and indirect anchorage and their effects on the primary stability of the miniscrew implants. MATERIALS AND METHODS: For this purpose, several computer-aided design/computer-aided manufacturing (CAD-CAM)-models were prepared from the CT data of a 21-year-old patient, and these were combined with virtually constructed models of brackets, arches, and miniscrew implants. Based on this, four finite element method (FEM) models were generated by three-dimensional meshing. Material properties, boundary conditions, and the quality of applied forces (direction and magnitude) were defined. After solving the FEM equations, strain values were recorded at predefined measuring points. The calculations made using the FEM models with direct and indirect anchorage were statistically evaluated. RESULTS: The loading of the compact bone in the proximity of the miniscrew was clearly greater with direct than it was with indirect anchorage. The more anchor teeth were integrated into the anchoring block with indirect anchorage, the smaller was the peri-implant loading of the bone. CONCLUSIONS: Indirect miniscrew anchorage is a reliable possibility to reduce the peri-implant loading of the bone and to reduce the risk of losing the miniscrew. The more teeth are integrated into the anchoring block, the higher is this protective effect. CLINICAL RELEVANCE: In clinical situations requiring major orthodontic forces, it is better to choose an indirect anchorage in order to minimize the risk of losing the miniscrew.

Kinetic study of the inhibition of CK2 by heparin fragments of different length.

The structure-activity relationships for the inhibition of protein kinase CK2 by heparin were investigated using purified heparin fragments of different length, varying from 4 to 24 oligosaccharide sugar units. The inhibitory potency was shown to decrease concomitant with the shortening of the heparin fragment length. The fragment of 24 oligosaccharide sugar units was the most potent inhibitor with a K(i) value of 22 nM which is close to the K(i) value for the commercial heparin mixture available. Shortening of the heparin from 24 to 12 sugar units had a moderate influence on the inhibitory potency causing an increase in K(i) values up to 151 nM while fragments shorter than 12 sugar units showed a more drastic increase in K(i) values reaching up to micromolar range. The mode of inhibition was studied in respect to the protein substrate beta-casein and it was shown to be competitive for the long as well as for the short heparin fragments. In contrast, the inhibition mode in respect to a synthetic peptide substrate RRRADDSDDDDD was found to be hyperbolic partial non-competitive mixed-type. Such a kinetic model suggests that heparin binds to a site on CK2 which does not overlap with the peptide substrate binding site and that a productive enzyme complex exists where both heparin and peptide substrate are simultaneously bound. This is in contrast to the competitive inhibition model of the phosphorylation of protein substrate beta-casein where the binding of the protein substrate and inhibitor was mutually exclusive.

Calpain and calpastatin in normal and Alzheimer-degenerated human brain tissue.

The Ca2(+)-dependent neutral proteases calpain I and II as well as their specific inhibitor, calpastatin, were isolated from normal and Alzheimer-degenerated frozen human brain tissue. In the Alzheimer group calpain I activity was higher in cortex than in mesencephalon. The calpastatin activity was lower in cortex in both groups. This may implicate a higher Ca2(+)-dependent proteolysis in cortex compared to mesencephalon. In the Alzheimer group the cortical calpain II level decreased with an increasing degree of neuropathological changes. In the control group, the level of calpastatin decreased as the number of plaques and tangles increased. Evidence was obtained for a correlation of net calpain activity and the extent of neuropathological changes in cortex.

Increased proteolytic activity in lymphocytes from patients with early onset Alzheimer's disease.

The levels of calpains (m-calpain and mu-calpain) in peripheral blood lymphocytes from patients with Alzheimer's disease were determined via Western blotting. The Ca-dependent proteolytic activity and the calpastatin activity were estimated using incubation with exogenous substrate. Evidence was obtained for an increased Ca-dependent proteolytic activity in lymphocytes from patients with early onset Alzheimer's disease. There was also an increased level of membrane-bound mu-calpain in this group of patients. The observed changes may be caused by a general dysregulation of Ca homeostasis in peripheral cells of early onset Alzheimer victims.

Phosphorylation of CaBP1 and CaBP2 by protein kinase CK2.

Several proteins in the mammalian endoplasmic reticulum are substrates for protein kinases. Many unidentified phosphoproteins from this compartment are described in the literature, and this prompted us to try to identify at least the more dominant ones. When solubilized bovine and murine microsomes were phosphorylated with protein kinase CK2 and [32P]ATP and separated on SDS-PAGE, the corresponding autoradiogram showed three dominant 32P-labeled proteins. These three [32P]phosphoproteins were identified as calcium-binding proteins (CaBP) 1, 2, and 4 after purification on a MonoQ column followed by SDS-PAGE, proteolytic cleavage and subsequent amino acid sequencing of the purified 32P-labeled peptides. All three were also phosphorylated by an endogenous kinase, found by us to be of the CK2 type. This kinase phosphorylated CaBP1 N-terminally at serine 427. Of the three proteins, only CaBP4 was previously known to be a substrate of CK2. The newly identified substrates CaBP 1 and 2 are members of the thioredoxin family and have a signal tetrapeptide in the C-terminal of the protein for retention in the ER. Serines and/or threonines in the C-terminal were phosphorylated in CaBP1 when the endogenous CK2 was used as protein kinase. A protein with the same molecular mass as CaBP1 on SDS-PAGE was phosphorylated when intact hepatocytes were grown in the presence of [32P] phosphate. The in vitro phosphorylation with protein kinase CK2 can be used as a specific and sensitive method for identification of CaBP1, 2, and 4 in microsomes.

Endosseous dental implants in orthodontic therapy.

This paper presents cases in which endosseous titanium implants are used in orthodontic treatment as an alternative method of providing anchorage, as well as solving prosthodontic problems, and shows that such an approach can be successful.

Orthodontic tooth movement in the mixed dentition. Histological study of a human specimen.

MATERIAL AND METHOD: We present a retrospective analysis of periodontal tissue reactions and clinically relevant phases of permanent tooth eruption and deciduous tooth resorption after half a year of orthodontic tooth movement in the upper and lower jaw of a deceased male (age 9 years 3 months). Specimens of the horizontal plane (lower jaw) and sagittal plane (upper jaw) were prepared by the ground microsection technique without prior decalcification. RESULTS: Histologically, reactions in the periodontal ligament presented as characteristic appositional/resorptive metaplastic processes in the areas of tension and pressure, with side effects such as root resorption and periodontal necrosis being only minor. In the upper jaw, an erupting permanent canine was closely associated with the tooth germ of the first premolar. Resorptive follicle activity had resulted in extensive erosion of the interradicular bone and root resorption in the area of the first premolars. CONCLUSION: These findings suggest that it might prove useful to take critical topographic findings as parameters for differential therapeutic decisions. Follicle-driven deciduous tooth resorption presenting partly as resorption lacunae and partly with linear characteristics was accompanied by resorptive/appositional remodeling of the alveolar socket as well as regressive changes in the supracrestal fibers of the marginal gingiva.

Effects of orthodontic bands on marginal periodontal tissues. A histologic study on two human specimens.

Eight banded teeth on two human specimens (9 years, male; 19 years, female) were analyzed regarding the fit of the orthodontic bands and periodontal reactions. Five teeth (three molars, two premolars) were evaluated histologically in the horizontal plane and three (one molar, two premolars) in the sagittal plane using the micro-section method according to Donath. The fit of the bands varied in occluso-apical direction. The mean of marginal gaps was x = 0.23 mm in the occlusal, x = 0.03 mm in the equatorial, and x = 0.28 mm in the cervical area. In the equatorial area the thin cement layer was largely homogeneous, whereas porosities and microfissures were found predominantly in thicker cement layers. 85% of the occlusal and cervical band margins revealed cement defects and/or erosions which were colonized by felted, partially densely compacted microbial plaque. With regard to the periodontal effects, the signs of inflammation in the buccolingual gingival areas were markedly less severe due to the supramarginal position of the band margins. The interdental gingiva of all teeth presented the histological pattern of an established gingival lesion. Leukocyte infiltration and inflammatory exudation in the area of the transseptal fibers were exceptionally pronounced in one lower molar (band exposure time: 6 months). At this site the connective tissue attachment close to the cementoenamel junction was severely damaged on the mesial surface and the pocket epithelium proliferated towards the apex, meaning progression from established gingivitis to an initial periodontal lesion. The histologic findings on these human periodontal tissues confirm that the application and hygiene control of orthodontic bands have to be performed with great care to avoid permanent periodontal destruction.

Functional appliance therapy with the Bionator.

Since the early 20th century, functional appliance therapy has been a significant part of orthodontic treatment, especially in Europe, where functional appliances have been used to treat many malocclusions, including some skeletal discrepancies. Although the success of functional appliance therapy as reported in numerous short-term studies from 1930 to 1975 led to an euphoric acceptance of this method, the few long-term studies, especially those comparing treated with untreated homogeneous control groups, indicated that the specific skeletal and dentoalveolar effects depended on the individual growth period and pattern of the patient. In this article, a specific functional appliance, the Bionator, is presented. Long-term follow-up studies provide indications for its use. At the present time, functional orthopedic appliance therapy has a more limited but well-defined place in our therapeutic approach. The type and character of the malocclusion determines the indications and contraindications of the functional appliance. Scientific and clinical experience has shown the importance of a differential diagnosis for each patient, which integrates etiology and morphogenesis in the individual treatment objectives for special skeletal, dentoalveolar, and functional regions. Individualization in the construction of the appliance, taking the above-mentioned factors into consideration, is essential for optimal clinical results.

[Experiences with active oral hygiene as a preventive treatment in patients with deciduous and mixed dentition]. / Erfahrungen mit aktiver Mundhygiene als Vorsorgebehandlung bei Patienten mit Milch- und Wechselgebiss.

The results of a study of active oral hygiene treatment in children between the ages of 4 and 12 was reported. It is absolutely imperative that both the children and the parents be highly motivated to carry out consistant oral hygiene. The basic level of oral hygiene for children can be considerably improved if the children are instructed in the appropiate technique for tooth brushing and allowed to practice; the children should be regularly checked by the dentist.

[Surgical and orthodontic treatment approach for cleidocranial dysostosis]. / Kieferchirurgische und kieferorthopadische Behandlungsmoglichkeiten bei der Dysostosis cleidocranialis.

Developmental deformities of the permanent dentition are of primary concern in the treatment of patients suffering from cleidocranial dysostosis. The therapeutic approach should be based on interdisciplinary cooperation between orthodontists as well as oral and maxillofacial surgeons. Therapy may include surgical exposure of impacted teeth in combination with removal of supernumerary teeth. Already during the surgical procedure orthodontic bands and brackets may be attached. The next step in treatment should consist of orthodontic alignment of the teeth and correction of the jaw relations. In most cases, midfacial hypoplasia and corresponding abnormal jaw relations are also present. This deformity is best treated with midfacial osteotomy. Following this second surgical intervention, orthodontic treatment is completed in order to establish an optimal result regarding function and esthetics.

[Local anesthesia and beta receptor blockers in dentistry. (Study on an injectable combination of lidocaine and betadrenol)]. / Lokalanästhesie und Beta-Rezeptorenblocker in der Zahnheilkunde (Untersuchungen über ein injizierbares Kombinationspräparat aus Lidocain und Betadrenol).

A double blind trial was undertaken to determine whether the addition of the beta-receptor blocker Betadrenol in two different doses to a lidocaine solution containing adrenaline could influence the exogenous and endogenous beta-adrenergic effects in the field of dental interventions under local anesthesia. It could be shown that already very small amounts of the beta-receptor blocker Betadrenol could suspend beta-adrenergic stimulation of the heart and so prevent unwanted circulatory reactions without side effects on the central nervous system.

[Jaw and dental abnormalities in children with cerebral movement disorders]. / Kiefer- und Geblissanomalien bei Kindern mit cerebralen Bewegungsstörungen

The dentitions of 146 children with cerebral palsy showed a high incidence of gnathic anomalies. There was, however, no relation between these anomalies and the severity of the neuropathological findings. Also the total number of anomalies was almost evenly distributed among the various clinical pictures such as spasticity, athetosis, ataxia. Although combinations of the individual anomalies were found most frequently, marked protrusions of the upper jaw were particularly impressive with 55%, and were followed by class II malformations (47%). In addition, almost every third tested child had an open bite.

[Tongue pathology and its effect on the stomatognathous system in juvenile cerebral movement disorders]. / Zungenpathologie und ihre Auswirkung auf das stomatognathe System bei cerebralen Bewegungsstörungen im Kindesalter

Studies in 146 children with cerebral palsy revealed a definite relation between malfunctioning, size, and location of the lingual muscle and the development of the dentition. The results may be regarded as a confirmation of the so-called functional adaptation theory first observed by ROUX in 1921. The formative influence of the maxillo-facial musculature-including the musculature of the tongue-on the development of the dentition is determined by the proper interaction of the various groups of muscles. Oral muscular malfunctioning, as is often observed in children with cerebral palsy, therefore has a direct influence on the malformation of the jaws and the dentition.

[Role of the family planning counselor in French Switzerland]. / La place de la conseillère de planning familial en Suisse romande.

PIP: There are 34 family planning counselors operating in 15 family planning centers in French speaking Switzerland. The role of the counselor has changed greatly during the years; from simply imparting information on contraception, the counselor is now in charge of teenage sexual education, and in charge of evaluating demands of pregnancy termination. Counselors must undergo a basic course of 1 year which includes both theory teaching and group work, and a practical course of at least 1 year to be spent within an active family planning center. A counselor must be able to interpret the particular situation of a patient at a somatic, psychological, cultural, and social level, and to give her the best possible advice. The counselor occupies a position which bridges the work of the psychologist and that of the doctor, and a strict collaboration with the medical personnel is essential.^ieng

KDEL motif interacts with a specific sequence in mammalian erd2 receptor.

The ER retention of lumenal proteins is achieved by a process which involves binding of escaped proteins via the C-terminal KDEL-tags to a KDEL receptor (erd2 receptor) in a post-ER compartment and return of the protein-receptor complex back to the ER. The transmembrane topology of the human KDEL receptor, which is an integral membrane protein, has been proposed. We have synthesised sets of cellulose-bound overlapping peptides covering the complete se quence of the receptor to study the interaction of the erd2 receptor with lumenal ER proteins, CaBP1 and CaBP2. At the next stage, the proposed lumenal loops of the receptor were more closely mapped. A short sequence, essential for the protein binding to the most efficient binding site of the receptor, was identified as 22KIWK25, which is in accordance with one of the proposed structural models of the receptor. The binding was of high specificity and was almost completely inhibited by KDEL-containing soluble peptides. The phosphorylation state of CaBP1/CaBP2 did not affect their binding to the KDEL receptor.