Interceptive Procedures Research Articles

A randomized controlled study of early headgear treatment on occlusal stability--a 13 year follow-up

The purpose of this investigation was to assess the long-term occlusal stability in a group treated early with headgear (HG) compared with a control group. The total study group comprised 68 children (40 males and 28 females) aged 7.6 years (standard deviation 0.3), randomly divided into two groups of equal size. In the first group, HG treatment was initiated immediately, while in the control group only minor interceptive procedures were performed during the follow-up period. Fixed appliance treatment, if needed, including extraction of permanent teeth due to crowding, was undertaken after the completion of early treatment. The records were available from the start of the early treatment and at follow-up after 2, 4, 8, and 13 years. The US-weighted Peer Assessment Rating (PAR) Index, graded according to the severity of malocclusion, was used to evaluate occlusal stability. Little's Irregularity Index (LII)and intercanine distance in the lower arch were measured at all time periods. The Aesthetic Component (AC) of the Index of Orthodontic Treatment Need (IOTN) scores was used for evaluation of dental aesthetics at the last follow-up. Parametric tests were applied for statistical analyses, except for the evaluation of aesthetics, where a non-parametric test was used. No significant differences were found when long-term stability between the HG and control groups was evaluated at the 13 year follow-up. Lower PAR scores were observed in patients treated without extraction of teeth. A greater irregularity in lower incisor alignment before treatment was found in subjects later treated with extractions. The findings of this study seem to suggest that treatment timing has only a minor influence on stability.

Effects of intercept pathogen inactivation on platelet function as analysed by free oscillation rheometry

Introduction The Intercept Blood System, using InterSol as additive solution, is used for inactivation of contaminating pathogens in PCs, thus reducing the risk for transfusion transmitted infection and making it possible to prolong the storage period. This study aimed at investigating the ability of Intercept treated platelets to induce clot formation, as measured by coagulation time using free oscillation rheometry (FOR), and to compare with that of platelets in concentrates with the additive solution T-Sol or plasma. Methods Seventy-four single-donor platelet units were diluted in InterSol ( n = 27) or T-Sol ( n = 47) to a mean plasma concentration of 38%. The Intercept treatment was performed by addition of amotosalen HCl to the InterSol PCs followed by UVA irradiation and treatment with a compound adsorption device (CAD). Forty-six units were collected and stored in 100% plasma for comparison. Clotting time was measured by FOR in fresh PCs (within 26 h after collection) after stimulation by a platelet activator. Soluble P-selectin was analysed as a marker of platelet activation in the Intercept and T-Sol PCs. Results The clotting time was shorter for Intercept treated platelets compared to platelets in T-Sol and plasma ( p < 0.05). There was no difference in clotting time between T-Sol and plasma PCs. Soluble P-selectin was higher for Intercept platelets than platelets in T-Sol ( p < 0.05). Conclusions The platelets treated with the Intercept procedure had good clot promoting capacity.

Considerações para elaboração de protocolo de assistência ortodôntica em saúde coletiva

This study offers help for drawing up a community health orthodontic assistance protocol, especially for the public health system. A preventive and interceptive orthodontic program is suggested through the inclusion of approaches in existing healthcare programs that may help prevent malocclusions, extending the services offered by Basic Healthcare Units to include fitting space retainer appliances and interceptive procedures. Possible occlusion problems are discussed and rated as high or low priority for treatment, stressing occlusal deviations that should not be treated precociously. Preventive and interceptive orthodontic treatment should primarily be offered to children with deciduous and mixed dentition. The management and inclusion of orthodontic procedures can be deployed through the management of physical, human and financial resources, establishing access criteria for these services. The use of an appropriate orthodontic assistance protocol and correct planning of orthodontic actions could pave the way for preventive and interceptive procedures at the Basic Healthcare Units, while more resources could be allocated to setting up Specialty Reference Centers offering more complex corrective orthodontic procedures.

The effects of early headgear treatment on dental arches and craniofacial morphology: an 8 year report of a randomized study

The aim of this study was to determine the long-term effects of early headgear (HG) treatment on craniofacial structures. The total study group comprised 68 children (40 males and 28 females) aged 7.6 years (standard deviation 0.3 years). The children, who had a Class II tendency in occlusion and moderate crowding, were randomly divided into two groups of equal size. In the first group, HG treatment was initiated immediately. In the second group, which served as a control group, only minor interceptive procedures were performed during the first follow-up period of 2 years. During the 8 year follow-up, orthodontic therapy, including fixed appliances and possible extractions, was carried out when necessary. The results showed that the most evident difference between the groups was the wider and longer dental arches in the HG group, which could only partly be explained by the higher rate of extractions in the control group. For the cephalometric measurements, the most significant difference was in the maxillary plane orientation. The peer assessment rating (PAR) score, showing the general outcome of treatment, was at the same level in both groups at follow-up. The deficit of the early HG treatment was the longer mean total treatment time, resulting from the two-phase treatment.

Thermodynamics of the MnO-Al2O3-TiO2 System.

Isothermal phase relations for the MnO-Al 2 O 3 -TiO 2 system have been investigated under moderately reducing conditions, P O2 =2.29 × 10 -11 atm and 1.91 × 10 10 atm at 1 673 K and 1 873 K, respectively, equilibrated with a saturating oxide tablet. Activities of MnO in the MnO-Al 2 O 3 -TiO 2 system have been measured in equilibrium with silver at 1 673 K and copper at 1 873 K, respectively. Iso-activity curves for MnO have been drawn from the experimental results of the activities as well as those for Al 2 O 3 and TiO 2 calculated by Schuhmann's tangent intercept procedure, which provide the deoxidation equilibrium of molten steels. The sulfide capacity significantly depends on MnO content in this ternary system. It slightly increases when Al 2 O 3 replaces TiO 2 at a constant MnO content in weight percent, whereas γ MnS considerably decreases.

Thermodynamics of the MnO-SiO2-TiO2 System at 1673 K.

The isothermal phase relations for the MnO-SiO 2 -TiO 2 system have been investigated at 1 673 K by a chemical equilibration technique. Iso-activity curves for MnO are drawn from the experimental results of the activities as well as those for SiO2 and TiO 2 calculated by Schuhmann's tangent intercept procedure. 1) Iso-activity curves are nearly parallel to the saturation lines for the respective components. In this system, the interaction between MnO and SiO2 is the strongest of all. The sulfide capacity mostly depends on MnO content in this ternary system. It slightly increases when SiO 2 is replaced by TiO 2 at a constant (MnO+MnS) content by molar basis, whereas γMns considerably decreases.

Theory and practice of stereological techniques applied to the estimation of cell number and nuclear volume in the testis.

The historical background to contemporary approaches to the estimation of cell/nuclear number and volume in the testes is reviewed. The limitations of older geometric model-based approaches to the estimation of cell/nuclear number are discussed, and the need for absolute estimates of cell number rather than ratio estimates is examined. The physical and optical disector approaches to the direct estimation of numerical density and, hence, absolute cell number are presented together with data illustrating their operational efficiency in the testis. New approaches to the direct estimation of nuclear/cell volume, using the point-sampled intercept family of methods, are presented and illustrated, using the example of the Sertoli cell nucleus. The use of both classical transverse and the newer vertical section approaches is explored. Estimation of Sertoli cell/nuclear volume in the volume (point-sampled intercept procedure) and number (nucleator and rotator methods) distributions on both conventional transverse and vertical sections is discussed. The use of transverse sections of the testis is shown to produce a consistent bias in the estimation of Sertoli cell nuclear volume in 120-day-old animals, with all the estimators. Comparison of the Sertoli cell nuclear volume (measured on vertical sections) in the volume and number-weighted distribution suggests a coefficient of variation of volume in the number distribution of 0.4-0.5, suggesting either a random or stage-dependent variation in Sertoli cell nuclear size which requires further exploration.

Jackrabbit Densities on Fair and Good Condition Chihuahuan Desert Range

This study was conducted on Chihuahuan desert range near Las Cruces, in southcentral New Mexico, to determine the relationship of blacktailed jackrabbit (Lepus californicus) densities to good (GC) and fair (FC) range condition. The Soil Conservation Service procedure was used to classify ecological range condition. Line transect procedures were used to estimate jackrabbit populations from July 1988 to December 1990. Concurrently vegetation cover and mean plant height were determined with the line intercept procedure. Jackrabbit densities on the fair condition range were higher (P < 0.10) than those on the good condition range. This difference is attributed to the fair condition range containing more protective cover and preferred forage than good condition range. Jackrabbit abundance showed no season (P < 0.10) or year differences (P < 0.10). Jackrabbits preferred grass-shrub mosaic habitats more than shrubland and grassland habitats. The need for diverse food sources and protective cover were apparently major determinants of habitat selection by jackrabbits. The good condition range contained greater (P < 0.10) grass cover and less (P < 0.10) shrub cover than the fair condition range. Our results indicated that maintaining Chihuahuan desert ranges in good to excellent condition is the best means of achieving lower abundance of jackrabbit populations.

Anatomische und physiologische Aspekte bei der Behandlung von Kiefergelenkstörungen

The specialty of orthodontics and its relationship to TMJ problems is in the thick of controversy. Several anatomic and physiologic aspects are discussed so as to improve the understanding of the multi-faceted problems. The use of this biologically-based information is likely to make therapy more successful. From a therapeutic point of view, it is incumbent on the dentist to institute early preventive or interceptive procedures.

How Reliable are Growth Back-Calculations Based on Otoliths?

Growth back-calculations from otoliths assume that the relationship between fish and otolith length is linear through time. The final (or observed) individual fish-otolith ratios are then combined to prepare a fish-otolith regression for the population, upon which the subsequent back-calculations are based. However, recent studies have demonstrated that the fish:otolith size ratio varies systematically with somatic growth rate, resulting in relatively large otoliths in slow-growing fish. Such a growth effect will result in a fitted fish-otolith regression which differs significantly from that of the mean of the individual fish-otolith slopes. Fraser–Lee growth back-calculations made from such a regression consistently underestimate previous lengths at age. The bias may explain the apparent ubiquity of Lee's phenomenon. Back-calculation bias was eliminated through use of an algorithm defining individual fish-otolith trajectories and a biologically determined, rather than a statistically estimated, intercept. Adaptations of the biological intercept back-calculations procedure accurately predicted previous lengths in the presence of both stochastic error and time-varying growth rates. When used to reevaluate some published back-calculations, the biological intercept procedure resulted in more accurate values than those previously estimated, and reduced or eliminated the presence of Lee's phenomenon.

Overbite changes associated with interceptive orthodontic procedures

Overbite changes associated with interceptive orthodontic procedures

Treatment planning

Treatment planning should be a specifically assigned part of our treatment schedule. The analysis, diagnosis, and treatment plan should be entered in the records carefully, preferably by typewriter. Certain palliative or interceptive procedures may be executed—some advantageously and some not. There are anomalies which may be treated equally well by any appliance therapy. Simplicity seems to be the indicated course. Borderline discrepancy problems are our greatest challenges. Some of these are mild, and some residual deficiency after treatment may be accepted. Other discrepancy dysplasias which are more severe, require firmer handling. Finally, there are the definite extraction problems. Whatever our conclusions on treatment planning, it must be based on purposeful objectives.

Astro-Fix by Computation

This paper describes a method for the reduction of simultaneous star altitude observations in pairs, whereby an unambiguous ‘fix’ is obtained without reference to the dead reckoning position and without use of the intercept procedure. The method is adequate in all latitudes. An especially swift reduction is possible for the moments at which two stars are situated at equal altitudes.When position is determined by means of two simultaneous star altitude observations and use is made of a single chosen position it is possible for the Marcq St. Hilaire intercepts to be so short that they can be regarded as negligible. When this occurs the chosen position is, in effect, the true position as indicated by the observations and no further work is required for a fix. If, in such a case, it is desired to have the Sumner lines of position represented on the chart it will be possible to draw them through the chosen position. The selection of such a chosen position may be made with certainty, in every instance, by computing numerical values for the latitude and the longitude of the appropriate intersection of the two circles of equal altitudes corresponding to the corrected observations. If the entire computation had to be done after the observations were made, the labour of this procedure would prohibit its use in rapid navigation. It happens, however, that the greater part of the work can be precomputed and presented for the navigator's use in a tabular form. These data are extremely compact and are permanent except for the need of occasional adjustment for precessional effects and on account of proper motions of the stars. No almanac would be required for use with such a table if the navigator were not dependent on it for his G.H.A. Aries. No knowledge of the dead reckoning position is employed in this computation; star observations suffice to determine the position without ambiguity.