scholarly journals Obtaining Glenoid Positioning Data from Scapular Palpable Points In Vitro

2013 ◽  
Vol 2013 ◽  
pp. 1-4
Author(s):  
Jordan H. Trafimow ◽  
Alexander S. Aruin

Both clinical and biomechanical problems affecting the shoulder joint suggest that investigators should study force transmission into and out from the scapula. To analyze force transmission between the humeral head and the glenoid, one must know the position of the glenoid. Studies have analyzed the position of the scapula from the positions of three palpable points, but the position of the glenoid relative to three palpable points has not been studied. Dry scapulae () were subjected to X-rays and a critical angle, (which relates the plane determined by the three palpable points on the scapula to a plane containing the glenoid center and the first two palpable points) was calculated. The mean value for was degrees. The obtained allows us to determine the position of the glenoid from three palpable points. This information could be used in calculation of forces across the shoulder joint, which in turn would allow optimizing the choice of strengthening exercises.

2012 ◽  
Vol 83 (1) ◽  
pp. 152-157 ◽  
Author(s):  
Erika L. Silva-Benítez ◽  
Veronica Zavala-Alonso ◽  
Gabriel A. Martinez-Castanon ◽  
Juan P. Loyola-Rodriguez ◽  
Nuria Patiño-Marin ◽  
...  

Abstract Objective: To study the shear bond strength (SBS), sites of failure, and micromorphology of bonded molar tubes used on teeth affected by dental fluorosis. Materials and Methods: This in vitro study included 140 first molars classified according to Dean's index for dental fluorosis. Samples were divided into seven groups: (1) healthy teeth etched for 15 seconds, (2) teeth with moderate fluorosis (MOF) etched for 15 seconds, (3) teeth with MOF etched for 150 seconds, (4) teeth with MOF microabrasion etched for 15 seconds, (5) teeth with severe fluorosis (SEF) etched for 15 seconds, (6) teeth with SEF etched for 150 seconds, and (7) teeth with SEF microabrasion etched for 15 seconds. All samples were incubated and were then submitted to the SBS test and evaluated with the modified adhesive remnant index (ARI) and analyzed by using a scanning electronic microscope. Results: The SBS mean value for healthy enamel was 20 ± 10.2 MPa. For the group with MOF, the etched 150-second mean value was the highest (19 ± 7.6 MPa); for the group with SEF treated with microabrasion and etched for 15 seconds, the mean value was (13 ± 4.1 MPa). Significant differences (P ≤ .05) were found in the ARI between healthy and fluorosed groups. Conclusions: Fluorotic enamel affects the adhesion of bonded molar tubes. The use of overetching in cases of MOF and the combination of microabrasion and etching in SEF provides a suitable adhesion for fixed appliance therapy.


2014 ◽  
Vol 7 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Rabindra N. Padhy ◽  
Nabakishore Nayak ◽  
Shakti Rath

Abstract Effects of chemical fertilizers (urea, super phosphate and potash) on toxicities of two carbamate insecticides, carbaryl and carbofuran, individually to the N2-fixing cyanobacterium, Cylindrospermum sp. were studied in vitro at partially lethal levels (below highest permissive concentrations) of each insecticide. The average number of vegetative cells between two polar heterocysts was 16.3 in control cultures, while the mean value of filament length increased in the presence of chemical fertilizers, individually. Urea at the 10 ppm level was growth stimulatory and at the 50 ppm level it was growth inhibitory in control cultures, while at 100 ppm it was antagonistic, i.e. toxicity-enhancing along with carbaryl, individually to the cyanobacterium, antagonism was recorded. Urea at 50 ppm had toxicity reducing effect with carbaryl or carbofuran. At 100 and 250 ppm carbofuran levels, 50 ppm urea only had a progressive growth enhancing effect, which was marked well at 250 ppm carbofuran level, a situation of synergism. Super phosphate at the 10 ppm level only was growth promoting in control cultures, but it was antagonistic at its higher levels (50 and 100 ppm) along with both insecticides, individually. Potash (100, 200, 300 and 400 ppm) reduced toxicity due to carbaryl 20 and carbofuran 250 ppm levels, but potash was antagonistic at the other insecticide levels. The data clearly showed that the chemical fertilizers used were antagonistic with both the insecticides during toxicity to Cylindrospermum sp.


1986 ◽  
Vol 11 (2) ◽  
pp. 258-260
Author(s):  
S. S. KRISTENSEN ◽  
E. THOMASSEN ◽  
F. CHRISTENSEN

Forty four patients with forty seven wrists suffering from Kienböck’s disease were re-examined. The mean observation time was 20.5 years. In all forty seven wrists the treatment had been immobilization. Using a standard X-ray projection, and a reliable method of ulnar variance measuring, the ulnar variance was determined by three observers independently. Comparing the result with the ulnar variance in normal wrists we found the so-called “ulnar minus variant” overrepresented in patients with Kienböck’s disease. However, comparing X-rays taken at the time of diagnosis with X-rays at re-examination, we found in eight out of forty seven wrists that a subchondral bone formation in the distal radius opposite the lunate bone had taken place. This bone formation will tend to enhance the negative value of ulnar variance measurements, and suggests an explanation of the overrepresentation of “ulnar minus variants” in Kienböck’s disease. Excluding these eight wrists from the material and comparing the mean ulnar variance value in the remaining thirty nine wrists with the mean value in normal wrists no statistical difference was shown. Based on these observations it seems unlikely that the “ulnar minus variant” has any bearing on the cause of Kienböck’s disease.


1982 ◽  
Vol 99 ◽  
pp. 589-595
Author(s):  
W. T. Sanders ◽  
J. P. Cassinelli ◽  
K. A. van der Hucht

Preliminary results of three X-ray surveys are presented. Out of a sample of 20 stars, X-rays were detected from four Wolf-Rayet stars and two 08f+ stars. The detected stars have about the same mean value as 0 stars for the X-ray to total luminosity ratio, LX/L = 10−7, but exhibit a much larger variation about the mean. The spectral energy distributions are also found to be like that of 0 stars in that they do not exhibit large attenuation of X-rays softer than 1 keV. This indicates that for both the 0 stars and WR stars much of the X-ray emission is coming from hot wisps or shocks in the outer regions of the winds and not from a thin source at the base of the wind. The general spectral shape and flux level place severe restrictions on models that attribute the lack of hydrogen emission lines to extremely high temperatures of the gas in the wind.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Miao Zhou ◽  
Hui Zhou ◽  
Shu-yi Li ◽  
Yuan-ming Geng

Abstract Purpose Implant location is performed after placement to verify that the safety of neighboring anatomic structure and the realizability of prosthetic plan. Routine postoperative location is based on radiological scanning and raises the concerns on radiation exposure and inconveniency in practice. In the present study a location method based on surface scanning was introduced and the accuracy of this method was assessed in vitro. Material and methods A total of 40 implants were placed in 10 resin mandible models. The models were scanned with intraoral scanner (IS group) and extraoral scanner (ES group). The implant position was located with fusing the images of surface scanning and cone beam computerized tomography (CBCT) after implant placement. Deviations were measured between positions located by surface scanner and postoperative CBCT with the parameters: central deviation at apex (cda), central deviation at hex (cdh), horizontal deviation at apex (hda), horizontal deviation at hex (hdh), vertical deviation at apex (vda), vertical deviation at hex (vdh) and angular deviation (ad). Results In IS group, the mean value of cda, cdh, hda, hdh, vda, vdh and ad was 0.27 mm, 0.23 mm, 0.12 mm, 0.10 mm, 0.21 mm, 0.19 mm and 0.72°, respectively. In ES group, the mean value of cda, cdh, hda, hdh, vda, vdh and ad was 0.28 mm, 0.25 mm 0.14 mm, 0.11 mm, 0.22 mm, 0.20 mm and 0.68°, respectively. The implant deviations in IS and ES groups were of no significant difference for any of the measurements. Conclusions Dental implant can be located via surface scanner with acceptable accuracy for postoperative verification. Further clinical investigation is needed to assess the feasibility of the method.


2016 ◽  
Vol 2016 ◽  
pp. 1-9
Author(s):  
Moses Frank Oduori ◽  
David Masinde Munyasi ◽  
Stephen Mwenje Mutuli

This paper sets out to perform a static force analysis of the single toggle jaw crusher mechanism and to obtain the force transmission characteristics of the mechanism. In order to obtain force transmission metrics that are characteristic of the structure of the mechanism, such influences as friction, dead weight, and inertia are considered to be extraneous and neglected. Equations are obtained by considering the balance of forces at the moving joints and appropriately relating these to the input torque and the output torque. A mechanical advantage, the corresponding transmitted torque, and the variations thereof, during the cycle of motion of the mechanism, are obtained. The mechanical advantage that characterizes the mechanism is calculated as the mean value over the active crushing stroke of the mechanism. The force transmission characteristics can be used as criteria for the comparison of different jaw crusher mechanism designs in order to select the most suitable design for a given application. The equations obtained can also be used in estimating the forces sustained by the components of the mechanism.


2021 ◽  
Vol 162 (46) ◽  
pp. 1848-1855
Author(s):  
Boglárka Rencz ◽  
Buthina Alhaddad ◽  
Boglárka Remport ◽  
Noémi Katinka Rózsa ◽  
Mitsuo Iinuma ◽  
...  

Összefoglaló. Bevezetés: A maradó fogak gyökér-korona arányának meghatározása nagy jelentőséggel bír a fogászati kezelési terv kialakításában és későbbi módosításában. Célkitűzés: Egészséges magyar, német és japán fiatalok maradó fogai gyökér-korona arányának meghatározása és összehasonlítása. Módszer: Hölttä módszerét alkalmaztuk. A mérés 95 magyar, 104 japán és 110 német fiatal páciens 2001 és 2006 között készült panorámaröntgen-felvételén történt. Eredmények: A gyökér-korona arány különbsége a nemek között nem szignifikáns, az egymásnak megfelelő antagonista fogak között sok esetben, de nem mindig, szignifikáns. A legnagyobb gyökér-korona arányt mindhárom populációban az alsó szemfogakon és az alsó második praemolaris fogakon mértük; a felső molarisok esetén a legkisebb az arány. A három nemzetet összehasonlítva szignifikáns különbséget (p≤0,001) nem találtunk egyetlen fogtípus esetében sem. A japán és a német populáció között minden fogtípus esetén szignifikáns volt a különbség a gyökér-korona arányokban. A japán és a magyar populáció összehasonlításakor a fogtípusok felénél találtunk szignifikáns különbséget. A magyar és a német populációt összehasonlítva nagyon kevés fogtípusnál találtunk szignifikáns különbséget. Megbeszélés: Az alsó állcsont fogainak gyökér-korona arányértékei nagyobb mértékben térnek el a populációk között, mint a felső állcsont fogainak esetében. A gyökér-korona arány átlagértéke a német populációban a legnagyobb. A második legnagyobb arányértékkel a magyar populáció rendelkezik, utána pedig a japán, néhány fogtípus kivételével: felső kismetszők, felső szemfogak és felső első molarisok. Következtetés: A legnagyobb gyökér-korona arány különbséget a német és a japán populáció között, a legkisebbet a magyar és a német populáció között találtuk. Cikkünk megmutatja az egyes fogtípusok gyökér-korona arányának normálértékét fiatal, egészséges magyar, német és japán populációban. Orv Hetil. 2021; 162(46): 1848–1855. Summary. Introduction: Defining the root-crown ratio of the permanent teeth is important in making or changing proper treatment plans in dentistry. Objective: To define and compare the root-crown ratios of the permanent teeth of healthy, young Hungarian, German, and Japanese populations. Method: We adapted Hölttä’s method. 95 Hungarian, 104 Japanese and 110 German young patients’ panoramic X-rays (made between 2001 and 2006) were involved in the investigation. Results: Difference between the genders was found non-significant; between the corresponding antagonists many times, but not all significant. The highest root-crown ratios were found in all investigated populations by the lower canines and premolars, the lowest by the upper molars. P≤0,001 was not found among the three populations. Significant differences were found between Japanese and German populations by all tooth-types; between Japanese and Hungarian populations by near half of the tooth-types; between Hungarian and German populations by only a few tooth-types. Discussion: More significant differences were found in root-crown ratios in the lower jaw among the populations. The mean value of the root-crown ratios was the highest in the German population; medium in the Hungarian population; and the least in the Japanese population, with a few exceptions: upper lateral incisors, canines and first molars. Conclusion: The biggest differences were found between the German and Japanese populations; the least between the Hungarian and the German populations. Our paper describes the control values of the root-crown ratios of the tooth types in young, healthy Hungarian, German, and Japanese populations. Orv Hetil. 2021; 162(46): 1848–1855.


2021 ◽  
Vol 6 (5) ◽  
pp. 178-183
Author(s):  
D. V. Menshova ◽  
N. S. Ponomarenko ◽  
I. A. Kuklin

The frequency of rotator cuff injuries in people over 45 years of age is 25.6–50 %, and  40  % of these injuries are massive. Shoulder rotator cuff injury causes disorders in biomechanics of the shoulder joint such as anterior-superior dislocation of the humeral head. Injury of the deltoid muscle combined with a massive rupture of the rotator cuff causes proximal dislocation of the humeral head during any active movement. In  the  treatment of these cases, surgical methods of treatment are used, such as transposition of the latissimus dorsi muscle, proximal capsule plasty, and reverse shoulder arthroplasty. We present a successful clinical case of treatment of a patient with chronic massive injury of the right shoulder joint rotator cuff tendons in combination with the injury of shoulder joint proximal capsule, dislocation of the right humerus head, and hypotrophy of the anterior portion of the deltoid muscle. We performed transposition of the latissimus dorsi tendon in combination with shoulder joint proximal capsule plasty with an autograft of the peroneal longus tendon. The check-up X-rays show that the dislocation of the right shoulder joint was eliminated. In the early postoperative period, the patient started physiotherapy exercises of the operated limb using abduction pillow. By the 7th day after surgery, the abduction of the operated limb reached 70°. The described surgical technique allows to restore congruence in the shoulder joint and the function of the injured limb in severe multiple injuries of the shoulder joint structures. 


1977 ◽  
Vol 37 (02) ◽  
pp. 216-221 ◽  
Author(s):  
Osamu Matsuo ◽  
Hisashi Mihara

SummaryTotal antiplasmin was measured in vitro and in vivo. In the former case, rabbit plasma was mixed with various concentrations of Urokinase (UK) and the least concentration for appearance of fibrinolytic activity was estimated. This concentration was multiplied by the plasma volume of the rabbit to give the in vitro total antiplasmin. The mean value for 14 rabbits was 4,068.6 units.In order to estimate the total antiplasmin in vivo, UK solution was infused into rabbits. The infusion speed was multiplied by the time of the first appearance of fibrinolytic activity to give the total antiplasmin, although when the infusion speed was low, fibrinolytic activity did not appear during infusion. The mean in vivo total antiplasmin calculated for 6 cases where the infusion speed was high and fibrinolytic activity was observed, was 28,699.8 units, i.e. about 7 (range, 3-11) times the in vitro value.


Jones & Sykes have observed that the superlattice lines in X-ray photographs of AuCu 3 , are not always as sharp as the main lines, and that the broadening depends markedly on the indices of the line. They explain these phenomena by assuming that the crystals of AuCu 3 contain many ‘anti-phase nuclei’ in which the superlattice is organized in different ways. In the present paper it is shown that the integral breadth of a reflexion from a crystal in which all the unit cells are not the same is λ J 0 /cos θ ƒ J t dt , where J t is the mean value of the product FF* of the structure factors of two unit cells separated a distance t in the hkl direction. Detailed calculations are made of the broadening to be expected from five different ways in which the nuclei can ‘change step’. Closest agreement with the observed broadening is given by a manner of ‘ changing step ’ in which the gold atoms avoid one another.


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