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Biomedical subjects

V Martinko

Publications and source records attributed to V Martinko.

At least 19 recordsLinked to original sources
PubMed1991

[Fundamentals of the biomechanics of hard tissues].

On the basis of an analysis of such methods that have led to the establishment of the Newtonian laws some problems of the interdisciplinary agreement between mechanics and biology, especially those concerning hard tissues, were discussed. In the light of examples it is shown that comparisons with technical constructions to explain form and function of bones are not sufficient since similarity of form is no proof of identical function. Mechanical phenomena of living matter can be investigated merely by their own movements whereby the differing qualities and reactions of the material have to be taken into priority consideration.

Animals↗
PubMed1991

[The construction principle of bone. II. Microstructure].

On the basis of the ultrastructure of the Haversian lamellar system of bones analyses from the biomechanical viewpoint were undertaken. Instead of computed results preference was given to comparisons with tubes, fibres and nets so as to demonstrate clearly the building principle and movement phenomena. From the course of the collagenous fibres the tensile strains could be discerned which facilitated to determine also the direction of the compressive strains. The mineral components of the bone tissue are oriented toward the direction of the compressive strains. The construction principle of the lamella, however, facilitates reversible deformations and thus regeneration processes which distinguishes it from other technical building principles.

Animals↗
PubMed1990

The gnathic system in obese and diabetics. II. (Changes in the hard tissues).

The authors pay increased attention to issues concerning correct interpretation of mechanical phenomena of the hard tissues that facilitate interdisciplinary cooperation with technical specialists. Equal attention is paid also to terms of compressive stress and compressive strain. Analyzing the crown of the teeth the authors found striking coincidence between the developing dental caries localization and lower values of compressive strains. The relationship found between dental caries and mechanical strains offers stimuli for new preventive measures. The present study furthermore points to the importance of medical bionics and its methods for solving some other problems of the gnathic system.

Dental Caries↗
PubMed1990

The gnathic system in obese and diabetics. I (Basic relationship of function and form).

The authors pay complex attention to the research of the gnathic system, focused first of all to the mechanical interactions towards solid formations of the gnathic system. The results of their analysis show, that in the first cell already differentation to tensile functions of the membrane and compressive functions of its contents (cytoplasm) exists. In the osseous tissue the mechanical strain is also distributed to different substances, reacting differently to the mechanical stress according to their aggregate state--the liquid state secures an equal distribution of the developing compression, the collagens intercept and cushion the arising traction, and the mineral component the oriented compressions. Therefore, the bone tissue markedly differs from the inorganic homogenous solid substances, where the distribution of the mechanical strain is different. A detailed analysis shows that the form and structure of the bones is in accord with the course of the developing compressive strain and dependent on the mechanical consistency of the consumed food.

Aging↗
PubMed1990

[The structural basis of bone I].

Divergent opinions on the relations between mechanical forces and bones motivated the authors to reevaluate the problem in its entirely. First, the most important environmental forces were recorded in order to be able to assess the primary relationships to living matters. The fundamental differences between the distribution of mechanical strain in a cell and in an inanimate solid substance were analysed. This analysis was reconducted on multicellulars. On the basis of embryologic experience and knowledge it was proved that the building principles of bony tissue is diametrically different from that of technical constructions. The mineralized substances serve to prop the supports necessary for muscular activity and take over the compressive strain, whereas the organic substances, and especially the collagens, take on the tensile strain in the bony tissue.

Bone Development↗
PubMed1989

[Biomechanics of the bones and skeleton. III. Microstructure].

The authors analyzed micro- and ultrastructure of Haversian system--osteon--from the aspect of mechanics--biomechanics. The evaluation takes into account biological factors and instead of mathematical formulae and calculations prefer a comparison with technical constructions, particularly for emphasizing differences or similarities. The analysis of osteon revealed that it consists of fibres, net and tubes. The orientation of tube-like lamellae is in the direction of compressive strain, whereas the resultant course of torison and bending stress may be well observed in the direction of collagen fibres. A slight assymetry of osteons suggests that they are stressed by pressure in a slightly excentric direction. In the course of stress lengthwise there is the development of extension of the Haversian canal supporting the blood flow in the capillary. In the course of stress in the osteon lengthwise there are developing pressure, torsion and bending strains. Liquid phase can, together with collagen, absorb considerable portion of kinetic energy, thereby decreasing the strain of external strengths to act on the fragile mineralized component. Without the viscous and collagen elements the mineralized component would not be able to resist the dynamic forces which develop during the stresses in the bone tissue. Identification of mechanic phenomena of osteon provides information on structural principle of the whole bones. The authors applied in their study the knowledge from the discovery of USSR No. 181 and a discovery of CSSR No. 43.

Biomechanical Phenomena↗
PubMed1987

[Biomechanical regularities of hard tissues in the human].

The interrelationship between acting forces and hard tissues of living beings is demonstrated on the basis of some examples. They give evidence that the structure of hard tissues is oriented toward higher pressure tensions. It is also demonstrated that living hard tissues react differently to mechanical impulses than liveless matter. It is also stressed that the science of statics is insufficient to explain the laws and reactions of living hard tissues.

Animals↗
PubMed1985

[The dentoalveolar junction].

A short survey on experiments carried out on human, dogs and models is presented. Special attention is paid to the periodontium. Registered deformation phenomena hint that the dentoalveolar system behaves as a reciprocally acting different elastic unit. This can be interpreted taking into account the mechanics of an anisotropic deformable matter. When the tooth is loaded, collagenous fibres of the periodontium are secondary activated to traction, in the course of which the fibrae alveolodentales apicales block dislocation of the apex radicis and not--as supposed in the past--getting out of the tooth from its alveolus.

Animals↗
PubMed1985

[Biomechanics of hard substances--bones and teeth].

Scientific publications of Wolff (1870, 1892) and Roux (1895) are evaluated on basis of the present knowledge about mechanics. It is demonstrated that their technical adviser was unable at that time to explain satisfactory the structure of bone. The likely way to approach the problem on basis of up-to-day knowledge in biomechanics are discussed. Some examples are briefly demonstrated to explain the relationship between mechanical forces and the bone-structure.

Biomechanical Phenomena↗