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Functional Matrix Hypothesis
In the development of vertebrate animals, the functional matrix hypothesis is a phenomenological description of bone growth. It proposes that "the origin, development and maintenance of all skeletal units are secondary, compensatory and mechanically obligatory responses to temporally and operationally prior demands of related functional matrices." The fundamental basis for this hypothesis, laid out by Columbia anatomy professor Melvin Moss is that bones do not ''grow'' but ''are grown'', thus stressing the ontogenetic primacy of function over form. This is in contrast to the current conventional scientific wisdom that genetic, rather than epigenetic (non-genetic) factors, control such growth. The theory was introduced as a chapter in a dental textbook in 1962.''New York Times'Dr. Melvin Moss, 83, Theorist on How Bones of Face Grow, Is Dead June 29, 2006 See also * Wolff's law Wolff's law, developed by the German anatomist and surgeon Julius Wolff (1836–1902) in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Embryogenesis
An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sperm cell. The resulting fusion of these two cells produces a single-celled zygote that undergoes many cell divisions that produce cells known as blastomeres. The blastomeres are arranged as a solid ball that when reaching a certain size, called a morula, takes in fluid to create a cavity called a blastocoel. The structure is then termed a blastula, or a blastocyst in mammals. The mammalian blastocyst hatches before implantating into the endometrial lining of the womb. Once implanted the embryo will continue its development through the next stages of gastrulation, neurulation, and organogenesis. Gastrulation is the formation of the three germ layers that will form all of the different parts of the body. Neurulation forms the nervous sys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertebrate
Vertebrates () comprise all animal taxa within the subphylum Vertebrata () ( chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, with currently about 69,963 species described. Vertebrates comprise such groups as the following: * jawless fish, which include hagfish and lampreys * jawed vertebrates, which include: ** cartilaginous fish (sharks, rays, and ratfish) ** bony vertebrates, which include: *** ray-fins (the majority of living bony fish) *** lobe-fins, which include: **** coelacanths and lungfish **** tetrapods (limbed vertebrates) Extant vertebrates range in size from the frog species ''Paedophryne amauensis'', at as little as , to the blue whale, at up to . Vertebrates make up less than five percent of all described animal species; the rest are invertebrates, which lack vertebral columns. The vertebrates traditionally include the hagfish, which do no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Columbia University College Of Dental Medicine
The Columbia University College of Dental Medicine, often abbreviated CDM, is one of the twenty graduate and professional schools of Columbia University. It is located at 630 West 168th Street in Manhattan, New York City. According to American Dental Education Association, CDM is one of the most selective dental schools in the United States based on average DAT score, GPA, and acceptance rate. In 2014, 2,029 people applied for 80 positions in its entering class. The median undergraduate GPA and average DAT score for successful applicants in 2020 were 3.62 and 22.8, respectively. History The College of Dental Medicine traces its origin to 1852, as the New York College of Dentistry, later the New York College of Dental and Oral Surgery. In 1916 Columbia University, recognizing dentistry as an integral part of the health sciences, established its own school of dental education and absorbed both the New York Post-graduate School of Dentistry and the New York School of Dental Hygiene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Anatomy
The human body is the structure of a human being. It is composed of many different types of cells that together create tissues and subsequently organ systems. They ensure homeostasis and the viability of the human body. It comprises a head, hair, neck, trunk (which includes the thorax and abdomen), arms and hands, legs and feet. The study of the human body involves anatomy, physiology, histology and embryology. The body varies anatomically in known ways. Physiology focuses on the systems and organs of the human body and their functions. Many systems and mechanisms interact in order to maintain homeostasis, with safe levels of substances such as sugar and oxygen in the blood. The body is studied by health professionals, physiologists, anatomists, and by artists to assist them in their work. Composition The human body is composed of elements including hydrogen, oxygen, carbon, calcium and phosphorus. These elements reside in trillions of cells and non-cellula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melvin Moss
Melvin Lionel Moss (1923 – June 26, 2006) was an American dentist known for creating the functional matrix hypothesis for growth and development. He was an anatomist and former dean of Columbia University College of Dental Medicine. Career Moss went to New York University and earned an undergraduate degree from there. He then attended Columbia Dental School and obtained his dental degree in 1946. Prior to dental school, he was part of the Dental Corps (United States Army). After his dental degree, Dr. Moss continued studying and received his PhD from Columbia in anatomy, specializing in physical Anthropology in 1954. Thereafter, he joined the school in 1955 as a faculty of anatomy. In 1968, Moss became the Dean of Columbia Dental School. He was also the professor emeritus of anatomy and oral biology in the Columbia University College of Physicians and Surgeons. Moss created the functional matrix hypothesis which is often used in the speciality of orthodontics Orthodontics is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ontogeny
Ontogeny (also ontogenesis) is the origination and development of an organism (both physical and psychological, e.g., moral development), usually from the time of fertilization of the egg to adult. The term can also be used to refer to the study of the entirety of an organism's lifespan. Ontogeny is the developmental history of an organism within its own lifetime, as distinct from phylogeny, which refers to the evolutionary history of a species. Another way to think of ontogeny is that it is the process of an organism going through all of the developmental stages over its lifetime. The developmental history includes all the developmental events that occur during the existence of an organism, beginning with the changes in the egg at the time of fertilization and events from the time of birth or hatching and afterward (i.e., growth, remolding of body shape, development of secondary sexual characteristics, etc.). While developmental (i.e., ontogenetic) processes can influence sub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conventional Wisdom
The conventional wisdom or received opinion is the body of ideas or explanations generally accepted by the public and/or by experts in a field. In religion, this is known as orthodoxy. Etymology The term is often credited to the economist John Kenneth Galbraith, who used it in his 1958 book ''The Affluent Society'':''E.g.,'Mark Leibovich, "A Scorecard on Conventional Wisdom", ''N.Y. Times'' (March 9, 2008) However, the term dates back to at least 1838. ''Conventional wisdom'' was used in a number of other works before Galbraith, occasionally in a benign''E.g.,'1 Nahum Capen, ''The History of Democracy'' (1874), page 477("millions of all classes alike are equally interested and protected by the practical judgment and conventional wisdom of ages"). or neutral''E.g.,'"Shallow Theorists", ''American Educational Monthly'' 383 (Oct. 1866)("What is the result? Just what conventional wisdom assumes it would be."). sense, but more often pejoratively.''E.g.,'Joseph Warren Beach, ''The Te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a basic unit of heredity and the molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and noncoding genes. During gene expression, the DNA is first copied into RNA. The RNA can be directly functional or be the intermediate template for a protein that performs a function. The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic traits. These genes make up different DNA sequences called genotypes. Genotypes along with environmental and developmental factors determine what the phenotypes will be. Most biological traits are under the influence of polygenes (many different genes) as well as gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epigenetic
In biology, epigenetics is the study of stable phenotypic changes (known as ''marks'') that do not involve alterations in the DNA sequence. The Greek prefix '' epi-'' ( "over, outside of, around") in ''epigenetics'' implies features that are "on top of" or "in addition to" the traditional genetic basis for inheritance. Epigenetics most often involves changes that affect the regulation of gene expression, but the term can also be used to describe any heritable phenotypic change. Such effects on cellular and physiological phenotypic traits may result from external or environmental factors, or be part of normal development. The term also refers to the mechanism of changes: functionally relevant alterations to the genome that do not involve mutation of the nucleotide sequence. Examples of mechanisms that produce such changes are DNA methylation and histone modification, each of which alters how genes are expressed without altering the underlying DNA sequence. Gene expression can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wolff's Law
Wolff's law, developed by the German anatomist and surgeon Julius Wolff (surgeon), Julius Wolff (1836–1902) in the 19th century, states that bone in a healthy animal will adapt to the loads under which it is placed. If loading on a particular bone increases, the bone will remodel itself over time to become stronger to resist that sort of loading. The internal architecture of the trabeculae undergoes adaptive changes, followed by secondary changes to the external cortical portion of the bone, perhaps becoming thicker as a result. The inverse is true as well: if the loading on a bone decreases, the bone will become less dense and weaker due to the lack of the stimulus required for continued bone remodeling, remodeling.Wolff J. "The Law of Bone Remodeling". Berlin Heidelberg New York: Springer, 1986 (translation of the German 1892 edition) This reduction in bone density (osteopenia) is known as stress shielding and can occur as a result of a hip replacement (or other prosthesis). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theories Of Craniofacial Growth
The development of craniofacial growth is a complicated phenomenon that has been the subject of much research for past 70 years. From the first theory in 1940s, many different ideas pertaining to how a face develops has intrigued the minds of researchers and clinicians alike. Key concepts Bone Remodeling is characterized by deposition and resorption of bone at different sites of a bone in the body, mostly for renewal and maintenance throughout life. This does not usually lead to change in size or shape of the bone. Bone Modeling is known as formation of new bone from either cartilage or by direct deposition, mostly during growth and development. This usually does lead to changes in size and shape over time. Growth Sites is a term proposed by Baume. Growth Sites serve as a location in the bone where the actual growth occurs. Growth sites are dependent on the growth centers for growth. Some examples include sutures of cranial vault, lateral cranial base and maxilla. Growth Center ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
