Titanium is a chemical element with symbol Ti and atomic number 22. It is a lustrous transition metal with a silver color, low density, high strength. Titanium is resistant to corrosion in sea water, aqua regia, chlorine. Titanium was discovered in Cornwall, Great Britain, by William Gregor in 1791, was named by Martin Heinrich Klaproth after the Titans of Greek mythology; the element occurs within a number of mineral deposits, principally rutile and ilmenite, which are distributed in the Earth's crust and lithosphere, it is found in all living things, water bodies and soils. The metal is extracted from its principal mineral ores by the Hunter processes; the most common compound, titanium dioxide, is a popular photocatalyst and is used in the manufacture of white pigments. Other compounds include a component of smoke screens and catalysts. Titanium can be alloyed with iron, aluminium and molybdenum, among other elements, to produce strong, lightweight alloys for aerospace, industrial processes, agri-food, medical prostheses, orthopedic implants and endodontic instruments and files, dental implants, sporting goods, mobile phones, other applications.
The two most useful properties of the metal are corrosion resistance and strength-to-density ratio, the highest of any metallic element. In its unalloyed condition, titanium is less dense. There are two allotropic forms and five occurring isotopes of this element, 46Ti through 50Ti, with 48Ti being the most abundant. Although they have the same number of valence electrons and are in the same group in the periodic table and zirconium differ in many chemical and physical properties; as a metal, titanium is recognized for its high strength-to-weight ratio. It is a strong metal with low density, quite ductile and metallic-white in color; the high melting point makes it useful as a refractory metal. It is paramagnetic and has low electrical and thermal conductivity. Commercially pure grades of titanium have ultimate tensile strength of about 434 MPa, equal to that of common, low-grade steel alloys, but are less dense. Titanium is 60% denser than aluminium, but more than twice as strong as the most used 6061-T6 aluminium alloy.
Certain titanium alloys achieve tensile strengths of over 1,400 MPa. However, titanium loses strength when heated above 430 °C. Titanium is not as hard as some grades of heat-treated steel. Machining requires precautions, because the material can gall unless sharp tools and proper cooling methods are used. Like steel structures, those made from titanium have a fatigue limit that guarantees longevity in some applications; the metal is a dimorphic allotrope of an hexagonal α form that changes into a body-centered cubic β form at 882 °C. The specific heat of the α form increases as it is heated to this transition temperature but falls and remains constant for the β form regardless of temperature. Like aluminium and magnesium, titanium metal and its alloys oxidize upon exposure to air. Titanium reacts with oxygen at 1,200 °C in air, at 610 °C in pure oxygen, forming titanium dioxide, it is, slow to react with water and air at ambient temperatures because it forms a passive oxide coating that protects the bulk metal from further oxidation.
When it first forms, this protective layer continues to grow slowly. Atmospheric passivation gives titanium excellent resistance to corrosion equivalent to platinum. Titanium is capable of withstanding attack by dilute sulfuric and hydrochloric acids, chloride solutions, most organic acids. However, titanium is corroded by concentrated acids; as indicated by its negative redox potential, titanium is thermodynamically a reactive metal that burns in normal atmosphere at lower temperatures than the melting point. Melting is possible only in a vacuum. At 550 °C, it combines with chlorine, it reacts with the other halogens and absorbs hydrogen. Titanium is one of the few elements that burns in pure nitrogen gas, reacting at 800 °C to form titanium nitride, which causes embrittlement; because of its high reactivity with oxygen and some other gases, titanium filaments are applied in titanium sublimation pumps as scavengers for these gases. Such pumps inexpensively and reliably produce low pressures in ultra-high vacuum systems.
Titanium is the ninth-most abundant element in the seventh-most abundant metal. It is present as oxides in most igneous rocks, in sediments derived from them, in living things, natural bodies of water. Of the 801 types of igneous rocks analyzed by the United States Geological Survey, 784 contained titanium, its proportion in soils is 0.5 to 1.5%. Common titanium-containing minerals are anatase, ilmenite, perovskite and titanite. Akaogiite is an rare mineral consisting of titanium dioxide. Of these minerals, only rutile and ilmenite have economic importance, yet they are difficult to find in high concentrations. About 6.0 and 0.7 million tonnes of those minerals were mined in 2011, respectively. Signi
Pathology is the study of the causes and effects of disease or injury. The word pathology refers to the study of disease in general, incorporating a wide range of bioscience research fields and medical practices. However, when used in the context of modern medical treatment, the term is used in a more narrow fashion to refer to processes and tests which fall within the contemporary medical field of "general pathology," an area which includes a number of distinct but inter-related medical specialties that diagnose disease through analysis of tissue and body fluid samples. Idiomatically, "a pathology" may refer to the predicted or actual progression of particular diseases, the affix path is sometimes used to indicate a state of disease in cases of both physical ailment and psychological conditions. A physician practicing pathology is called a pathologist; as a field of general inquiry and research, pathology addresses four components of disease: cause, mechanisms of development, structural alterations of cells, the consequences of changes.
In common medical practice, general pathology is concerned with analyzing known clinical abnormalities that are markers or precursors for both infectious and non-infectious disease and is conducted by experts in one of two major specialties, anatomical pathology and clinical pathology. Further divisions in specialty exist on the basis of the involved sample types and physiological systems, as well as on the basis of the focus of the examination. Pathology is a significant field in medical research; the study of pathology, including the detailed examination of the body, including dissection and inquiry into specific maladies, dates back to antiquity. Rudimentary understanding of many conditions was present in most early societies and is attested to in the records of the earliest historical societies, including those of the Middle East and China. By the Hellenic period of ancient Greece, a concerted causal study of disease was underway, with many notable early physicians having developed methods of diagnosis and prognosis for a number of diseases.
The medical practices of the Romans and those of the Byzantines continued from these Greek roots, but, as with many areas of scientific inquiry, growth in understanding of medicine stagnated some after the Classical Era, but continued to develop throughout numerous cultures. Notably, many advances were made in the medieval era of Islam, during which numerous texts of complex pathologies were developed based on the Greek tradition. So, growth in complex understanding of disease languished until knowledge and experimentation again began to proliferate in the Renaissance and Baroque eras, following the resurgence of the empirical method at new centers of scholarship. By the 17th century, the study of microscopy was underway and examination of tissues had led British Royal Society member Robert Hooke to coin the word "cell", setting the stage for germ theory. Modern pathology began to develop as a distinct field of inquiry during the 19th Century through natural philosophers and physicians that studied disease and the informal study of what they termed “pathological anatomy” or “morbid anatomy”.
However, pathology as a formal area of specialty was not developed until the late 19th and early 20th centuries, with the advent of detailed study of microbiology. In the 19th century, physicians had begun to understand that disease-causing pathogens, or "germs" existed and were capable of reproduction and multiplication, replacing earlier beliefs in humors or spiritual agents, that had dominated for much of the previous 1,500 years in European medicine. With the new understanding of causative agents, physicians began to compare the characteristics of one germ’s symptoms as they developed within an affected individual to another germ’s characteristics and symptoms; this realization led to the foundational understanding that diseases are able to replicate themselves, that they can have many profound and varied effects on the human host. To determine causes of diseases, medical experts used the most common and accepted assumptions or symptoms of their times, a general principal of approach that persists into modern medicine.
Modern medicine was advanced by further developments of the microscope to analyze tissues, to which Rudolf Virchow gave a significant contribution, leading to a slew of research developments. By the late 1920s to early 1930s pathology was deemed a medical specialty. Combined with developments in the understanding of general physiology, by the beginning of the 20th century, the study of pathology had begun to split into a number of rarefied fields and resulting in the development of large number of modern specialties within pathology and related disciplines of diagnostic medicine; the term pathology comes from the Ancient Greek roots of pathos, meaning "experience" or "suffering" and -logia, "study of". The modern practice of pathology is divided into a number of subdisciplines within the discrete but interconnected aims of biological research and medical practice. Biomedical research into disease incorporates the
Enzymes are macromolecular biological catalysts. Enzymes accelerate chemical reactions; the molecules upon which enzymes may act are called substrates and the enzyme converts the substrates into different molecules known as products. All metabolic processes in the cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps; the study of enzymes is called enzymology and a new field of pseudoenzyme analysis has grown up, recognising that during evolution, some enzymes have lost the ability to carry out biological catalysis, reflected in their amino acid sequences and unusual'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Most enzymes are proteins; the latter are called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the reaction rate by lowering its activation energy; some enzymes can make their conversion of substrate to product occur many millions of times faster.
An extreme example is orotidine 5'-phosphate decarboxylase, which allows a reaction that would otherwise take millions of years to occur in milliseconds. Chemically, enzymes are like any catalyst and are not consumed in chemical reactions, nor do they alter the equilibrium of a reaction. Enzymes differ from most other catalysts by being much more specific. Enzyme activity can be affected by other molecules: inhibitors are molecules that decrease enzyme activity, activators are molecules that increase activity. Many therapeutic drugs and poisons are enzyme inhibitors. An enzyme's activity decreases markedly outside its optimal temperature and pH, many enzymes are denatured when exposed to excessive heat, losing their structure and catalytic properties; some enzymes are used commercially, in the synthesis of antibiotics. Some household products use enzymes to speed up chemical reactions: enzymes in biological washing powders break down protein, starch or fat stains on clothes, enzymes in meat tenderizer break down proteins into smaller molecules, making the meat easier to chew.
By the late 17th and early 18th centuries, the digestion of meat by stomach secretions and the conversion of starch to sugars by plant extracts and saliva were known but the mechanisms by which these occurred had not been identified. French chemist Anselme Payen was the first to discover an enzyme, diastase, in 1833. A few decades when studying the fermentation of sugar to alcohol by yeast, Louis Pasteur concluded that this fermentation was caused by a vital force contained within the yeast cells called "ferments", which were thought to function only within living organisms, he wrote that "alcoholic fermentation is an act correlated with the life and organization of the yeast cells, not with the death or putrefaction of the cells."In 1877, German physiologist Wilhelm Kühne first used the term enzyme, which comes from Greek ἔνζυμον, "leavened" or "in yeast", to describe this process. The word enzyme was used to refer to nonliving substances such as pepsin, the word ferment was used to refer to chemical activity produced by living organisms.
Eduard Buchner submitted his first paper on the study of yeast extracts in 1897. In a series of experiments at the University of Berlin, he found that sugar was fermented by yeast extracts when there were no living yeast cells in the mixture, he named the enzyme that brought about the fermentation of sucrose "zymase". In 1907, he received the Nobel Prize in Chemistry for "his discovery of cell-free fermentation". Following Buchner's example, enzymes are named according to the reaction they carry out: the suffix -ase is combined with the name of the substrate or to the type of reaction; the biochemical identity of enzymes was still unknown in the early 1900s. Many scientists observed that enzymatic activity was associated with proteins, but others argued that proteins were carriers for the true enzymes and that proteins per se were incapable of catalysis. In 1926, James B. Sumner crystallized it; the conclusion that pure proteins can be enzymes was definitively demonstrated by John Howard Northrop and Wendell Meredith Stanley, who worked on the digestive enzymes pepsin and chymotrypsin.
These three scientists were awarded the 1946 Nobel Prize in Chemistry. The discovery that enzymes could be crystallized allowed their structures to be solved by x-ray crystallography; this was first done for lysozyme, an enzyme found in tears and egg whites that digests the coating of some bacteria. This high-resolution structure of lysozyme marked the beginning of the field of structural biology and the effort to understand how enzymes work at an atomic level of detail. An enzyme's name is derived from its substrate or the chemical reaction it catalyzes, with the word ending in -ase. Examples are alcohol dehydrogenase and DNA polymerase. Different enzymes that catalyze the same chemical reaction are called isozymes; the International Union of Biochemistry and Molecular Biology have developed a nomenclature for enzymes, the EC numbers. The first number broadly classifies the enzyme based on its mechanism; the top-level classification is: EC 1, Oxidoreductases: catalyze oxidation/reducti
Waxes are a diverse class of organic compounds that are lipophilic, malleable solids near ambient temperatures. They include higher alkanes and lipids with melting points above about 40 °C, melting to give low viscosity liquids. Waxes are soluble in organic, nonpolar solvents. Natural waxes of different types occur in petroleum. Waxes are organic compounds. Natural waxes may contain unsaturated bonds and include various functional groups such as fatty acids and secondary alcohols, ketones and fatty acid esters, aromatic compounds may be present. Synthetic waxes consist of homologous series of long-chain aliphatic hydrocarbons that lack functional groups. Waxes are synthesized by many animals; those of animal origin consist of wax esters derived from a variety of carboxylic acids and fatty alcohols. In waxes of plant origin, characteristic mixtures of unesterified hydrocarbons may predominate over esters; the composition depends not only on species, but on geographic location of the organism. The best known animal wax is beeswax used in constructing the honeycombs of honeybees, but other insects secrete waxes.
A major component of the beeswax is myricyl palmitate, an ester of triacontanol and palmitic acid. Its melting point is 62-65 °C. Spermaceti occurs in large amounts in the head oil of the sperm whale. One of its main constituents is another ester of a fatty acid and a fatty alcohol. Lanolin is a wax obtained from wool. Plants secrete waxes into and on the surface of their cuticles as a way to control evaporation and hydration; the epicuticular waxes of plants are mixtures of substituted long-chain aliphatic hydrocarbons, containing alkanes, alkyl esters, fatty acids and secondary alcohols, ketones, aldehydes. From the commercial perspective, the most important plant wax is carnauba wax, a hard wax obtained from the Brazilian palm Copernicia prunifera. Containing the ester myricyl cerotate, it has many applications, such as confectionery and other food coatings and furniture polish, floss coating, surfboard wax. Other more specialized vegetable waxes include ouricury wax. Plant and animal based waxes or oils can undergo selective chemical modifications to produce waxes with more desirable properties than are available in the unmodified starting material.
This approach has relied on green chemistry approaches including olefin metathesis and enzymatic reactions and can be used to produce waxes from inexpensive starting materials like vegetable oils. Although many natural waxes contain esters, paraffin waxes are hydrocarbons, mixtures of alkanes in a homologous series of chain lengths; these materials represent a significant fraction of petroleum. They are refined by vacuum distillation. Paraffin waxes are mixtures of saturated n- and iso- alkanes and alkyl- and naphthene-substituted aromatic compounds. A typical alkane paraffin wax chemical composition comprises hydrocarbons with the general formula CnH2n+2, such as hentriacontane, C31H64; the degree of branching has an important influence on the properties. Microcrystalline wax is a lesser produced petroleum based wax that contains higher percentage of isoparaffinic hydrocarbons and naphthenic hydrocarbons. Millions of tons of paraffin waxes are produced annually, they are used in foods, in candles and cosmetics, as non-stick and waterproofing coatings and in polishes.
Montan wax is a fossilized wax extracted from lignite. It is hard, reflecting the high concentration of saturated fatty acids and alcohols. Although dark brown and odorous, they can be purified and bleached to give commercially useful products; as of 1995, about 200 million kilograms/y were consumed. Polyethylene waxes are manufactured by one of three methods: 1- direct polymerization of ethylene; each production technique generates products with different properties. Key properties of low molecular weight polyethylene waxes are viscosity and melt point. Polyethylene waxes produced by means of degradation or recovery from polyethylene resin streams contain low molecular weight materials that must be removed to prevent volatilization and potential fire hazards during use. Polyethylene waxes manufactured by this method are stripped of low molecular weight fractions to yield a flash point > 500°F. Many polyethylene resin plants produce a low molecular weight stream referred to as Low Polymer Wax. LPW is unrefined and contains volatile oligomers, corrosive catalyst and may contain other foreign material and water.
Refining of LPW to produce a polyethylene wax involves removal of hazardous catalyst. Proper refining of LPW to produce polyethylene wax is important when being used in applications requiring FDA or other regulatory certification. Waxes are consumed industrially as components of complex formulations for coatings; the main use of polyethylene and polypropylene waxes is in the formulation of colourants for plastics. Waxes confer matting effects and wear resistance to paints. Polyethylene waxes are incorporated into inks in the form of dispersions to decrease friction, they are employed as release agents, find use as slip agents in furniture, confer corrosion resistance. Waxes such as paraffin wax or beeswax, hard fats such as tallow are used to make can
Base of skull
The base of skull known as the cranial base or the cranial floor, is the most inferior area of the skull. It is composed of the lower parts of the skull roof. Structures found at the base of the skull are for example: There are five bones that make up the base of the skull: Ethmoid bone Sphenoid bone Occipital bone Frontal bone Temporal bone Occipital sinus Superior sagittal sinus Superior petrosal sinus Foramen cecum Optic foramen Foramen lacerum Foramen rotundum Foramen magnum Foramen ovale Jugular foramen Internal auditory meatus Mastoid foramen Sphenoidal emissary foramen Foramen spinosum Frontoethmoidal suture Sphenofrontal suture Sphenopetrosal suture Sphenoethmoidal suture Petrosquamous suture Sphenosquamosal suture Sphenoidal lingula Subarcuate fossa Dorsum sellae Jugular process Petro-occipital fissure Condylar canal Jugular tubercle Tuberculum sellae Carotid groove Fossa hypophyseos Posterior clinoid processes Sigmoid sulcus Internal occipital protuberance Internal occipital crest Ethmoidal spine Vestibular aqueduct Chiasmatic groove Middle clinoid process Groove for sigmoid sinus Trigeminal ganglion Middle cranial fossa Anterior cranial fossa Middle meningeal artery Cribriform plate Posterior cranial fossa Nasociliary nerve Hypoglossal canal
Epithelium is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. Epithelial tissues line the outer surfaces of organs and blood vessels throughout the body, as well as the inner surfaces of cavities in many internal organs. An example is the outermost layer of the skin. There are three principal shapes of epithelial cell: squamous and cuboidal; these can be arranged in a single layer of cells as simple epithelium, either squamous, columnar, or cuboidal, or in layers of two or more cells deep as stratified, either squamous, columnar or cuboidal. In some tissues, a layer of columnar cells may appear to be stratified due to the placement of the nuclei; this sort of tissue is called pseudostratified. All glands are made up of epithelial cells. Functions of epithelial cells include secretion, selective absorption, transcellular transport, sensing. Epithelial layers contain no blood vessels, so they must receive nourishment via diffusion of substances from the underlying connective tissue, through the basement membrane.
Cell junctions are well employed in epithelial tissues. In general, epithelial tissues are classified by the number of their layers and by the shape and function of the cells; the three principal shapes associated with epithelial cells are—squamous and columnar. Squamous epithelium has cells; this is found as the lining of the mouth, the blood vessels and in the alveoli of the lungs. Cuboidal epithelium has cells whose height and width are the same. Columnar epithelium has cells taller. By layer, epithelium is classed as either simple epithelium, only one cell thick or stratified epithelium having two or more cells in thickness or multi-layered – as stratified squamous epithelium, stratified cuboidal epithelium, stratified columnar epithelium, both types of layering can be made up of any of the cell shapes. However, when taller simple columnar epithelial cells are viewed in cross section showing several nuclei appearing at different heights, they can be confused with stratified epithelia; this kind of epithelium is therefore described as pseudostratified columnar epithelium.
Transitional epithelium has cells that can change from squamous to cuboidal, depending on the amount of tension on the epithelium. Simple epithelium is a single layer of cells with every cell in direct contact with the basement membrane that separates it from the underlying connective tissue. In general, it is found where filtration occur; the thinness of the epithelial barrier facilitates these processes. In general, simple epithelial tissues are classified by the shape of their cells; the four major classes of simple epithelium are: simple squamous. Simple squamous. Simple cuboidal: these cells may have secretory, absorptive, or excretory functions. Examples include small collecting ducts of kidney and salivary gland. Simple columnar. Non-ciliated epithelium can possess microvilli; some tissues are referred to as simple glandular columnar epithelium. These secrete mucus and are found in stomach and rectum. Pseudostratified columnar epithelium; the ciliated type is called respiratory epithelium as it is exclusively confined to the larger respiratory airways of the nasal cavity and bronchi.
Stratified epithelium differs from simple epithelium. It is therefore found where body linings have to withstand mechanical or chemical insult such that layers can be abraded and lost without exposing subepithelial layers. Cells flatten as the layers become more apical, though in their most basal layers the cells can be squamous, cuboidal or columnar. Stratified epithelia can have the following specializations: The basic cell types are squamous and columnar classed by their shape. Cells of epithelial tissue are scutoid shaped packed and form a continuous sheet, they have no intercellular spaces. All epithelia is separated from underlying tissues by an extracellular fibrous basement membrane; the lining of the mouth, lung alveoli and kidney tubules are all made of epithelial tissue. The lining of the blood and lymphatic vessels are of a specialised form of epithelium called endothelium. Epithelium lines both the outside and the inside cavities and lumina of bodies; the outermost layer of human skin is composed of dead stratified squamous, keratinized epithelial cells.
Tissues that line the inside of the mouth, the esophagus, the vagina, part of the rectum are composed of nonkeratinized stratified squamous epithelium. Other surfaces that separate body cavities from the outside environment are lined by simple squamous, columnar, or pseudostratified epithelial cells. Other epithelial cells line the insides of the lungs, the gastrointestinal tract, the reproductive and urinary tracts, make up the exocrine and endocrine glands; the outer surface of the cornea is covered with fast-growing regenerated epithelial cells. A specialised form of epithelium – endothelium forms the inner lining of blood vessels and the heart, is known as vascular endotheliu
Otorhinolaryngology is a surgical subspecialty within medicine that deals with conditions of the ear and throat and related structures of the head and neck. Doctors who specialize in this area are called otorhinolaryngologists, otolaryngologists, ENT doctors, ENT surgeons, or head and neck surgeons. Patients seek treatment from an otorhinolaryngologist for diseases of the ear, throat, base of the skull, for the surgical management of cancers and benign tumors of the head and neck; the term is a combination of New Latin combining forms derived from four Ancient Greek words: οὖς ous, "ear", ῥίς rhis, "nose", λάρυγξ larynx, "larynx" and -λογία logia, "study". Otorhinolaryngologists are physicians who, in the United States, complete at least five years of surgical residency training; this is composed of six months of general surgical training and four and a half years in specialist surgery. In Canada and the United States, practitioners complete a five-year residency training after medical school.
Following residency training, some otolaryngologist-head & neck surgeons complete an advanced sub-specialty fellowship, where training can be one to two years in duration. In the United States and Canada, otorhinolaryngology is one of the most competitive specialties in medicine in which to obtain a residency position following medical school. In the United Kingdom entrance to otorhinolaryngology higher surgical training is competitive and involves a rigorous national selection process; the training programme consists of 6 years of higher surgical training after which trainees undertake fellowships in a sub-speciality prior to becoming a consultant. In this type of surgery, a surgeon harvests a muscle from the back or from the abdominal region for reconstruction of the skull or the cranial vault. Latissimus is another word for back in the medical field as well as rectus abdominis, your abdominal area; the muscle is sometimes useful for sealing off the central nervous system in ones body and allowing it to heal the complex wounds.
A study was down with five patients who underwent the free muscle transfer for a smile reconstruction. Two of the five patients prior to this surgery had failed their first free muscle transfer; the next two patients had vascular anomalies and one had a previous distal ligation of the facial vessels. In three of the cases, they used a submental vein, in all the cases they used a donor submental artery. “In all 5 the gracilis vascular pedicle comprised a muscular branch of the profunda femoris together with its venae comitantes, with the artery and vein ranging in size from 1.0 to 1.5 mm and 2.0 to 2.5 mm, respectively. The submental artery provided an excellent size match in all cases, ranging in size from 1.0 to 1.5 mm”. The first patient was a 45 year old woman who developed a dense flaccid right facial paralysis at the age of 33; the second patient was an 8 year old girl who had developed dense flaccid left facial paralysis after a laser treatment at four weeks for, “bilateral infantile segmental hemangiomas in the distribution of the mandibular division of the trigeminal nerve.
“. The third case was a 19 year old male who had developed a segmental right facial paralysis after a excision of a infantile parotid hemangioma at the age of 2; the fourth case was a 20 year old woman who had developed dense flaccid right facial paralysis after a biopsy of a pontomedullary junction tumor at the age of 2. Lastly, case five was a 19 year old woman. Bone defects are the most difficult reconstructions as it requires precise alignment. Bone transfer is used for the mandibular reconstruction, but it now allows surgeons to use it for the midface and the orbito maxillary. If for some reason the fibula is not available for transfer, another option the team may go is using the back rib free flap; this allows the transfer to give the bone volume for the patients. The earliest first bone transfer was done all the way back in 2000 BCE when the Peruvian priest implanted a metallic plate to reconstruct the contour defects of the religious trephination. In 1668, a man by the name of Jobs van Meekeren reported the use of dog bone grafts to reconstruct the calvarium in the soldier.
“…the ideal of the future: the insertion of a piece of living bone which will fill the gap and will continue to live without absorption.”. The radial forearm is the most dominant use of flap to be used to coverage up damages. Today, the anterolateral thigh flap is being used on patients for the head and the neck because it has an ideal match for the site and it is easy to harvest. If a surgeon chose to remove/harvest the tissue, safe places are the following. Microvascular reconstruction repair is a common operation, done on patients who see a Otorhinolaryngologist. Microvascular reconstruction repair is a surgical procedure that involves moving a composite piece of tissue from the patient's body and moves it to the head and or neck. Microvascular head and neck reconstruction is used to treat head and neck cancers, including those of the larynx and pharynx, oral cavity, salivary glands, calvarium, sinuses and skin; the tissue, most common moved during this procedure is from the arms, legs and can come from the skin, fat, or muscle.
When doing this procedure, the decision on, moved is determined on the reconstructive needs. T