Anthropology ortho /certified fixed orthodontic courses by Indian dental academy

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Anthropology ortho /certified fixed orthodontic courses by Indian dental academy

  1. 1. Anthropology and orthodontics www.indiandentalacademy.com
  2. 2. INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  3. 3. Contents      Introduction Anthropology-basics Classification of human groups Classification of mammals Dental features of primate apes humans   Anthropologic studies Anthropometry www.indiandentalacademy.com
  4. 4. Why anthropology?  Orthodontists are functioning anthropologists.  We measure the bones of the face skull and teeth and study the relationship of these structures.  Thus we should be interested in learning about the origins of human beings and evolutionary development of our anatomy. www.indiandentalacademy.com
  5. 5. What is anthropology?  The word anthropology derives from the Greek anthropos, meaning "man," and logos, meaning "study.“  Therefore, anthropology is the study of people. It is the study of humans in all places and at all times  It is a search, an investigation into what we are now, from where we came and how we got to be the way we are today. www.indiandentalacademy.com
  6. 6. Branches of anthropology  There are four main branches in the study of people:  Sociocultural anthropology Archaeology Linguistics Physical anthropology    Applied anthropology www.indiandentalacademy.com
  7. 7. www.indiandentalacademy.com
  8. 8.     Sociocultural anthropology -understand human social organization and culture. Archaeology - study material remains of human activity in order to reconstruct how different cultures adjust to varying situations through time and to explain stability and change. Anthropological linguist- examines the history, function, structure, and physiology of one of a people‘s most definitive characteristics- language. Applied anthropology - concerned with the application of anthropological ideas to current human problems. www.indiandentalacademy.com
  9. 9.  Physical anthropology- studies the biological nature and evolution of humankind.  Physical anthropology focuses on the place of man in nature.  It is a search into the ancestry, development, genetic, and other characteristics of the human species. www.indiandentalacademy.com
  10. 10.     Paleontology -The study of fossils. Paleoanthropology - the study of the fossils of modern humans and human ancestors. Anthropometry - systematic art of measuring and taking observations on man, his skeleton, his brain, or other organs, by the most reliable means and methods for scientific purposes. Primatology www.indiandentalacademy.com
  11. 11.        Forensic anthropology –It is a specialized area of physical anthropology. It is the identification of human remains for legal purposes. Teeth are especially important for several reasons. Dental records are common Contain many details Can endure more harsh conditions Dental anthropology - It is the study of teeth as recorded in casts of living mouths or as seen in the www.indiandentalacademy.com skulls of archaeological and fossil collections.
  12. 12. Some Characteristics of Humankind    Physical anthropologists study the characteristics that define us as human. THE DEPENDENCE ON CULTURE Culture is learned, nonrandom, systematic behavior and knowledge that is transmitted from person to person and from generation to generation. Culture changes through time and is a main contributor to human adaptability. www.indiandentalacademy.com
  13. 13.  THE HUMAN BRAIN AND ITS ABILITY TO SYMBOLIZE  One thing that makes the human brain a revolutionary instrument is the potential for speech.  A symbol is anything, whether it be visual, oral, tactile, or olfactory, that represents something else that is distant in time and space. www.indiandentalacademy.com
  14. 14.  BIPEDALISM  The ability to walk consistently on two legs, is a human trait.  Although human anatomy is adapted for bipedal locomotion, the neural control needed to walk bipedaly is learned behavior. www.indiandentalacademy.com
  15. 15. Myths about Humankind  THE MYTHS ABOUT HUMAN ANTIQUITY- humans developed last  THE MYTH OF TECHNOLOGY- some things are biologically impossible ,similarly others are technologically infeasible or improbable. It is not likely that we will solve the world's food problem through technology.  If technological "progress" is not accompanied by appropriate social change and ecological responsibility, people may drown in the poisons of their own industrial wastes. www.indiandentalacademy.com
  16. 16.  1. 2.  THE MYTH OF PLENTY- cannot continue to grow in number limited number of plants lack of space THE MYTH OF HUMAN SUPERIORITY- Anthropocentricity www.indiandentalacademy.com
  17. 17. THE CLASSIFICATION OF HUMAN GROUPS         Folk taxonomies These categories reflect specific cultural traditions and differ from society to society. Folk Taxonomies of Race Greeks and barbarians Caucasoids, Mongoloids, Negroids, whites , African Americans, Indians and Asians etc. Do they reflect reality? YES and NO Many forms of behavior are determined by them. But no anthropologically. www.indiandentalacademy.com
  18. 18. Scientific Classification  Carolus Linnaeus- skin color, geographical location, and personality traits.     H. sapiens Africanus negreus (black) H. sapiens Americanus rubescens (red) H. sapiens Asiaticus fucus (darkish) H. sapiens Europeus albescens (white). www.indiandentalacademy.com
  19. 19.            Various criteria used for classificationSkin colour Blood group Fossil record Geographic distribution New classification- J. Friedrich Blumenbach Caucasian Mongolian Ethiopian Malayan American. www.indiandentalacademy.com
  20. 20.  1. 2. 3. 4. 5. 6. 7. 8. 9. Garn's classification based on geographical distribution Amerindian (the aboriginal inhabitants of North and South America) Asiatic Australian Melanesian (peoples of New Guinea and neighboring islands) Micronesian (peoples of the islands of the northwest Pacific) Polynesian Indian (peoples of the subcontinent of India) African European. www.indiandentalacademy.com
  21. 21. Humans place in living order www.indiandentalacademy.com
  22. 22. CLASSIFICATION OF THE MAMMALS  Mammals belong to the class Mammalia, which is divided into two subclasses containing three groups that correspond to the three major kinds of mammals. www.indiandentalacademy.com
  23. 23.     Prototherian mammals (monotremes) Platypus and the Echidna Lay eggs also produce milk. They possess both reptilian and mammalian characteristics. www.indiandentalacademy.com
  24. 24.  Therian mammals  They produce live young.  Can be divided into two infraclasses.    Metatheria – marsupials (pouched mammals) Metatherian offspring are born while they are still fetuses. The fetus then crawls into the mother's, pouch or fold, where it continues to develop and mature. www.indiandentalacademy.com
  25. 25.   Eutheria- These are the placental mammals Their young remain inside the mother, nourished by the placenta, until they reach an advanced state of development. www.indiandentalacademy.com
  26. 26. The primate order      Every order has a characteristic feature like: Chiroptera ie. the bats have wings Carnivora have sharp teeth So, what is special about primates? Adaptability This is a response to arboreal habitat. www.indiandentalacademy.com
  27. 27. Features of primates     Shared retained featuresPresence of clavicle. Presence of radius and ulna Pentadactylism www.indiandentalacademy.com
  28. 28.      Shared derived features. Arboreal. Replacement of claws by nails. Ability to grasp- great toe and opposable thumb Sense of touch- tactile pads. www.indiandentalacademy.com
  29. 29.      Poor sense of smell Highly advanced vision-binocular, stereoscopic and coloured. More intelligent Social Produce single births. www.indiandentalacademy.com
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  31. 31. THE ORIGIN OF JAWS  A major event in Vertebrate evolution was the evolution of jaws.  New structures do not simply arise from nothing. They develop as modifications of preexisting structures.    The jawless vertebrates have skeletal elements, gill bars, that support the gill slits. In early fish, the first gill bars enlarged to become primitive jaw. www.indiandentalacademy.com
  32. 32.     Filter feeding restricted the jawless vertebrates to very small food particles. The evolution of jaws enabled them to prey on one another and to proliferate. Today these jawed vertebrates are represented by the sharks and bony fish. Land vertebrates eventually evolved from a population of freshwater bony fish. www.indiandentalacademy.com
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  34. 34. WHAT IS DENTAL ANTHROPOLOGY?  Dental Anthropology is the study of teeth in a perspective beyond clinical science.  That perspective includes the study of dental growth, theories on dental origin, primate dentition, and population variation.  The first comprehensive review of research on primate dentition was by Krogman in 1927. www.indiandentalacademy.com
  35. 35.  What do dental anthropologists do?  (1) Genetically controlled variables such as tooth crown size and morphology are used to trace phylogenetic relationships and historic trends in size, shape, and number of teeth.  (2) Crown wear and dental pathology give clues to dietary and cultural behavior.  (3) Gross and microscopic defect analyses reflect disease and dietary stress.  (4) Intentional cultural modifications of teeth reflect society and culture of people, both present and past. www.indiandentalacademy.com
  36. 36.  (5) Bite marks, distinctive patterns of occlusion and wear, missing and filled teeth, and radiographic landmarks make teeth pivotal in many cases of forensic identification.  (6) The comparative anatomy of teeth provides crucial evidence for systematics (classification) and determining biological relatedness. www.indiandentalacademy.com
  37. 37. Terminology in dental anthropology      Homodont Heterodont Monophyodont Diphyodont Polyphyodont www.indiandentalacademy.com
  38. 38. Crown Form      Bunodont (Gr = mound or hill) teeth have coneshaped tubercles or cones; they are low crowned with well-developed roots. example is the posterior teeth in the pig. Selenodont (Gr = the moon) teeth have cusps transformed into half-moon shapes. The concave side faces laterally in the upper jaw; lingually in the lower jaw. example is in the cheek teeth of sheep. www.indiandentalacademy.com
  39. 39.  Sectorial (L = secare to cut) teeth are blade-like teeth adapted to cutting the diet into pieces and swallowing them whole.  Lophodont (Gr = crest) molars are ridged teeth that have transverse ridges as in the tapir.  Bilophodont molars have two sets of transverse ridges.  Polylophodont molars have many ridges as seen in the elephant molar www.indiandentalacademy.com
  40. 40.  Brachydont (Gr = short) teeth have low crowns and welldeveloped roots. This condition is seen in humans  Hypsodont (Gr = height) teeth have long crowns and short roots as seen in the horse. In them, it is a functional adaptation for continuous wear sustained by chewing grass with a high abrasive silica content.  Tusks are incisors or canines of continuous growth that protrude beyond the lips when the mouth is closed. www.indiandentalacademy.com
  41. 41. Primate dentition          Mammals are characterised byHeterodont Diphyodont Primate teeth Four kind of teethIncisors Canines Premolars molars www.indiandentalacademy.com
  42. 42. www.indiandentalacademy.com
  43. 43.       The Incisors are broad, cutting type of tooth with a simple structure Described as spatulate The incisors are used to grasp food. Primates that eat fruit use their incisors to tear small pieces Smaller food objects, such as seeds and grass are usually passed directly back to the cheek teeth. Primates that specialize in this type of diet often have smaller incisors than do the fruit eaters. www.indiandentalacademy.com
  44. 44. Dental comb • • • • Prosimians are characterized by the development of a dental comb which is formed by lower incisors and canines that project forward horizontally The lower canine is included in the comb. The functions of the canine are taken over by the first premolar, which then become canine like in appearance. The animal uses comb for grooming the fur and for scraping gum and resins off the bark of trees. www.indiandentalacademy.com
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  46. 46.    Canine- pointed ,curved usually larger than other teeth Function- grasping, stabbing, ripping and tearing food Plays a role in defense. www.indiandentalacademy.com
  47. 47.    Premolars and molarsCalled as cheek teeth Function-chewing www.indiandentalacademy.com
  48. 48. DENTAL FORMULAS    The types and numbers of teeth are designated in dental formulas. Dental formula of the common ancestor of living placental mammals is 3.1.4.3 3.1.4.3 Primate evolution is characterized by a loss of teeth in the dental formula. www.indiandentalacademy.com
  49. 49. www.indiandentalacademy.com
  50. 50. APE DENTITION  The incisors of the great apes are quite broad and spatula-like  Upper incisors are implanted at an angle  Canine is large and projecting.  Spaces present in relation to canine ie primate spaces. www.indiandentalacademy.com
  51. 51.  When the animal closes its mouth, the canines interlock, each fitting into a space, or diastema in the opposite jaw.  In the upper jaw the diastema is in front of the canine, while in the lower jaw it is behind the canine.  Sexual dimorphism is present www.indiandentalacademy.com
  52. 52.    Arches are ‘U’ shaped. Sectorial premolar. Upper molar has 4 cusps and lower has 5 cusps called as Y-5 pattern www.indiandentalacademy.com
  53. 53. Hominid dentition  Size of teeth is decreased  Arch length is reduced  All teeth are at same level  Canine is not projecting  Premolar is not sectorial www.indiandentalacademy.com
  54. 54.  No diastema  Curved or parabolic arch  Incisors are narrower and are vertical  Not much of sexual dimorphism  Molars have more rounded cusps  Thick enamel-more crushing due to tough and hard diet www.indiandentalacademy.com
  55. 55. www.indiandentalacademy.com
  56. 56. The jaw     The human jaw is smaller and is shorter relative to the skull than is the ape jaw. This is because human food is processed, so no need to exert much pressure. Apes have a simian shelf which is absent in humans-a reinforcement or buttressing. A prominent chin is a feature of humans www.indiandentalacademy.com
  57. 57. www.indiandentalacademy.com
  58. 58.      Size of muscles of mastication is smaller. Apes have large jaw & teeth and a large masseter. Thus, have a robust zygomatic. A large temporalis is associated with flaring zygomatic arch. In humans this is slender and non flaring www.indiandentalacademy.com
  59. 59. ULTRASTRUCTURE OF TOOTH ENAMEL    Electron microscope studies have shown that the structure of tooth enamel is very regular, yet variations exist among species. There are three major patterns in the arrangement of prisms. Distinct differences in pattern exist between living hominids and living and fossil anthropoids. www.indiandentalacademy.com
  60. 60.        Pattern 1 prisms are found in insectivores and many bats. Pattern 2 prisms are found in most hoofed mammals, rodents, and marsupials. Prisms with pattern 3, often called the "keyhole" pattern, are commonly found in humans. All three enamel types can be found in the primate order. Pattern 3 is found in human enamel Pattern 2 is frequently found in the enamel of the rhesus monkey Pattern 1 in the lemurs. www.indiandentalacademy.com
  61. 61. DENTITION AND DIET  Primates have 3 dietary adaptations  Insectivores (insect eating) Frugivores(fruit eaters) Folivores(leaf eaters)   www.indiandentalacademy.com
  62. 62.  Special dental adaptations to special dietary requirements.  Molars of folivores are characterized by development of shearing crest  Insectivores molars have high pointed cusps to puncture the outer skeleton of insects.  Frugivores have molars with rounded cusps, few crests. www.indiandentalacademy.com
  63. 63. www.indiandentalacademy.com
  64. 64. Development of Hominoids       Comprise of apes and humans. First hominoids belong to early miocene era. Were called as ‘dental apes’ . Because dentition resembles that of modern apes. Fossils were discovered in 1930’s in africa. Important genus is ‘proconsul’. www.indiandentalacademy.com
  65. 65.      Features Vertically implanted incisors Slender canines Thin enamel on molars V shaped dental arch. www.indiandentalacademy.com
  66. 66.  There was migration of various species to Eurasia from Africa.  Jay Gould- said that the correct image for the visualization of evolution is that of a "copious branching bush" not that of a tree or ladder. www.indiandentalacademy.com
  67. 67. Miocene hominoids Dryomorphs–Africa, Europe eg: procunsul  Ramamorphs-eastern Europe, India ,Pakistan eg:shivapithecus  Pliomorphs   1. 2. 3. 4. 5. 6. Features of Ramamorphs Thick enamel on molars Low cusps Small canines Sexual dimoprhism Broad central incisors Orthognathous mandible Suggesting coarse diet www.indiandentalacademy.com
  68. 68. The skull of Sivapithecus. www.indiandentalacademy.com
  69. 69.     1. 2. 3. 4. Gigantopithacus – it was probably the largest ape that ever lived. It may have been as tall as 2.75m and may have weighed as much as 272 kg. Found in India ,Pakistan and China FeaturesSmall vertically implanted incisors Reduced canines worn flat by the chewing of coarse vegetation Lack of a diastema Crowding of the molars & premolars www.indiandentalacademy.com
  70. 70. www.indiandentalacademy.com
  71. 71. What did gigantopithecus have for dinner?       Paleoanthropology includes the reconstruction of information about the life of extinct forms. Eg:diet Recent advances in this field are the identification of phytoliths. These are plant specific minerals which are preserved during fossilisation. Pieces of silica; visible under SEM. Giganthopithecus diet include grasses like bamboo and fruits. www.indiandentalacademy.com
  72. 72. Australopithecus      Belong to family Hominidae The other genus is Homo Considered to be the earliest forms in the direct line leading to modern humans. Fossils found mostly in Africa They extinct 900,000 million years ago www.indiandentalacademy.com
  73. 73. www.indiandentalacademy.com
  74. 74. Australopithecine Dentition    Australopithecine dentition is very hominid-like. A greater degree of sexual dimorphism. Resembles apes in some features and simultaneously is different in many ways. www.indiandentalacademy.com
  75. 75.       Features Posterior teeth lie in a fairly straight line except for the third molar which is positioned inward. The upper incisors are relatively large and project forward. The canines project above the tooth row and are conical in shape, in contrast to the spatulate shape of the modern human canine. Arch size is intermediate b/w modern humans and apes They have shallow palate. www.indiandentalacademy.com
  76. 76. Kenya Ethiopia www.indiandentalacademy.com
  77. 77. Genus Homo      Classification Consist of 3 species Homo habilis ( handy human being) Homo erectus (erect human being) Homo sapiens (wise human being)-the only living member of the genus www.indiandentalacademy.com
  78. 78.              H.habilis Had large jaw and teeth Although molars and premolars decreased in size. Face was broad and flat H.erectus Were found in Java and china Shows reduction in jaw size More similar to Homo sapiens Arches diverge posteriorly More emphasis on incisors and canine Suggesting meat in diet Mandible lacks a chin Have a mandible torus www.indiandentalacademy.com
  79. 79. H sapiens   Found in Africa,Asia &Europe. Had dental caries and abscess in the jaw www.indiandentalacademy.com
  80. 80. Neandertals  Some believe they are the direct ancestors of modern humans belonging to species H.sapiens  Others believe them to be a separate species which was highly advanced in themselves Neandertals Modern humans www.indiandentalacademy.com
  81. 81. Features Enlarged facial sinus 2. Forward projecting face 3. Teeth project forward 4. Gap b/w last molar and ramus 5. Varying development of chin 6. Arthritis in TMJ-excess stress may be they were using teeth as tools 7. Incisors larger than modern humans 8. Molars and premolars are similar 9. Third molars were small sometimes 10. Showed high wear of teeth 1. www.indiandentalacademy.com
  82. 82. www.indiandentalacademy.com
  83. 83. Homo sapiens sapiens   Believed to be originally from Africa 130000 years ago to present date www.indiandentalacademy.com
  84. 84. Anthropologic studies  Blandin made the first attempt to describe facial growth (1836), finding that the pterygoid process backs up to the posterior aspect of the maxilla  T. Wingate Todd (1885-1938) an English physician and anatomist, made his great contributions by undertaking growth studies.  He established standards of normal growth and development at any period of childhood.  Using comparative anatomy and paleontology, Milo Hellman in 1927 demonstrated posterior growth of the face by surface additions to the maxillary tuberosities as the face swings out from beneath the cranium during growth. www.indiandentalacademy.com
  85. 85.  The 1920s saw a final burst of anthropologic studies  In 1922, Keith and Campion, by superimposing drawings of skulls of different ages, found that the face grows mostly forward, a bit upward, and considerably downward, whereas mandibular growth is up and back.  In 1924, Brash published The Growth of the Jaws and Palate, in which he stated that, when he injected a red dye (madder) into a pig’s skull, he found a delicate balance between deposition and resorption, depending on the functional demands made on it. www.indiandentalacademy.com
  86. 86.  1929, William K. Gregory (1876-1970) published From Fish to Man, describing changes traced through 10 successive stages of phylogenetic development of the human face.  Wilton M. Krogman contributed an anthropologic comparison between the growth patterns of the anthropoid and the human head. www.indiandentalacademy.com
  87. 87. Impacted canine in a prehistoric skull       Angle orthodontist 1996 Skull was found in 1984 in Vukovar,Croatia Specimen was of a female subject 35 to 45 years old Age of the specimen was 2700 to 2400BC In the maxilla left canine was impacted. Similar reports have been published by Iseri and Uzel &Sullivan and Hellman www.indiandentalacademy.com
  88. 88. www.indiandentalacademy.com
  89. 89.  Normally hypodontia and impacted teeth are considered evolutionary alterations  But impaction also occurred in prehistoric man  Therfore it implies that the abnormality in eruption of teeth is not caused by modified conditions brought about by modern civilization www.indiandentalacademy.com
  90. 90.  Takashii Kaji did a study on Japanese population to evaluate the presence of 3rd molar germs (AJO 2001) www.indiandentalacademy.com
  91. 91. www.indiandentalacademy.com
  92. 92. ANTHROPOLOGY AND MALOCCLUSION  In the 1930s, Weston Price travelled the world to document the nutritional habits and physical degeneration of people living on contemporary 'civilized' diets.  He found a significant increase in malocclusion in societies living on contemporary diets of prepared foods from domesticated crops.   Malocclusion arises from the lack of chewing stress with the modern processed diet. This disuse has reduced jaw growth and increased the incidence of occlusal variation. Numerous studies are documented by Corrucinni (1991) which confirm and extend the findings by Price www.indiandentalacademy.com
  93. 93.  COMPARISON IN AN ISOLATED RURAL COMMUNITY IN TRANSITION  A rural community in the Mammoth Cave region of central Kentucky was surveyed over a 25 year period as it made the transition to industry and mechanized farming.  The diet at the outset was home-produced foods (especially dried pork and fried cornbread) which provided consistently stressful chewing.  The transition was from this to a diet of purchased supermarket foods. This study was of special interest since diet changed but residence did not. www.indiandentalacademy.com
  94. 94.  Arch breadth was smaller and significantly more variable in younger individuals.  Bigonial breadth, measured from an area affected by the medial pterygoid and masseter muscle action was considerably smaller in the younger sample.  This study tends to suggest that there is a genetic predisposition or susceptibility to be diverted from programmed oral growth pathway by environmental factors.  Lack of function, therefore, led to a different phenotypic expression--one with more occlusal variation. www.indiandentalacademy.com
  95. 95.   OCCLUSAL VARIATION IN NORTHWEST INDIA Children of similar genetic heritage, but differing lifestyles have been studied side-by-side in India.  The communities studied included children born into a higher socioeconomic urban class and children from rural communities with its traditional dietary and residence habits.  Significant differences were found in the samples. The lowest socioeconomic group had less variation from ideal occlusal relations and had wider (broader) maxillary arches.  Lack of functional stimulation could explain occlusal changes that were observed: small jaws with normal-size teeth, resulting in crowding plus maxillary narrowing. www.indiandentalacademy.com
  96. 96. THE BEGG HYPOTHESIS AND THE EPIDEMIOLOGY OF MALOCCLUSION    Dr.P. R. Begg has studied both living and deceased Australian Aborigines and has used them as a model for Stone Age man. He wrote his doctoral thesis “the evolutionary reduction & degeneration of man’s jaws & teeth” in 1939. In 1954 he published paper entitled “Stone age man’s dentition  In 1954, Begg reasoned that the relatively low incidence of malocclusion in Stone Age Man is due to the reduction by more than half an inch in the total length of each of his dental arches.  This was caused by tooth attrition so that the smaller crowns could be more easily accommodated into the jaws  Begg also argued that retention of unworn occlusal-cusp was not a feature of non-modern societies www.indiandentalacademy.com
  97. 97.  According to him the function of cusps is transitory: they establish mandibular and condylar position.  A flat plane occlusion allows protrusive and lateral movments without cuspal interferences and is therefore less susceptible to TMJ disturbances www.indiandentalacademy.com
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  99. 99. THE ETIOLOGY OF THIRD MOLAR IMPACTIONS  Humans evolved in a high dental attrition environment  Combined with physiological mesial drift, humans would effectively achieve an increasing retromolar space as they age.  The delayed eruption of the third molar seems to be an evolutionary adaptation to interproximal wear of the cheek teeth.  The recent secular trend in increasing impactions does not seem to be a genetic change in humans. It is, instead, merely a response to a soft food diet. Without interproximal wear of the teeth, there simply is not enough room for third molar www.indiandentalacademy.com
  100. 100. DENTAL CARIES  The clearest single factor in caries epidemiology is sugar.  This is demonstrated by the decrease in the rate of caries during sugar rationing in Japan, Norway, and the Island of Jersey during World War II.  Dental caries also occurs amongst the great apes. particularly the chimpanzees.  Of the great apes, chimpanzees have a diet most similar to our own; in the wild their diet includes a lot of fruit in addition to leaves, flowers, nuts, termites.  Gorillas, which are primarily leaf eaters, have a much lower rate of dental caries. The orangutan in intermediate between chimpanzees and gorillas.  In the most ancient hominids, the incidence of caries is less than 1%. www.indiandentalacademy.com
  101. 101. TOOTH AGENESIS  Agenesis of one or more teeth is one of the most common of human developmental anomalies  Agenesis and polygenesis has been reported for the apes and Old World monkeys. The frequency of agenesis amongst the hominoids is highest in humans and is found most frequently in the molar region. www.indiandentalacademy.com
  102. 102. ANTHROPOMETRICS IN ORTHODONTICS   The quantification of man is a function of modern biology. Anthropometry+ craniometry =cephalometry www.indiandentalacademy.com
  103. 103. ANTHROPOMETRIC AND CEPHALOMETRIC PROCEDURES       INSTRUMENTS Measuring tape- Flexible steel tape graduated in millimeters. Anthropometer- Hollow sliding rods, graduated in millimeters, used for taking various measurements including vertical and transverse body measurements. Sliding Calipers -This is employed to measure head and face diameters. Sliding Compass- To measure smaller diameters of the head. Head Spanner- To determine height of the head. www.indiandentalacademy.com
  104. 104. Various measurements  Head Length- The maximum glabella occipital diameter  Is obtained with the spreading calipers.  This dimension is taken from the most prominent point on the glabella to a point on the vertical line bisecting the occiput www.indiandentalacademy.com
  105. 105.  Head breadth - is the greatest transverse diameter measured in the horizontal plane above the supramastoids and the zygomatic crests.  This measurement is taken with the spreading calipers. www.indiandentalacademy.com
  106. 106.  Head circumference - is taken with a steel tape through the most prominent part of the occiput and just above the supra-orbital ridges.  Head Height - www.indiandentalacademy.com
  107. 107.      Facial Height- (Sliding calipers). Total facial height -nasion (N) to Gnathion (Gn) Upper facial height -nasion (N) to Prosthion (Pr) Dental height -from prosthion to infradentale. Lower facial height - infradentale to gnathion (Gn). www.indiandentalacademy.com
  108. 108.     Facial Width – Bizygomatic -zygion to zygion Bigonial - gonion to gonion. Maximum Mouth Breadth - The maximum breadth of the mouth when the face is in a relaxed condition (from cheilion to cheilion). www.indiandentalacademy.com
  109. 109. CRANIOFACIAL INDEXES  Definition- An index in anthropometry is the ratio of a smaller to a larger measurement taken as equivalent to 100 and expressed in terms of a percentage.  To determine the proportional relation of the breadth (width) of the head to its length (depth), it is equated to the value of 100, and the breadth then is expressed as a ratio of 100. www.indiandentalacademy.com
  110. 110.     Cephalic index is grouped under three categories defined by Martin as follows: Dolichocephaly Mesocephaly Brachycephaly 75.9 76.0 - 80.9 81.0  The cephalic index at the 4th month of intrauterine life is very high, since until this time width grows faster than length.  After this period the ratio falls rapidly, The cephalic index decreases before birth and the head is relatively dolichocephalic (anteroposteriorly longheaded). www.indiandentalacademy.com
  111. 111.  The facial index- it is the ratio of the length of the face to the width  The index of the upper face to the lower face may be obtained in the same manner.  The index increases slightly annually as the child grows; the face becomes relatively broader www.indiandentalacademy.com
  112. 112.  The palatal index -is the ratio of the breadth to the length  Breadth of the palate is taken from the mesial pits of the right and the left first molars.  Length is taken from the inner alveolar point between the maxillary central incisors to the posterior nasal spine as seen on the roentgenogram or dry skull. www.indiandentalacademy.com
  113. 113. Conclusion  Anthropology not only provides an insight into the human evolution but also gives us a better understanding of the development of malocclusion and the probable etiology behind it. www.indiandentalacademy.com
  114. 114. www.indiandentalacademy.com Leader in continuing dental education www.indiandentalacademy.com

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