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Anthropology
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Table Of Contents
IntroductionWhat Is Anthropology.Importance and the purpose of Life Studies(Anthropology)Classification of Anthropology
Physical AnthropologyCultural AnthropologyLinguistic AnthropologyArcheology
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Evolution The Various Eras of Evolution.
Theories of Evolution Homonidae Evolution Process Evolution of Human Face Evolution of the jaw and joints Evolution of teeth and its attachment apparatus
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Conclusion: Future :Where is it all leading us leading us
Concept of Attritional Occlusion Carabelli Trait
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Anthropology is the broad scientific study of humankind’s differences, cultural and biological, against the background of the nature all humans
share around the world and throughout time.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
hat Is the Importance and the purpose of Life Studies
(Anthropology)
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
The fundamental questions addressed by anthropologists are
"What does it mean to be human?" and
"How did we become human?"
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Included in anthropology are four main subdivisions:
Physical Anthropology
Cultural Anthropology
Archaeology
Linguistic Anthropology
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Physical Anthropology
Involves mechanisms of biological evolution, genetic inheritance, human adaptability and variation,
primatology, and the fossil record of human evolution.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Cultural AnthropologyBranch of Anthropology that deals with Culture,,
subsistence and other economic patterns, kinship, sex and marriage, socialization, social control, political
organization, class, ethnicity, gender, religion, and cultural changes .
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Linguistic Anthropology
The human communication process focusing on the importance of socio-cultural influences; nonverbal
communication; and the structure, function, and history of languages and dialects
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Archaeology
Prehistory and early history of cultures around the world; major trends in cultural evolution; and techniques for finding, excavating, dating, and analyzing material
remains of past societies.
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Prokaryotes&
Eukaryotes
Ocean Species Rapidly Diversify
Primitive Fishes, Corals,
molluscs
MostInvertebrates
& FewVertebrates
FISHES CRABS
AND AMPHIBIANS
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Reptiles, giant Insects
AppearInsects,
Reptiles spread,Trilobites die
off
Dinosaurs,Insects thrive.Birds appear
Mammals,Spiders flourish
Primates appear
Humans Thrive ManySpecies die
Off.
Dinosaurs die out Birds
thrive
Dinosaurs,Mammals
Marine reptilesappear
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When an organism
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Darwin and HMS BeagleIn 1835 the British naval ship Beagle reached the Galapagos Islands off South America's west coast. There, a young biologist named Charles Darwin collected samples of the plants and animals and took notes of his observations. Darwin was awed by the enormous variety of life inhabiting these islands and concluded that life must be ever changing, or evolving, to create such diversity. Upon returning to England, Darwin spent 20 years studying his Galapagos Islands samples and notes.
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He observed variations among local populations of a species and saw that local conditions acted to select
the traits that enabled one population of the species to survive better than another. He decided that it was in this way, through the process of natural selection by the environment, that evolution occurred. In 1859
Darwin published his conclusions in the book On the Origin of Species by Means of Natural Selection.
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.Albino fish are easy targets
A large number of trout and salmon fish born in artificial breeding farms are white (albino), yet it is nearly impossible
to find an albino trout or salmon fish in the wild. Normal rainbow trout are striped and spotted with various shades of brown and yellow. To a heron or kingfisher,these colours
look much like the bottom of a stream, making it difficult for the bird to spotted fish. Albino fish below the water , which
are white, are easy for the waterfowl to spot and rarely survive long enough to produce offspring.
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Pollution and Natural SelectionIn the 1800’s pollution in the English cities enabled natural selection to operate on a group of peppered
moths .When industrialization began most peppered moths were pale with black splodges which gave them the appearance of lichen on tree barks ,hiding them
from the predators .Only a few moths were dark. Soon, soot from the factories turned the city trees and
buildings dark brown these pale moths became visible to the birds .Within few years ,dark moth became common in cities, and speckled form prevailed in
cleaner countryside.
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..Theory of Orthogenesis
(Development in Straight Line)
Haldane and Julian Huxley say that evolution proceeds in any particular direction only ,not because of any
advantage gained by the race ,or because of any direct molding effect of surrounding, but because of some
inner urge ,some necessity for the hereditary constitution to change in just that particular way.
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• "The affinities of all the beings of the same class have sometimes been represented by a great tree... As buds give rise by growth to fresh buds, and these if vigorous, branch out and overtop on all sides many a feebler branch, so by generation I believe it has been with the great Tree of Life, which fills with its dead and broken branches the crust of the earth, and covers the surface with its ever branching and beautiful ramifications."
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The first humans survived by scavenging, gathering, and huntingEarly scavengers
and hunters may have depleted populations of some of their
prey and some competing carnivores
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
The human branch of the primate tree is only a few million years old
Apes and hominids probably diverged from a common ape-like ancestor
This occurred between 5 and 7 million years ago
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
The earliest hominids were a diverse group
Various species of Australopithecus date from about 4 to 1 million years ago
Our own species, Homo sapiens, is the only hominid that has not become extinct
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Upright posture evolved well before our enlarged brain
Australopithecines had relatively small brains This indicates that bipedalism preceded the
evolution of the enlarged brainBipedalism is a basic human trait.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Homo and the evolution of larger brains Homo habilis, an early African hominid, coexisted with
some of the australopithecines.They had larger brains and made simple tools
They may also have given rise to the more advanced Homo erectus
Homo erectus spread out of Africa over most of the Old World. They eventually gave rise to Homo sapiens
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
When and where did modern humans arise?
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
One of the regional descendents of H. erectus was the stocky and muscular Neanderthals
They lived throughout Europe from about 200,000 to 40,000 years ago
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Some paleoanthropologists think that modern humans arose from the regionally diverse populations of
archaic Homo sapiens in Africa, Europe, and Asia.
Others believe that modern Homo sapiens came from a second group in Africa. This group arose around
100,00 years ago. They migrated out of AfricaThey replaced regional populations of archaic
peoples
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Major milestones in the evolution of Homo sapiens are the evolution of an erect stance, a large brain a prolonged period of parental care. We have not
changed much biologically since modern humans first appeared.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Our culture —the accumulated knowledge, customs, beliefs, arts, and other products—has evolved enormously
There have been three main stages in cultural change
BUT
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Scavenging-gathering-hunting was the first major stage of culture
The first humans survived by scavenging, gathering,
and hunting
Early scavengers and hunters may have depleted
populations of some of their
prey and some competing carnivores.
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Agriculture was a second major stage of culture
Agriculture arose about 10,000-15,000 years ago.
People settled down and began growing food and domesticating animals
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The machine age is the third major stage of culture
The Industrial Revolution began in the 1700sIndustrialization brought a change from hand production to energy-intensive, large-scale machine production
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Anthropometry is a division of anthropology, it has been described by Hrdlicka as the systemized art of
measuring and taking observations on man ,his skeleton, his brain or other organs, by the most reliable means and
methods and for scientific purposes.Measurement of the form and relationship of the
components of the head , particularly the jaws and especially the teeth are sufficient to differentiate
between the ape and man .
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Craniometry is a subdivision of anthropometry,has been an important study in orthodontic research, because
orthodontics is concerned primarily with the correction of morphologic deviations from the accepted norms in
dentofacial area. Measurements of the extent of these deviations entails some knowledge of physical
anthropology and the ability to recognize and use the anthropologic landmarks.
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Lucy, Australopithecus
aferensis, lived about 3.2 million years ago in what is
now Hadar, Ethiopia.Lucy's limbs reveal upright
walking to be a very old habit. Lucy came to life in late 1974,
when anthropologist Don Johanson was fresh out of
graduate school and working in the badlands at Hadar.
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A mandible and partial postcranial skeleton of a single individual was found in 1994. Analysis and publication on this find has yet to be made. Once completed, this should provide significant insight
into the positional repertoire of Ardipithecus ramidus, dispelling all doubt as to whether or not this truly was a bipedal hominid.
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Though not recognized as such for 30 years, the first Australopithecus anamensis discovery
occurred in the Kanapoi region of East Lake Turkana in 1965 by a Harvard University
expedition.
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The species A. Afarensis is one of the better known australopithecines, with regards to the number of
samples attributed to the species. The species was named by D. Johanson and T. White in 1978.
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Very little is known about Australopithecus aethiopicus, since so few specimens have been attributed to the species, but the features that are known provide important insights into the
possible evolutionary history between the robust and gracile australopithecines.
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The africanus material is seen as different things by different people. Some see this as a regional
variation or subspecies of afarensis, some see it as two completely different species, and some
consider the africanus material to be the descendants of afarensis.
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The discovery of the specimen OH 5 ("Zinj") of this species in 1959, by
Mary Leakey, was a watershed in the history of paleoanthropology.
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In January 1964, the team announced the new species Homo habilis. The name was
suggested by Raymond Dart, and means "handy man," in reference to this hominids
supposed tool making prowess.
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As a general rule of thumb, one can consider most attributed ergaster specimens to be early
erectus geographically confined to Africa
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Homo ergaster is one of the more problematic of somewhat accepted species designations currently tossed around in anthropological literature. Each individual researcher that sees ergaster as a valid taxon ( in biology, a term used to denote any group or rank in the classification of organisms, e.g., class, order, family sees different specimens as belonging or not belonging to the taxon.)
Many researchers deny any validity to the species at all. On the whole though, most researchers see too little difference between ergaster and erectus to form the basis of a species of the former, separated from the latter.
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One of the most important erectus specimen is the Nariokotome Boy, KNM-WT 15000. This specimen was discovered by a team
led by R. Leakey and A. Walker at Nariokotome, Kenya, in 1984. This is the most complete early human skeleton ever
discovered.
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The beginning of paleoanthropology as a scientific discipline began on an August day in 1856. On that
day the specimen that was to become known as Neanderthal 1 was discovered in the Feldhofer
grotto, in the Neander Valley, Germany.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Broad, vertical, flattened, enveloped by an enormous balloon-shaped cranium with a bulbous forehead
overhanging tiny, retrusive jaws, a small mouth, a chin, and the curious vestige of a narrow fleshy snout—an owl-
eyed face showing changing expressions.
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If u have not already guessed it this is the human face for you
Although somehow beautiful to our eyes, this has to be an "odd" design by ordinary
mammalian standards
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
There have been many theories over the years; but regrettably, we may never know for sure what the primary
factors were that initiated the long evolutionary chain of interrelated adaptations throughout the whole body that
relate to the many design features of our facial heritage. We can, however, partially explain the anatomic,
developmental, and functional meaning of each factor in this series of mutually dependent changes.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Concept 1Man is one of the few truly bipedal mammals. Our upright posture
involves a great many anatomic and functional adaptations throughout every part of the body, and no one of these would work without all the others. We have "feet," and the human foot stands
by itself, as it were, as a unique anatomic feature of man.
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The designs of the toes, foot bones, arch of the foot, ankle, leg bones, pelvis, and vertebral column all
interrelate in the anatomic composite that provides upright body stance
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The head is in a balanced positionon an upright spine. The arms and
hands have become freed. The manipulation of food and other
objects and defense, offense, and so forth, utilize primarily the
hands, rather than the shortened jaws.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
The enormous enlargement and the resultant configuration of the brain have caused a "flexure"
(bending) of the human cranial base. This relates to two key features.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
First, the spinal cord is aligned vertically, a change that permits upright, bipedal body
stance with free arms and hands.
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Second, the orbits have undergone a rotation in conjunction with frontal lobe expansion. This aligns them so that they point in the forward
direction of upright body movement. The body has become vertical, but the neutral visual axis is thereby still horizontal, as in other mammals.
(Note: The muzzle of a typical animal points obliquely downward in the "neutral" position, not straight forward. This positions the orbital axis
approximately parallel with the ground and toward the direction of body movement.)
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The cranial base of the typical mammal is flat, in contrast to the human cranium, and the spinal cord passes into a
horizontally directed vertebral column.
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The head is in a balanced position on an upright spine. The arms and hands have become freed. The
manipulation of food and other objects and defense, offense, and so forth, utilize primarily the hands,
rather than the shortened jaws.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
The large size of the human brain also relates to a rotation of the orbits toward the midline . This results in a binocular
arrangement of the orbits, a feature that complements finger-controlled manipulation of food, tools, weapons, and so forth. The absence of a long, protrusive muzzle does not
block the close-up vision of hand-held objects. The human mind directs the free hands that can work with three-dimensional perspective in an upright stance on feet.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Complete orbital rotation into a forward-pointing direction, however, has also caused a marked reduction in the
interorbital part of the face. This is significant, because the area involved is the root of the nasal region, and the result of man's close-set eyes is a narrow & necessarily quite short nose. The olfactory sense in Homo has become a much less
dominant factor in environmental awareness and is far exceeded by many other mammalian groups
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Reduction in nasal protrusion is accompanied by a more or less equivalent reduction of the jaw (nasal reduction
apparently paced this evolutionary process). The whole face has necessarily become reduced in horizontal length as a
result. However, the face has also been rotated into a nearly vertical alignment in relationship to the massive
enlargement of the brain and the flexure of the cranial base.
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The whole face has necessarily become reduced in horizontal length
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
The nasal mucosa is ordinarily an active site involved in temperature regulation in most mammals. Vasoconstriction
and vasodilation of the vessels in the massive spread of mucosa covering the turbinates control the amount of heat
retention or loss. Because of marked nasal reduction in man, however, this function has been largely taken over by the relatively hairless and sweat gland—loaded integument.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Control of blood flow in the dermis, combined with sweat gland activity, provides the equivalent for nasal
thermoregulation. This is possible in man (and in a very few other species, such as the pig) because of a near-naked
skin.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
In thick-furred animals, thermoregulation is carried out by regulating heat transfers in the nasal mucosa, panting to release excess heat, limited perspiration in hairless areas (such as the pads of the paws), and a Huffing of the fur to increase dead air insulation.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
All mammalian forms have reinforcement "pillars" built into the architectonic design of the craniofacial complex. These pillars are parts of bones that provide a buttress for structural support and biomechanical stress resistance that
balances the physical properties of the skull against the composite of forces acting within it, including growth
itself, just as the framework of a building provides generalized support and stability
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Although customarily described with reference to tooth positions, the nature of support goes well beyond just
accommodation to masticatory forces. In the human face, one of these is the "key ridge," which is a vertical column of thickened maxillary bone approximately centered above
the functionally important area around the upper first molar.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Mechanical support then continues from this ridge into and through the lateral orbital rim on to the
supraorbital-reinforced frontal bone.
The second maxillary molar is reinforced by a vertical sheet of bone, the posterolateral orbital wall, which
extends directly above this tooth
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
The human face is exceptionally wide because the brain and cranial floor are wide. However, the face has been almost engulfed by the massive brain behind and above it. Note the wondrously, incredibly colossal size of the human cranium, in comparison with that of the typical
mammal.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
The expanded frontal lobes of the human brain lie above the eyes and almost the whole remainder of the face,
rather than behind, and a forehead has thus been added. This also relates to the rotation of the orbits into vertical, forward-facing positions as well as to the rotation of the
face as a whole into a downward-backward position.
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The expansion of the various parts of the cerebral hemispheres has created sizable pockets in the cranial
floor). Each of these endocranial fossae relates to specific lobes of the brain on the inside of the cranial floor and to specific parts of the face, pharynx, and so forth, on the outside. We can utilize our knowledge of
these brain-cranial floor-facial relationships to advantage in analyzing the structure of the face and
the basis for its many variations in form and pattern.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
The first documented vertebrates were called Agnatha. They are minute fish like animals without jaws. The evolution of vertebrates started with the
expansion of mouth cavity and disappearance of one or two anterior gill arches. The early jawed
vertebrates were called placodermi.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
The vertebrate with jaws are divided into five classes: Fishes ,amphibians, reptiles, birds and mammals. Until
the evolution of mammals, the vertebrate mandible consisted of several dermal bones which articulate with
the skull at a joint formed by two enchondral bones derived form the cartilage bars of the first brachial arch.
In mammal only one dermal bone ( the dentary) is retained as the mandible.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
A variety of evidence supports this concept. The gradual appearance of such a bony process on the mandible can be seen in a fossil series of related reptilian skulls. A similar
sequence occurs in the embryonic development of the temporomandibular joint in man and all other mammals studied. The articular tissue of this joint originates in a
very different manner from that seen in the usual synovial joint.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
The bony homologues of the jaw joints and related structures in reptiles and mammals are shown in table Within the class of mammals , parallel evolution in the
temporomandibular joint , producing marked differences in form and function as the jaws became specialized .
shearing (lion), grinding (cow), grasping (porpoise),and biting and chewing (man).
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Among the modern vertebrates only the Class Aves (birds) lack teeth. Two types of conditions prevail
among the tooth bearing vertebrates. The so called lower vertebrates (bony and cartilaginous fishes,
amphibia is, and reptiles generally are characterized by polyphyodontia, whereby teeth are continually
being replaced by successors. Mammals, on the other hand, may be either monophyodont, or diphyodont
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
In the former condition there is but one set of teeth which has no successors, in the latter there are two sets, one being the primary or deciduous dentition, the other
the secondary or permanent teeth. Certain insectivora are monophyodont, but most mammals are diphyodont.
The lower vertebrates are homodont, a condition typified by teeth which are alike, while mammals are
heterodont in that there are various kinds of teeth in the same dentition
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
The morphology of the teeth quite accurately reflects the functions they subserve within the species.
Among mammals these functions include: piercing. tearing, trapping, digging, combing, scraping, grinding, crushing, and shearing: These varying properties may aid the animal in fighting, obtaining food, and securing
a mate.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Since the teeth are placed in the most anterior part of the animal, well in front of the brain and the eyes, they, along with the olfactory organ make the first contact with the environment and are hence of primary importance for survival. Few
animals can sustain in the wild state if their teeth were much less than typical for the species.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Since there is a high correlation between tooth form and its function, it is possible for the paleontologist in many cases to describe quite accurately much of the life habits
of a prehistoric animal from a study of the fossil teeth alone.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
EvolutionAbout 250,000,000 years ago the first, or stem, reptiles evolvcd. They are called Cotylosaurs and they gave rise to a group of reptiles, the Synapsids, which dominated
life on earth for perhaps fifty or sixty million years. Two successive radiations took place among the Synapsids, one originating from a group known as the Pelycosaurs
and giving rise to a reptilian series called Sphenacodotiia.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
The latter, in turn, gave rise to the Therapsids, which flourished in Permian times and which included among
its various types flesh-eating reptiles known as Theriodonts.
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250,000,000 years ago the first, or stem, reptiles evolvcd. They Were called Cotylosaurs
Synapsids, which dominated life on earth for perhaps fifty or sixty million years
Pelycosaurs
And giving rise to a reptilian series called Sphenacodotiia.
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Radiation from the Theriodontia produced the Cynodonts, probably the first mammal-like reptiles. It is from the Cynodonts
that many types of mammals originated.
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gave rise to the Therapsids, which flourished in Permian times and which included among its various types flesh-
eating reptiles known as Theriodonts
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
EVOLUTION OF HUMAN MOLAR TEETH :Six main theories have been advanced to explain the evolution of the complicated multiple-cusped teeth of mammals, including man, from the simpler teeth of reptiles.1) Concrescence theory2) Cingulum theory 3) Kinetogenetic theoiy4) Tritubercular theory
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
5) Multitubercular theory6) Dimer's theory
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Concrescence theory :
Ameghino, Rose and Kekenthal were all with the opinion mammalian teeth were developed from simpler cones (Haplodont teeth) and the modern multiple -cusped teeth are formed by the fusion of 2 or more of these simple haplodont teeth into a compound tooth.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Cingulum theory :In this theory- mammalian teeth are derived from haplodont teeth.
"Marrett Tims" considered that basal ridge or cingulum, which surrounds a tooth at its neck, develops into a fresh cusp or cusps- which explains to a great extent the evolution of complex tooth
form."Osborn" says that, by the elevation of cingulum ino prominence and its disappearance in others - regarded as the mother of cusps."Mummery" states that it would certainly appear that accessory
cusps arises from the cingulum..
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Kinetogenetic theory :Ryder, who upholds this theory, again regards the earliest mammalian teeth as haplodont in origin.
He mentioned that the movements of TMJ. govern the form of the tooth. The simple cones become flattened by mutual pressure, and the ridge and hollows are produced
by the movements of the lower jaw in mastication.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
There is definite relationship between the form and movement of the condyle and the forms of teeth.
Many authorities admit, this connection between tooth form and movement of condyle but consider that Ryder's
view of it is the exact reverse of the true sequellae . They mention and that the shade and movement of the joint are modified and formed by the diet and by the
shape of the teeth.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
S. Glasstone removed the tooth germs from the embryos of rats and rabbits and grew them in vitro. As there is no
TMJ movement here to effect the forms of teeth. Therefore, the factors responsible for the morphology of
the tooth are intrinsic to the tooth germ and Glasstone found that rats and rabbits tended to develop extra cusps
when grown in vitro.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Tritubercular theory or Cope - Osborn Theory
This theory, 1st advanced by Cope and later elaborated by Osborn, sometimes called the "Cope-Osborn theory". He
considered that multicuspid mammalian teeth are developed from a simple haplodont or reptilian form of tooth by the addition of extra cusps.triconodont teeth.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
In this theory - original haplodont cone is known as the PROTOCONE when this original cone has two small
accessory cones on .its mesial and distal surface and it is known as PROTODONT TOOTH.
These small accessory cones develop in size until the tooth appears to consists of 3 cones in a straight line and
this is known as TRICONODONT TEETH.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
The anterior cusp - paracone - upper teeth- paraconid - lower teeth
The large middle cusp - protocone - upper teeth - protoconoid - lower teeth
The posterior cusp - metacone - upper teeth
- metaconid - lower teeth
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Owing to shortening of jaws, these triconodont teeth are said to be compressed anteroposteriorly until the cusps form a
triangle instead of straight line.
In upper teeth Protocone is squeezed to the lingual side to form the large anterior lingual cusps while the paracone and
the metacone are squeezed to buccal side.In lower teeth
Protoconid is forced to the buccal side to form anterior buccal cusp and paraconid and metaconid
are forced to lingual side,
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
In certain teeth, owing to the diet, some cusps of the TRIGON are lost and replaced by cusps from the
additional part known as the TALON. Which it crushing or masticating element of the tooth and developed from
the enlargement of cingulum.In human upper molar, which has 4 cusps, all 3 cusps is of
trigon and cingulum has developed into a 4th cusp. (Hypocone) behind protocone
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
In lower molar, which has 5 cusps, the paraconid is lost and the metaconid slips forward to take paraconid
position.Only 2 cusps of trigon remain - protoconid and metaconid and additional 3 cusps, hypoconoid, entaconid and hypoconolid belong to the talon.
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Human premolars are said to derive - lingual cusps - by development of cingulum.
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Leche, Taeker, Rose studying tooth germs from the embryos of marsupials, ungulates and man, agreed
that the 1st cusp to be. developed is the PARACONE.
Woodward, says that anterior BUCCAL CUSP is the 1st to develop in both upper and lower jaws.
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Multitubercular (or polybuny) theory :- Forsyth Major, refutes the statement that the 1st
mammalian tooth can be traced back to a simple haplodont or a tritubercular tooth. He considers that the 1st
molariform tooth was a multitubercular tooth and the tritubercular tooth is derived from an earlier form which
was multitubercular.
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Forshyth Major considers that human molars and modern mammalian molar (whether tritubercular or not) are derived from multitubercular teeth by reduction in
the number or tubercle.
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Dimer theory :
It is the result of investigation by Prof. Bolk of Amsterdam and advances the view that there is one origin for all mammalian teeth, whether, incisors,
canine, premolars or molars.
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
He agrees with the concrescence, kinetogenetic andcingulum theories and differs from the tritubercular theory,
which explains evolution of premolar and the talon of molar in one way and the trigon of molar in another.
Bolk's views are expressed under 4 headings :
Hypothesis of triconodonty The hypothesis of dimery
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Hypothesis of concentration Hypothesis of equivalence
Hypothesis of triconodonty –
He affirms that, mammalian teeth are evolved from a triconodont teeth, not a haplodont with one large and 2
small cusps in a straight line antero posteriorly..
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
THE HYPOTHESIS OF DIMERY :- Every mammalian tooth is homologous with two
reptilian tooth.- The labial and incisal portion of the incisors, canines
and buccal cusps of premolars and molars - one series of reptilian teeth.
- Cingulum of incisors, canine and lingual cusps of premolars and molars represent a second or later series of
reptilian teeth.-
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Each longitudinal half of human tooth Monomere the buccal half. Protomere and The lingual half Deuteromere .
These together form a dimerous tooth.- Minute tuberculum impar or tubercle of carabelli
found occasionally on lingual aspect of deuteromere of the upper 1st molar.
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Hypothesis of equivalence :Elements of mammalian set of teeth are all
morphologically alike. - The terms monocuspidate and multicuspidate possess only a descriptive anatomical value and do not indicate
any morphogenetic differences.- The tooth germ 'of every tooth possesses the
potentiality of developing all the cusps found in the most complicated tooth of set.
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Dr. Begg noticed the teeth of Australian aboriginals who died before white man came to Australia. These
exhibited not only extensive occlusal and interproximal wear, but also exhibited an almost total lack of caries,
periodontal disease and tooth crowding.
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
He recognized along with several others that such an example of stone age man’s attritional
occlusion represented the true occlusion for man and not a pathological condition. Civilized man’s unworn dentition with all its related
problems is abnormal
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Attrition causes continual changes in the shapes and size of teeth, mesial migration and continual
eruption in the presence of attritional results in their moving occluso mesially in the jaws.
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Modern man and concieved normal
occlusion
Normal treatment goal using Begg
Technique
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
The Carabelli Trait
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
In 1842, Carabelli gave his name to a frequently occurring tubercle on the lingual aspect of mesio lingual cusp (protocone)
of the maxillary first permanent molar. Since that time, there has developed a vast literature relative to its classification, frequency,
comparative anatomy, evolutionary history, etiology, and morpho-genesis. The most recent comprehensive summary of the subject (Korenhof, I960) clearly points out the lack of agreement
among investigators in any aspect of the problem.
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
The wide range of hypothesis and conjecture concerning the Carabelli trait might properly be attributed to the paucity of research concerning its embryology. At least three theories
have been advanced explaining the occurrence of the Carabelli trait. One holds that the Carabelli cusp has its
origin in the cingulum, and numbers among its proponents Gregory (1922), Cope (1888), Osborn (1907), Adioff (1908),
and Korenhoff (1960).
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
A second school, led by Rose (1892) and Baufjeiff (1896),.claims that the Carabelli cusp arose as a seperate tooth germ. •The third group bases its rea soning upon the "Dimer" theory of Bolk (1914) in calling upon a "trito-mere" for the
origin of the cusp. -Other explanations are brought forth by in dividual authors such as Weidenreich (1937), who considered
the Carabelli cusp as an accidental variation" of the protocone,
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
It is indeed a most remarkable phenomenon in the history of biological researchthat so little is known
about a structure of which so much has been written.As Jorgensen rightfully points out that “our actual
knowledge of the evolutionary and racialsignificance of Carabelli's cusp is quite
disproportionate to the number of pages published about this structure.
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Butler's Field TheoryReference is often made to specific teeth which seem to
show more variation than others. Much of this descriptive information on dental variation can be simplified if
Butler's Field Theory is understood. In 1939, Butler, an English paleontologist, proposed that the mammalian dentition can be divided into several developmental
fields. Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Within each field, there is a "key" . tooth—one that is more stable developmentally—and on either side of this key tooth, the remaining teeth within the field become progressively less stable. The three fields include those for molars, premolars, incisors, mid
canines
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
The three fields include those for molars/ premolars, incisors, mid canines. Considering each quadrant separately the molar/premolar field would consist of the first molar as the key tooth. the second and third molars on the distal end
of the field, and the first and second premolars on the mesial end. The theory predicts that the third molar and first
premolar would be most variable in size and shape. Most clinicians would agree on the third molar but not on the
first premolar.
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Actually the earliest mammals had four premolars and some of the higher primates. including man, have lost the first two, so that the premolars that we refer to as first and second should really be labeled third and fourth. The point is that as Butler's theory predicted, the premolars farthest
from the first molar were the first to be lost in an evolutionary sense and therefore can be considered the
least stable.
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Adapting Butler's theory to the human dentition , Dalilberg suggested the following fields and gradients of
stability among teeth—the arrows indicate decreasing stability.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
EVOLUTION OF SOCKET OR ATTACHMENTS OF TEETH :
There are 4 methods of tooth attachment in the animal world :1) Fibrous2) Hinged3) Anchylosis4) Gomphosis
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Fibrous :- Seen in shark and rays- In this type of attachment the teeth are fixed by means of fibrous bands to the submucosa of the fibrous membrane which covers the jaws.- The teeth are developed on the lingual side of the jaw and move with the membrane up to the crest of the jaw where they come into use and over to the buccal side-where they are shed."- There is no calcified tissue intervening between the teeth and the jaws and therefore there is no homologous to the human alveolus.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Hinged teeth : Occurs in angler, hake, cod, and pike and many
others The teeth allow ingress of the prey but prevent
egress.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Example-ANGLERThis fish has 2 rows of teeth an outer ankylosed and inner
hinged row.- A hinged tooth is supplied posteriorly by fibrous elastic ligament, while its anterior free edge rests upon a buttress
of bone.- The teeth bent towards the throat, the hinge compresses and teeth return to their original positions upon the force
being removed.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Anchylosis attachment :- When a tooth is fixed to the jaw by calcified tissue it
is said to be anchyiosed.- There is no intervention of fibrous or uncalcified
tissue.Eel fish : The teeth of the Eel rest upon little cylinder or
cups of bone of attachment and is described as " Acrodont anchylosis".
-Little fibrous "annular ligament" surrounds the base of tooth and allows a slight movement.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Gomphosis (attachment in sockets)- Seen in man, mammalia, reptiles and in some fish eg
: saw fish, pristis.- In man, mammals and crocodile, a membrane
(alveolar dental membrane) exists between the tooth and the socket of bone in which the tooth is situated. To these persisting sockets the term " thecodont" has
applied.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Brash has shown that in case of pig when the teeth are lost, the alveolar processes becomes
transformed into basal portion of the jaw and that new sockets form for the successional teeth.
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Gomphosis (attachment in sockets)- Seen in man, mammalia, reptiles and in some fish eg : saw fish,
pristis.- In man, mammals and crocodile, a membrane (alveolar dental membrane) exists between the tooth and the socket of bone in
which the tooth is situated. To these persisting sockets the term " Thecodont" has applied.
Brash has shown that in case of pig when the teeth are lost, the alveolar processes becomes transformed into basal portion of the
jaw and that new sockets form for the successional teeth..
324
Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Anthropology as a science has provided us with an insight into our past .The most important lessons that this science teaches us is that Evolution is an ever progressive process . Today we
humans consider ourselves to be a privy to mother nature’s secrets of life ,the evidence can be seen with the aggressive
cloning ,customised D.N.A. planned offsprings, non discriminate use of natural resourses and creation of an utter chaos in the ecological balance of the planet by our species.
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Are we really challenging nature or are we fitting into its bigger plan for
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Varun Malhotra, Department of orthodontics , Bapuji Dental College and Hospital
Thank you
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ReferencesThe anthropology of modern human teeth – G. Richard Scott. & TurnerScience and practice of occlusion – Charles McNeillOrigins of life on earth – Gray’s Anatomy – pg 7.Orthodontics : Practice & Technique – J.A. SalzmannContemporary Orthodontics – William R. Proffit.Plan of Face – Enlow – Ch. 5Illustrated encyclopeadia on evolution of life – Time LifeAttritional Occlusion – Begg & KeslingDevelopment of Function & Evolution of teeth – Mark F. Teaford & SmithThe morphogenesis of the TMJ – Moffit 1966
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Stone age man’s occlusion – Am J Orth 1959; 40; 298 Dental variation among populations – D.C.N.A genetics –
1975 Evolution of dental occlusion form fish to man – W.K.
Gregory – Angle Orthodontics – Vol 11 No. 3 The Anatomic Museum – Marshal D.G. – AJO – 1992 Anthropology – World Book
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