Evolution & development of periodontium 22.08.14

PRESENTED BY;
DR. CHERRY CHAMRIA
Evolution & Development Of
Periodontium

Contents
 Defination of Evolution.
 Theories Of Evolution-Darwin’s Theory
Lamarck’s Theory
 Genetic Evidence of Evolution
 Evolution Of Periodontium: Process Of Evolution
 Evolution of the Periodontium: Cementum
Alveolar Bone
Periodontal Ligament
Gingiva.
 Defination of Development
 Developmental Theories
 Development Of the Periodontium: Cementum
Alveolar Bone
Periodontal Ligament
Gingiva.

Evolution of the Periodontium
“Evolution is the change in the
inherited characteristics of biological
populations over successive
generations”
Experienced by group of people
Darwin, Charles- “On the Origin of Species”

Theories of Evolution-Darwin’s Theory.
Darwin has defined evolution as “descent
with modification”
 When members of a population die, they
are replaced by the progeny of parents
better adapted to survive and reproduce in
the enviorment in which natural selection
takes place.
Past-Apes Present-Humans Future-Mutants.?

Darwin’s Theory
Descent with modification refers to the passing on of traits
from parent organisms to their offspring.

Darwin’s Theory
Common descent is the scientific theory that all living organisms
on Earth descended from a common ancestor.

Darwin’s Finches
1) thicker beak-
feed on seeds,
that r crushed
between beaks
3) still narrower &
sharper- called as
“vampire “ finches,
creeps on the sea
birds & feeds itself.
2)narrower
beaks- eat
insects.
4)woodpecker
finches that
pick a twig,
make them
sharp and then
poke it into
dead branches
to pry out grubs
as meal.

Lamarck’s Theory of Evolution
 The idea that an
organism can pass on
characteristics that is
acquired during its
lifetime to its
offspring.
Lamarck said
“Individuals lose
characteristics they do
not require (DISUSE)
And develop
characteristics that are
useful(USE)
Ref: Invertebrate zoology and paleontology

Gene Mutation
 A mutation is a change in DNA, the hereditary
material of life.
Genetics in Dentistry, 2010.
Author: Pal GP, Mahato Niladri Kumar

Gene Mutation & Evolution
MYH16 gene over the years
became a pseudogene, lead
to decrease in the size of
jaw musculature &
increase in brain size.
It caused narrower jaws,
smaller teeth and space for
the 3rd molar became less.
3rd molar is almost
vestigeal now on account
of the MYH-16
Mutation accounts for the
graceful human jaw, in
contrast to apes protruding
facial ridges.

Origin Of teeth In Vertebrates
 The first occurence of tooth
like structures was found in
the posterior pharynx of
jawless fishes about 500
million years ago.
 It is still unclear whether
oral teeth evolved with jaws
for predation and
mastication or first
appeared as external dental
armour as protection from
predation.

Evolution & Dentistry
Reduction of size of teeth over 2000 years

Invention of
stone tools for
food preparation
widely reduced
the teeth size.
Pottery
furthur
reduced teeth
size- as food
could be
warmed &
hence easy to
consume.
However as man
started walking, the
hands had
greater role in
obtaining food.
Longer jaws became
short.
Sharper
canines
required to
catch prey
from the
teeth

Emes et al.
REVIEW
On The Evolution of Human Jaws and Teeth: A Review
• Yusuf Emes (1), Buket Aybar (2), Serhat Yalcin (2) •
1 - Research Assistant, Istanbul University Faculty of Dentistry, Department of Oral and Maxillofacial Surgery,
Istanbul, Turkey
2 - Professor, Istanbul University Faculty of Dentistry, Department of Oral and Maxillofacial Surgery, Istanbul,
Turkey
Address for correspondence:
Dr. Yusuf EmesE- mail: emes @istanbul.edu.tr
Bull Int Assoc Paleodont. 2011;5(1):37-47.
Abstract
The jaws and teeth of Homo sapiens have evolved, from the last common ancestor of chimpanzee and men to their
current form. Many factors such as the foods eaten and the processing of foods by fire and tools have effected this
evolution course. The evolution of the masticatory complex is related to other anatomical features such as brain size
and bipedal posture, and leads to important proceedings like the formation of speech and language. In this review,
the evolution of human jaws and teeth and its impact on the general course of human evolution is discussed.
Conclusion
The evolution of human masticatory complex is strongly related to diet, the
use of tools and fire, and has a more important part in the evolution of
mankind more than the dentists know.

PERIODONTIUM
 Periodontium refers to the specialised tissues that both surround and
support the teeth, maintaining them in the maxillary and mandibular
bones.
Parts of the Periodontium
 Cementum.
 Alveolar Bone.
 Periodontal Ligament.
 Gingiva.
Ten Cate‘s oral histology 7th edition

Evolution of Cementum
Evolution: There is a replacement of the ankylosis of the tooth & bone
to a ligamentous suspension of the tooth. Because of this, movement of
the mammalian teeth is made possible, resulting in continual repositioning
as required by the jaw growth & also tooth-wear.

Evolution of Alveolar Socket/Bone.
This evolution was explained by
Simpson which is referred to as
“Chance Similarity”
Bones grown in shape & size in
response to frequent and
habitual strains & loose mass in
the absence of force
This explains the epigenetic
trait in size of alveolar process.
In early man, the teeth were big,
and alveolar sockets were large
to hold on to the teeth, but as
the forces for chewing reduced,
the teeth size decreased hence
the size of the alveloi also
decreased.

 There is a fundamental difference in the
manner of attachment of early man and teeth.
In the ancesters the teeth are ankylosed to the
bone. In the mammals, they are suspended in
their sockets by ligaments.
 In the early man-the teeth “move” with the
bones to which they are fused , whereas now
they move as independent units. This
movement is made possible by the remodeling
of the periodontium.
 The evolutionary change replaces the ankylosis
of tooth and bone to a ligamentous suspension
of the tooth. This change permits movement of
mammalian teeth and the continued
repositioning necessitated by jaw growth or
tooth wear.
Evolution of the Periodontal Ligament

3 Types of teeth implantation are
recognized:
Acrodont
a tooth is
attached to the
apex of the jaw.
Pleurodont
a tooth is
attached to the
lingual surface of
the jaw.
Thecodont-
a tooth is set into a
deep socket in the
jaw.
Evolution And History Of The Periodontal Ligament - A Review.
The Internet Journal of Medical Technology. 2012 Volume 6

By a Hinge
By Ankylosis
By implantation in bony sockets
(Gomphosis)
Attachment of Gingiva by means of Fibrous
Membrane
Evolution And History Of The Periodontal Ligament - A Review.
The Internet Journal of Medical Technology. 2012 Volume 6

Development is the specified state of
growth or advancement in a short
period of time.
Experienced by individuals.
Development of the Periodontium

Development of Jaws
 The most
anterior of the
brachial arches
undergoes
tranformation to
form the upper
& lower jaws.
Ref: Human Embroyology by Dr. Bruce M. Carlson

 The primitive oral cavity, or
stomodeum is lined by stratified
squamous epithelium called oral
ectoderm, which contacts the
endoderm of the foregut to form
the bucco-pharyngeal membrane,
which ruptures in about the 27th
day(1st month) of gestation.
 Surrounding the stomodeum are
several tissue prominences that
constitute the building blocks of the
face.
 Most of the cells lining this are
neural crestal /ectomesenchymal in
origin
Ref: Human Embroyology by Dr. Bruce M.
Carlson

At 4-5 weeks, the primordia
consists of 5 major prominences-
1) Unpaired frontonasal
2) Paired naso Medial
3) Paired naso-Lateral
4) Paired maxillary &
5) Mandibular prominence.
Ref: Human Embroyology by Dr. Bruce M.
Carlson

Ref: Human Embroyology by Dr. Bruce M. Carlson

Development Of the Periodontium
 Oral Epithelium Forms Enamel Organ-which forms
the Gingival epithelium.
 Ectomesenchyme forms the Dental papilla- which
forms PDL, Alveolar bone, Cementum
Ref: Oral Cells & Tissue by P.R Garant, DMD

 Periodontium is defined as those
tissues which support & invest the
tooth.
 It provides the support necessary to
maintain the teeth in function.
Parts:
 Cementum
 Alveolar Bone
 Periodontal Ligament
 Gingiva
Carranza’s Clinical Periodontology-11th Edition

Cementum
Also called “The other bone”
It is a hard avascular connective
tissue that covers the roots of
teeth
It is the mineralised dental tissue
covering the anatomic roots of
human teeth.
 It covers and protects the root
dentin (covers the opening of
dentinal tubules)
 It provides attachment to the
periodontal fibers
 It compensates for tooth
resorption
Histology of oral tissue – Ten Cate , 7th edition
Orbans Oral Histology & Embryology-12th edition

Development of Cementum
 Subdivided into:
 Pre-funtional –formed
during root formation
 3.75-7.75 years
 Functional- occurs
when tooth is about to
reach occlusion
 Throughout life
Periodontology 2000. Vol. 13, 1997, 41-75

Cementum formation
occurs along the
entire tooth
Development of Cementum
Outer & inner enamel
epithelium forms the bilayer of
cells and proliferate
downward and form Hertwig’s
epithelial root sheath.

HERS sends inductive signal to ectomesenchymal pulp
cells to secrete predentin by differentiating into
odontoblasts. These odontoblasts secrete the organic
matrix of the first formed root predentin.

HERS becomes interrupted, this break
allows, the newly formed predentin to
come in contact with the dental follicle
and the cells derived from them are
cementoblasts.
Cementoblasts lay down cementum
These cells 1st form compartments
with cellular processes that demarcate
intrinsic collagen fibers that are
parallel to the long axis of the root
surface . Extrinsic fibers are formed
later
Image from cell

The HERS-epithelial cells never completely
disappear & they persist in small clusters called
Epithelial cell rests of malassez

First layer of cementum is actually
formed by the inner cells of the
HERS and is deposited on the
root’s surface is called intermediate
cementum or Hyaline layer of
Hopewell-Smith
Deposition occurs before the HERS
disintegrates which seals of the
dentinal tubules
Intermediate cementum is situated
between the granular dentin layer
of Tomes and the secondary
cementum that is formed by the
cementoblasts (which arise from
the dental follicle)

Types of cementum
Acellular cementum: covers the root
adjacent to dentin.
Cellular cementum:covers the apical area
and overlying acellular cementum. Also
common in interradicular areas
Cementum is more cellular as the
thickness increases in order to maintain
Viability.

Role of the epithelial cell rests of Malassez in the development,
maintenance and regeneration of periodontal ligament tissues
Jimin Xiong, Stan Gronthos, P. Mark Bartold
Abstract
Periodontitis is a highly prevalent inflammatory disease that results in damage to the tooth-supporting
tissues, potentially leading to tooth loss. Periodontal tissue regeneration is a complex process that involves
the collaboration of two hard tissues (cementum and alveolar bone) and two soft tissues (gingiva and
periodontal ligament). To date, no periodontal-regenerative procedures provide predictable clinical
outcomes. To understand the rational basi. An important structure during tooth root development, the
Hertwig's epithelial root sheath is not only a barrier between the dental follicle and dental papilla cells but is
also involved in determining the shape, size and number of roots and in the development of dentin and
cementum, and may act as a source of mesenchymal progenitor cells for cementoblasts. In adulthood, the
epithelial cell rests of Malassez are the only odontogenic epithelial population in the periodontal ligament.
Although there is no general agreement s of regenerative procedures, a better understanding of the events
associated with the formation of periodontal components will help to establish reliable strategies for clinical
practice. An important aspect of this is the role of the Hertwig's epithelial root sheath in periodontal
development and that of its descendants, the epithelial cell rests of Malassez, in the maintenance of the
periodontiumon the functions of the epithelial cell rests of Malassez, accumulating evidence suggests that the
putative roles of the epithelial cell rests of Malassez in adult periodontal ligament include maintaining
periodontal ligament homeostasis to prevent ankylosis and maintain periodontal ligament space, to prevent
root resorption, to serve as a target during periodontal ligament innervation and to contribute to cementum
repair. Recently, ovine epithelial cell rests of Malassez cells have been shown to harbor clonogenic epithelial
stem-cell populations that demonstrate similar properties to mesenchymal stromal/stem cells, both
functionally and phenotypically. Therefore, the epithelial cell rests of Malassez, rather than being ‘cell rests’,
as indicated by their name, are an important source of stem cells that might play a pivotal role in periodontal
regeneration.
Periodontology 2000 Volume 63, Issue 1, pages 217–233, October 2013

J Periodontal Res. 2008 Aug;43(4):478-81.
Cell death and quantitative reduction of Rests of Malassez according to age.
Gonçalves JS, Sasso-Cerri E, Cerri PS.
Department of Morphology, Laboratory of Histology and Embryology, Dental School,
São Paulo State University (UNESP), Araraquara, SP, Brazil.
 BACKGROUND AND OBJECTIVE: Rests of Malassez are clusters of epithelial cells that remain
in the periodontal ligament throughout life. However, it has been reported that the number of
these structures decreases with age, and some epithelial cells undergo apoptosis in rests of
Malassez of young and adult rats. Therefore, the purpose of the present study was to investigate
the incidence of epithelial cell death and the quantitative changes in the rests of Malassez in rat
molars of different ages.
 MATERIAL AND METHODS: Fragments containing the upper molars of rats aged 29, 45 and 120
d were fixed, decalcified and embedded for analysis by light microscopy. In the sections stained
by hematoxylin and eosin, the number of rests of Malassez and the number of nuclei of these
epithelial structures were obtained. Moreover, the nuclei exhibiting typical features of cell death
were also counted in each rest of Malassez. The terminal deoxynucleotidyl transferase-mediated
dUTP nickend labeling (TUNEL) method for detection of cell death was also carried out.
 RESULTS: In all groups examined, some rests of Malassez exhibited epithelial cell nuclei with
typical features of apoptosis and some of them were also TUNEL positive. From 29 to 120 d of
age in rats, the quantitative analysis showed a significant decrease in the total number of rests of
Malassez in the cervical, middle and furcation regions of the periodontal ligament. Moreover, a
significant decrease of epithelial cell nuclei was concomitant to an increase in the frequency of
cell death in the oldest rats.
 CONCLUSION: These results suggest that epithelial cell death by apoptosis may be, at least in
part, responsible for the reduction in the number of rests of Malassez according to age.

Alveolar Process/Bone
 The specialised bone,
that contains the alveoli
or sockets of the teeth &
supports the teeth
 If teeth are lost, alveolar
process disappears.
 Mainly comprised of
 Buccal surface
 Outer cortical bone
 Alveloar bone proper
 Supporting bone

 Jaw Bones mainly
comprise of Alveolar Bone
& Basal Bone
 Alveloar bone dissapers
(resorbed ) in edentulous
cases and gets down to
basal bone.
 Basal bone houses the
major nerves and blood
vessels, and functions as a
site of muscle attachment.
Ref: Oral Cells and tissues: P.R Garant DMD

Intramembraneous
ossification is the direct
formation of the bone within
highly vascular sheets of the
mesenchyme.
Near the end of the 2nd
month of fetal life, in late bell
stage, the mandible and
maxilla form a groove that is
opened toward the surface of
the oral cavity known as
bony crypt. This contains
loose mesenchyme with
cytoplasmic processes.
Development of Alveolar Process
Ref: Oral Cells and tissues: P.R Garant DMD

A centre of osteogenesis develops that is
in association with capillaries & they
adhere to the cytoplasmic processes of the
mesenchyme.
These cells differenciate into osteoblasts
and secrete bone matrix. Once surrounded
by bone matrix they are called osteocytes.
The deposition of this gradually reduces
the space between the crypt wall & the
tooth, to the dimentions of the PDL.
As tooth germs start to develop, bony
septa forms gradually. The alveolar
process starts developing during tooth
eruption.
Orban’s Oral Histology & Embryology 13th edition
By G.S Kumar.

The development of the periodontium: The origin of alveolar bone
Faculty of Dentistry, University of Toronto, 124 Edward Street, Toronto,
Canada
The Anatomical Record 01/2005; 173(1):69 - 77. DOI:
10.1002/ar.1091730106
ABSTRACT: First molar tooth germs consisting of dental organ, dental
papilla and dental follicle were dissected from one-day old mice and
transplanted subcutaneously into young adult animals of the same strain.
Three to four weeks after implantation the host animals were sacrificed and
the transplants harvested. The transplants were prepared for either routine
histological examination or for electron microscopy. Forty tooth germs
continued development with the formation of a periodontium consisting of
cement, periodontal ligament and bone. Electron microscopical examination
of this material demonstrated the presence of lymphocytes in association
with the subcutaneous bone and thereby suggested the origin of the bone
from donor tissue.

Development of PDL
 The PDL is derived from
the dental sac tissue
investing the tooth germ.
 The PDL is derived
embryonically from the
ectomesenchymal tissues.
 Development of PDL
begins with root
formation.

Development of PeriodontalLigament.
 The fibre bundles rich in
fibroblasts originate at the root
dentin.
 These nasant fibroblasts are
tightly packed by the action of
cementoblasts.
 During tooth development , as
PDL matures, the width of the
ligament merge & form the
principal fiber bundles(laid down
coronally).
 During development of the fringe
fibres, fibroblasts exhibit
cytoplasmic polarity which causes
attachement to the cementum.

Initially , the fibers become
embedded in the cementum as
Sharpey’s fibers and are laid down
in a coronal direction within the
region identified as the developing
PDL , giving them an orientation
almost parallel to the root surface.
Fiber formation and deposition
occur sequentially from newly
forming cemento-enamel
junction(CEJ) to the tooth root.

Then, fibers deposited become:
Dentogingival and Transseptal
fibers of gingiva .
By the time 1/3rd of root
formation is complete fibers are
inserted within the cementum
matrix from the CEJ and
traverse coronally following the
outline of the newly formed
crown.
Ref: Orban’s Oral Histology & Embryology-13th Edition

 5 types of fibre attachment: Trans-septal, Oblique, Horizontal, Apical &
Interradicular.
 Eruptive movement & establishment of occlusion then modify the
attachment of PDL.
Periodontal Ligaments Attachements.
Ref: Orban’s Oral Histology & Embryology-13th Edition

The gingival tissues are composed of a
superficial epithelium of ectodermal
origin(oral mucosa) & underlying
connective tissue of mesodermal
origin(developing tooth germ)
Development of the Gingiva
Ref -P. Mark Bartold ,A Sampath Narayan- Biology of the Periodontal connective tissue

Development of Gingiva
As an erupting tooth approaches the oral
epithelium, the enamel epithelium rapidly
proliferates, forming the thick reduced enamel
epithelium
- Periodontology 2000, Vol. 24, 2000, 9–27

As the crown erupts further, the reduced enamel
epithelium ( ameloblast +cells of stratum
intermedium ) overlying the enamel fuses with the
oral epithelium, undergoes transformation whereby
the reduced enamel epithelium gradually becomes
junctional epithelium(enamel cuff) and
establishes the dentogingival junction

The JE maintains a direct attachment to
the tooth surface.
During eruption, contact is established
between the reduced enamel epithelium
and the oral gingival epithelium.

Key Molecules In Periodontium Development
Molecules in periodontium Function
A) GROWTH FACTORS
I. Transforming growth factor beta(including
BMP)
Promote cell differentiation & subsequently
cementogenesis
II. Pletelet derived growth factor &
insulin like growth factor
Promote cementogenesis by altering cell cycle
activities
III. Fibroblast growth factor All key events for formation & regeneration of
periodontal tissues.
B) ADHESION MOLECULES
I. Bone sialoprotein Promote adhesion of selected cell to newly form root
& also involved in promoting mineralization
II. osteopontin Regulate the extent of crystal growth in cementum
C) EPITHELIAL / ENAMEL PROTEIN Epithelial – mescenchymal interaction & may
promote periodontal repair directly or indirectly
D) COLLAGENS TYP I & III play key role in Periodontal tissues
development & regeneration
 Typ XII may assist in maintaining PDL space Vs
continuous cementum formation
Histology of oral tissue – Ten Cate , 7th edition

Thesleff et al (1995), suggested roles of growth factors in
reciprocal epithelial-mesenchymal tissues signaling during
advancing tooth morphogenesis.

International Journal of Oral Science (2012) 4, 177–181; doi:10.1038/ijos.2012.61; published online 7 Dec 2012
REVIEW ARTICAL
Molecular regulatory mechanism of tooth root development
Xiao-Feng Huang1 and Yang Chai2
Abstract
The root is crucial for the physiological function of the tooth, and a healthy root allows an artificial crown to
function as required clinically. Tooth crown development has been studied intensively during the last few decades,
but root development remains not well
understood. Here we review the root development processes, including cell fate determination, induction of
odontoblast and cementoblast differentiation, interaction of root epithelium and mesenchyme, and other molecular
mechanisms. This review summarizes our current understanding of the signaling cascades and mechanisms
involved in root development. It also sets the stage for de novo tooth regeneration.
CONCLUSION
We have made important great progress in studies of tooth root development in the last 10 years. Development of
ectodermal organs involves similar processes and, in some cases, the same genes as those used earlier in
development. Like the tooth crown, tooth root development involves the interaction of the dental epithelium and
the cranial neural crest-derived mesenchyme. These reciprocal interactions are mediated by a series of signals,
including from TGF-B, BMP, FGF and other molecules. By the function of homebox genes, such as NfIc and
Msx1/2. This review provides an overview of root development and highlights the developmental biology of the
tooth root. We hope that knowledge about the cell fate of the HERS, interaction of dental epithelial and
mesenchymal cells, and other molecular mechanisms during tooth root development will facilitate tooth
regeneration studies in the future.

From molecules to mastication: the development and evolution of teeth.
Department of Orofacial Sciences and Program in Craniofacial and Mesenchymal Biology, University of
California San Francisco, San Francisco, CA, USA.
Wiley interdisciplinary reviews. Developmental biology 03/2013; 2(2):165-82. DOI: 10.1002/wdev.63
Source: PubMed
ABSTRACT: Teeth are unique to vertebrates and have played a central role in their evolution. The molecular
pathways and morphogenetic processes involved in tooth development have been the focus of intense
investigation over the past few decades, and the tooth is an important model system for many areas of
research. Developmental biologists have exploited the clear distinction between the epithelium and the
underlying mesenchyme during tooth development to elucidate reciprocal epithelial/mesenchymal
interactions during organogenesis. The preservation of teeth in the fossil record makes these organs invaluable
for the work of paleontologists, anthropologists, and evolutionary biologists. In addition, with the recent
identification and characterization of dental stem cells, teeth have become of interest to the field of
regenerative medicine. Here, we review the major research areas and studies in the development and evolution
of teeth, including morphogenesis, genetics and signaling, evolution of tooth development, and dental stem
cells.
Conclusion: Important advances have been made in our understanding of the development and evolution of
the teeth. The tooth provides valuable model for the elucidation of major biological questions and the
identification. The rapid increase in our understanding of dental development in extant & extinct vertebrate
species using techniques including 3D imaging, genetic manipulations, omics analyses and genome wide
association studies make this an exciting time to study development and evolution of teeth.

International Journal of Oral Science (2013) 5, 75–84; doi:10.1038/ijos.2013.41; published online 28 June 2013
Bone morphogenetic protein-2 gene controls tooth root
development in coordination with formation of the periodontium
Audrey Rakian, Wu-Chen Yang, Jelica Gluhak-Heinrich, Yong Cui, Marie A Harris, Demitri
Villarreal,Jerry Q Feng, Mary MacDougall and Stephen E Harris
Abstract
Formation of the periodontium begins following onset of tooth-root formation in a coordinated
manner after birth. Dental follicle progenitor cells are thought to form the cementum, alveolar bone
and Sharpey’s fibers of the periodontal ligament (PDL). However, little is known about the
regulatory morphogens that control differentiation and function of these progenitor cells, as well as
the progenitor cells involved in crown and root formation. We investigated the role of bone
morphogenetic protein-2 (Bmp2) in these processes by the conditional removal of the Bmp2 gene
using the Sp7-Cre-EGFP mouse model. Sp7-Cre-EGFP first becomes active at E18 in the first molar,
with robust Cre activity at postnatal day 0 (P0), followed by Cre activity in the second molar, which
occurs after P0. There is robust Cre activity in the periodontium and third molars by 2 weeks of age.
When the Bmp2 gene is removed, major defects are noted in root, cellular cementum and
periodontium formation. First, there are major cell autonomous defects in root-odontoblast
terminal differentiation. Second, there are major alterations in formation of the PDLs and cellular
cementum, correlated with decreased nuclear factor IC (Nfic), periostin and α-SMA+ cells. Third,
there is a failure to produce vascular endothelial growth factor A (VEGF-A) in the periodontium and
the pulp leading to decreased formation of the microvascular and associated candidate stem cells in
the Bmp2-cKOSp7-Cre-EGFP. Fourth, ameloblast function and enamel formation are indirectly altered
in the Bmp2-cKOSp7-Cre-EGFP. These data demonstrate that the Bmp2 gene has complex roles in
postnatal tooth development and periodontium formation.

Evolution & development of periodontium 22.08.14

Evolution & development of periodontium 22.08.14

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Viewers also liked

Viewers also liked (20)

Similar to Evolution & development of periodontium 22.08.14

Similar to Evolution & development of periodontium 22.08.14 (20)

Recently uploaded

Recently uploaded (20)

Evolution & development of periodontium 22.08.14