1. The primitive oral cavity is lined by a 2-3 cell thick layered epithelium covering embryonic connective tissue formed from neural crest cells.
2. Tooth development involves three overlapping phases: initiation, morphogenesis, and histogenesis, during which dental tissues differentiate.
3. The first sign of tooth development is the formation of a continuous epithelial band around the primitive oral cavity, which divides into vestibular and dental lamina. The dental lamina then invaginates and forms 20 buds for the primary teeth.
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For first year dental student, i got this from the internet.. Hope this can help u guys understand more about the tooth development.. Btw, good luck for minitest OB tomorrow.. No sacrifice, no victory!
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
Introduction
Initiation of tooth development
Development of tooth
Stages of tooth development
Histophysiology
Development of enamel
Development of dentin
Development of pulp
Development of cementum
Development of root
Nerve and vascular supply during early development
Formation of the permanent dentition
Formation of supporting tissues
Tooth eruption
Theories of tooth eruption.
Developmental anomalies of tooth
References
BE UPDATE TO IT,, AS IT IS 3 years back from 2017
Kindly mail me if you feel, needy of this presentation
you can find my mail id @ slide share,,, if not mail me @
sukesh3567@gmail.com.
Good luck
Growth & development of tooth & tongue/ dental crown & bridge coursesIndian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Tooth development /certified fixed orthodontic courses by Indian dental ...Indian dental academy
The Indian Dental Academy is the Leader in
continuing dental education , training dentists
in all aspects of dentistry and offering a wide
range of dental certified courses in different
formats.
Indian dental academy provides dental crown &
Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit
www.indiandentalacademy.com ,or call
0091-9248678078
For first year dental student, i got this from the internet.. Hope this can help u guys understand more about the tooth development.. Btw, good luck for minitest OB tomorrow.. No sacrifice, no victory!
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
Introduction
Initiation of tooth development
Development of tooth
Stages of tooth development
Histophysiology
Development of enamel
Development of dentin
Development of pulp
Development of cementum
Development of root
Nerve and vascular supply during early development
Formation of the permanent dentition
Formation of supporting tissues
Tooth eruption
Theories of tooth eruption.
Developmental anomalies of tooth
References
BE UPDATE TO IT,, AS IT IS 3 years back from 2017
Kindly mail me if you feel, needy of this presentation
you can find my mail id @ slide share,,, if not mail me @
sukesh3567@gmail.com.
Good luck
Growth & development of tooth & tongue/ dental crown & bridge coursesIndian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
A Brief Description about the development of teeth. Understanding the process of tooth development is of particular importance for the dentist; as developmental disturbances may occur at any stage of this process resulting in different types of tooth anomalies.
Tooth development can be classified either based on morphology or histology
Morphological stages:
Bud stage
Cap stage
Bell stage:
* Early
* Advanced
Physiological stages:
Initiation
Proliferation
Histodifferentiation
Morphodifferentiation
Apposition
The initiation of tooth development begins at 37 days of development
with formation of a continuous horseshoe-band of thickened epithelium
in the location of upper and lower jaws – Primary Epithelial Band
Dental lamina appears as a thickening
of the oral epithelium adjacent to
condensation of ectomesenchyme
20 areas of enlargement or knobs
appear, which will form tooth buds
for the 20 primary teeth
Not all will appear at the same time.
The first to develop are those of the
anterior mandible region
At this early stage the tooth buds
have already determined their crown morphology
Successional lamina: lamina from
which permanent teeth develop
The dental lamina begins to function
at 6th prenatal week and continues to
15th year of birth (3rd molar)
Tooth development is a continuous process, however can be
divided into 3 stages:
1. Bud Stage
2. Cap Stage
3. Bell Stage
4. Hertwigs epithelial root sheath and root formation
The bud stage is represented by the first epithelial incursion into the ectomesenchyme of the jaw.
The epithelial cells show little if any change in shape or function.
The supporting ectomesenchymal cells are packed closely beneath and around the epithelial bud. As the epithelial bud continues to proliferate into the ectomesenchyme, cellular density increases immediately adjacent to the epithelial outgrowth.
This process is classically referred to as a condensation of the ectomesenchyme.
The epithelium of the dental lamina separated from the underlying ectomesenchyme by basement membrane.
Bud stage is characterized by rounded, localized growth of
epithelium surrounded by proliferating mesenchymal cells,which are packed closely beneath and around the epithelial buds
The transition from bud to cap marks the onset of morphologic differences between tooth germs that give rise to different types of teeth.
Differential cellular division in the epithelial bud initiates a change in shape so that now the epithelial outgrowth assumes a more complex outline with a flattened internal portion along which the mesenchymal condensation densifies.
As the tooth bud grows larger, it drags along with it part of the dental lamina; thus from that point on, the developing tooth is tethered to the dental lamina by an extension called the lateral lamina.
At this early stage of tooth development, identifying the formative elements of the tooth and its supporting tissues is already possible.
The epithelial outgrowth, which superficially resembles a cap sitting on a ball of condensed ectomesenchyme , is still referred to widely as the dental organ but actually should be called the enamel organ, because it eventually will form the enamel of the tooth. Henceforth, the term enamel organ is used.
Condensation of the ectomesenchyme immediately subjacent to the tooth bud caused by lack of extracellular matrix secretion by the cells thus preventing separation.
Upload By : Ahmed Ali Abbas
Babylon University College of Dentistry
download this file from Website on google theoptimalsmile.wix.com/dentistry
Oral histology
The early development of tooth from six week of prenatal life. Description of different stages- bud,cap and bell stage and amelogenesis, dentinogenesis. Description of root development.
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
• TOOTH DEVELOPMENT (EMBRYOLOGY)
• . The initiation of tooth development-6th week of IUL
• . The oral stratified squamous epithelium covers the primordia of the future maxillary and mandibular processes in a horseshoe-shaped pattern.
• . Tooth development starts when stratified squamous epithelium begins to thicken and forms the dental lamina.
• . The stratified squamous oral epithelium covers an embryonic connective tissue that is called the ectomesenchyme because of its derivation from the neural crest cells. condensed area of ectomesenchyme forms the future dental papilla and subsequently the pulp.
• . BUD STAGE (FORMATION OF ENAMEL ORGAN)
• . CAP STAGE (OUTER AND INNER ENAMEL EPITHELIUM)
• The convex surface consists of the cuboidal epithelial cells and is called the outer enamel epithelium. The concave surface, called the inner enamel epithelium, consists of elongated epithelial cells with polarized nuclei that later differentiate into ameloblasts.
• . The inner and the outer enamel epithelium, the cells begin to separate due to the deposition of intercellular mucoid fluid rich in glycogen that forms a branch reticular arrangement called the stellate reticulum.
• . The ectomesenchyme surrounding the dental papilla and the enamel organ condenses and becomes more fibrous, it is called the dental follicle or the dental sac—the precursor of the cementum, the periodontal ligament (PDL), and the alveolar bone.
• . BELL STAGE (CERVICAL LOOP)
• . The junction of the outer and the inner enamel epithelium at the rim of the enamel organ becomes a distinct zone called the cervical loop.
• . The buds of the permanent molars, which have no primary predecessors.
• . The squamous cells between the stellate reticulum and the inner enamel epithelium form the stratum intermedium.
• . Stratum intermedium → Enamel
• Ectomesenchyme → Dentin
• Dental papilla → Pulp
• Dental follicle or dental sac → Cementum, the periodontal ligament(PDL), and the alveolar bone.
• Primary dentin is formed in increments of 4–8 μm per day and is continually deposited until the end of tooth development.
• . large-diameter collagen fibers known as von Korff fibers are deposited at right angles to the basement membrane in the extracellular matrix of the acellular zone. This process creates the organic matrixof the first-formed dentin or mantle dentin.
• The organic matrix or predentin is deposited around the odontoblastic processes. The predentin later calcifies and thereby forms the dentinal tubules.
• Primary dentin differs from the mantle dentin in which the matrix originates solely(only) in the odontoblasts.
• The mineralization of primary dentin originates from the previous mineralized dentin.
PERITUBULAR DENTIN
As the incremental deposition of dentin continues toward the center of the pulp, the diameter of the odontoblastic processes is reduced peripherally.
more mineralized and it is harder than primary dentin, is called peritubular dentin.70% inorganic material
• Dentin consist
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
Prix Galien International 2024 Forum ProgramLevi Shapiro
June 20, 2024, Prix Galien International and Jerusalem Ethics Forum in ROME. Detailed agenda including panels:
- ADVANCES IN CARDIOLOGY: A NEW PARADIGM IS COMING
- WOMEN’S HEALTH: FERTILITY PRESERVATION
- WHAT’S NEW IN THE TREATMENT OF INFECTIOUS,
ONCOLOGICAL AND INFLAMMATORY SKIN DISEASES?
- ARTIFICIAL INTELLIGENCE AND ETHICS
- GENE THERAPY
- BEYOND BORDERS: GLOBAL INITIATIVES FOR DEMOCRATIZING LIFE SCIENCE TECHNOLOGIES AND PROMOTING ACCESS TO HEALTHCARE
- ETHICAL CHALLENGES IN LIFE SCIENCES
- Prix Galien International Awards Ceremony
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
NYSORA Guideline
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New Directions in Targeted Therapeutic Approaches for Older Adults With Mantl...i3 Health
i3 Health is pleased to make the speaker slides from this activity available for use as a non-accredited self-study or teaching resource.
This slide deck presented by Dr. Kami Maddocks, Professor-Clinical in the Division of Hematology and
Associate Division Director for Ambulatory Operations
The Ohio State University Comprehensive Cancer Center, will provide insight into new directions in targeted therapeutic approaches for older adults with mantle cell lymphoma.
STATEMENT OF NEED
Mantle cell lymphoma (MCL) is a rare, aggressive B-cell non-Hodgkin lymphoma (NHL) accounting for 5% to 7% of all lymphomas. Its prognosis ranges from indolent disease that does not require treatment for years to very aggressive disease, which is associated with poor survival (Silkenstedt et al, 2021). Typically, MCL is diagnosed at advanced stage and in older patients who cannot tolerate intensive therapy (NCCN, 2022). Although recent advances have slightly increased remission rates, recurrence and relapse remain very common, leading to a median overall survival between 3 and 6 years (LLS, 2021). Though there are several effective options, progress is still needed towards establishing an accepted frontline approach for MCL (Castellino et al, 2022). Treatment selection and management of MCL are complicated by the heterogeneity of prognosis, advanced age and comorbidities of patients, and lack of an established standard approach for treatment, making it vital that clinicians be familiar with the latest research and advances in this area. In this activity chaired by Michael Wang, MD, Professor in the Department of Lymphoma & Myeloma at MD Anderson Cancer Center, expert faculty will discuss prognostic factors informing treatment, the promising results of recent trials in new therapeutic approaches, and the implications of treatment resistance in therapeutic selection for MCL.
Target Audience
Hematology/oncology fellows, attending faculty, and other health care professionals involved in the treatment of patients with mantle cell lymphoma (MCL).
Learning Objectives
1.) Identify clinical and biological prognostic factors that can guide treatment decision making for older adults with MCL
2.) Evaluate emerging data on targeted therapeutic approaches for treatment-naive and relapsed/refractory MCL and their applicability to older adults
3.) Assess mechanisms of resistance to targeted therapies for MCL and their implications for treatment selection
NVBDCP.pptx Nation vector borne disease control programSapna Thakur
NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
Recomendações da OMS sobre cuidados maternos e neonatais para uma experiência pós-natal positiva.
Em consonância com os ODS – Objetivos do Desenvolvimento Sustentável e a Estratégia Global para a Saúde das Mulheres, Crianças e Adolescentes, e aplicando uma abordagem baseada nos direitos humanos, os esforços de cuidados pós-natais devem expandir-se para além da cobertura e da simples sobrevivência, de modo a incluir cuidados de qualidade.
Estas diretrizes visam melhorar a qualidade dos cuidados pós-natais essenciais e de rotina prestados às mulheres e aos recém-nascidos, com o objetivo final de melhorar a saúde e o bem-estar materno e neonatal.
Uma “experiência pós-natal positiva” é um resultado importante para todas as mulheres que dão à luz e para os seus recém-nascidos, estabelecendo as bases para a melhoria da saúde e do bem-estar a curto e longo prazo. Uma experiência pós-natal positiva é definida como aquela em que as mulheres, pessoas que gestam, os recém-nascidos, os casais, os pais, os cuidadores e as famílias recebem informação consistente, garantia e apoio de profissionais de saúde motivados; e onde um sistema de saúde flexível e com recursos reconheça as necessidades das mulheres e dos bebês e respeite o seu contexto cultural.
Estas diretrizes consolidadas apresentam algumas recomendações novas e já bem fundamentadas sobre cuidados pós-natais de rotina para mulheres e neonatos que recebem cuidados no pós-parto em unidades de saúde ou na comunidade, independentemente dos recursos disponíveis.
É fornecido um conjunto abrangente de recomendações para cuidados durante o período puerperal, com ênfase nos cuidados essenciais que todas as mulheres e recém-nascidos devem receber, e com a devida atenção à qualidade dos cuidados; isto é, a entrega e a experiência do cuidado recebido. Estas diretrizes atualizam e ampliam as recomendações da OMS de 2014 sobre cuidados pós-natais da mãe e do recém-nascido e complementam as atuais diretrizes da OMS sobre a gestão de complicações pós-natais.
O estabelecimento da amamentação e o manejo das principais intercorrências é contemplada.
Recomendamos muito.
Vamos discutir essas recomendações no nosso curso de pós-graduação em Aleitamento no Instituto Ciclos.
Esta publicação só está disponível em inglês até o momento.
Prof. Marcus Renato de Carvalho
www.agostodourado.com
Knee anatomy and clinical tests 2024.pdfvimalpl1234
This includes all relevant anatomy and clinical tests compiled from standard textbooks, Campbell,netter etc..It is comprehensive and best suited for orthopaedicians and orthopaedic residents.
Pulmonary Thromboembolism - etilogy, types, medical- Surgical and nursing man...VarunMahajani
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Couples presenting to the infertility clinic- Do they really have infertility...Sujoy Dasgupta
Dr Sujoy Dasgupta presented the study on "Couples presenting to the infertility clinic- Do they really have infertility? – The unexplored stories of non-consummation" in the 13th Congress of the Asia Pacific Initiative on Reproduction (ASPIRE 2024) at Manila on 24 May, 2024.
3. Under a light microscope the newly formed stomatodeum (primitive oral
cavity) can be seen to be lined by a primitive 2-3 cells of thick layered
epithelium which covering the ectomesenchyme which is an embryonic
connective tissue that is formed from the neural crest cells. The
ectomesenchyme consists of spindle-shaped cell separated by ground
substance.
2015oral histology lab. 3
4. Tooth development can be divided into three overlapping phases,
which are:-
• Initiation: during this phase, the sites of the future teeth are established with the
appearance of tooth germs along an invagination of the oral epithelium called
dental lamina.
• Morphogenesis: during this phase, the shape of the teeth are determined by a
combination of cell proliferation and cell movement.
• Histogenesis: during this phase, differentiation of cell (begun during
morphogenesis) proceed to give rise to the fully formed dental tissues, both
mineralized (such as enamel, dentin and cementum) and unminaralized (such as
pulp and periodontal ligament).
2015oral histology lab. 4
5. The first sign of tooth development begins when the embryo is about 5-6 weeks
old when a continuous band of thickened epithelium forms around the primitive
oral cavity in the presumptive upper and lower jaws. These bands are roughly
horseshoe shaped and correspond in position to the future dental arches of the
upper and lower jaws. Each primary epithelial band quickly give rise to two
subdivisions, a buccally located vestibular lamina and a lingual one which is dental
lamina.
2015oral histology lab. 5
6. Vestibular lamina: the vestibule or sulcus ( between the check and
tooth bearing areas) forms as a result of the proliferation of the vestibular
lamina into the ectomesenchyme. Its cells rapidly enlarge and then
degenerate to form a cleft that becomes the vestibule.
Dental lamina: in the jaws, the neural crest cells induce the oral
epithelia to proliferate and form the dental lamina, which is the first sign
of tooth development. This lamina then invaginates as a sheet of
epithelial cells into the underlying mesenchyme around the perimeter of
both maxillary and mandibular jaws.
Along the leading edges of the lamina 20 areas of enlargement next
appear, which are the forming buds of the 20 primary teeth, successional
tooth buds form the permanent dentition are lingual to the buds of the
primary predecessors. Permanent molars develop posterior to the primary
molars, which developed in about 4 years after-birth.
2015oral histology lab. 6
7. Morphological stages of tooth development
Bud stage: the enamel organ resembles a small bud. Round or ovoid swellings at ten
different points arise from dental lamina in each jaw, corresponding to the future
position of deciduous teeth. They are the primordial of enamel organs (the tooth buds),
thus the development of the tooth germ is initiated, proliferation of cells is still faster
than adjacent ectomesenchymal cells. These epithelial condensation is poorly
morphodifferentiated and histodifferentiated. Enamel organ in this stage consist of
peripherally located low columnar cells and centrally located polygonal cells. There is a
condensation of ectomesenchymal cells adjacent to the amel organ. The enamel organ is
separated from the adjacent ectomesenchyme by basement membrane.
2015oral histology lab. 7
8. Cap stage: as the epithelial bud continues to proliferate into the ectomesenchyme,
morphogenesis has progressed, the deeper surface of the enamel organ invaginate to form a cap-
shaped structure. Although, enamel organ appearing relatively poorly histodifferentiated, a
greater distinction develops between the more rounded cells in the central portion of the enamel
organ and the peripheral cells which are becoming arranged to form the outer and inner enamel
epithelia. In the late cap stage of tooth development, the central cells of the enlarging enamel
organ have become separated (through maintaining contact by desmosomes), the intercellular
spaces containing significant quantities of glycosaminoglycans. The resulting tissue is termed the
stellate reticulum, although it is not fully developed until the late bell stage. The cells of the outer
enamel epith. remain cuboidal, where as those of inner enamel epith become more columnar. The
adjacent ectomesenchymal cells are continue to prolipherat and surround the enamel organ. The
part of the ectomesenchyme lying beneath the inner enamel epithelia is called dental papilla. The
ectomesenchymal tissue surrounding both enamel organ and dental papilla is called dental sac or
dental follicle.
2015oral histology lab. 8
9. Transitory structures:
1-Enamel knot: it is a localized mass of cells in the center of the inner enamel
epithelia. The enamel knot is a signaling center of the tooth that provides
positional information for tooth morphogenesis and regulates the growth
of tooth cusps. The enamel knot produces a range of molecular signals from all
the major signaling families, such as Fibroblast Growth Factors (FGF), Bone
morphogenetic proteins (BMP) and other signals.
2-Enamel cord: it’s a strand arises in enamel organ as a vertical extension of
the enamel knot at the early bell stage of development. Its termed enamel
septum when enamel cord extend from enamel knot to the outer enamel
epithelia.
2015oral histology lab. 9
10. 3-Enamel niche: it's an apparent structure in the histological section, created because
the dental lamina is a sheet rather than a single strand and often contains a concavity
filled with connective tissue. A section through this arrangement creates the
impression that the tooth germ has a double attachment to the oral epithelium by two
separate strands.
2015oral histology lab. 10