This document provides an overview of the periodontal ligament. It begins by defining key terms like periodontium and periodontal ligament. It then describes the development, structure, cells, extracellular components, and functions of the periodontal ligament. Specifically, it notes that the periodontal ligament is composed of collagen fibers and ground substance that connect the cementum and alveolar bone. It houses various cell types, including fibroblasts, osteoblasts, cementoblasts, and progenitor cells. The document discusses how the principal collagen fibers develop and attach to the root surface. It also examines how the periodontal ligament maintains homeostasis between the hard tissues.
Development of naso maxillary complex /certified fixed orthodontic courses by...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
case study on C O Kindergarten and Nursery, Japan and Little Millenium, Sonipat, Haryana
a case study on an international playschool and another in the Haryana, India.
giving the information on: introduction to the topic that is the playschool, user profile, location of the chosen site, how to reach the site, landmarks, division of spaces, site description, concept of the design, interiors, climatic conditions, inference to the case studies, and sources of the information.
Dr. K.S.Chhajer is the best hair transplant, cosmetic surgeon, nose, breast surgery, open rhinoplasty, cleft lip & palate and burn contracture doctor in Kolkata.
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.
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.
Presentation of the workshop 'Making Astronomy Accessible for All' at Universe Awareness 2015 International Workshop by Amelia Ortiz, Lina Canas, and Thilina Heenatigala.
Development of naso maxillary complex /certified fixed orthodontic courses by...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
case study on C O Kindergarten and Nursery, Japan and Little Millenium, Sonipat, Haryana
a case study on an international playschool and another in the Haryana, India.
giving the information on: introduction to the topic that is the playschool, user profile, location of the chosen site, how to reach the site, landmarks, division of spaces, site description, concept of the design, interiors, climatic conditions, inference to the case studies, and sources of the information.
Dr. K.S.Chhajer is the best hair transplant, cosmetic surgeon, nose, breast surgery, open rhinoplasty, cleft lip & palate and burn contracture doctor in Kolkata.
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.
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.
Presentation of the workshop 'Making Astronomy Accessible for All' at Universe Awareness 2015 International Workshop by Amelia Ortiz, Lina Canas, and Thilina Heenatigala.
https://aodaitailoc.vn/ Áo Dài Cưới Tài Lộc Địa Điểm Cho Thuê Áo Dài Bưng Quả, Áo Dài Cưới Đẹp Giá Rẻ Khuyến Mãi Hàng Đầu Khu Vực Hồ Chí Minh. Địa Chỉ 35/14/9 Nguyễn Tư Giản, Phường 12, Quận Gò Vấp, TP.HCM #tailoc #aodaitailoc #aodaicuoitailoc
Recently, it has become increasingly evident that we have engineers and scientists reaching a professional level of practice without a clear understanding of the scientific method, its origins, and its fundamental workings. There also appears to be a lack of appreciation of our total dependence on the truths that science continually reveals. How this situation ensued appears to vary from country to country, and the flavour of education system encountered by students. But a common complaint is the progressive dumbing down of the science curriculum along with a dire shortage of qualified teachers. This also seems to be compounded with the increasing speciation of science and engineering into narrower and narrower disciplines. So this situation (crisis?) prompted a request for a corrective series of foundation lectures focussed on healing these educational flaws across relevant disciplines, graduating and practicing levels. This then is the first in this foundation series.
In a world that appears riven by social media, ill-informed opinion, rumour, and conspiracy theories in preference to facts and established truths, it can be alarming to see scientists, doctors, and engineers challenged by vacuous statements that often hold sway over the hard-won truths of science. Moreover, large numbers of people do not understand the ‘scientific method’ and what makes it so powerful.
Paradoxically, those challenging science and scientists based on their belief systems do so using technologies that can only be furnished by scientific methodologies. For sure; no religion, belief system, great political mind, anarchist, professional protester, or social commentator will produce a TV set, mobile phone, laptop, tablet, supercomputer, MRI Scanner, AI system, or vaccine! But they will criticise, challenge, and be abusive based on their ignorance and inability.
So, this is the world that now influences the minds of young aspiring students, and this presentation is designed to go beyond the simple exposition and statement of the scientific principles and method, to provide an ancient, modern, and forward-looking perspective. It also includes a complex ‘worked example’ to highlight the rigour that must be applied to establish any truth!
5 1 6 T o w a r d A l t e r n a t i v e s i n H e a l t h .docxalinainglis
5 1 6 T o w a r d A l t e r n a t i v e s i n H e a l t h C a r e
S o l o t n o n , H . A . 1 9 8 4 . T h e E x a r c i s e M y t D . N e w Y o r k :
H a r c o u r t B r a c e J o v a n o v i c h .
S p i l m a n , M . A . , A . C i o e t z , J . S c h u l t z , R . B e l l i n g h a m ,
a n d D . J o h n s o n . 1 9 8 6 . E f f e c t s o f a H e a l t h P r o m o -
t i o n P r c r g r a n t . J o u r n a l o f O c c u p a t i o n a l M e d i c i n e
2 8 : 2 8 . 5 - 8 9 .
S t e i n , . f . 1 9 8 5 . I n d u s t r y ' s N e w B o t t o m L i n e o n H e a l t h
Ciare Costs: Is Less Better? Hastings Center Report
l - 5 ( . 5 ) : l 4 * 1 8 .
S t e r l i r r g , J . D . , a r . r c l f . . f . W e i n k a m . 1 9 8 6 . E x t e n t , P e r -
s i s t e n c c a n c l C l o n s t a n c y o f t h e l { c a l t h y W o r k e r o r
H c r l t l . r y P e r s o n F . f f e c t b v A l l a n d S e l e c t e d C l a u s e s o f
Death. Journal of Occupational Medicine 28:348-
5 3 .
S y m e , L . S . , a n d L . F . B e r k m a n . 1 9 7 6 . S o c i a l C l a s s ,
Susceptibility and Illness. American Jonrnal of Epr
demiologl' I 04: l-8. ,
U.S. Department of Health, E,ducation, and !ilelfare.
1,979. Healthy People: The Surgeon General's Re-
port on Health Promotion and Disease Preuention.'Washingtorr.
'Walsl.r, D.C. 1984. Corporate Smoking Policies: A
Revrew and an Analysis. Journal of Ocarpational
M e d i c i n e 2 6 : 1 7 - 2 2 .
A Cesn FoR RrpocussrNc Upsrnndtvt: THE Pouucet
EcoruouY oF lrrlurss
. l o h n B . M c K i n l a y
M y f r i c n c l , I r v i n g Z o l a , r e l a t e s t l - r e s t o r y o f a
p h y s i c i : r r r t r y i n g t o e x p l a i n t h e d i l c m r n a s o f t h e
r n o c l e r n p r a c t i c e < l f r r e d i c i n e :
" Y o u k n o r , " ' , " l r c s a i c l , " s o r l e t i r n e s i t f e e l s l i k e t l - r i s .
T h e r c I a m s f a n c l i n g b y t l r e s h o r e o f a s w i f t l y f l o w -
i n g r i v c r a n t l I h e e r t h c c r y o f l c l r o w n i n g m a n . S o I
j r r n r p i n t o t l i c r i v c r , p u t n 1 y r r r n s a r o u n c l h i m , p u l l
h i r n t o s h o r e a n c l a p p l y a r t i l i c i a l r c s p i r a t i o n . . f u s t
w l r c n h c b c g i n s t o b r c a t h c , t h e r c i s r r t o t h e r c r y f o r
h c l p . S o I j u m p i r r t o t l r c r i v e r , r c : r c h h i m , p u l l h i n r
t o s h o l c , a p p l v a r t i f i c i e l r c s p i r a t i o n , a r - r d t h e n j u s t
a s h e b c g i r r s t o b r e a t h e , r l n o t h e r c r y f o r h e l p . S o
b a c l < i n t l r c r i v e r r r g r r i n , r c r r c h i n g , p u l l i n g , a p p l y i n g ,
b r c a t h i n g a l i c l t h c n r u r o t h c r v e l l . A g a i n a n c l a g a i n ,
w i t h o u t e u .
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
Role of Physiotherapy in treating Tennis elbow.pptxPHYSIOREVIVE _
Initially a physiotherapist In Delhi will ask you to move and flex your arm and muscles as part of the diagnostic process to localise the source of the discomfort. Some scans, such x-rays or MRIs, could be performed to rule out the possibility of other conditions, like arthritis.
These lecture slides, by Dr Sidra Arshad, offer a quick overview of the physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar lead (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
6. Describe the flow of current around the heart during the cardiac cycle
7. Discuss the placement and polarity of the leads of electrocardiograph
8. Describe the normal electrocardiograms recorded from the limb leads and explain the physiological basis of the different records that are obtained
9. Define mean electrical vector (axis) of the heart and give the normal range
10. Define the mean QRS vector
11. Describe the axes of leads (hexagonal reference system)
12. Comprehend the vectorial analysis of the normal ECG
13. Determine the mean electrical axis of the ventricular QRS and appreciate the mean axis deviation
14. Explain the concepts of current of injury, J point, and their significance
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. Chapter 3, Cardiology Explained, https://www.ncbi.nlm.nih.gov/books/NBK2214/
7. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
https://aodaitailoc.vn/ Áo Dài Cưới Tài Lộc Địa Điểm Cho Thuê Áo Dài Bưng Quả, Áo Dài Cưới Đẹp Giá Rẻ Khuyến Mãi Hàng Đầu Khu Vực Hồ Chí Minh. Địa Chỉ 35/14/9 Nguyễn Tư Giản, Phường 12, Quận Gò Vấp, TP.HCM #tailoc #aodaitailoc #aodaicuoitailoc
Recently, it has become increasingly evident that we have engineers and scientists reaching a professional level of practice without a clear understanding of the scientific method, its origins, and its fundamental workings. There also appears to be a lack of appreciation of our total dependence on the truths that science continually reveals. How this situation ensued appears to vary from country to country, and the flavour of education system encountered by students. But a common complaint is the progressive dumbing down of the science curriculum along with a dire shortage of qualified teachers. This also seems to be compounded with the increasing speciation of science and engineering into narrower and narrower disciplines. So this situation (crisis?) prompted a request for a corrective series of foundation lectures focussed on healing these educational flaws across relevant disciplines, graduating and practicing levels. This then is the first in this foundation series.
In a world that appears riven by social media, ill-informed opinion, rumour, and conspiracy theories in preference to facts and established truths, it can be alarming to see scientists, doctors, and engineers challenged by vacuous statements that often hold sway over the hard-won truths of science. Moreover, large numbers of people do not understand the ‘scientific method’ and what makes it so powerful.
Paradoxically, those challenging science and scientists based on their belief systems do so using technologies that can only be furnished by scientific methodologies. For sure; no religion, belief system, great political mind, anarchist, professional protester, or social commentator will produce a TV set, mobile phone, laptop, tablet, supercomputer, MRI Scanner, AI system, or vaccine! But they will criticise, challenge, and be abusive based on their ignorance and inability.
So, this is the world that now influences the minds of young aspiring students, and this presentation is designed to go beyond the simple exposition and statement of the scientific principles and method, to provide an ancient, modern, and forward-looking perspective. It also includes a complex ‘worked example’ to highlight the rigour that must be applied to establish any truth!
5 1 6 T o w a r d A l t e r n a t i v e s i n H e a l t h .docxalinainglis
5 1 6 T o w a r d A l t e r n a t i v e s i n H e a l t h C a r e
S o l o t n o n , H . A . 1 9 8 4 . T h e E x a r c i s e M y t D . N e w Y o r k :
H a r c o u r t B r a c e J o v a n o v i c h .
S p i l m a n , M . A . , A . C i o e t z , J . S c h u l t z , R . B e l l i n g h a m ,
a n d D . J o h n s o n . 1 9 8 6 . E f f e c t s o f a H e a l t h P r o m o -
t i o n P r c r g r a n t . J o u r n a l o f O c c u p a t i o n a l M e d i c i n e
2 8 : 2 8 . 5 - 8 9 .
S t e i n , . f . 1 9 8 5 . I n d u s t r y ' s N e w B o t t o m L i n e o n H e a l t h
Ciare Costs: Is Less Better? Hastings Center Report
l - 5 ( . 5 ) : l 4 * 1 8 .
S t e r l i r r g , J . D . , a r . r c l f . . f . W e i n k a m . 1 9 8 6 . E x t e n t , P e r -
s i s t e n c c a n c l C l o n s t a n c y o f t h e l { c a l t h y W o r k e r o r
H c r l t l . r y P e r s o n F . f f e c t b v A l l a n d S e l e c t e d C l a u s e s o f
Death. Journal of Occupational Medicine 28:348-
5 3 .
S y m e , L . S . , a n d L . F . B e r k m a n . 1 9 7 6 . S o c i a l C l a s s ,
Susceptibility and Illness. American Jonrnal of Epr
demiologl' I 04: l-8. ,
U.S. Department of Health, E,ducation, and !ilelfare.
1,979. Healthy People: The Surgeon General's Re-
port on Health Promotion and Disease Preuention.'Washingtorr.
'Walsl.r, D.C. 1984. Corporate Smoking Policies: A
Revrew and an Analysis. Journal of Ocarpational
M e d i c i n e 2 6 : 1 7 - 2 2 .
A Cesn FoR RrpocussrNc Upsrnndtvt: THE Pouucet
EcoruouY oF lrrlurss
. l o h n B . M c K i n l a y
M y f r i c n c l , I r v i n g Z o l a , r e l a t e s t l - r e s t o r y o f a
p h y s i c i : r r r t r y i n g t o e x p l a i n t h e d i l c m r n a s o f t h e
r n o c l e r n p r a c t i c e < l f r r e d i c i n e :
" Y o u k n o r , " ' , " l r c s a i c l , " s o r l e t i r n e s i t f e e l s l i k e t l - r i s .
T h e r c I a m s f a n c l i n g b y t l r e s h o r e o f a s w i f t l y f l o w -
i n g r i v c r a n t l I h e e r t h c c r y o f l c l r o w n i n g m a n . S o I
j r r n r p i n t o t l i c r i v c r , p u t n 1 y r r r n s a r o u n c l h i m , p u l l
h i r n t o s h o r e a n c l a p p l y a r t i l i c i a l r c s p i r a t i o n . . f u s t
w l r c n h c b c g i n s t o b r c a t h c , t h e r c i s r r t o t h e r c r y f o r
h c l p . S o I j u m p i r r t o t l r c r i v e r , r c : r c h h i m , p u l l h i n r
t o s h o l c , a p p l v a r t i f i c i e l r c s p i r a t i o n , a r - r d t h e n j u s t
a s h e b c g i r r s t o b r e a t h e , r l n o t h e r c r y f o r h e l p . S o
b a c l < i n t l r c r i v e r r r g r r i n , r c r r c h i n g , p u l l i n g , a p p l y i n g ,
b r c a t h i n g a l i c l t h c n r u r o t h c r v e l l . A g a i n a n c l a g a i n ,
w i t h o u t e u .
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
Role of Physiotherapy in treating Tennis elbow.pptxPHYSIOREVIVE _
Initially a physiotherapist In Delhi will ask you to move and flex your arm and muscles as part of the diagnostic process to localise the source of the discomfort. Some scans, such x-rays or MRIs, could be performed to rule out the possibility of other conditions, like arthritis.
These lecture slides, by Dr Sidra Arshad, offer a quick overview of the physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar lead (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
6. Describe the flow of current around the heart during the cardiac cycle
7. Discuss the placement and polarity of the leads of electrocardiograph
8. Describe the normal electrocardiograms recorded from the limb leads and explain the physiological basis of the different records that are obtained
9. Define mean electrical vector (axis) of the heart and give the normal range
10. Define the mean QRS vector
11. Describe the axes of leads (hexagonal reference system)
12. Comprehend the vectorial analysis of the normal ECG
13. Determine the mean electrical axis of the ventricular QRS and appreciate the mean axis deviation
14. Explain the concepts of current of injury, J point, and their significance
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. Chapter 3, Cardiology Explained, https://www.ncbi.nlm.nih.gov/books/NBK2214/
7. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
Muktapishti is a traditional Ayurvedic preparation made from Shoditha Mukta (Purified Pearl), is believed to help regulate thyroid function and reduce symptoms of hyperthyroidism due to its cooling and balancing properties. Clinical evidence on its efficacy remains limited, necessitating further research to validate its therapeutic benefits.
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.
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
Adv. biopharm. APPLICATION OF PHARMACOKINETICS : TARGETED DRUG DELIVERY SYSTEMSAkankshaAshtankar
MIP 201T & MPH 202T
ADVANCED BIOPHARMACEUTICS & PHARMACOKINETICS : UNIT 5
APPLICATION OF PHARMACOKINETICS : TARGETED DRUG DELIVERY SYSTEMS By - AKANKSHA ASHTANKAR
Local Advanced Lung Cancer: Artificial Intelligence, Synergetics, Complex Sys...Oleg Kshivets
Overall life span (LS) was 1671.7±1721.6 days and cumulative 5YS reached 62.4%, 10 years – 50.4%, 20 years – 44.6%. 94 LCP lived more than 5 years without cancer (LS=2958.6±1723.6 days), 22 – more than 10 years (LS=5571±1841.8 days). 67 LCP died because of LC (LS=471.9±344 days). AT significantly improved 5YS (68% vs. 53.7%) (P=0.028 by log-rank test). Cox modeling displayed that 5YS of LCP significantly depended on: N0-N12, T3-4, blood cell circuit, cell ratio factors (ratio between cancer cells-CC and blood cells subpopulations), LC cell dynamics, recalcification time, heparin tolerance, prothrombin index, protein, AT, procedure type (P=0.000-0.031). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and N0-12 (rank=1), thrombocytes/CC (rank=2), segmented neutrophils/CC (3), eosinophils/CC (4), erythrocytes/CC (5), healthy cells/CC (6), lymphocytes/CC (7), stick neutrophils/CC (8), leucocytes/CC (9), monocytes/CC (10). Correct prediction of 5YS was 100% by neural networks computing (error=0.000; area under ROC curve=1.0).
Rasamanikya is a excellent preparation in the field of Rasashastra, it is used in various Kushtha Roga, Shwasa, Vicharchika, Bhagandara, Vatarakta, and Phiranga Roga. In this article Preparation& Comparative analytical profile for both Formulationon i.e Rasamanikya prepared by Kushmanda swarasa & Churnodhaka Shodita Haratala. The study aims to provide insights into the comparative efficacy and analytical aspects of these formulations for enhanced therapeutic outcomes.
2. CONTENTS
• Introduction
• Development of the PDL & principal
fibres
• PDL collagen fiber attachment to the
root surface
• PDL Homeostasis
• Cells
– Synthetic cells
– Resorptive cells
– Progenitor cells
– Relationship between cells
– Epithelial rests of Malassez
– Defence cells
• Extracellular substance
– Fibers
– Ground substance
• Structures present in connective
tissue
• Functions
• Age changes
• Clinical considerations
3. PERIODONTIUM: The tissues that invest and support the teeth including the gingiva,
alveolar mucosa, cementum, periodontal ligament, and alveolar and supporting bone.
The PERIODONTAL LIGAMENT is composed of a complex vascular and highly cellular
connective tissue that surrounds the tooth root and connects it to the inner wall of the
alveolar bone.
The PERIODONTAL LIGAMENT is the soft, richly vascular and cellular connective tissue
which surrounds the roots of the teeth and joins the root cementum with the socket
wall.
The PERIODONTAL LIGAMENT occupies the periodontal space, which is located between
the cementum and the periodontal surface of the alveolar bone and extends coronally
to the most apical part of the lamina propria of the gingiva.
- Glossary of Periodontal Terms, 4th
edition
- Carranza's Clinical periodontology, 13th
edition
- Lindhe’s Clinical periodontology and Implant dentistry, 6th
edition
- Orban’s oral histology and embryology, 12th
edition
6. • Coronally, to the most apical part of
the lamina propria of the gingiva,
and demarcated by the alveolar
crest fibres.
• At the apical foramen, it is
continuous with the dental pulp.
• Ranges in width from 0.15 to 0.38
mm.
7. • An hour glass appearance, thinnest
around the middle third of the root.
• Shows a progressive decrease in
thickness with age.
• The ligament appears, as the
periodontal space of 0.4 to 1.5 mm
on radiographs.
• The periodontal spaces of the
permanent teeth are said to be
narrower than those of deciduous
teeth.
ACCORDING TO AGE :
In young adults (11-16 yrs) – 0.21
mm.
In mature adults (32-52 yrs) – 0.18
mm.
In older adults (51-67 yrs) – 0.15
mm.
Orban’s Oral Histology and Embryology, 12th edition
8. T h e d e v e l o p m e n t o f t h e p e r i o d o n t a l l i g a m e n t
b e g i n s w i t h r o o t f o r m a t i o n p r i o r t o t o o t h
e r u p t i o n .
T h e c o n t i n u o u s p r o l i f e r a t i o n o f t h e i n n e r a n d
e x t e r n a l e n a m e l e p i t h e l i u m f o r m s t h e c e r v i c a l
l o o p o f t h e t o o t h b u d .
T h i s s h e a t h o f e p i t h e l i a l c e l l s g r o w s a p i c a l l y, i n
t h e f o r m o f H e r t w i g ’ s e p i t h e l i a l r o o t s h e a t h ,
b e t w e e n t h e d e n t a l p a p i l l a a n d t h e d e n t a l
f o l l i c l e .
A t t h i s s t a g e , t h e s h e a t h f o r m s a c i r c u m f e r e n t i a l
s t r u c t u r e e n c o m p a s s i n g d e n t a l p a p i l l a
s e p a r a t i n g i t e x t e r n a l l y f r o m d e n t a l f o l l i c l e
c e l l s .
9. T h e d e n t a l f o l l i c l e c e l l s , l o c a t e d b e t we e n t h e
a lve o l a r b o n e a n d t h e e p i t h e l i a l ro o t s h e a t h , a re
c o m p o s e d o f t wo s u b p o p u l a t i o n s ;
Mesenchymal cells
of the dental
follicle proper
The perifollicular
mesenchyme
Dental
follicle cells
10. T h e m e s e n c h y m a l c e l l s o f t h e p e r i f o l l i c u l a r
m e s e n c h y m e b o u n d e d b y t h e d e n t a l f o l l i c l e p r o p e r
a n d t h e d e v e l o p i n g a l v e o l a r b o n e a r e s t e l l a t e -
s h a p e d , s m a l l , a n d r a n d o m l y o r i e n t e d .
I n c o n t r a s t t o t h e d e n t a l f o l l i c l e p r o p e r, t h e c e l l s o f
t h e p e r i f o l l i c u l a r m e s e n c h y m e a r e r a t h e r w i d e l y
s e p a r a t e d .
U l t r a s t r u c t u r a l s t u d y o f t h e s e c e l l s i n d i c a t e s t h a t
t h e y c o n t a i n a n e u c h r o m a t i c n u c l e u s a n d s m a l l
c y t o p l a s m t h a t c o n t a i n s a s m a l l n u m b e r o f s h o r t
c i s t e r n a e o f r o u g h e n d o p l a s m i c r e t i c u l u m ,
m i t o c h o n d r i a , f r e e r i b o s o m e s , a n d a n i n a c t i v e G o l g i
a r e a .
T h e s e c e l l s a l s o h a v e s e v e r a l l o n g a n d t h i n
11. As the root formation continues, cells in the
perifollicular area gain their polarity, increased
cellular volume and synthetic activity.
These cells become elongated and contain
increased numbers of rough endoplasmic reticulum
and mitochondria and an active Golgi complex.
As a result, they actively synthesize and deposit
collagen fibrils and glycoproteins in the developing
periodontal ligament.
Mostly type I collagen is secreted, which assembles
as collagen bundles extending from bone and
cementum surfaces.
Establish continuity across the ligament space and
thereby secure an attachment of the tooth to the
bone.
12. D
E
V
E
L
O
P
M
E
N
T
O
F
P
R
I
N
C
I
P
A
L
F
I
B
R
E
S
Immediately before tooth eruption, and for sometime
thereafter, active fibroblasts adjacent to cementum of the
coronal third of the root, appear to become aligned in an
oblique direction to the long axis of the tooth.
when the tooth erupts, the crest of the alveolar bone
is coronal to the CEJ and the developing fibers are
directed obliquely.
When the tooth moves during eruption, the level of the
alveolar crest coincides with the CEJ junction and the
oblique fibres become horizontally aligned.
13. The horizontal fibers termed as alveolar crest fibers have
become oblique once again but with the difference that
now the CEJ has reversed its relation to the alveolar
attachment and is positioned in a coronal direction.
Once the teeth come into function and the apical fiber
group is formed, the definitive periodontal ligament
architecture is established.
Alveolar crest fiber Initially oblique
Then
horizontal
Finally
again
oblique
14. • First, small, fine,
brush‐like fibrils are
detected arising from the
root cementum and
projecting into the
periodontal ligament
space.
• At this stage the surface
of the bone is covered by
osteoblasts.
• From the surface of the
bone only a small
number of radiating, thin
collagen fibrils can be
seen.
• Later on, the number and
thickness of fibers entering the
bone increase.
• These fibers radiate towards the
loose connective tissue in the
mid‐portion of the periodontal
ligament space, which contains
more or less randomly oriented
collagen fibrils.
• The fibers originating from the
cementum are still short, while
those entering the bone gradually
lengthen.
• The terminal portions of these
fibers carry finger‐like projections.
• The fibers originating from
the cementum
subsequently increase in
length and thickness and
fuse in the periodontal
ligament space with the
fibers originating from the
alveolar bone.
• When the tooth, following
eruption, reaches contact in
occlusion and starts to
function, the principal fibers
become organized into
bundles and run
continuously from the bone
to the cementum.
Lindhe’s
Clinical
periodontology
and
Implant
dentistry,
6
th
edition
15. PERIODONTAL LIGAMENT HOMEOSTASIS
The periodontal ligament has the capacity to maintain its width more or less overtime
despite the fact, that it is squeezed in between two hard tissues.
Studies indicate that the population of cells, within the periodontal ligament, both during
development and regeneration, secrete molecules that can regulate the extent of
mineralization and prevent ankylosis.
Various molecules have been proposed, which play a role in maintaining an unmineralized
periodontal ligament :
Periodontal cells can inhibit mineralised bone nodule formation by bone stromal cells;
the inhibition may be dependant on prostaglandin production.
Msx2 prevents the osteogenic differentiation of periodontal ligament fibroblasts, by
repressing Runx2 transcriptional activity.
The balance between the activities of bone sialoprotein and osteopontin may also
contribute in maintaining an unmineralized periodontal ligament region.
Matrix ‘Gla’ protein, an inhibitor of mineralization; role in preserving the width of the
16. – Glycosaminoglycans or RGD-cementum attachment protein, a collagen
associated protein; role in maintaining the unmineralized state of the
periodontal ligament.
• Periodontal ligament has the capacity to adapt to functional changes;
When the functional demand
increases
When there is reduction in
function
21. C E L L S W I T H T H E S E M O R P H O LO G I C C H A R AC T E R I S T I C S ;
22. T h e p r e d o m i n a n t c e l l i n t h e p e r i o d o n t a l
l i g a m e n t .
V a r i e t y o f i t s c e l l p o p u l a t i o n s w i t h d i f f e r e n t
f u n c t i o n a l c h a r a c t e r i s t i c s ;
fibroblasts on the bone side of the ligament show abundant
alkaline phosphatase activity than those on the tooth side.
D e v e l o p m e n t a l d i f f e r e n c e s ;
a) Fibroblasts near cementum are derived from ectomesenchymal
cells of the investing layer of dental papilla, while
b) Fibroblasts near alveolar bone are derived from perivascular
mesenchyme.
23. Also have well
developed
cytoskeleton and show
adherens and gap
junctions.
MORPHOLOGY
• Flattened irregular disc like
• Large cells with extensive cytoplasm and abundant organelles, associated
with protein synthesis and secretion.
• Nucleus occupies a large volume of the cells with one or more prominent
nucleoli.
• Long and thin cytoplasmic extensions that form three-dimensional veils
that compartmentalize collagen fibrils into fibers.
• Have cilia ; associated with control of cell cycle or inhibition of centriolar
activity.
24. R e g u l a r l y d i s t r i b u t e d t h r o u g h o u t t h e l i g a m e n t ;
o r i e n t e d w i t h t h e i r l o n g ax i s o f p a r a l l e l t o t h e
d i r e c t i o n o f c o l l a g e n f i b r i l s .
G e n e r a t e a n o r g a n i z a t i o n a l p a t t e r n , a s t h e y h a v e
t h e a b i l i t y t o b o t h s y n t h e s i z e a n d s h a p e t h e
p r o t e i n s o f t h e e x t r a c e l l u l a r m a t r i x , i n w h i c h
c o l l a g e n f i b r i l s f o r m b u n d l e s , t h a t i n s e r t i n t o
t o o t h a n d b o n e a s S h a r p e y ’ s f i b e r s .
Characterized by rapid turnover of
extracellular matrix in particular collagen.
25. R o l e o f f i b r o b l a s t s -
a. To produce the structural connective tissue proteins,
collagen and elastin,
b. As well as to produce glycoproteins and glycosaminoglycans
that comprise the periodontal ligament ground substance.
c. Also secrete an active collagenase and a family of enzymes
collectively known as matrix metalloproteinases (MMPs).
d. Responsible for the formation and remodeling of the
periodontal ligament fibers.
e. Maintain the width, by preventing encroachment of bone and
cementum into periodontal space.
26. • The osteoblasts covering the
periodontal surface of the alveolar
bone constitute a modified endosteum
and not a periosteum.
• A cellular layer, but not an outer
fibrous layer, is present on the
periodontal surface of the alveolar
bone.
27. • Cells contact one another through desmosomes
and tight junctions.
• Are also in contact with underlying osteocytes
through cytoplasmic processes.
28. These cells line the surfac
of cementum, but are not
regularly arranged as
osteoblasts.
29. • Cuboidal with a large vesicular
nucleus, with one or more nucleoli
and abundant cytoplasm.
• Organelles for protein synthesis and
secretion are present.
• Have abundant mitochondria and
less amounts of RER than
periodontal ligament fibroblasts.
Shows gap junctions and
desmosomes and has receptors for
growth hormone and epidermal
growth factor.
Cells actively depositing
cellular cementum;
• Exhibit abundant
basophilic cytoplasm
and cytoplasmic
processes
• The nuclei are folded
and irregularly shaped.
Cells depositing acellular
cementum do not have
prominent cytoplasmic
processes.
MORPHOLOGY
30.
31. OSTEOCLASTS
• Cells that resorb bone.
• Tend to be large and
multinucleated but can also be
small and mononuclear.
32. • Eosinophilic cytoplasm.
• Appear to occupy bays in bone or surround the end of a
bone spicule.
• Exhibit numerous mitochondria and lysosomes
• Abundant Golgi saccules
• Free ribosomes but little RER.
• Part of the plasma membrane lying adjacent to bone that is
being resorbed is raised in characteristic folds and is
termed the ruffled or striated border.
• The ruffled border is separated from the rest of the plasma
membrane by a zone of specialized membrane that is closely
applied to the bone, the underlying cytoplasm of which
tends to be devoid of organelles and has been called the
clear zone.
• The bone related to the ruffled border can be seen undergoing
resorption.
• Exposed to highly acidic pH by virtue of the active pumping protons
by the osteoclasts into this environment.
O
S
T
E
O
C
L
A
S
T
S
33. FIBROBLASTS
• The cells show rapid degradation of collagen by fibroblast phagocytosis and that is
the basis of rapid turnover of collagen in periodontal ligament.
• The degradation of collagen may be expected to include both intracellular and
extracellular events.
• EXTRACELLULAR EVENTS –
– Degradation involve Collagenase (MMP-1); to cleave the triple helical portion of
molecules within the fibril.
– Together with MMP-IV, it leads to denaturation of collagen under physiological
conditions.
– The rest of the molecule undergoes further proteolysis by MMP-11 (gelatinase)
and MMP-V.
– Before any of these collagenase activities can occur, glycoproteins such as
fibronectin and proteoglycans on fibril surface, which mask the collagenase
binding site must be removed by stromelysin (MMP-III).
34. When a collagen fibril is phagocytosed by
the fibroblast, a banded fibril surrounded
by an electron-lucent zone is seen .
Subsequently, the banded fibrils are
surrounded by electron-dense
zone.
At this stage phagosome fuses with
primary lysosomes to form a
phagolysosome
At the terminal stage, fibrils show indistinct banding
and are surrounded by electron dense zone; the
fibril loses its characteristic structure by this point.
35. CEMENTOCLASTS
• Resembles osteoclasts and are occasionally found in
normal functioning periodontal ligament.
• Not remodelled in the fashion of alveolar bone and
periodontal ligament but that it undergoes
continual deposition during life.
• Resorption of cementum can occur under certain
circumstances; the mononuclear cementoclasts or
multinucleated giant cells, often located in
Howship’s lacunae, are found on the surface of the
cementum.
• Origin is unknown; conceivable that they arise in
36.
37. P r o g e n i t o r c e l l s a r e t h e c e l l s , w h i c h h a v e t h e c a p a c i t y
t o u n d e r g o m i t o t i c d i v i s i o n a n d r e p l a c e t h e
d i f f e r e n t i a t e d c e l l s d y i n g a t t h e e n d o f t h e i r l i f e o r a s a
r e s u l t o f t r a u m a .
L o c a t e d i n p e r i v a s c u l a r r e g i o n , a n d e x h i b i t s o m e
c l a s s i c a l c y t o l o g i c a l f e a t u r e s o f s t e m c e l l s ;
38. • T h e r e a r e c e l l s w i t h c h a r a c t e r i s t i c s of
m e s e n c h y m a l s t e m c e l l s c a pa b l e of s u s t a i n e d
r e n e w a l a n d t i s s u e r e g e n e r a t i o n .
• T h e y r e m a i n w i t h i n t h e P D L a n d a r e r e s p o n s i b l e
f o r t i s s u e h o m e o s t a s i s , s e r v i n g a s a s o u r c e of
r e n e w a b l e p r o g e n i t o r c e l l s g e n e r a t i n g
c e m e n t o b l a s t s , o s t e o b l a s t s a n d f i b r o b l a s t s
t h r o u g h o u t a d u l t l i f e .
• I n t h e e v e n t of i n j u r y t o t h e p e r i o d o n t i u m , t h e s e
m e s e n c h y m a l s t e m c e l l s c o u l d b e a c t i va t e d
t o w a r d s t e r m i n a l d i f f e r e n t i a t i o n a n d t i s s u e r e p a i r
39. R E L AT I O N S H I P B E T W E E N C E L L S
C e l l s of P D L f o r m a t h r e e - d i m e n s i o n a l n e t w o r k .
A s s o c i a t e d w i t h b o n e , f i b r o u s C T, a n d c e m e n t u m
a r e s e p a r a t e d f r o m o n e a n o t h e r, b u t a d j a c e n t
c e l l s g e n e r a l l y a r e i n c o n t a c t w i t h t h e i r
n e i g h b o u r s , u s u a l l y t h r o u g h t h e i r p r o c e s s e s .
T h e n a t u r e of j u n c t i o n s n o t c l e a r, a l t h o u g h
a p p e a r t o b e z o n u l a o c c l u d e n s , i n f a c t
c o n c e i va b l y g a p j u n c t i o n s .
40.
41. • First described by MALASSEZ in 1884.
• Found close to the cementum.
• These are the remnants of the epithelium of Hertwig’s epithelial root
sheath.
• At the time of cementum formation, the continuous layer of epithelium that
covers the surface of the newly formed dentin breaks into lacelike strands.
• The epithelial rests persist as a network, strands, islands, or tubulelike
structures near and parallel to the surface of the root.
• In cross sections, they appear clusterlike; the arrangement appear like a duct
with the cells separated from the surrounding connective tissue by a basal
lamina.
• Abundantly located in the furcation areas.
• Could be involved in periodontal repair and regeneration.
• Less numerous in older individuals and more numerous in children.
• Upto the second decade, most commonly found in apical region, later mainly
42. HOW IT IS DIFFERENT FROM FIBROBLASTS??
Close packing of their cuboidal cells.
Nucleus stains more deeply and is prominent.
Cytoplasm is scanty, and shows Tonofibrils that insert into the
desmosomes found between the cells and into the
hemidesmosomes between the cells and the basal lamina.
Tight junctions are also seen.
Mitochondria distributed throughout the cytoplasm.
RER and Golgi apparatus are poorly developed, indicating
of protein synthesis.
Epithelial cell rests attach to and spread rapidly on fibronectin,
vitronectin and type I collagen present in the extracellular
matrix.
43.
44. MAST CELLS
• Relatively small, round or oval cell having a diameter of
about 12 to 15 µm.
• Often associated with blood vessels.
• Characterized by numerous cytoplasmic granules, which
frequently obscure small, round nucleus.
0.5-1 µm in diameter.
Positively stained by the periodic acid-Schiff
reaction.
Dense, membrane-bound vesicles of varying
sizes.
Contain heparin and histamine.
Degranulates when stimulated.
45. • Cytoplasm contains free ribosomes, short profiles of granular and
endoplasmic reticulum, few round mitochondria, and a prominent Golgi
apparatus.
• Occasionally may be seen in the healthy periodontal ligament.
Role
• In the inflammatory reaction; degranulate in response to antigen-
antibody formation on their surface.
• Release of histamine causes proliferation of endothelial cells and
mesenchymal cells.
• Regulation of endothelial and fibroblast cell populations.
46. MACROPHAGES
• Found in the PDL predominately located adjacent
to blood vessels.
• Numerous microvilli, lysosomes,
and membrane bound vesicles.
• Paucity of RER and Golgi complex.
Derived from blood monocytes.
Horseshoe or kidney shaped
nucleus, generally of regular
contour, exhibits a dense uneven
layer of peripheral chromatin.
Nucleoli are rarely seen.
Cell surface is generally raised in
microvilli.
Cytoplasm contains numerous free
ribosomes and lysosomes.
RER is relatively sparse with widely
spaced polysomes that are
composed of only 2-4 ribosomes
each.
Golgi apparatus is not well
developed
RESTING MACROPHAGES WANDERING MACROPHAGES
47.
48. ROLE
P h a g o c y t o s i n g d e a d c e l l s
S e c r e t i n g g r o w t h f a c t o r s t h a t r e g u l a t e t h e
p r o l i f e r a t i o n of a d j a c e n t f i b r o b l a s t s .
A l s o s y n t h e s i z e a r a n g e of m o l e c u l e s l i ke
i n t e r f e r o n s , p r o s t a g l a n d i n s a n d f a c t o r s t h a t
e n h a n c e t h e g r o w t h of f i b r o b l a s t s a n d
e n d o t h e l i a l c e l l s .
49. EOSINOPHILS
Occasionally seen in the
PDL.
Possess granules that
consist of one or more
crystalloid structures.
Capable of phagocytosis.
51. FIBERS
• M a i n l y CO L L AG E N O U S .
• M a y b e s m a l l a m o u n t s of OX Y TA L A N A N D R E T I C U L I N
F I B E R S , a n d
• E L A S T I N F I B E R S i n s o m e s p e c i e s .
52. PRINCIPAL FIBERS
• The principal fibers are collagenous in nature.
• Composed of 3 polypeptide α-chain coiled around each other- Triple helix.
• Arranged in bundles approx. 5 µm in diameter.
• Follow a wavy course.
• Within each bundle, subunits present are called collagen fibrils; have transverse
striations with a characteristic periodicity of 64 nm.
• Primarily composed of type I & III collagen; more than 70% is type I and 20% is type III.
• Small amounts of type V and type VI collagens, and traces of type IV and type VII
collagen are also found in the ligament.
• Type IV and VII are associated with epithelial cell rests and blood vessels.
53.
54. ALVEOLODENTAL
LIGAMENT
• The principal fiber group is the Alveolodental ligament.
• FIVE FIBER GROUPS;
ALVEOLAR CREST
HORIZONTAL
OBLIQUE
APICAL
* INTERRADICULAR GROUP
(In multirooted teeth)
55. • These fibers extend obliquely from
the cementum just beneath the
junctional epithelium to the alveolar
crest.
• Resist tilting, intrusive, extrusive, and
rotational forces.
56. HORIZONTAL
• Horizontal fibers extend at right angles
to the long axis of tooth from cementum
to alveolar bone.
• Parallel to the occlusal plane of the arch.
• These fibers are located immediately
apical to the level of alveolar crest fiber
group; limited to the coronal 1/4th of the
PDL.
• These fibers resists horizontal and
tipping forces.
57. OBLIQUE
• Nearly 2/3rd of the PDL.
• Inserted into the alveolar bone at a
position coronal to their attachment to
cementum; oblique orientation in the PDL
space.
• These fibers mainly resists the vertical and
intrusive forces.
• They bear the brunt of vertical masticatory
stresses and transfer them on to the
alveolar bone.
58. APICAL
• From the cementum to the root tip.
• Radiate through the PDL space to
become anchored into the fundus of
bony socket.
• Resist luxation forces, may prevent
tipping and probably protect delicate
blood and lymph vessels and nerves
traversing the PDL space at the apex.
• They do not occur on incompletely
59. • Inserted into the cementum from
the crest of interradicular septum in
multirooted teeth.
• Resist tooth tipping, torquing and
luxation.
• Total loss of these fibers in chronic
inflammatory periodontal disease.
62. ELASTIC FIBERS
E l a s t i c m e s h w o r k i n t h e P D L i s c o m p o s e d o f
m a n y e l a s t i n l a m e l l a e w i t h p e r i p h e r a l o x y t a l a n
f i b e r s a n d e l u a n i n f i b e r s .
THREE TYPES:
• EL ASTIN
• ELUANIN
• OXY TAL AN
MATURE ELASTIC FIBERS
IMMATURE ELASTIC FIBERS
63. ELASTIN
• Mature elastic fibers consist of a
microfibrillar component surrounding
an amorphous core of elastin.
• High %age of glycine, proline, and
hydrophobic residues, with little
hydroxyproline and no hydroxylysine.
• Observed only in walls of afferent
blood vessels
64. ELUANIN
• Bundles of microfibrils
embedded in a relatively small
amount of amorphous elastin.
• Found within the fibers of the
gingival ligament.
65. OXYTALAN
• Consists of microfibrillar component only.
• Approx. 0.5µm to 2.5µm in diameter.
• Orientation- tend to run in an axial direction,
from cementum or possibly bone eventually
embedding into the wall of the blood vessel.
• Within PDL proper, longitudinally orientated,
crossing the oblique fibers perpendicularly.
• Play a part in supporting the blood vessels of
the PDL
• May have a role in tooth support.
66. I
N
T
E
R
M
E
D
I
A
T
E
P
L
E
X
U
S
Earlier, it was
believed that the
fibers followed a
wavy course from
cementum to bone
and are joined in
the mid region of
the PDL space,
giving rise to a
zone of distinct
appearance, the so-
called intermediate
intermediate
plexus.
Research over past
years suggests that
cemental fibers meet
and fuse with osseous
fibers, no such plexus
remains.
Secondly, the entire
PDL is metabolically
active, not just the
middle or intermediate
intermediate zone.
(Thomas M. Hassel)
The recent
concept, fibers
cross the entire
width of PDL space,
but branch en
route and join
neighbouring
fibers to form a
complex three
dimensional
network.
* N o i n t e r m e d i a t e p l e x u s i s s e e n a c r o s s t h e P D L
s p a c e i n t e e t h o f n o n c o n t i n u o u s g r o w t h .
67.
68. • Gel like matrix in which are embedded the cellular and fibrous components
such as collagen.
• Contain 70% water.
• Occupied by non collagenous proteins, which represent 10% of total
protein found in the PDL..
• Consists mainly of hyaluronate, GAGs, proteoglycans, and glycoproteins.
• All components of the ground substance are presumed to be secreted by
fibroblasts.
• Two proteoglycans identified in the PDL; proteodermatan sulfate and
chondroitin sulfate.
• GAGs are linear polymers of disaccharide repeat sequence; contains heparin
69. • Substrate adhesion molecules such as tenascin, osteonectin, laminin,
undulin, and fibronectin have also been identified.
– Fibronectin and osteonectin are uniformly distributed.
– Tenascin commonly found in the attachment zones located near the
cementum and alveolar bone; may act to transfer the forces of
mastication and the stresses of tooth support to specific protein
structures.
– Laminin has been found principally in the basement membrane of
the epithelial rests of Malassez.
– Undulin found to be associated with tightly packed major collagen
fibrils.
70.
71. ARTERIAL SUPPLY
• Main blood supply is from superior and inferior
alveolar arteries. The blood vessels are derived from
the following:
– Branches from apical vessels supplying the
pulp.
– Branches from intra-alveolar vessels: Vessels
run horizontally and penetrate the alveolar bone
to enter into the periodontal ligament.
– Branches from gingival vessels: These enter
from the coronal direction.
• The arterioles and capillaries ramify and form a rich
network.
72. Arterioles range from a diameter of 15-50 µm with an avg. diameter of 20 µm.
The crevicular capillary loops arise from circular plexus of 1-4 intercommunicating
vessels of 6-30 µm diameter at the level of JE.
Blood supply increases from incisors to molars.
Single rooted teeth - gingival third > apical third > middle third.
In molars, gingival area > middle third = apical third.
Venous drainage -
Accompanying the arterial counterparts.
Larger in diameter with an average of 28 µm.
Receive blood from the capillary network and also specialized shunts called
glomera in the PDL.
73. T h e f l o w i s v i a t h e a l v e o l a r l y m p h c h a n n e l s w h i c h
a r e j o i n e d b y t h e d e n t a l a n d i n t e r r a d i c u l a r l y m p h
c h a n n e l s .
88. VI. ERUPTIVE
Provides space and acts as a medium for cellular
remodeling and hence continued eruption, and
approximal shift occurs.
89.
90.
91.
92.
93. CEMENTICLES
Small calcified bodies.
Remain free or fused into large calcified
mass or may be joined with the
cementum.
When adherent with the cementum,
they form excementoses.
Degenerated epithelial cells form the
nidus for their calcification.
Old age
95. • Chronic periodontal disease can lead to infusion of
microorganisms into the blood stream.
• The pressure receptors in ligament have a protective role.
Apical blood vessels are protected from excessive
compression by sensory apparatus of the teeth.
• The rate of mesial drift of tooth is related to health, dietary
factor and age. It varies from 0.05 to 0.7mm per year.
96. TRAUMA
• The trauma can result from number of
ways:
Abnormal occlusal function, accidental
blows.
Premature contacts from high points in
restoration.
Excessive orthodontic forces.
• All of the above leads to pulpal injury
result in periapical changes.
Over instrumentation during
RCT causes profuse periapical
haemorrhage and
dissemination of dentin debris
beyond the apical foramina.
It result in edematous PDL,
intense neutrophil
inflammatory infiltrate.
97. • When there is very less damage to PDL –
Adjacent PDL proliferates.
Inflammatory resorption : When there is
infection – inflammation of bone and PDL –
which is replaced by granulation tissue.
Replacement resorption :
When there is severe
damage to PDL - resorption
of bone, cementum, PDL -
it is replaced by the bone.
Results in ankylosis of tooth
98. ORTHODONTIC TOOTH
MOVEMENT
• Depends on resorption and formation of
bone and periodontal ligament (i.e.
remodelling).
• When a orthodontic force is applied
through PDL to the tooth, there is an initial
compression of PDL on pressure side
followed by the bone-resorption, whereas
in tension side there is bone apposition.
• Application of large amount of force result
in necrosis and death of PDL
Editor's Notes
Runx2- runt related transcription factor 2, Msx2 homeobox protein is a part of chemical signaling pathway known as the bone morphogenic protein pathway, regulates various cellular processes and is involved in the growth of cells , including new bone cells
Striations caused by the overlapping arrangement of the tropocollagen molecules.