The document discusses the temporomandibular joint (TMJ) and muscles of mastication. It covers the evolution, embryology, anatomy, histology and biomechanics of the TMJ. The TMJ is a synovial diarthrodial joint that allows gliding and rotational movements. It involves the mandibular condyle articulating with the temporal bone. The muscles of mastication include the masseter, temporalis, medial pterygoid and lateral pterygoid muscles. Common TMJ disorders include disc displacements, derangements, and inflammatory conditions like synovitis, capsulitis and arthritis.
this presentation describes the detail anatomy of Temporo-mandibular joint with respect to its articulating surfaces, ligaments, muscles and blood and nerve supply.
this presentation describes the detail anatomy of Temporo-mandibular joint with respect to its articulating surfaces, ligaments, muscles and blood and nerve supply.
The temporomandibular joint is the joint of the jaw and is frequently referred to as TMJ. The TMJ is a bilateral synovial articulation between the mandible and temporal bone. The name of the joint is derived from the two bones which form the joint: the upper temporal bone which is part of the cranium (skull), and the lower jawbone or mandible.
There are six main components of the TMJ.
Mandibular condyles
Articular surface of the temporal bone
Capsule
Articular disc
Ligaments
Lateral pterygoid
Basics about TMJ ( development fuction movement etc ) with classification of tmj disorders and stress on tmj examination.
Also covers muscles of masstication
Muscles of mastication are the group of muscles that help in movement of the mandible as during chewing and speech. We need to study these muscles as they control the opening & closing the mouth & their role in the equilibrium created within the mouth. They also play a role in the configuration of face.
A Brief description of the causes and clinical manifestations of the internal derangement of the temporomandibular joint , with particular emphasis on Disc Displacements .
The temporomandibular joint is the joint of the jaw and is frequently referred to as TMJ. The TMJ is a bilateral synovial articulation between the mandible and temporal bone. The name of the joint is derived from the two bones which form the joint: the upper temporal bone which is part of the cranium (skull), and the lower jawbone or mandible.
There are six main components of the TMJ.
Mandibular condyles
Articular surface of the temporal bone
Capsule
Articular disc
Ligaments
Lateral pterygoid
Basics about TMJ ( development fuction movement etc ) with classification of tmj disorders and stress on tmj examination.
Also covers muscles of masstication
Muscles of mastication are the group of muscles that help in movement of the mandible as during chewing and speech. We need to study these muscles as they control the opening & closing the mouth & their role in the equilibrium created within the mouth. They also play a role in the configuration of face.
A Brief description of the causes and clinical manifestations of the internal derangement of the temporomandibular joint , with particular emphasis on Disc Displacements .
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.
Arthrocentesis of the temporomandibular jointAhmed Adawy
Dr. Ahmed M. Adawy, Professor Emeritus, Dep. Oral & Maxillofacial Surgery. Former Dean, Faculty of Dental Medicine, Al-Azhar University. Arthrocentesis of the temporomandibular joint refers to lavage of the upper joint space, hydraulic pressure and manipulation to release adhesions of the “anchored disc phenomenon” and improve motion. The technique of arthrocentesis is discussed together with the indications and contraindications of the procedure. Further, the presentation includes modifications of the standard technique.
Temporomandibular joint is the most complex and unique joint of the body and to understand its surgical anatomy is very important in the surgical management of its disorders .
The prostate is an exocrine gland of the male mammalian reproductive system
It is a walnut-sized gland that forms part of the male reproductive system and is located in front of the rectum and just below the urinary bladder
Function is to store and secrete a clear, slightly alkaline fluid that constitutes 10-30% of the volume of the seminal fluid that along with the spermatozoa, constitutes semen
A healthy human prostate measures (4cm-vertical, by 3cm-horizontal, 2cm ant-post ).
It surrounds the urethra just below the urinary bladder. It has anterior, median, posterior and two lateral lobes
It’s work is regulated by androgens which are responsible for male sex characteristics
Generalised disease of the prostate due to hormonal derangement which leads to non malignant enlargement of the gland (increase in the number of epithelial cells and stromal tissue)to cause compression of the urethra leading to symptoms (LUTS
Report Back from SGO 2024: What’s the Latest in Cervical Cancer?bkling
Are you curious about what’s new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Women’s Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
These lecture slides, by Dr Sidra Arshad, offer a quick overview of 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 leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
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. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
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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.
Title: Sense of Smell
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 primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
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!
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Ve...kevinkariuki227
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
- Video recording of this lecture in English language: https://youtu.be/lK81BzxMqdo
- Video recording of this lecture in Arabic language: https://youtu.be/Ve4P0COk9OI
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
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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
These simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
3. JOINT
• Joint is a junction between two or more bones & is
responsible for movement, growth or transmission of
forces.
• Classification
Based on
function
Synarthosis Diarthosis
6. Diarthosis - Synovial joint
• Permits significant movement
• Features:
- 2 bones (articular surface covered by hyaline cartilage)
- capsule
- synovial fluid
• Classified based on shape of articular surfaces
7. TEMPOROMANDIBULAR JOINT
So called a temporomandibular joint as the involving bones are
the mandible & the os temporale.
Synonyms:
Compound
system
Synovial
joint
Ginglymo
arthrodial
joint,
Diarthoidal
joint
8. Evolution
• Amphibian skull: Confinement of teeth to dentary bone.
• Articulation : between the terminal portion of the meckel’s
cartilage (articulare) & palatoquadrate bar.
• Reptile skull: Joint in the same palatoquadrate & articulare but
dentary joint is increased in size.
9. • Mammal like reptile fossil:
– Dentary is increased greatly & possess a coronoid process.
– Jaw articulation is still the same.
• Mammals: Dentary articulates with the temporal bone.
10. Embryology of TMJ
• Ontogenetically & Phylogenitically tmj is a secondary joint.
• Temperomandibular joint
11. • 7th week - Articulation between malleus and incus at the
dorsal end of Meckel’s cartilage - PRIMARY
JOINT .
• 8th week- Membranous Bone laid down in a plate like form
lateral to Meckels cartilage.
• 10 weeks- evidence of future joint as mesenchyme between the
condylar cartilage & developing temporal bone.
12.
13. • 12 weeks:
2 mesenchymal condensations
Condylar grows dorsolaterally
Ossification of temporal blastema
Inferior joint cavity
Differentiation of condylar into cartilage & Sup.joint cavity
Formation of disc
14. • 13th week : Condyle and articular disk have moved up into
contact with temporal bone.
• Remnant of meckels cartilage - sphenomandibular ligament
• Full differentiation of all articular surfaces occurs by 4th fetal
month.
16. GENES REQUIRED FOR THE
FORMATION OF TMJ
• Key gene noted to be expressed in condylar cartilage is
INDIAN HEDGEHOG (IHH)
Secreted by prehypertrophic chondrocytes that are just
entering the differentiation pathway.
17. • FGF and FGF receptor (Fgfr) gene families - all stages of bone
development.
• Fgfr1 – periosteum of the condyle and fossa
• Fgfr2 – perichondrium of the condyle and fossa
• Fgfr3 - immature chondrocytes of the condyle .
18. Pecularities of tmj
A. Bilateral diarthosis
B. Articular surface covered by fibrocartilage
C. Last joint among diarthoidals to begin development
D. Development from 2 blastemas
Synovial joint( 7th week) TMJ
19. Articular surface of tmj
• Upper – articulae eminence of mandibular fossa of temporal
bone
• Lower – condylar process of mandible
mandibular fossa of temporal bone
condylar process of mandible
22. 1. CONDYLE:
• Transversely elliptical in shape
• Head is covered with fibro-cartilage-articulates with anterior
part of mandibular fossa of temporal bone
26. • Between Attachments to capsular ligament is tendinous fibres
of superior lateral pterygoid
• Disc attaches to capsular ligament not only anteriorly &
posteriorly but also medially & laterally.
27. • Movements of tmj:
– Superior cavity: Gliding movement.
– Inferior cavity: Rotatory +Gliding movement
• Functions of articular disc
i. Separation
ii. Protection
iii. stabilization
During functional movements of
condyle
28. Synovial membrane
• Internal surfaces of cavity are surrounded
by specialized endothelial cells forming
synovial lining.
• The lining located at the anterior border
of retrodiscal tissue produces synovial
fluid.
29. Synovial fluid
• Ultra filtrate of blood plasma
• Clear or pale yellow, viscous, slightly alkaline fluid.
• Dialysate of blood that also contains mucin( hyaluronic acid)
lymphocytes, monocytes, and macrophages.
• Functions
a. Nutrition of articular cartilage
b. Lubrication of the joint cavity
c. Prevents wear & tear.
30. character Normal plasma Synovial fluid
Chief content water Hyaluronic acid
protein High protein content Low protein content
amount 55% of total blood
volume
2ml
31. Mechanism of lubrication
• Primary mechanism of
lubrication
• Prevents friction in
moving joint
Boundary
lubrication
• Facilitates Metabolic
exchange
• Eliminates small amount
of friction in Compressed
but not moving joint
Weeping
lubrication
32. Ligaments
• Collagenous & act predominantly as restraints to motion of the
condyle and the disc.
Functional
ligaments
Accessory
ligaments
35. 1. Outer oblique portion:
Resists excessive dropping of condyle during mouth
opening
Oop resists the impingement submandibular &
retromandibular structures..
36. 2. Inner horizontal portion:
Prevents further posterior movement of condyle into the
gleniod fossa
Eg: During extreme trauma to mandible, neck of condyle
fractures before the retrodiscal tissues are injured.
41. Sphenomandibular ligament
• Derived from fibrous envelope of Meckel’s cartilage of first
branchial arch
• No significant movement
42. Stylomandibular ligament
• Formed by thickening of deep fascia
• Separates parotid gland from submandibular gland
43. HISTOLOGY OF TMJ
• 4 distinct zones in the articular surfaces of condyle &
mandibular fossa
i. Articular zone
ii. Proliferative zone
iii. Fibro Cartilagenous zone
iv. Calcified zone
53. • Applied anatomy
a) The motor part of mandibular nerve is tested by asking the
patient to clench his teeth and then feeling for the contracting
masseter and temporalis muscles.
b) If one masseter is paralysed the jaw deviates to paralyzed side
on opening the mouth by action of normal lateral pterygoid of
opposite side.
59. • Applied anatomy
Bleeding created by needle puncture in medial pterygoid
muscle produces a hematoma followed by fibrosis and
subsequent trismus.
61. • Nerve supply - branch of ant div of madibular nerve
• Blood supply: Maxillary artery.
• Action- Depression, protrusion & side to side movements
62. • When medial and lateral pterygoids of two sides act together
they protrude the mandible so that lower incisors project in
front of upper.
• Upper head - Chewing
• lower head - Protrusion.
64. • Sphenomandibularis-5th muscle
• Discovered by Dunn et al in the mid
1990s at University of Maryland,
Baltimore.
• Considered to be a part of temporalis.
• Origin- Infratemporal surface of greater
wing of sphenoid bone.
Insertion-Temporal crest of mandible.
65. • Blood supply- From maxillary artery, from vessels of medial
pterygoid.
• Nerve supply- Not yet determined
• Function: Considered as an elevator muscle of mandible
67. EXAMINATION OF TMJ
• Interincisally : 53- 58 mm
• Restricted mouth opening:
– Mouth opening : < 40 mm
– Lateral & protrusive movement:< 8mm
68. PALPATION OF TMJ
• Pain & tenderness of TMJ is determined by digital palpation
when mandible is in both stationary & dynamic movements.
• Lateral palpation
• Posterior palpation
69.
70. AUSCULTATION :
Click : single sound with short duration. If loud = popping
Crepitus: multiple gravel like sounds.
71. GERBER RESILIENCE TEST:
Enables to measure the resilience & thickness of the discus
articularis.
useful to plan possible corrections that is necessary through
dental occlusion.
Normal range :0.6 to 0.9mm & even up to 1.2mm
73. I. Musculoskeletal stability:
Orthopedically Stable joint is when the condyles are in their antero
superior position in the glenoid fossa, resulting against posterior
slopes of articular eminence with discs properly interposed.
74. II. Ligaments:
Stabilise the joint by limiting the movement
Ligaments elongate but are not streched
Compromising the normal jaw function
75. III. Interarticular pressure:
• Pressure between the articular surfaces of articular eminence
& the condyle
• Absence of inter articular pressure results in separation of
joints and dislocation
76. Functional
appliance
Increased
contractile
activity of the
LPM
Intensification of
repetitive activity of
the retrodiscal pad
Increase in growth
stimulating factors
Change in
trabecular
orientation
Supplementary
lengthening of
mandible
Additional
subperiosteal
ossification of
posterior border of
mandible
Additional
growth of
condylar
cartilage
OPERATION OF FUNCTONAL APPLIANCES
77. TemporomandibularJoint Disorders
A. Derangement of condyle -disc complex
i) Disc displacements
ii) Disc dislocation with reduction
iii) Disc dislocation without reduction
B. Structural incompatibility of the articular surfaces
1. Deviation in form
a. Disc
b. Condyle
c. Fossa
78. 2. Adhesions
a. Disc to condyle
b. Disc to fossa
3. Subluxation
4. Spontaneous dislocation
C. Inflammatory disorders
1. Synovitis/ capsulitis
2. Arthritidis
79. 3. Osteoarthritis
4. Polyarthritidis
D. Inflammatory disorders of associated structures
a)Temporal tendonitis
b)Stylomandibular ligament inflammation
80. Disc displacement:
Causes:
• Break down of normal rotation of condyle due to elongation of
discal ligaments& inferior retrodiscal lamina resulted from
trauma.
• Thinning of posterior border of disc predisposes to
derangement
81. • Displaced condyle
positioned anteriorly by
lateral pterygoid.
• Constant application results in
thinning of posterior disc &
allows the disc to be displaced
more anteriorly.
Clinical examination
normal range of movements
Joint sounds are seen
82.
83. • Disc dislocation with reduction :
Disc dislocation:
Further elongation of inf.retrodiscal lamina , discal ligament &
sufficient thinning of posterior border.
Results in slippage of joint. Disc & condyle no longer articulate
disc dislocation.
If the patient can manipulate to reposition the condyle onto
posterior border of disc , disc is termed reduced in nature
84. Management:
• Reduce the intracapsular pain
• Definitive treatment of disc displacement is to reestablish a
normal condyle disc relationship.
• Anterior positioning appliance by Format .
– This appliance is worn 24 hrs a day for3 to 6 months.
– Appliance repositions the condyle back into the disc
85. Disc displacement with out reduction:
• Further elongation leads to loss in elasticity of superior
retrodiscal lamina & recapturing is difficult.
• Anterior positioning appliance - contraindicated because it will
aggrevate the condition by forcing the disc even more forward.
• Supportive therapy/ surgical therapy is indicated.
Deviation in form:
• Supportive therapy - Patient education
• In case of muscle hyperactivity : stabilization appliance is
used.
86. Adhesions:
When adhesions are present breaking the fibrous attachment is
only definitive treatment
It is done by using arthroscopic surgery
Subluxation:
• Only definitive treatment by surgical alteration of joint i.e, by
eminectomy.
• Supportive therapy .
Spontaneous dislocation:
• surgical therapy is indicated
87. Conclusion
Temporomandibular joint & Masticatory muscles form the
vital part of orofacial system both structurally and
functionally.
It is crucial for an orthodontist to recognize the
musculoskeletal stability of the joint and be aware of problems
related to deviation from this point.
88. References:
• Management of Temporomandibular Disorders & Occlusion –
Jeffrey Okeson III
• Principles of Oral and Maxillofacial Surgery- Peterson's Vol 1
• Dentofacial Orthopedics with Functional Appliances – Graber,
Rakosi, Petrovic, II ed
• Text book of oral histology- Ten cate
• Human anatomy – B.D Chaurasias 5th Ed
• Grey’s anatomy – 38th edition
• Craniofacial development: Sperber
• Graber, Vanarsdal, Vig
Editor's Notes
Synarthosis : permits little if any movement
Diarthosis : synovial joint
Fibrous joint: Two bones are connected by fibrous tissue.
Suture: joint which permits little or no movement. histology indicates its function is to permit growth as its articulating surfaces are covered by osteogenic layer –responsible for new bone formation to maintain suture as the skull bones are separated by the expanding brain.
Syndesmosis: bony components are some distance apart but still connected by interosseous ligament. Eg:joint b/w radius & ulna
Gomphosis: socketed attachment of tooth to bone by fibrous periodontal ligament.
Primary cartilage: bone & cartilage are in direct apposition eg: Costochondral junction
Secondary: sequence: bone- cartilage-fibrous tissue- cartilage-bone eg: pubic symphysis
Generally Presence of Atleast 3 bones = compound but TMJ inspite of having only 2 bones is considered as a compound joint as the articular disc serves as a nonossified bone.
Provides hinging movemts in one plane, so called – ginglimoid joint
Also provides gliding movements: arthoidal joint
Thus technically termed as ginglymoarthoidal joint.
Only diarthoidal joint with growth potential in the articular cartilage.
Ontogenicall: embroyological. Incudomalleal joint is first formed.
Phylogenetic: evolutionary. The primary joint i.e incudo malleal joint is equivalent to jaw joint of reptiles. thus tmj formed now is a sec joint phylogenetically.
Tmj:Two blastemas i.e. the condylar and the temporal blastemas will grow separately and approach each other the intervening tissue between them will then form the articular disc
Temporal appears first & both blastemas are separate
Appearance of cleft above condylar – inferior
Only when such articular contact has been made, do the joint cavities develop,
Cavitation occurs by degradation rather than enzymatic liquefaction or cell death.
Articular eminence becomes prominent only after eruption of deciduous teeth
The condyle is an important growth site in the mandible with similarities to the growth plate of the long bones, and it displays four distinct zones: a fibrous cell layer, a progenitor cell layer, a zone of flattened chondrocytes, and a zone of hypertrophic chondrocytes
Ihh plays an indirect role in regulating the rate of chondrocyte differentiation by acting in a negative feedback loop with a second secreted protein, parathyroidhormone-related protein (PTHrP), in the periarticular perichondrium
Ihh, in conjunction with PTHrP, plays a crucial role in organizing the growth plate
The transcription factor Sox9 was highly expressed in proliferating chondrocytes in the condyle and has an essential role in cartilage development
Synovial joint with 1 blastema
Medial pole more prominent
Mediolateraally:18-23mm
Antero postero width:8-10mm
Posterior:Greater articular surface
Saggital plane:central thin zone- intermediate zone
Thick anterior & posterior zones
Posterior is slightly thicker
Superiorly - elastic fibers, -superior retrodiscal lamina .
Attaches the articular disc posteriorly to the tympanic plate.
Inferiorly - cheifly collagen fibres - inferior retrodiscal lamina.
Attaches the disc to the posterior margin of the articular surface of the condyle.
The remaining body of the retro discal tissue is attached posteriorly to a large venous plexus, which fills with blood as the condyle moves forward.
The superior and inferior attachment of the disc anteriorly is to the capsule.
Superiorly it is attached to the anterior margin of the articular eminence and inferiorly it is to the anterior margin of the articular surface of the condyle.
Both of these are made up of collagen fibers.
Between Attachments to capsular ligament is tendinous fibres of superior lateral pterygoid
Divides joint space into superior cavity:mandibular fossa & superior surface of the disc
Inferior cavity: mandibular condyle & inferior surface of disc
At birth it covers all internal surfaces but it is lost from articular surfaces as function commences.
The flexibility of the inner surface of the capsule is increased by villi of the synovial membrane which disperse the synovial fluid
Dialysate: fluid that passes through membranes. (since articular surfaces are avascular)
The non-vascularized tissues of the joint are dependent on synovial fluid for nutrition. Hence, the thinner mid-portion of the disc and the articular cartilage covering the condyle, fossa and eminence are dependent on the pumping of synovial fluid.
Normal total blood volume is 5 litres.
Ligaments associated with the TMJ are composed of collagen, which do not stretch and.
Superiorly - to articular tubercle on the root of zygomatic bone
Inferiorly –posteriolateral border of neck of mandible.
Outer oblique portion:
Normally a condyle rotates around a fixed point until the TM ligament becomes tight at the point of insertion .
After this to provide further mouth opening the condyle has to translate downwards & forward across articular eminence.
2nd point: If only rotation occurs there will be damage to the
Whenever force is applied to mandible, condyle displaces posteriorly. This ligament is tightened& prevents further posterior movement of condyle into the gleniod fossa protecting the retro discal tissue injury
These ligaments attach the articular disc to the medial and lateral poles of the condyle
Medial:attaches medial edge of disc to medial pole of condyle
Allows movement of the disc passively with condyle as it anteriorly & posteriorly
Responsible for hinging movement of the TMJ , which occurs between the condyle & articular disc.
Superiorly – temporal bone along the borders of articular surfaces of fossa & eminence.
Inferiorly – attached around the neck of the mandible
Anteriorly- blends with insertion of lateral pterygoid muscle
2. In the joint cavities
3. As well innervated
Superiorly – spine of sphenoid
Inferiorly – lingula of the mandible
Extends from tip of the styloid process of temporal bone to the angle of the mandible
Function: limits excessive protrusive movements.
Articular zone
Found adjacent to the joint cavity & outermost functional surfac
Made up of dense fibrous connective tissue & collagen fibrous is arranged in bundles – arranged parallel to articular surface
Tightly packed to withstand the force of mastication
Proliferative zone
Mainly cellular
Undifferentiated mesenchymal tissue is found
Responsible for the proliferation of articular cartilage in response to the functional demands placed on articular surface.
Fibrocartilaginous zone
Collagen fibrils are arranged in bundles in crossing pattern
Offers resistance against compressive & lateral forces
Calcified cartilage zone:
Made up of chondroblast & chondrocytes
{Chondrocytes become hypertropic, die, & have their cytoplasm evacuated forming bone cells from within the medullary cavity
The surface of the extracellular matrix scaffolding provides an active site for remodelling activity}
Lymphatic vessels from anterior surface drain into
Superficial portion:
Inferior 2/3rd of zygomatic arch
Angle of mandible,lower border of lateral surface of ramus
Middle portion:
Origin: Inner aspect of zygomatic arch
Lower portion of lateral surface of ramus
Inferior portion
Origin: Deeper aspect of zygomatic arch
Insertion: Upper portion of mandibular ramus and coronoid process
Action:
Elevation.
Superficial fibres - protrusion of mandible
masseteric branch of anterior division of mandibular nerve
Blood supply: maxillary artery, a branch of external carotid artery.
First first fingers are placed on each zygomatic arch( anterior to TMJ)
Then They are dropped down slightly to the portion of the masseter attached to the zygomatic arch.
once palpated the deep masseter, then the fingers drop to inferior attachment of the body of the ramus.(superficial masseter)
Insertion:- medial aspect of coronoid process & anterior border of ramus of mandible
Anterior fibres orient vertically.
Most posterior fibres almost horizontally and intervening fibres with intermediate degrees of obliquity like a fan.
Arises from Chronic strain of temporalis muscle, pulling the tendon that attaches to mandible causes
superficial head :Tuberosity of maxilla& inserts into Angle of mandible
deep head : medial surface of lateral pterygoid plate & inserts into angle
Medial pterygoid nerve: leaves mandibular nerve immediately when it comes out of foramen ovale
Palpation
Intraorally ,to palpate the medial pterygoid muscle slide the index finger a little posterior to the insertion site of inferior alveolar nerve block, to where the muscle is felt & press laterally.
Superior portion:from the roof of temporal fossa(greater wing of sphenoid)
Inferior portion: from the lateral surface of lateral pterygoid plate.
Insertion- by a tendon into-
neck of the mandible,
ant part of capsule of tmj
through capsule into the meniscus
During closure of mouth, backward gliding of anterior disc and mandibular condyle controlled by slow elongation of lateral pterygoid while masseter and temporalis restore jaw to occlusal position.
Superior fibres of massetr [protrusion]
Posterior fibers of temporalis [retrusion]
Sprahyoid:Geniohyoid, Mylohyoid & Digastric [depresion]
Distance between incisal edges of maxillary & mandibular teeth
Lateral jaw palpation: palpates the lateral poles of condyle with index finger or two fingers placed near tragus, the patient is asked to slowly open & close the mouth.
Once position is verified medial force is applied to determine the pain
Posterior jaw position: Palpate the posterior surface of condyle during opening & closing of mandible.
condyle displaces the little finger when in full occlusion
if pain present, then positive
0.3mm special tinfoil allows step-by-step checking of the “discus articularis”. One keeps adding additional layers of
0.3mm special tinfoil, making the blocking of the bite progressively greater, until
the patient is no longer able to clench the contra-laterally placed test-foil.
Direction of force of temporalis muscle is predominantly superior. Therefore these muscles elevate condyles in a straight superior position.
Masseter & medial pterygoid provide forces in superio anterior position & seat condyles superiorly & anteriorly against the slopes of articular eminence
Fig 1& 2 together result in musculoskeletal stability of tmj.
Osteo: bony articular surfaces are affected.
Poly :group of disorders in which articular surfaces are inflamed.
