Mucocele and ranula are lesions caused by the extravasation of mucus from salivary glands into surrounding tissues. Mucoceles are commonly caused by trauma that severs or obstructs salivary ducts, allowing mucus to pool in surrounding tissues. Ranulas specifically occur on the floor of the mouth associated with sublingual or submandibular gland ducts. Histologically, they consist of mucus-filled cavities surrounded by granulation tissue and inflammatory cells. Treatment involves complete surgical excision to prevent recurrence.
This slide is about oral hairy leukoplakia. it is basically a type of oral manifestation of some viral disease like HIV and HSV 4 (Epstein Barr virus )
Odontogenic keratocyst (OKC) is the cyst arising from the cell rests of dental lamina. It can occur anywhere in the jaw, but commonly seen in the posterior part of the mandible. Radiographically, most OKCs are unilocular when presented at the periapex and can be mistaken for radicular or lateral periodontal cyst.
This slide is about oral hairy leukoplakia. it is basically a type of oral manifestation of some viral disease like HIV and HSV 4 (Epstein Barr virus )
Odontogenic keratocyst (OKC) is the cyst arising from the cell rests of dental lamina. It can occur anywhere in the jaw, but commonly seen in the posterior part of the mandible. Radiographically, most OKCs are unilocular when presented at the periapex and can be mistaken for radicular or lateral periodontal cyst.
DENTIGEROUS CYST- an odontogenic cyst that surrounds the crown of impacted tooth , develops by fluid accumulation between REE(reduced enamel epithelium) and the enamel surface , resulting in a cyst which the crown located within the lumen.
Cysts &tumors of salivary glands /certified fixed orthodontic courses by Indi...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
This presentation will will give you the idea of a dermatological disoders with clinicopathological features.
A vesiculobullous disease is a type of mucocutaneous disease characterized by vesicles and bullae (i.e. blisters).
Definition
General properties
Composition
Function of saliva
Formation of saliva
Method for collecting saliva
Advantages
Limitations
Analysis of saliva done for the diagnosis of systemic disease
Definition:
by Stedmann’s & Lipincott medical dictionary.
A clear, tasteless, odourless, slightly acidic (pH 6.8) viscous fluid, consisting of the secretion from the parotid, sublingual, submandibular salivary glands and the mucous glands of the oral cavity.
General properties
Volume: 1000 to 1500 mL of saliva is secreted per day and, it is approximately about 1 ml/ minute.
Contribution by each major salivary gland is:
i. Parotid glands: 25%
ii. Submandibular glands: 70%
iii. Sublingual glands: 5%.
Reaction: Mixed saliva from all the glands is slightly acidic with pH of 6.35 to 6.85.
Specific gravity: It ranges between 1.002 and 1.012.
Tonicity: Saliva is hypotonSalivary flow
The average person produces approximately 0.5 L – 1.5 L per day
Unstimulated Flow (resting salivary flow―no external stimulus)
Typically 0.2 mL – 0.3 mL per minute
Stimulated Flow (response to a stimulus, usually taste, chewing, or medication [eg, at mealtime])
Typically 1.5 mL – 2 mL per minute
INTRODUCTION
Tongue is a muscular organ
Situated in the floor of the mouth
FUNCTION
Taste
Speech
Mastication
Deglutition
EXTERNAL FEATURES
Tongue has
A Root
A tip
A body
ROOT
Is attached to the mandible and soft palate above and hyoid bone below.
These attachments prevent the swallowing of the tongue.
In between the 2 bones it is related to the geniohyoid and mylohyoid muscles.
TIP
Of the tongue forms the anterior free end which lies behind the upper incisor teeth.
BODY
Has
A curved upper surface or dorsum
An inferior or ventral surface MUSCLES OF THE TONGUE
Middle fibrous septum divides the tongue into right and left halves.
Intrinsic muscles
Superior longitudinal
Inferior longitudinal
Transverse
Vertical
Extrinsic muscles
Genioglossus
Hyoglossus
Styloglossus
Palatoglossus
Central face begins to develop by 4th week, when olfactory placodes appear on both sides of the frontonasal process.
Gradually both placodes develop to form the median and lateral nasal process.
Upper lip is formed by 6th week by fusion of two median nasal processes in midline and the maxilllary process of the 1st branchial arch.
PRE-NATAL GROWTH AND DEVELOPMENT OF PALATEFormation of primary and secondary palate
Elevation of palatal shelves
Fusion of palatal shelves
Introduction
Epidemiology
Etiology
Manifestations
TNM staging
Squamous cell carcinoma is defined as malignant epithelial neoplasm exhibiting squamous differentiation as characterised by the formation of keratin and/or the presence of intercellular bridges.
( Pindborg et al, 1997).
Occipital (2-4)
Superior nuchal line between sternocleidomastoid and trapezius
Occipital part of scalp
Superficial cervical lymph nodes
Accessary lymph nodes
Mastoid (1-3)
Superficial to sternocleidomastoid insertion
Posterior parietal scalp
Skin of ear, posterior external acoustic meatus
Superior deep cervical nodes Accessary lymph nodes
Preauricular (2-3)
Anterior to ear over parotid fascia
Drains areas supplied by superficial temporal artery
Anterior parietal scalp
Anterior surface of ear
Superior deep cervical lymph nodes
Parotid (up to 10 or more)
About parotid gland and under parotid fascia
Deep to parotid gland
External acoustic meatus
Skin of frontal and temporal regions
Eyelids, tympanic cavity
Cheek, nose (posterior palate)
Superior deep cervical lymph nodes
Facial
Superficial(up to 12)
Maxillary
Buccal
Mandibular
Distributed along course of facial artery and vein
Skin and mucous membranes of eyelids, nose, cheek
Submandibular nodes
Deep
Distributed along course of maxillary artery lateral to lateral pterygoid muscle
Temporal and infratemporal fossa
Nasal pharynx
Superior deep cervical lymph nodesSuperficial
Anterior jugular vein between superficial cervical fascia and infrahyoid fascia
Skin, muscles, and viscera of infrahyoid region of neck
Superior deep cervical lymph nodes
Deep
Between viscera of neck and investing layer of deep cervical fascia
Adjoining parts of trachea, larynx, thyroid gland
Superior deep cervical lymph nodes
Anterior cervical/Superficial
Submental (2-3)
Submental triangle
Chin
Medial part of lower lip
Lower incisor teeth and gingiva
Tip of tongue
Cheeks
Submandibular lymph node to jugulo-omohyoid lymph node and superior deep cervical lymph nodes
Is a phenomenon of reflex sequence of muscle contractions that propels the ingested materials and pooled saliva from the mouth to the stomach.
PATTERNS
Infantile (visceral) swallow
Adult/mature swallow
ADULT SWALLOWING
Is composed of 4 stages
Voluntary
Preparatory phase
Oral or buccal
Involuntary: Controlled By Medulla and Lower Pons
Pharyngeal
b. Oesophageal
• Function
• External features
• Papillae of tongue
• Muscles of the tongue
• Arterial supply
• Venous drainage
• Lymphatic drainage
• Nerve supply
• Histology
• Development of tongue -
Intrinsic muscles
Superior longitudinal
Inferior longitudinal
Transverse
Vertical
- Extrinsic muscles
Genioglossus
Hyoglossus
Styloglossus
Palatoglossus
1. Vallate or circumvallate papillae
These are large in size 1-2mm in diameter and are 8-12 in number.
They are situated immediately in front of the sulcus terminalis.
Each papillae are cylindrical projection surrounded by a circular sulcus.
The walls of the papilla are raised above the surface.
2. Fungiform papillae
Are numerous
Near the tip and margins of the tongue, but some of them are scattered over the dorsum.
These are smaller than the vallate papillae but larger than the filliform papillae.
Each papilla consists of a narrow pedicle and a large rounded head.
They are distinguished by their bright red colour.
3. Filliform papillae
Conical papilla
Cover the presulcal area of the dorsum of the tongue and gives it a characteristic velvety appearance.
They are the smallest and most numerous of the lingual papillae.
Each are pointed and covered with keratin
The apex is often split into filamentous processes.
Fifth cranial nerve
Have a large sensory root and a small motor root.
Motor root arises – arises from the lateral aspect of lower pons (cranially) the motor root cross the apex of the petrous temporal bone beneath the superior petrosal sinus, to enter the middle cranial fossa.
Sensory root – arises from the lateral aspect of lower pons (caudally).
RELATIONS
Medially
(a) internal carotid artery
(b) posterior part of cavernous sinus
Laterally - middle meningeal artery
Superiorly - parahippocampal gyrus
Inferiorly
motor root of trigeminal nerve
(b) greater petrosal nerve
(c) apex of the petrous temporal bone
(d) foramen lacerum.OPTHALIMIC DIVISION
Terminal branches of Ophthalmic division of trigeminal nerve, are
1. Frontal
Supratrochlear
Supraorbital
2. Nasociliary
Branch of ciliray ganglion
2-3 long ciliary nerves
Posterior ethmoidal
Infratrochlear
Anterior ethmoidal
3. Lacrimal
Branches
From main trunk
Meningeal branch
Nerve to medial pterygoid
From the anterior trunk
Sensory branch
Buccal nerve
Motor branch
Masseteric
Deep temporal nerve
Nerve to lateral pterygoid
From the posterior trunk
Auriculotemporal
Lingual
Inferior alveolar nerves
COTTON-WOOL APPEARANCE
Active phase showing disorganised bone architecture with numerous, large, multinucleated osteoclasts. The stroma is vascular and fibrous
The late phase features thick trabeculae with a prominent mosaic pattern of prominent, hematoxyphilic, cement lines at the interfaces of episodes of resorption followed by deposition.
Paget disease showing very prominent blue cement lines. The lamellae are arranged haphazardly giving an overall effect of a jigsaw puzzle.
Hume- “caries is essentially a progressive loss by acid dissolution of the apatite component of the enamel then the dentin or of the cementum then dentin.”
According to location:
Pit or Fissure caries
Smooth Surface caries
According to rapidity:
Acute
Chronic
Arrested
According to occurrence:
Primary (Virgin) caries
Secondary (Recurrent) caries
According to the site of occurrence:
Enamel caries
Cemental caries.
Acidogenic [ Miller’s Chemico-parasitic] theory.
Proteolytic theory.
Proteolysis- chelation theory.
The lymphatic system has three functions:
Fluid recovery.
Immunity
Lipid absorption
The lymphatic vessels of the small intestine receive the special designation of lacteals or chyliferous vessels.
The components of the lymphatic system are :-
lymph, the recovered fluid;
Lymphatic vessels, which transport the lymph;
Lymphatic tissue, composed of aggregates of lymphocytes and macrophages that populate many organs of the body; and
Lymphatic organs, in which these cells are especially concentrated and which are set off from surrounding organs by connective tissue capsules.
A Magnified Microscopic Image Is Worth More Than A Thousand Words.
DARK FIELD MICROSCOPE
PHASE CONTRAST MICROSCOPY
POLARIZED LIGHT MICROSCOPY
FLUORESCENT MICROSCOPY
STEREO MICROSCOPE
ELECTRON MICROSCOPY
Maxillary Second Premolar
the maxillary first premolar in function
Less angular ,rounded crown in all aspects.
Single root
Smaller crown cervico occlusally
Root length is as great or greater
BUCCAL ASPECT
Not as long as that of the first premolar
Less pointed
Mesial slope is
shorter than the distal slope
Buccal ridge of the crown may not be so prominent whencompared with the first premolarLINGUAL ASPECT
Lingual cusp is longer making the crown longer on the lingual sideMESIAL ASPECT
Cusps of second premolar are shorter with the buccal and lingual cusps more nearly the same length
Greater distance between cusp tips-that widens the occlusal surface buccolingually
No developmental depression on the mesial surface of the crown as on the first premolar
Crown surface is convex instead
No deep dev. Groove crossing the mesial marginal ridgeOCCLUSAL ASPECT
Outline of the crown is more rounded or oval rather than angular
Central dev. groove is shorter and more irregular
Tendency toward multiple supplementary grooves radiating from the central groove that may extend out to the cusp ridges
Makes for an irregular occlusal surface and gives a very wrinkled appearance
Centered in the maxilla, one on either side of median line, with mesial surface of each in contact with mesial surface of other
Two in number
Larger than the lateral incisor
These teeth supplement each other in function, and they are similar anatomically
Shearing or cutting teeth
Major function is to punch and cut food material during the process of mastication
These teeth have incisal ridges or edges rather than
cusps such as are found on canines & posterior teeth
First evidence of calcification
Crown completion
Eruption
Root completion
3-4 months
4-5 years
7-8 years
10-11 years
PHYSICAL PROPERTIES
CHEMICAL PROPERTIES
STRUCTURE OF ENAMEL
DEVELOPMENT OF ENAMEL
EPITHELIAL ENAMEL ORGAN
AMELOGENESIS
LIFE CYCLE OF AMELOBLASTS
AGE CHANGES IN ENAMEL
DEFECTS OF AMELOGENESIS
CLINICAL IMPLICATIONS
PRENATAL GROWTH OF MANDIBLE
Occurs between the 4th and 7th week of intrauterine life.
4th week of intrauterine life
Formation of the head fold
Following which the developing brain and the pericardium form 2 prominent bulges on the ventral aspect of the embryo.
The 2 bulges are separated from each other by a shallow depression called stomatoedum (corresponding to the primitive mouth).
Floor of the stomatodeum is formed by the Buccopharyngeal membrane, which separates the stomatodeum from the foregut.Soon, mesoderm covering the developing forebrain proliferates, and forms a downward projection that overlaps the upper part of the stomatodeum – this downward projection is called frontonasal process.
Since the formation of various parts of the face involves fusion of diverse components.
Occasionally this fusion can be incomplete give rise to various anomalies
MANDIBULOFACIAL DYSOSTOSIS OR FIRST ARCH SYNDROME
- Entire first arch may remain underdeveloped on one or both sides, affecting
Lower eyelid
Maxilla
Mandible
External ear.
- Prominence of the cheek is absent
- Ear is displaced ventrally and caudally
Face develops in humans between 4th – 10th week of intrauterine life.
prenatal growth of the maxilla
DEVELOPMENT OF UPPER LIP
Development of lower lip
Development of nose
hare lip
OBLIQUE FACIAL CLEFT
macrostomia
lateral facial cleft
microstomia
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...University of Maribor
Slides from:
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Track: Artificial Intelligence
https://www.etran.rs/2024/en/home-english/
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
2. The mucocele is a common lesion of the oral mucosa involving salivary glands
and their ducts.
They result from
Traumatic severance of a salivary duct
Produced by biting the lips or cheek
Pinching the lip by extraction forceps and the like, leading to spillage of
mucin into the sorrounding tissues.
Such trauma has been implicated in the formation of mucoceles.
There is no known history of trauma in many cases.
cyst lack epithelial lining they are not true cyst.
MUCOCELE
3.
4. Mucoceles are commonly observed in all decades of life,
with increased predilection in children and young adults,
possibly because of the higher chance of trauma in latter
age group.
Clinically it appears as a raised , domeshaped
vesicles,ranging in size from 1 to 2 mm to several
centimetres.
There might be a history of rupture, collapse, and refilling
which may be repeated.
The mucoceles may lie deep in the tissues or exceptionally
superficial and thus depending upon the location it present
5. ETIOLOGY AND PATHOGENESIS
The mucous retention phenomenon is a common lesion although only
few studies have been reported.
Many authorities formerly believed that this type of lesion resulted from
1.obstruction of the duct of a minor salivary gland, but experimental
investigations on mice by Bhaskar and his associates and rats by
Standiush and Shafer failed to produce mucous retention phenomenonby
ligation of the submaxillary and sublingual gland ducts.
2. The studies of Bhaskar demonstrated instead that if the salivary duct
was severed so that a continuous pooling of of saliva occured in the
6. These investigations appear to indicate that traumatic severance of a
salivary duct, such as that produced by biting of the lipss or cheek or
pinching the lip by extraction forceps, preecedes the development of the
retention phenomenon.
It is also possible that chronic partial obstruction of the salivary duct ,
partial obstruction could result from a small piece of intraductal calculus
may be the etiologic importance.
Occasional cases of calculus in the ducts of accesory salivary glands or
sialolithiasis have also been reported.
Thus mucocele often have been classifiedas
1.an extra vassaation mucocele
7. HISTOLOGIC FEATURES
Mucoceles consist of a cicumscibed cavity in the
connective tissue and submucosa producing an
obvious elevation of the mucosa with thinning of the
epithelium as though it were stretched.
The wall of the cavity is made up of lining of
compressed fibrous connective tissue and fibroblasts.
8. The connective tissue wall is essentially granulation
tissue but in any event it usually shows infiltration by
abundant number of polymorphonuclear leukocytes,
lymphocytes and plasma cells
9. The lumen of the cyst like cavity is filled with the spilled mucin containing
variable numbers of cells,chiefly leukocytes and foamy
histiocyes(macrophages).
Occasional mucoceles demonstrate an intact flattened epithelial lining. It
is probable that this simply represents the portion of the excreatory duct
bordering the line of severance, if severance is actually the manner in
which these lesion develop.
The flattened epithelial lining has been reffered to as epithelium of the
“feeder duct” in other instances the epithelium lined mucocele represents
a mucous retention cyst.
10. TREATMENT
Treatment of the mucous retention phenomenon is excission.
If the lesion is simply incised, its contents will be evacuated but rapidly
filled as soon as healed.
There is occasional recurrence after excision, but this possibility is less
likely if the associated salivary gland acini are removed also.
The excised tissue should be given for microscopic examination to rule out
the possibility of a salivary gland tumor.
11. RANULA
The ranula is a form of mucocele which specifically occurs in the floor of
the mouth in association with the ducts of the submaxillary and
sublingual gland.
The etiology and pathogenesis appered to be same as the retention cyst.
Some authors believed that it may arise through duct blockage or through
the devepment of the ductal aneurysm.
12. CLINICAL FEATURES
The lesion which is rare compared to the usual mucocele, develops as a slow
enlarging painless mass on side of the floor of the mouth . Since the lesion is
usually deep seated one, the overlying mucosa is normal in appearance.
If the lesion is superficial the mucosa may have a translucent bluish color.
13. HISTOLOGIC FEATURES
The microscopic features are simillar that of smaller mucocele except that
a definite epithelial lining is sometimes present.
Because of this lining most investigators consider raula as a true retention
cyst.
14. PATHOPHYSIOLOGY
The development of mucoceles and ranulas depend on the disruption of the
flow of saliva from the secretory apparatus of the salivary glands.The
lesions are most often associated with mucus extravasation into the
adjacent soft tissue caused by a traumatic ductal insult;the insults include a
crush type injury and severance of the excreatory duct of the minor salivary
gland.
The disruption of the secretory glands results in extravassation of the
mucous from the gland into the sorrounding soft tissue
15. The rupture of an acinar structure caused by hypertension from the ductal
obstruction is another possible mechanism for the development of such
lesion.
Furthermore, trauma that results in damage to the glandular parenchymal
cells in the salivary gland lobules is another potential mechanism.
Regarding superficial mucoceles,trauma does not always appear to play
important role in the pathogenesis.