NEET MDS Synopsis
MUSCLE
Anatomy
MUSCLE
Types:
Skeletal (voluntary)
Cardiac (involuntary)
Smooth (involuntary)
Distal Shoe Space Maintainer
PedodonticsDistal Shoe Space Maintainer
The distal shoe space maintainer is a fixed appliance used in pediatric
dentistry to maintain space in the dental arch following the early loss or
removal of a primary molar, particularly the second primary molar, before the
eruption of the first permanent molar. This appliance helps to guide the
eruption of the permanent molar into the correct position.
Indications
Early Loss of Second Primary Molar:
The primary indication for a distal shoe space maintainer is the
early loss or removal of the second primary molar prior to the eruption
of the first permanent molar.
It is particularly useful in the maxillary arch, where bilateral
space loss may necessitate the use of two appliances to maintain proper
arch form and space.
Contraindications
Inadequate Abutments:
The presence of multiple tooth losses may result in inadequate
abutments for the appliance, compromising its effectiveness.
Poor Patient/Parent Cooperation:
Lack of cooperation from the patient or parent can hinder the
successful use and maintenance of the appliance.
Congenitally Missing First Molar:
If the first permanent molar is congenitally missing, the distal
shoe may not be effective in maintaining space.
Medical Conditions:
Certain medical conditions, such as blood dyscrasias, congenital
heart disease (CHD), rheumatic fever, diabetes, or generalized
debilitation, may contraindicate the use of a distal shoe due to
increased risk of complications.
Limitations/Disadvantages
Overextension Risks:
If the distal shoe is overextended, it can cause injury to the
permanent tooth bud of the second premolar, potentially leading to
developmental issues.
Underextension Risks:
If the appliance is underextended, it may allow the molar to tip
into the space or over the band, compromising the intended space
maintenance.
Epithelialization Prevention:
The presence of the distal shoe may prevent complete
epithelialization of the extraction socket, which can affect healing.
Eruption Path Considerations:
Ronnermann and Thilander (1979) discussed the path of eruption,
noting that drifting of teeth occurs only after eruption through the
bone covering. The lower first molar typically erupts occlusally to
contact the distal crown surface of the primary molar, using that
contact for uprighting. Isolated cases of ectopic eruption should be
considered when evaluating the eruption path.
Fourth Generation:
Pharmacology
Fourth Generation:
These are extended spectrum antibiotics. They are resistant to beta lactamases.
Cefipime
Staphylococcal aureus
General Pathology
Staphylococcal aureus
- cutaneous infections
- furuncles (boils)
- carbuncles (more complicated furuncle with multiple sinuses)
- impetigo (often mixed with Streptococcus and has a more bullous appearance than crusted)
- hidradenitis suppurative (abscess of apocrine glands→e.g., axilla)
- nail bed (paronychial infection)
- postoperative wound or stitch abscess
- postpartum breast abscesses
toxin related skin rashes
- infants and young children develop toxic epidermal necrolysis or Ritter's syndrome (scalded baby syndrome)→large, red areas of denuded skin and generalized bulla formation.
- toxic shock syndrome (TSS) is due to a toxin producing strain of Staphylococcus aureus (bacteriophage induced) usually, but not exclusively in tampon wearing (hyperabsorbent type), menstruating women; 1-4 day prodrome of high fever, myalgias, arthralgias, mental confusion, diarrhea and on erythematous rash that occurs during or soon after menses; rash predominantly on hands and feet with eventual desquamation in 5-12 days.
Amino Acid Catabolism
Biochemistry
Amino Acid Catabolism
Glutamine/Glutamate and Asparagine/Aspartate Catabolism
Glutaminase is an important kidney tubule enzyme involved in converting glutamine (from liver and from other tissue) to glutamate and NH3+, with the NH3+ being excreted in the urine. Glutaminase activity is present in many other tissues as well, although its activity is not nearly as prominent as in the kidney. The glutamate produced from glutamine is converted to a-ketoglutarate, making glutamine a glucogenic amino acid.
Asparaginase is also widely distributed within the body, where it converts asparagine into ammonia and aspartate. Aspartate transaminates to oxaloacetate, which follows the gluconeogenic pathway to glucose.
Glutamate and aspartate are important in collecting and eliminating amino nitrogen via glutamine synthetase and the urea cycle, respectively. The catabolic path of the carbon skeletons involves simple 1-step aminotransferase reactions that directly produce net quantities of a TCA cycle intermediate. The glutamate dehydrogenase reaction operating in the direction of a-ketoglutarate production provides a second avenue leading from glutamate to gluconeogenesis.
Alanine Catabolism
Alanine is also important in intertissue nitrogen transport as part of the glucose-alanine cycle. Alanine's catabolic pathway involves a simple aminotransferase reaction that directly produces pyruvate. Generally pyruvate produced by this pathway will result in the formation of oxaloacetate, although when the energy charge of a cell is low the pyruvate will be oxidized to CO2 and H2O via the PDH complex and the TCA cycle. This makes alanine a glucogenic amino acid.
Arginine, Ornithine and Proline Catabolism
The catabolism of arginine begins within the context of the urea cycle. It is hydrolyzed to urea and ornithine by arginase.
Ornithine, in excess of urea cycle needs, is transaminated to form glutamate semialdehyde. Glutamate semialdehyde can serve as the precursor for proline biosynthesis as described above or it can be converted to glutamate.
Proline catabolism is a reversal of its synthesis process.
The glutamate semialdehyde generated from ornithine and proline catabolism is oxidized to glutamate by an ATP-independent glutamate semialdehyde dehydrogenase. The glutamate can then be converted to α-ketoglutarate in a transamination reaction. Thus arginine, ornithine and proline, are glucogenic.
Methionine Catabolism
The principal fates of the essential amino acid methionine are incorporation into polypeptide chains, and use in the production of α -ketobutyrate and cysteine via SAM as described above. The transulfuration reactions that produce cysteine from homocysteine and serine also produce α -ketobutyrate, the latter being converted to succinyl-CoA.
Regulation of the methionine metabolic pathway is based on the availability of methionine and cysteine
Phenylalanine and Tyrosine Catabolism
Phenylalanine normally has only two fates: incorporation into polypeptide chains, and production of tyrosine via the tetrahydrobiopterin-requiring phenylalanine hydroxylase. Thus, phenylalanine catabolism always follows the pathway of tyrosine catabolism. The main pathway for tyrosine degradation involves conversion to fumarate and acetoacetate, allowing phenylalanine and tyrosine to be classified as both glucogenic and ketogenic.
Tyrosine is equally important for protein biosynthesis as well as an intermediate in the biosynthesis of several physiologically important metabolites e.g. dopamine, norepinephrine and epinephrine
Viral infectious diseases
General Medicine
Chickenpox
Chickenpox is caused by the varicella-zoster virus (VZV), also known as human herpes virus 3 (HHV-3)
Chickenpox is highly infectious and spreads from person to person by direct contact or through the air from an infected person’s coughing or sneezing
A persons with chickenpox is contagious 1-2 days before the rash appears and until all blisters have formed scabs It takes 5- 10 days
0-21 days after contact with an infected person for someone to develop chickenpox
start as a 2-4 mm red papule which develops an irregular outline (rose petal).
A thin-walled, clear vesicle (dew drop) develops on top of the area of redness. This "dew drop on a rose petal" lesion is very characteristic for chicken pox
After about 8-12 hours the fluid in the vesicle gets cloudy and the vesicle breaks leaving a crust.
The fluid is highly contagious, but once the lesion crusts over, it is not considered contagious. The crust usually falls off after 7 days sometimes leaving a craterlike scar
Vaccination
Routine vaccination against varicella zoster virus has dramatically reduced the incidence of disease
Herpes simplex virus
The herpes simplex virus (HSV) (also known as Cold Sore, Night Fever, or Fever Blister) is a virus that manifests itself in two common viral infections, each marked by painful, watery blisters in the skin or mucous membranes (such as the mouth or lips) or on the genitals
the two most common are type 1 (HSV-1) and type 2 (HSV-2). HSV-1 is more common and generally considered to be associated with orofacial infection, usually the lips
HSV-2 is associated with the infection of the genitals, although both types can affect either region. HSV-2 infection is of particular concern because of the largely asymptomatic nature of the infection, and the shedding of infective virions even in asymptomatic individuals.
Orofacial infection
Prodromal symptoms
Skin appears irritated
Sore or cluster of fluid-filled blisters appear
Lesion begins to heal, usually without scarring
These infections usually occur on lips especially near the vermilion border. Rarely will a cold sore appear inside the mouth. The sores may appear to be either weeping or dry, and may resemble a pimple, insect bite, or lesion. Vesicles may also appear on the fingers, an infection called whitlow.
Genital infection
Prodromal symptoms
Sore appears
Lesion begins to heal, usually without scarring
In men, the lesions may occur on the shaft of the penis, in the genital region, on the inner thigh, buttocks, or anus. In women, lesions may occur on or near the pubis, labia, clitoris, vulva, buttocks, or anus
Treatments
antiviral medications for controlling herpes outbreaks, including acyclovir (Zovirax), valacyclovir (Valtrex), famcyclovir (Famvir), and pencyclovir
All drugs in this class depend on the activity of the viral thymidine kinase to convert the drug to a monophosphate form and subsequently interfere with viral DNA replication.
Pencyclovir's primary advantage over acyclovir is that it has a far longer cellular half-life
Docosanol works by preventing the virus from fusing to cell membranes, thus barring entry into the cell for the virus
Tromantadine is another antiviral drug effective against herpes.
Herpes zoster
Herpes zoster, colloquially known as shingles, is the reactivation of varicella zoster virus, leading to a crop of painful blisters over the area of a dermatome
Signs and symptoms
pain is the first symptom. This pain can be characterized as stinging, tingling, numbing, or throbbing, and can be pronounced with quick stabs of intensity.
Then 2-3 crops of red lesions develop, which gradually turn into small blisters filled with serous fluid.
Shingles blisters are unusual in that they only appear on one side of the body . That is because the chickenpox virus can remain dormant for decades, and does so inside the spinal column or a nerve fiber.
If it reactivates as shingles, it affects only a single nerve fiber, or ganglion, which can radiate to only one side of the body.
The blisters therefore only affect one area of the body and do not cross the midline
The rash and pain usually subside within 3 to 5 weeks. The most common chronic complication of herpes zoster is postherpetic neuralgia.
serious effects including partial facial paralysis (usually temporary), ear damage, or encephalitis may occur.
Shingles on the upper half of the face (the first branch of the trigeminal nerve) may result in eye damage
Treatment
Aciclovir (an antiviral drug) inhibits replication of the viral DNA, and is used both as prophylaxis (e.g. in patients with AIDS) and as therapy for herpes zoster.
Steroids are often given in severe cases
A vaccine called live attenuated Oka/Merck VZV that has been proven successful in preventing it
Influenza
Influenza, commonly known as the flu or the grippe, is a contagious disease of the upper airways and the lungs, caused by an RNA virus
Symptoms
The virus attacks the respiratory tract, is transmitted from person to person by saliva droplets expelled by coughing, and causes the following symptoms:
Fever
Headache
Fatigue/Sore joints (can be extreme)
Dry cough
Sore throat
Nasal congestion
Sneezing
Irritated eyes
Body aches
Extreme coldness
Treatment
get plenty of rest, drink a lot of liquids
acetaminophen to relieve the fever and muscle aches
Children and teenagers with flu symptoms (particularly fever) should avoid taking aspirin as taking aspirin in the presence of influenza infection (especially influenza type B) can lead to Reye syndrome, a rare but potentially fatal disease of the liver
Mumps
Mumps or epidemic parotitis is a viral disease of humans.
Caused by a paramyxovirus, and is spread from person to person by saliva droplets or direct contact
Symptoms
The more common symptoms of mumps are:
Swelling of the parotid gland (or parotitis) in >90% of patients.
Fever
Headache
Sore throat
Orchitis
A physical examination confirms the presence of the swollen glands
If there is uncertainty about the diagnosis, serology or a saliva test for the virus may be carried out.
Rubella
caused by the Rubella virus
Symptoms
swollen glands or lymph nodes (may persist for up to a week)
fever (rarely rises above 38 degrees Celsius [100.4 degrees Fahrenheit])
rash (Appears on the face and then spreads to the trunk and limbs. It appears as pink dots under the skin. It appears on the first or third day of the illness but it disappears after a few days with no staining or peeling of the skin)
Forchheimer's sign occurs in 20% of cases, and is characterized by small, red papules on the area of the soft palate flaking, dry skin
inflammation of the eyes
nasal congestion
joint pain and swelling
pain in the testicles
loss of appetite
headache
nerves become weak or numb (very rare)
rubella can cause congenital rubella syndrome in the fetus of an infected pregnant woman.
Treatment
No specific treatment
MMR Vaccine is effective prevention
Poliomyelitis
infantile paralysis, is a viral paralytic disease.
The causative agent, a virus called poliovirus (PV), enters the body orally, infecting the intestinal wall.
It may proceed to the blood stream and into the central nervous system causing muscle weakness and often paralysis
Meningitis
Meningitis is inflammation of the membranes (meninges) covering the brain and the spinal cord.
Symptms
The classical symptoms of meningitis are headache, neck stiffness and photophobia (intolerance of bright light); the trio is called meningism.
Fever and chills are often present, along with myalgia.
An altered state of consciousness or other neurological deficits may be present depending on the severity of the disease.
In meningococcal meningitis or septicaemia, a petechial rash may appear.
A lumbar puncture to obtain cerebrospinal fluid (CSF) is usually indicated to determine the cause and direct appropriate treatment.
Convulsions and hydrocephalus are known complications of meningitis.
Diagnosis
examination of the cerebrospinal fluid
In patients with focal neurological deficits or signs of increased intracranial pressure, a CT scan of the head
Treatment
a broad spectrum intravenous antibiotic should be started immediately , often a third generation cephalosporin
Corticosteroids to relieve brain pressure and swelling and to prevent hearing loss that is common in patients with Haemophilus influenza meningitis
anticonvulsants such as dilantin or phenytoin to prevent seizures and corticosteroids to reduce brain inflammation
Vaccinations against Haemophilus influenzae (Hib) have decreased early childhood meningitis.
Null Hypothesis in Dentistry and applications
Public Health DentistryThe null hypothesis is a fundamental concept in scientific research,
including dentistry, which serves as a starting point for conducting experiments
or studies. It is a statement that assumes there is no relationship, difference,
or effect between the variables being studied. The null hypothesis is often
denoted as H₀.
In dentistry, researchers may formulate a null hypothesis to test the efficacy
of a new treatment, the relationship between oral health and systemic
conditions, or the prevalence of dental diseases. The purpose of the null
hypothesis is to provide a baseline against which the results of the study can
be compared to determine if the observed effects are statistically significant
or not.
Here are some common applications of the null hypothesis in dentistry:
1. Comparing Dental Treatments: Researchers might formulate a
null hypothesis that a new treatment is no more effective than the standard
treatment. For example, "There is no significant difference in the reduction of
dental caries between the use of fluoride toothpaste and a new, alternative
dental gel."
2. Oral Health and Systemic Conditions: A null hypothesis could
be used to test if there is no correlation between oral health and systemic
diseases such as diabetes or cardiovascular disease. For instance, "There is no
significant relationship between periodontal disease and the incidence of
stroke."
3. Dental Materials: Studies might use a null hypothesis to
assess the equivalence of different materials used in dental restorations. For
example, "There is no difference in the longevity of composite resin fillings
compared to amalgam fillings."
4. Dental Procedures: Researchers may compare the effectiveness
of new surgical techniques with traditional ones. The null hypothesis would be
that the new procedure does not result in better patient outcomes. For instance,
"There is no significant difference in post-operative pain between
laser-assisted versus traditional scalpel gum surgery."
5. Epidemiological Studies: In studies examining the prevalence
of dental diseases, the null hypothesis might state that there is no difference
in the rate of cavities between different population groups or regions. For
example, "There is no significant difference in the incidence of dental caries
between children who consume fluoridated water and those who do not."
6. Dental Education: Null hypotheses can be used to evaluate
the impact of new educational methods or interventions on dental student
performance. For instance, "There is no significant improvement in the manual
dexterity skills of dental students using virtual reality training compared to
traditional methods."
7. Oral Hygiene Products: Researchers might hypothesize that a
new toothpaste does not offer any additional benefits over existing products.
The null hypothesis would be that "There is no significant difference in plaque
reduction between the new toothpaste and the market leader."
To test the null hypothesis, researchers conduct statistical analyses on the
data collected from their studies. If the results indicate that the null
hypothesis is likely to be true (usually determined by a p-value greater than
the chosen significance level, such as 0.05), they fail to reject it. However,
if the results suggest that the null hypothesis is unlikely to be true,
researchers reject the null hypothesis and accept the alternative hypothesis,
which posits a relationship, difference, or effect between the variables.
In each of these applications, the null hypothesis is essential for maintaining
a rigorous scientific approach to dental research. It helps to minimize the risk
of confirmation bias and ensures that conclusions are drawn from objective
evidence rather than assumptions or expectations.
VIRAL DISEASES -RABIES
General Pathology
VIRAL DISEASES
RABIES (Hydrophobia)
An acute infectious disease of mammals, especially carnivores, characterized by CNS pathology leading to paralysis and death.
Etiology and Epidemiology
Rabies is caused by a neurotropic virus often present in the saliva of rabid animals
Pathology
The virus travels from the site of entry via peripheral nerves to the spinal cord and the brain, where it multiplies; it continues through efferent nerves to the salivary glands and into the saliva.
microscopic examination shows perivascular collections of lymphocytes but little destruction of nerve cells. Intracytoplasmic inclusion bodies (Negri bodies), usually in the cornu Ammonis, are pathognomonic of rabies, but these bodies are not always found.
Sign/Symptoms
In humans, the incubation period varies from 10 days to > 1 yr and averages 30 to 50 days.
Rabies commonly begins with a short period of depression, restlessness, malaise, and fever. Restlessness increases to uncontrollable excitement, with excessive salivation and excruciatingly painful spasms of the laryngeal and pharyngeal muscles. The spasms, which result from reflex irritability of the deglutition and respiration centers, are easily precipitated Hysteria due to fright
Prognosis and Treatment
Death from asphyxia, exhaustion, or general paralysis usually occurs within 3 to 10 days after onset of symptoms