NEET MDS Synopsis
Neutralization Test
General Microbiology
Neutralization Test
These are basically of two types:
• Toxin neutralization
• Virus neutralization
In toxin neutralization homologous anti-bodies prevent the biological effect of toxin as observed in vivo in experimental animals (e.g. detection of toxin of Clostridia and Corynebacterium diphthenae) or by in vitro method (e.g. Nagler’s method).
In virus neutralization test various methods are available by which identity of virus can be established as well as antibody against a virus can be estimated.
Methicillin
Pharmacology
Methicillin
Methicillin is an antibiotic related to penicillin and other beta-lactam containing antibiotics. It is often used to treat infections caused by bacteria carrying an antibiotic resistance, e.g., staphylococci. As methicillin is deactivated by gastric acid, it has to be administered by injection.
Uses Methicillin serves a purpose in the laboratory to determine antibiotic sensitivity in microbiological culture.
Degrees of Mental Disability
PedodonticsDegrees of Mental Disability
Mental disabilities are often classified based on the severity of cognitive
impairment, which can be assessed using various intelligence scales, such as the
Wechsler Intelligence Scale and the Stanford-Binet Scale. Below is a detailed
overview of the degrees of mental disability, including IQ ranges and
communication abilities.
1. Mild Mental Disability
IQ Range: 55-69 (Wechsler Scale) or 52-67 (Stanford-Binet
Scale)
Description:
Individuals in this category may have some difficulty with academic
skills but can often learn basic academic and practical skills.
They typically can communicate well enough for most communication
needs and may function independently with some support.
They may have social skills that allow them to interact with peers
and participate in community activities.
2. Moderate Mental Disability
IQ Range: 40-54 (Wechsler Scale) or 36-51
(Stanford-Binet Scale)
Description:
Individuals with moderate mental disability may have significant
challenges in academic learning and require more support in daily
living.
Communication skills may be limited; they can communicate at a basic
level with others but may struggle with more complex language.
They often need assistance with personal care and may benefit from
structured environments and support.
3. Severe or Profound Mental Disability
IQ Range: 39 and below (Severe) or 35 and below
(Profound)
Description:
Individuals in this category have profound limitations in cognitive
functioning and adaptive behavior.
Communication may be very limited; some may be mute or communicate
only in grunts or very basic sounds.
They typically require extensive support for all aspects of daily
living, including personal care and communication.
OCCLUSION AND DENTAL DEVELOPMENT-Stages-Deciduous dentition period
Dental Anatomy
Deciduous dentition period.
-The deciduous teeth start to erupt at the age of six months and the deciduous dentition is complete by the age of approximately two and one half years of age.
-The jaws continue to increase in size at all points until about age one year.
-After this, growth of the arches is lengthening of the arches at their posterior (distal) ends. Also, there is slightly more forward growth of the mandible than the maxilla.
1. Many early developmental events take place.
-The tooth buds anticipate the ultimate occlusal pattern.
-Mandibular teeth tend to erupt first. The pattern for the deciduous incisors is usually in this distinctive order:
(1) mandibular central
(2) maxillary central incisors
(3) then all four lateral incisors.
-By one year, the deciduous molars begin to erupt.
-The eruption pattern for the deciduous dentition as a whole is:
(1) central incisor
(2) lateral incisor
(3) deciduous first molar
(4) then the canine
(5) then finally the second molar.
-Eruption times can be variable.
2. Occlusal changes in the deciduous dentition.
-The overjet tends to diminish with age. Wear and mandibular growth are a factor in this process.
-The overbite often diminishes with the teeth being worn to a flat plane occlusion.
-Spacing of the incisors in anticipation of the soon-to-erupt permanent incisors appears late. Permanent anterior teeth (incisors and canines) are wider mesiodistally than deciduous anterior teeth. In contrast, the deciduous molar are wider mesiodistally that the premolars that later replace them.
-Primate spaces occur in about 50% of children. They appear in the deciduous dentition. The spaces appear between the upper lateral incisor and the upper canine. They also appear between the lower canine and the deciduous first molar.
ACRYLIC RESINS
Dental Materials
ACRYLIC RESINS
Use. Acrylic (unfilled) resins are used as temporary crown material. Temporary crowns are placed to protect the crown preparation and provide patient comfort during the time the permanent crown is being constructed
Blood Groups
PhysiologyBlood Groups
Blood groups are created by molecules present on the surface of red blood cells (and often on other cells as well).
The ABO Blood Groups
The ABO blood groups are the most important in assuring safe blood transfusions.
Blood Group
Antigens on RBCs
Antibodies in Serum
Genotypes
A
A
Anti-B
AA or AO
B
B
Anti-A
BB or BO
AB
A and B
Neither
AB
O
Neither
Anti-A and anti-B
OO
When red blood cells carrying one or both antigens are exposed to the corresponding antibodies, they agglutinate; that is, clump together. People usually have antibodies against those red cell antigens that they lack.
The critical principle to be followed is that transfused blood must not contain red cells that the recipient's antibodies can clump. Although theoretically it is possible to transfuse group O blood into any recipient, the antibodies in the donated plasma can damage the recipient's red cells. Thus all transfusions should be done with exactly-matched blood.
The Rh System
Rh antigens are transmembrane proteins with loops exposed at the surface of red blood cells. They appear to be used for the transport of carbon dioxide and/or ammonia across the plasma membrane. They are named for the rhesus monkey in which they were first discovered.
There are a number of Rh antigens. Red cells that are "Rh positive" express the one designated D. About 15% of the population have no RhD antigens and thus are "Rh negative".
The major importance of the Rh system for human health is to avoid the danger of RhD incompatibility between mother and fetus.
During birth, there is often a leakage of the baby's red blood cells into the mother's circulation. If the baby is Rh positive (having inherited the trait from its father) and the mother Rh-negative, these red cells will cause her to develop antibodies against the RhD antigen. The antibodies, usually of the IgG class, do not cause any problems for that child, but can cross the placenta and attack the red cells of a subsequent Rh+ fetus. This destroys the red cells producing anemia and jaundice. The disease, called erythroblastosis fetalis or hemolytic disease of the newborn, may be so severe as to kill the fetus or even the newborn infant. It is an example of an antibody-mediated cytotoxicity disorder.
Although certain other red cell antigens (in addition to Rh) sometimes cause problems for a fetus, an ABO incompatibility does not. Rh incompatibility so dangerous when ABO incompatibility is not
It turns out that most anti-A or anti-B antibodies are of the IgM class and these do not cross the placenta. In fact, an Rh−/type O mother carrying an Rh+/type A, B, or AB fetus is resistant to sensitization to the Rh antigen. Presumably her anti-A and anti-B antibodies destroy any fetal cells that enter her blood before they can elicit anti-Rh antibodies in her.
This phenomenon has led to an extremely effective preventive measure to avoid Rh sensitization. Shortly after each birth of an Rh+ baby, the mother is given an injection of anti-Rh antibodies. The preparation is called Rh immune globulin (RhIG) or Rhogam. These passively acquired antibodies destroy any fetal cells that got into her circulation before they can elicit an active immune response in her.
Rh immune globulin came into common use in the United States in 1968, and within a decade the incidence of Rh hemolytic disease became very low.
Anchorage in Orthodontics
Orthodontics
Anchorage in orthodontics refers to the resistance that the anchorage area
offers to unwanted tooth movements during orthodontic treatment. Proper
understanding and application of anchorage principles are crucial for achieving
desired tooth movements while minimizing undesirable effects on adjacent teeth.
Classification of Anchorage
1. According to Manner of Force Application
Simple Anchorage:
Achieved by engaging a greater number of teeth than those being
moved within the same dental arch.
The combined root surface area of the anchorage unit must be at
least double that of the teeth to be moved.
Stationary Anchorage:
Defined as dental anchorage where the application of force tends to
displace the anchorage unit bodily in the direction of the force.
Provides greater resistance compared to anchorage that only resists
tipping forces.
Reciprocal Anchorage:
Refers to the resistance offered by two malposed units when equal
and opposite forces are applied, moving each unit towards a more normal
occlusion.
Examples:
Closure of a midline diastema by moving the two central incisors
towards each other.
Use of crossbite elastics and dental arch expansions.
2. According to Jaws Involved
Intra-maxillary Anchorage:
All units offering resistance are situated within the same jaw.
Intermaxillary Anchorage:
Resistance units in one jaw are used to effect tooth movement in the
opposing jaw.
Also known as Baker's anchorage.
Examples:
Class II elastic traction.
Class III elastic traction.
3. According to Site
Intraoral Anchorage:
Both the teeth to be moved and the anchorage areas are located
within the oral cavity.
Anatomic units include teeth, palate, and lingual alveolar bone of
the mandible.
Extraoral Anchorage:
Resistance units are situated outside the oral cavity.
Anatomic units include the occiput, back of the neck, cranium, and
face.
Examples:
Headgear.
Facemask.
Muscular Anchorage:
Utilizes forces generated by muscles to aid in tooth movement.
Example: Lip bumper to distalize molars.
4. According to Number of Anchorage Units
Single or Primary Anchorage:
A single tooth with greater alveolar support is used to move another
tooth with lesser support.
Compound Anchorage:
Involves more than one tooth providing resistance to move teeth with
lesser support.
Multiple or Reinforced Anchorage:
Utilizes more than one type of resistance unit.
Examples:
Extraoral forces to augment anchorage.
Upper anterior inclined plane.
Transpalatal arch.
Parathyroid Hormone
Biochemistry
Parathyroid Hormone
Parathyroid hormone (PTH), parathormone or parathyrin, is secreted by the chief cells of the parathyroid glands.
It acts to increase the concentration of calcium (Ca2+) in the blood, whereas calcitonin (a hormone produced by the parafollicular cells of the thyroid gland) acts to decrease calcium concentration.
PTH acts to increase the concentration of calcium in the blood by acting upon the parathyroid hormone 1 receptor (high levels in bone and kidney) and the parathyroid hormone 2 receptor (high levels in the central nervous system, pancreas, testis, and placenta).
Effect of parathyroid hormone in regulation of serum calcium.
Bone -> PTH enhances the release of calcium from the large reservoir contained in the bones. Bone resorption is the normal destruction of bone by osteoclasts, which are indirectly stimulated by PTH forming new osteoclasts, which ultimately enhances bone resorption.
Kidney -> PTH enhances active reabsorption of calcium and magnesium from distal tubules of kidney. As bone is degraded, both calcium and phosphate are released. It also decreases the reabsorption of phosphate, with a net loss in plasma phosphate concentration. When the calcium:phosphate ratio increases, more calcium is free in the circulation.
Intestine -> PTH enhances the absorption of calcium in the intestine by increasing the production of activated vitamin D. Vitamin D activation occurs in the kidney. PTH converts vitamin D to its active form (1,25-dihydroxy vitamin D). This activated form of vitamin D increases the absorption of calcium (as Ca2+ ions) by the intestine via calbindin.