NEET MDS Synopsis
Proteins
PhysiologyProteins:
about 50 - 60% of the dry mass of a typical cell
subunit is the amino acid & amino acids are linked by peptide bonds
2 functional categories = structural (proteins part of the structure of a cell like those in the cell membrane) & enzymes
Enzymes are catalysts. Enzymes bind temporarily to one or more of the reactants of the reaction they catalyze. In doing so, they lower the amount of activation energy needed and thus speed up the reaction
Nail Biting Habits
OrthodonticsNail Biting Habits
Nail biting, also known as onychophagia, is one of the most
common habits observed in children and can persist into adulthood. It is often
associated with internal tension, anxiety, or stress. Understanding the
etiology, clinical features, and management strategies for nail biting is
essential for addressing this habit effectively.
Etiology
Emotional Problems:
Persistent nail biting may indicate underlying emotional issues,
such as anxiety, stress, or tension. It can serve as a coping mechanism
for dealing with these feelings.
Psychosomatic Factors:
Nail biting can be a psychosomatic response to stress or emotional
discomfort, manifesting physically as a way to relieve tension.
Successor of Thumb Sucking:
For some children, nail biting may develop as a successor to thumb
sucking, particularly as they transition from one habit to another.
Clinical Features
Dental Effects:
Crowding: Nail biting can contribute to dental
crowding, particularly if the habit leads to changes in the position of
the teeth.
Rotation: Teeth may become rotated or misaligned
due to the pressure exerted during nail biting.
Alteration of Incisal Edges: The incisal edges of
the anterior teeth may become worn down or altered due to repeated
contact with the nails.
Soft Tissue Changes:
Inflammation of Nail Bed: Chronic nail biting can
lead to inflammation and infection of the nail bed, resulting in
redness, swelling, and discomfort.
Management
Awareness:
The first step in management is to make the patient aware of their
nail biting habit. Understanding the habit's impact on their health and
appearance can motivate change.
Addressing Emotional Factors:
It is important to identify and treat any underlying emotional
issues contributing to the habit. This may involve counseling or therapy
to help the individual cope with stress and anxiety.
Encouraging Outdoor Activities:
Engaging in outdoor activities and physical exercise can help reduce
tension and provide a positive outlet for stress, potentially decreasing
the urge to bite nails.
Behavioral Modifications:
Nail Polish: Applying a bitter-tasting nail polish
can deter nail biting by making the nails unpalatable.
Light Cotton Mittens: Wearing mittens or gloves can
serve as a physical reminder to avoid nail biting and can help break the
habit.
Positive Reinforcement:
Encouraging and rewarding the individual for not biting their nails
can help reinforce positive behavior and motivate them to stop.
Conditioning and Behavioral Responses
PedodonticsConditioning and Behavioral Responses
This section outlines key concepts related to conditioning and behavioral
responses, particularly in the context of learning and emotional responses in
children.
1. Acquisition
Acquisition refers to the process of
learning a new response to a stimulus through conditioning. This is the
initial stage where an association is formed between a conditioned stimulus
(CS) and an unconditioned stimulus (US).
Example: A child learns to associate the sound of a
bell (CS) with receiving a treat (US), leading to a conditioned response
(CR) of excitement when the bell rings.
2. Generalization
Generalization occurs when the conditioned
response is evoked by stimuli that are similar to the original conditioned
stimulus. This means that the learned response can be triggered by a range
of similar stimuli.
Example: If a child has a painful experience with a
doctor in a white coat, they may generalize this fear to all doctors in
white coats, regardless of the specific individual or setting. Thus, any
doctor wearing a white coat may elicit a fear response.
3. Extinction
Extinction is the process by which the
conditioned behavior diminishes or disappears when the association between
the conditioned stimulus and the unconditioned stimulus is no longer
reinforced.
Example: In the previous example, if the child visits
the doctor multiple times without any unpleasant experiences, the fear
associated with the doctor in a white coat may gradually extinguish. The
lack of reinforcement (pain) leads to a decrease in the conditioned response
(fear).
4. Discrimination
Discrimination is the ability to
differentiate between similar stimuli and respond only to the specific
conditioned stimulus. It is the opposite of generalization.
Example: If the child is exposed to clinic settings
that are different from those associated with painful experiences, they
learn to discriminate between the two environments. For instance, if the
child visits a friendly clinic with a different atmosphere, they may no
longer associate all clinic visits with fear, leading to the extinction of
the generalized fear response.
Serotonin or 5-hydroxytryptamine
Pharmacology
Serotonin or 5-hydroxytryptamine (5-HT)
It is a neurotransmitter, widely distributed in the CNS, beginning in the midbrain and projecting into thalamus, hypothalamus, cerebral cortex, and spinal cord. CNS serotonin is usually an inhibitory neurotransmitter and is associated with mood, the sleep-wake cycle.
Serotonin is thought to produce sleep by inhibiting CNS activity.
In the blood, 5-HT is present in high concentration in platelets (regulator of platelets function) and also high concentration in intestine
Pharmacological effects:
Smooth muscles. 5-HT stimulates the G.I smooth muscle; it increases the peristaltic movement of intestine.
Serotonin contracts the smooth muscle of bronchi;
Blood vessels. If serotonin is injected i.v, the blood pressure usually first rises, because of the contraction of large vessels and then falls because of arteriolar dilatation. Serotonin causes aggregation of platelets.
Specific agonists
- Sumatriptan a selective 5-HT1D used in treatment of acute migraine.
- Buspirone a selective 5-HT1A used in anxiety.
- Ergotamine is a partial agonist used in migraine. It acts on 5-HT1A receptor.
Nonspecific 5-HT receptor agonist
o Dexfenfluramine used as appetite suppressant.
Specific antagonists
o Spiperone (acts on 1A receptor) and
o Methiothepin (acts on 1A, 1B, 1D receptors)
Weine Classification
Endodontics
Weine Classification
The Weine classification divides root canal systems into three main categories:
The pulp canal system is complex, and it may branch, divide, and rejoin.
Weine categorized the root canal systems in any root
into four basic types. Others, using cleared teeth in which the root canal
systems had been stained with hematoxylin dye, found a
much more complex canal system. They identified eight pulp space
configurations, that can be briefly described as following :
Type I : A single canal extends from the pulp chamber to the apex (1).
Type II: Two separate canals leave the pulp chamber and join short of the
apex to form one canal (2-1).
Type III: One canal leaves the pulp chamber and divides into two in the root;
the two then merge to exit as one canal (1-2-1).
Type IV: Two separate, distinct canals extend from the pulp chamber to the
apex (2).
Type V: One canal leaves the pulp chamber and divides short of the apex into
two separate, distinct canals with separate apical foramina (1-2).
Type VI: Two separate canals leave the pulp chamber, merge into the body of
the root, and redivide short of the apex to exit as two distinct canals (2-1-2).
Type VII: One canal leaves the pulp chamber, divides and then rejoins in the
body of the root, and finally redivides into two distinct canals short of the apex (1-2-1-2).
Type VIII: Three separate, distinct canals extend from the pulp chamber to
the apex (3).
Primary vs. secondary disorders
General Pathology
Primary vs. secondary disorders - Most nutritional disorders in developed countries are not due to simple dietary deficiencies but are rather a secondary manifestation of an underlying primary condition or disorder.
• Chronic alcoholism
• Pregnancy and lactation
• Renal dialysis
• Eating disorders
• Prolonged use of diuretics
• Malabsorption syndromes
• Neoplasms
• Food fads
• Vegans
• AIDS
Physiology
PhysiologyPhysiology - science that describes how organisms FUNCTION and survive in continually changing environments
Classifications of epidemiologic research
Public Health Dentistry
Classifications of epidemiologic research
1. Descriptive research —involves description, documentation, analysis, and interpretation of data to evaluate a current event or situation
a. incidence—number of new cases of a specific disease within a defined population over a period of time
b. Prevalence—number of persons in a population affected by a condition at any one time
c. Count—simplest sum of disease: number of cases of disease occurrence
d. Proportion—use of a count with the addition of a denominator to determine prevalence:
does not include a time dimension: useful to evaluate prevalence of caries in schoolchildren or tooth loss in adult populations
e. Rate— uses a standardized denominator and includes a time dimension. for example. the number of deaths of newborn infants within first year of life per 1000 births
2. Analytical research—determines the cause of disease or if a causal relationship exists between a factor and a disease
a. Prospective study—planning of the entire study is completed before data are collected and analyzed; population is followed through time to determine which members develop the disease; several hypotheses may be tested at on time
b. Cohort study—individuals are classified into groups according to whether or not they pos- sess a particular characteristic thought to be related to the condition of interest; observations occur over time to see who develops dis ease or condition
c. Retrospective study— decision to carry out an investigation using observations or data that have been collected in the past; data may be incomplete or in a manner not appropriate for study
d. Cross-sectional study— study of subgroups of individuals in a specific and limited time frame to identify either initially to describe current status or developmental changes in the overall group from the perspective of what is typical in each subgroup
e. Longitudinal study—investigation of the same group of individuals over an extended period of time to identify a change or devel opment in that group
3. Experimental research—used when the etiology of the disease is established and the researcher wishes to determine the effectiveness of altering some factor or factors; deliberate applying or withholding of the supposed cause of a condition and observing the result