NEET MDS Synopsis
Theory of Object Relations
PedodonticsMargaret S. Mahler’s Theory of Object Relations
Overview of Mahler’s Theory
Margaret S. Mahler's theory of object relations focuses on the development of
personality in early childhood through the understanding of the child's
relationship with their primary caregiver. Mahler proposed that this development
occurs in three main stages, each characterized by specific psychological
processes and milestones.
Stages of Childhood Development
Normal Autistic Phase (0 – 1 Year):
Description: This phase is characterized by a state
of half-sleep and half-wakefulness. Infants are primarily focused on
their internal needs and experiences.
Key Features:
The infant is largely unaware of the external environment and
caregivers.
The primary goal during this phase is to achieve equilibrium
with the environment, establishing a sense of basic security and
comfort.
Normal Symbiotic Phase (3 – 4 Weeks to 4 – 5 Months):
Description: In this phase, the infant begins to
develop a slight awareness of the caregiver, but both the infant and
caregiver remain undifferentiated in their relationship.
Key Features:
The infant experiences a sense of oneness with the caregiver,
relying on them for emotional and physical needs.
There is a growing recognition of the caregiver's presence, but
the infant does not yet see themselves as separate from the
caregiver.
Separation-Individualization Phase (5 to 36 Months):
This phase is crucial for the development of a sense of self and
independence. It is further divided into four subphases:
a. Differentiation (5 – 10 Months):
Description: The infant begins to recognize the
distinction between themselves and the caregiver.
Key Features:
Increased awareness of the caregiver's presence and the
environment.
The infant may start to explore their surroundings while still
seeking reassurance from the caregiver.
b. Practicing Period (10 – 16 Months):
Description: During this period, the child actively
practices their emerging mobility and independence.
Key Features:
The child explores the environment more freely, often moving
away from the caregiver but returning for comfort.
This stage is marked by a sense of exhilaration as the child
gains new skills.
c. Rapprochement (16 – 24 Months):
Description: The child begins to seek a balance
between independence and the need for the caregiver.
Key Features:
The child may exhibit ambivalence, wanting to explore but also
needing the caregiver's support.
This phase is characterized by emotional fluctuations as the
child navigates their growing autonomy.
d. Consolidation and Object Constancy (24 – 36 Months):
Description: The child develops a more stable sense
of self and an understanding of the caregiver as a separate entity.
Key Features:
The child achieves object permanence, recognizing that the
caregiver exists even when not in sight.
This phase solidifies the child's ability to maintain emotional
connections with the caregiver while exploring independently.
Merits of Mahler’s Theory
Applicability to Children: Mahler's theory provides
valuable insights into the emotional and psychological development of
children, particularly in understanding the dynamics of attachment and
separation from caregivers.
Demerits of Mahler’s Theory
Lack of Comprehensiveness: While Mahler's theory offers
important perspectives on early childhood development, it is not considered
a comprehensive theory. It may not account for all aspects of personality
development or the influence of broader social and cultural factors.
Forces Required for Tooth Movements
OrthodonticsForces Required for Tooth Movements
Tipping:
Force Required: 50-75 grams
Description: Tipping involves the movement of a
tooth around its center of resistance, resulting in a change in the
angulation of the tooth.
Bodily Movement:
Force Required: 100-150 grams
Description: Bodily movement refers to the
translation of a tooth in its entirety, moving it in a straight line
without tipping.
Intrusion:
Force Required: 15-25 grams
Description: Intrusion is the movement of a tooth
into the alveolar bone, effectively reducing its height in the dental
arch.
Extrusion:
Force Required: 50-75 grams
Description: Extrusion involves the movement of a
tooth out of the alveolar bone, increasing its height in the dental
arch.
Torquing:
Force Required: 50-75 grams
Description: Torquing refers to the rotational
movement of a tooth around its long axis, affecting the angulation of
the tooth in the buccolingual direction.
Uprighting:
Force Required: 75-125 grams
Description: Uprighting is the movement of a tilted
tooth back to its proper vertical position.
Rotation:
Force Required: 50-75 grams
Description: Rotation involves the movement of a
tooth around its long axis, changing its orientation within the dental
arch.
Headgear:
Force Required: 350-450 grams on each side
Duration: Minimum of 12-14 hours per day
Description: Headgear is used to control the growth
of the maxilla and to correct dental relationships.
Face Mask:
Force Required: 1 pound (450 grams) per side
Duration: 12-14 hours per day
Description: A face mask is used to encourage
forward growth of the maxilla in cases of Class III malocclusion.
Chin Cup:
Initial Force Required: 150-300 grams per side
Subsequent Force Required: 450-700 grams per side
(after two months)
Duration: 12-14 hours per day
Description: A chin cup is used to control the
growth of the mandible and improve facial aesthetics.
Airway Management in Medical Emergencies
Oral and Maxillofacial SurgeryAirway Management in Medical Emergencies: Tracheostomy and Cricothyrotomy
1. Establishing a Patent Airway
Immediate Goal: The primary objective in any emergency
involving airway obstruction is to ensure that the patient has a clear and
patent airway to facilitate breathing.
Procedures Available: Various techniques exist to
achieve this, ranging from nonsurgical methods to surgical interventions.
2. Surgical Interventions
A. Tracheostomy
A tracheostomy is a surgical procedure that
involves creating an opening in the trachea (windpipe) through the neck to
establish an airway.
Indications:
Prolonged mechanical ventilation.
Severe upper airway obstruction (e.g., due to tumors, trauma, or
swelling).
Need for airway protection in patients with impaired consciousness
or neuromuscular disorders.
Procedure:
An incision is made in the skin over the trachea,
A tracheostomy incision is made between
the second and third tracheal rings, which is below the larynx. The
incision is usually 2–3 cm long and can be vertical or horizontaland the trachea is
then opened to insert a tracheostomy tube.
This procedure requires considerable knowledge of anatomy and
technical skill to perform safely and effectively.
B. Cricothyrotomy
Definition: A cricothyrotomy is a surgical procedure
that involves making an incision through the skin over the cricothyroid
membrane (located between the thyroid and cricoid cartilages) to establish
an airway.
Indications:
Emergency situations where rapid access to the airway is required,
especially when intubation is not possible.
Situations where facial or neck trauma makes traditional intubation
difficult.
Procedure:
A vertical incision is made over the cricothyroid membrane, and a
tube is inserted directly into the trachea.
This procedure is typically quicker and easier to perform than a
tracheostomy, making it suitable for emergency situations.
3. Nonsurgical Techniques for Airway Management
A. Abdominal Thrust (Heimlich Maneuver)
The Heimlich maneuver is a lifesaving
technique used to relieve choking caused by a foreign body obstructing the
airway.
Technique:
The rescuer stands behind the patient and wraps their arms around
the patient's waist.
A fist is placed just above the navel, and quick, inward and upward
thrusts are applied to create pressure in the abdomen, which can help
expel the foreign object.
Indications: This technique is the first-line approach
for conscious patients experiencing airway obstruction.
B. Back Blows and Chest Thrusts
Back Blows:
The rescuer delivers firm blows to the back between the shoulder
blades using the heel of the hand. This can help dislodge an object
obstructing the airway.
Chest Thrusts:
For patients who are obese or pregnant, chest thrusts may be more
effective. The rescuer stands behind the patient and performs thrusts to
the chest, similar to the Heimlich maneuver.
Berkson's Bias
Public Health DentistryBerkson's Bias is a type of selection bias that occurs in
case-control studies, particularly when the cases and controls are selected from
a hospital or clinical setting. It arises when the selection of cases
(individuals with the disease) and controls (individuals without the disease) is
influenced by the presence of other conditions or factors, leading to a
distortion in the association between exposure and outcome.
Key Features of Berkson's Bias
Hospital-Based Selection: Berkson's Bias typically
occurs in studies where both cases and controls are drawn from the same
hospital or clinical setting. This can lead to a situation where the
controls are not representative of the general population.
Association with Other Conditions: Individuals who are
hospitalized may have multiple health issues or risk factors that are not
present in the general population. This can create a misleading association
between the exposure being studied and the disease outcome.
Underestimation or Overestimation of Risk: Because the
controls may have different health profiles compared to the general
population, the odds ratio calculated in the study may be biased. This can
lead to either an overestimation or underestimation of the true association
between the exposure and the disease.
Example of Berkson's Bias
Consider a study investigating the relationship between smoking and lung
cancer, where both cases (lung cancer patients) and controls (patients without
lung cancer) are selected from a hospital. If the controls are patients with
other diseases that are also related to smoking (e.g., chronic obstructive
pulmonary disease), this could lead to Berkson's Bias. The controls may have a
higher prevalence of smoking than the general population, which could distort
the perceived association between smoking and lung cancer.
Implications of Berkson's Bias
Misleading Conclusions: Berkson's Bias can lead
researchers to draw incorrect conclusions about the relationship between
exposures and outcomes, which can affect public health recommendations and
clinical practices.
Generalizability Issues: Findings from studies affected
by Berkson's Bias may not be generalizable to the broader population,
limiting the applicability of the results.
Mitigating Berkson's Bias
To reduce the risk of Berkson's Bias in research, researchers can:
Select Controls from the General Population: Instead of
selecting controls from a hospital, researchers can use population-based
controls to ensure a more representative sample.
Use Multiple Control Groups: Employing different control
groups can help identify and account for potential biases.
Stratify Analyses: Stratifying analyses based on
relevant characteristics (e.g., age, sex, comorbidities) can help to control
for confounding factors.
Conduct Sensitivity Analyses: Performing sensitivity
analyses can help assess how robust the findings are to different
assumptions about the data.
Measles (rubeola)
General Pathology
Measles (rubeola)
-incubation period 7 to 14 days
-begins with fever (up to 40 degrees C), cough, conjunctivitis (photophobia is first sign), and coryza (excessive mucous production)Æfollowed by Koplik's spots (red with white center) in the mouth, posterior cervical Lymphadenopathy, and a generalized, blanching, maculopapular, brownish-pink rash (viral induced vasculitis) beginning at the hairline and extending down over the body which gradually resolves in 5 days with some desquamation.
Punch Biopsy Technique
Oral and Maxillofacial SurgeryPunch Biopsy Technique
A punch biopsy is a medical procedure used to obtain a small
cylindrical sample of tissue from a lesion for diagnostic purposes. This
technique is particularly useful for mucosal lesions located in areas that are
difficult to access with conventional biopsy methods. Below is an overview of
the punch biopsy technique, its applications, advantages, and potential
limitations.
Punch Biopsy
Procedure:
A punch biopsy involves the use of a specialized instrument called
a punch (a circular blade) that is used to remove a
small, cylindrical section of tissue from the lesion.
The punch is typically available in various diameters (commonly
ranging from 2 mm to 8 mm) depending on the size of the lesion and the
amount of tissue needed for analysis.
The procedure is usually performed under local anesthesia to
minimize discomfort for the patient.
Technique:
Preparation: The area around the lesion is cleaned
and sterilized.
Anesthesia: Local anesthetic is administered to
numb the area.
Punching: The punch is pressed down onto the
lesion, and a twisting motion is applied to cut through the skin or
mucosa, obtaining a tissue sample.
Specimen Collection: The cylindrical tissue sample
is then removed, and any bleeding is controlled.
Closure: The site may be closed with sutures or
left to heal by secondary intention, depending on the size of the biopsy
and the location.
Applications
Mucosal Lesions: Punch biopsies are particularly useful
for obtaining samples from mucosal lesions in areas such as:
Oral cavity (e.g., lesions on the tongue, buccal mucosa, or gingiva)
Nasal cavity
Anus
Other inaccessible regions where traditional biopsy methods may be
challenging.
Skin Lesions: While primarily used for mucosal lesions,
punch biopsies can also be performed on skin lesions to diagnose conditions
such as:
Skin cancers (e.g., melanoma, basal cell carcinoma)
Inflammatory skin diseases (e.g., psoriasis, eczema)
Advantages
Minimal Invasiveness: The punch biopsy technique is
relatively quick and minimally invasive, making it suitable for outpatient
settings.
Preservation of Tissue Architecture: The cylindrical
nature of the sample helps preserve the tissue architecture, which is
important for accurate histopathological evaluation.
Accessibility: It allows for sampling from
difficult-to-reach areas that may not be accessible with other biopsy
techniques.
Limitations
Tissue Distortion: As noted, the punch biopsy technique
can produce some degree of crushing or distortion of the
tissues. This may affect the histological evaluation, particularly in
delicate or small lesions.
Sample Size: The size of the specimen obtained may be
insufficient for certain diagnostic tests, especially if a larger sample is
required for comprehensive analysis.
Potential for Scarring: Depending on the size of the
punch and the location, there may be a risk of scarring or changes in the
appearance of the tissue after healing.
Dental Indices
Public Health Dentistry
Plaque index (PlI)
0 = No plaque in the gingival area.
1 = A thin film of plaque adhering to the free gingival margin and adjacent to the area of the tooth. The plaque is not readily visible, but is recognized by running a periodontal probe across the tooth surface.
2 = Moderate accumulation of plaque on the gingival margin, within the gingival pocket, and/or adjacent to the tooth surface, which can be observed visually.
3 = Abundance of soft matter within the gingival pocket and/or adjacent to the tooth surface.
Gingival index (GI)
0 = Healthy gingiva.
1= Mild inflammation: characterized by a slight change in color, edema. No bleeding observed on gentle probing.
2 = Moderate inflammation: characterized by redness, edema, and glazing. Bleeding on probing observed.
3 = Severe inflammation: characterized by marked redness and edema. Ulceration with a tendency toward spontaneous bleeding.
Modified gingival index (MGI)
0 = Absence of inflammation.
1 = Mild inflammation: characterized by a slight change in texture of any portion of, but not the entire marginal or papillary gingival unit.
2 = Mild inflammation: criteria as above, but involving the entire marginal or papillary gingival unit.
3 = Moderate inflammation: characterized by glazing, redness, edema, and/or hypertrophy of the marginal or papillary gingival unit.
4 = Severe inflammation: marked redness, edema, and/or hypertrophy of the marginal or papillary gingival unit, spontaneous bleeding, or ulceration.
Community periodontal index (CPI)
0 = Healthy gingiva.
1 = Bleeding observed after gentle probing or by visualization.
2 = Calculus felt during probing, but all of the black area of the probe remains visible (3.5-5.5 mm from ball tip).
3 = Pocket 4 or 5 mm (gingival margin situated on black area of probe, approximately 3.5-5.5 mm from the probe tip).
4 = Pocket > 6 mm (black area of probe is not visible).
Periodontal screening and recording (PSR)
0 = Healthy gingiva. Colored area of the probe remains visible, and no evidence of calculus or defective margins is detected.
1 = Colored area of the probe remains visible and no evidence of calculus or defective margins is detected, but bleeding on probing is noted.
2 = Colored area of the probe remains visible and calculus or defective margins is detected.
3 = Colored area of the probe remains partly visible (probe depth between 3.5-5.5 mm).
4 = Colored area of the probe completely disappears (probe depth > 5.5 mm).
Benzodiazepines
Pharmacology
Benzodiazepines
All metabolites are active sedatives except the final glucuronide product.
Elimination half-life varies a great deal from drug to drug.
?-Hydroxylation is a rapid route of metabolism that is unique to triazolam,
midazolam, and alprazolam.
This accounts for the very rapid metabolism and short sedative actions of these
drugs.
Pharmacological effects of benzodiazepines
- Antianxiety.
- Sedation.
- Anticonvulsant (including drug-induced convulsions).
- Amnesia, especially drugs like triazolam.
- Relax skeletal muscle (act on CNS polysynaptic pathways).
Indications
- IV sedation, (e.g., midazolam, diazepam, lorazepam).
- Antianxiety.
- Sleep induction.
- Anticonvulsant (e.g., diazepam, clonazepam).
- Panic disorders.
- Muscle relaxation.
Adverse effects
- Ataxia, confusion.
- Excessive sedation.
- Amnesia (not a desired effect with daytime sedation).
- Altered sleep patterns (increase stage 2 and decrease stage 4 sleep).