NEET MDS Synopsis
Wilson’s disease
General Pathology
Wilson’s disease
Caused by a decrease in ceruloplasmin, a serum protein that binds copper, resulting in metastatic copper deposits.
Common organs affected include:
(1) Liver, leading to cirrhosis.
(2) Basal ganglia.
(3) Cornea, where Kayser-Fleischer rings (greenish rings around the cornea) are observed.
Concepts Proposed to Attain Balanced Occlusion
ProsthodonticsConcepts Proposed to Attain Balanced Occlusion
Balanced occlusion is a critical aspect of complete denture design, ensuring
stability and function during mastication and speech. Various concepts have been
proposed over the years to achieve balanced occlusion, each contributing unique
insights into the arrangement of artificial teeth. Below are the key concepts:
I. Concepts for Achieving Balanced Occlusion
1. Gysi's Concept (1914)
Overview: Gysi suggested that arranging 33° anatomic
teeth could enhance the stability of dentures.
Key Features:
The use of anatomic teeth allows for better adaptation to various
movements of the articulator.
This arrangement aims to provide stability during functional
movements.
2. French's Concept (1954)
Overview: French proposed lowering the lower occlusal
plane to increase the stability of dentures while achieving balanced
occlusion.
Key Features:
Suggested inclinations for upper teeth:
Upper first premolars: 5° inclination
Upper second premolars: 10° inclination
Upper molars: 15° inclination
This arrangement aims to enhance the occlusal relationship and
stability of the denture.
3. Sear's Concept
Overview: Sears proposed balanced occlusion for
non-anatomical teeth.
Key Features:
Utilized posterior balancing ramps or an occlusal plane that curves
anteroposteriorly and laterally.
This design helps maintain occlusal balance during functional
movements.
4. Pleasure's Concept
Overview: Pleasure introduced the concept of the
"Pleasure Curve" or the posterior reverse lateral curve.
Key Features:
This curve aids in achieving balanced occlusion by allowing for
better distribution of occlusal forces.
It enhances the functional relationship between the upper and lower
dentures.
5. Frush's Concept
Overview: Frush advised arranging teeth in a
one-dimensional contact relationship.
Key Features:
This arrangement should be reshaped during the try-in phase to
obtain balanced occlusion.
Emphasizes the importance of adjusting the occlusal surfaces for
optimal contact.
6. Hanau's Quint
Overview: Rudolph L. Hanau proposed nine factors that
govern the articulation of artificial teeth, known as the laws of balanced
articulation.
Nine Factors:
Horizontal condylar inclination
Protrusive incisal guidance
Relative cusp height
Compensating curve
Plane of orientation
Buccolingual inclination of tooth axis
Sagittal condylar pathway
Sagittal incisal guidance
Tooth alignment
Condensation: Hanau later condensed these nine factors
into five key principles for practical application.
7. Trapozzano's Concept of Occlusion
Overview: Trapozzano reviewed and simplified Hanau's
quint and proposed his triad of occlusion.
Key Features:
Focuses on the essential elements of occlusion to streamline the
process of achieving balanced occlusion.
II. Monoplane or Non-Balanced Occlusion
Monoplane occlusion is characterized by an arrangement of teeth that serves a
specific purpose. It includes the following concepts:
Spherical Theory: Proposes that the occlusal surfaces
should be arranged in a spherical configuration to facilitate movement.
Organic Occlusion: Focuses on the natural relationships
and movements of the jaw.
Occlusal Balancing Ramps for Protrusive Balance:
Utilizes ramps to maintain balance during protrusive movements.
Transographics: A method of analyzing occlusal
relationships and movements.
Sears' Occlusal Pivot Theory
Overview: Sears also proposed the occlusal pivot theory
for monoplane or balanced occlusion, emphasizing the importance of a pivot
point for functional movements.
III. Lingualized Occlusion
Overview: Proposed by Gysi, lingualized occlusion
involves positioning the maxillary posterior teeth to occlude with the
mandibular posterior teeth, enhancing stability and function.
Key Features:
The maxillary teeth are positioned more centrally, while the
mandibular teeth are positioned buccally.
This arrangement allows for better functional balance and esthetics.
Neurotransmitters
Pharmacology
Neurotransmitters can be classified into:
1. Biogenic amines:
ACh, NA, DA, 5-HT, Histamine
2. Amino acids:
Excitatory (glutamate & asparate)
Inhibitory (GABA& glycine)
3. Others:
Adenosine, melatonin
Digit Sucking and Infantile Swallow
PedodonticsDigit Sucking and Infantile Swallow
Introduction to Digit Sucking
Digit sucking is a common behavior observed in infants and young children. It
can be categorized into two main types based on the underlying reasons for the
behavior:
Nutritive Sucking
Definition: This type of sucking occurs during
feeding and is essential for nourishment.
Timing: Nutritive sucking typically begins in the
first few weeks of life.
Causes: It is primarily associated with feeding
problems, where the infant may suck on fingers or digits as a substitute
for breastfeeding or bottle-feeding.
Non-Nutritive Sucking
Definition: This type of sucking is not related to
feeding and serves other psychological or emotional needs.
Causes: Non-nutritive sucking can arise from
various psychological factors, including:
Hunger
Satisfying the innate sucking instinct
Feelings of insecurity
Desire for attention
Examples: Common forms of non-nutritive sucking
habits include:
Thumb or finger sucking
Pacifier sucking
Non-Nutritive Sucking Habits (NMS Habits)
Characteristics: Non-nutritive sucking habits are often
comforting for children and can serve as a coping mechanism in stressful
situations.
Implications: While these habits are generally normal
in early childhood, prolonged non-nutritive sucking can lead to dental
issues, such as malocclusion or changes in the oral cavity.
Infantile Swallow
Definition: The infantile swallow is a specific pattern
of swallowing observed in infants.
Characteristics:
Active contraction of the lip musculature.
The tongue tip is positioned forward, making contact with the lower
lip.
Minimal activity of the posterior tongue and pharyngeal musculature.
Posture: The tongue-to-lower lip contact is so
prevalent in infants that it often becomes their resting posture. This can
be observed when gently moving the infant's lip, causing the tongue tip to
move in unison, suggesting a strong connection between the two.
Developmental Changes: The sucking reflex and the
infantile swallow typically diminish and disappear within the first year of
life as the child matures and develops more complex feeding and swallowing
patterns.
Properties of Acrylic Resins
Dental Materials
Properties of Acrylic Resins.
They have a low thermal conductivity. These resins are not easily washed out by the acids of the oral cavity (low solubility). Acrylic resins are also resilient, which allows them to be used in stress-bearing areas.
Acrylic resins exhibit a moderate shrinkage of from 3 to 8 percent. This shrinkage and low marginal strength can lead to marginal leakage. Acrylic resins have a low resistance to wear. Acrylic resins cannot be used over a zinc oxide and eugenol-type base because eugenol interferes with the acrylic curing process.
Mixing. Insufficient mixing will cause an uneven color or streaks in the mixture. Overmixing will cause the material to harden before it can be placed
Poor distortion resistance at higher temperatures, therefore dentures should not be cleaned in hot water
Good resistance to color change
Absorbs water and must be kept hydrated (stored in water when not in mouth) to prevent dehydration cycling and changes in dimensions
Not resistant to strong oxidizing agents
Low strength; however, flexible, with good fatigue resistance
Poor scratch resistance; clean tissue-bearing surfaces of denture with soft brush and do not use abrasive cleaners
SULPHONAMIDES
Pharmacology
SULPHONAMIDES
Derivative of sulphonilamide (Para-amino Benzene (PABA ) sulphonamide).
Anti-bacterial spectrum
Bacteriostatic to gram + and gram - bacteria. but bactericidal concentrations arce attained in urine. S pyogencs. H influenzae.E coli, few- Staph aureus. gonococci. pneumococci, proteus, shigella and Lymphogranuloma venereum.
Mechanism of action
Inhibits bacterial folate synthetase as they compete with PABA
Less soluble in acid urine and may precipitate to cause crystalluria.
Accumulate in patients with renal failure and can cause toxicity
Classification
Shart Acting (4-8 Hrs) sulphadiazine, sulphamethizole.
Intermediate acting(8-16 Hrs): sulphamethoxazole , sulphaphenazole
Long Acting(l-7days): sulphamethoxypyridazine.
Ultralong Acting(3-8days): sulfaline
Adverse effects
I. nausea, vomiting and epigastric pain
2. crystalluria
3. hypersensitivity-like polyarthritis nodosa. Steven-Johnson Syndrome. photosenstivity
4.hemolysis in G-6PD deficiency
5. kernicterus
They inhibit metabolism of phenytoin. tolbutamide. methotrexate
Therapeutic Use
UTI Meningitis, Streptococcal pharyngitis, Bacillary Dysentery
Cephalometric Landmarks
OrthodonticsKey Cephalometric Landmarks
Sella (S):
The midpoint of the sella turcica, a bony structure located at the
base of the skull. It serves as a central reference point in
cephalometric analysis.
Nasion (N):
The junction of the frontal and nasal bones, located at the bridge
of the nose. It is often used as a reference point for the anterior
cranial base.
A Point (A):
The deepest point on the maxillary arch, located between the
anterior nasal spine and the maxillary alveolar process. It is crucial
for assessing maxillary position.
B Point (B):
The deepest point on the mandibular arch, located between the
anterior nasal spine and the mandibular alveolar process. It is
important for evaluating mandibular position.
Pogonion (Pog):
The most anterior point on the contour of the chin. It is used to
assess the position of the mandible in relation to the maxilla.
Gnathion (Gn):
The midpoint between Menton and Pogonion, representing the most
inferior point of the mandible. It is used in various angular
measurements.
Menton (Me):
The lowest point on the symphysis of the mandible. It is used as a
reference for vertical measurements.
Go (Gonion):
The midpoint of the contour of the ramus and the body of the
mandible. It is used to assess the angle of the mandible.
Frankfort Horizontal Plane (FH):
A plane defined by the points of the external auditory meatus (EAM)
and the lowest point of the orbit (Orbitale). It is used as a reference
plane for various measurements.
Orbitale (Or):
The lowest point on the inferior margin of the orbit (eye socket).
It is used in conjunction with the EAM to define the Frankfort
Horizontal Plane.
Ectocanthion (Ec):
The outer canthus of the eye, used in facial measurements and
assessments.
Endocanthion (En):
The inner canthus of the eye, also used in facial measurements.
Alveolar Points:
Points on the alveolar ridge of the maxilla and mandible, often used
to assess the position of the teeth.
Importance of Cephalometric Landmarks
Diagnosis: These landmarks help orthodontists diagnose
skeletal and dental discrepancies, such as Class I, II, or III
malocclusions.
Treatment Planning: By understanding the relationships
between these landmarks, orthodontists can develop effective treatment plans
tailored to the individual patient's needs.
Monitoring Progress: Cephalometric landmarks allow for
the comparison of pre-treatment and post-treatment radiographs, helping to
evaluate the effectiveness of orthodontic interventions.
Research and Education: These landmarks are essential
in orthodontic research and education, providing a standardized method for
analyzing craniofacial morphology.
X-linked Recessive Diseases List
Pathology
Alport’s Sd: "hereditary nephritis", type IV collagen deficiency, alternating thickening & thinning of GBM, COL4A5 mutation, hearing loss, ocular abnormalities (lens & cornea), hematuria (gross or micro) since childhood.
Bruton’s Agammaglobulinemia: btk gene defect, no mature B cells or plasma cells, low lymphoid tissue, hepatitis, enterovirus infxs, first 6 months protected by maternal ab (no symptoms)
Becker’s Muscular Dystrophy: altered dystrophin gene, later onset than Duchene's, slow progression, relatively normal life span, less severe, rare cardiac involvement.
Chronic Granulomatose Disease (CGD): NAPDH oxidase deficiency, recurrent catalase (+) infxs, nitroblue tetrazolium test negative (yellow)
Congenital Aqueductus Stenosis: MCC of congenital obstructive hydrocephalus.
Color blindness (red-green): can't distinguish shades of red and green (usually blue-green)
Duchene’s muscular Dystrophy: dystrophin gene mutation (Xp21), absent dystrophyn protein, MC & severe of muscular dystrophies, normal until 5yo, short life span (<30yo), progressive muscle weakness, calf pseudohypertrophy, <3 failure, arrythmias, respiratory insufficiency and infxs (decreased mucociliary clearence). Pneumonias CC of death.
Fabry’s Disease: alpha Galactosidase A, Ceramide trihexose accumulation, angiokeratomas, renal failure, peripheral neuropathy.
Glucose 6-P Dehydrogenase (G6PD) Deficiency: chronic hemolytic anemia, MCC of enzymatic deficiency HA, Heinz bodies, bite cells. Triggers are infections, drugs (antimalarial), fava beans
Hemophilia A & B: factor VIII & IX deficiency respectively. PTT prolongation.
Hunter Disease: iduronate sulfatase deficiency, heparan sulfate accumulation, no corneal clouding, aggressive behaviour.
Inherited Nephrogenic Diabetes Insipidus: V2 receptors in collecting duct don't respond to ADH.
Lesch-Nyhan Sd: HGPRT1 deficiency, spastic cerebral palsy, self-mutilation, hyperuricemia, oral crystals in diapers, early death.
Menkes Disease: ATP7A gene mutation (copper efflux protein), Cu+ is lysil oxidase cofactor, Cu+ accumulates in intestine & kidneys; deficient in other tissues = deficient collagen cross linking; steely 'kinky' hair, MR, arterial tortuosity, hypotonia.
Ornithine Transcarbamoylase Deficiency: urea cycle, orotic aciduria + hyperammonemia (no megaloblastic anemia), orotic acid accumulation, increased glutamine . Cerebral edema, lethargy, vomiting, hyperventilation, convulsions, coma, death.
SCID: IL-receptor, Gamma chain deficiency
Wiskott Aldrich Sd: combined partial B & T immunodeficiency, IgM deficiency, thrombocytopenia, eczema.