NEET MDS Synopsis
HERPES SIMPLEX
General Pathology
HERPES SIMPLEX
An infection with herpes simplex virus characterized by one or many clusters of small vesicles filled with clear fluid on slightly raised inflammatory bases.
The two types of herpes simplex virus (HSV) are HSV-1 and HSV-2. HSV-1 commonly causes herpes labialis, herpetic stomatitis, and keratitis; HSV-2 usually causes genital herpes, is transmitted primarily by direct (usually sexual) contact with lesions, and results in skin lesions
Primary infection of HSV-1 typically causes a gingivostomatitis, which is most common in infants and young children. Symptoms include irritability, anorexia, fever, gingival inflammation, and painful ulcers of the mouth.
Primary infection of HSV-2 typically occurs on the vulva and vagina or penis in young adults
Herpetic whitlow, a swollen, painful, and erythematous lesion of the distal phalanx, results from inoculation of HSV through a cutaneous break or abrasion and is most common in health care workers.
Esthetic Preformed Crowns
PedodonticsEsthetic Preformed Crowns in Pediatric Dentistry
Esthetic preformed crowns are an important option in pediatric dentistry,
providing a functional and aesthetic solution for restoring primary teeth.
Here’s a detailed overview of various types of esthetic crowns used in children:
i) Polycarbonate Crowns
Advantages:
Save time during the procedure.
Easy to trim and adjust with pliers.
Usage: Often used for anterior teeth due to their
aesthetic appearance.
ii) Strip Crowns
Description: These are crown forms that are filled with
composite material and bonded to the tooth. After polymerization, the crown
form is removed.
Advantages:
Most commonly used crowns in pediatric dental practice.
Easy to repair if damaged.
Usage: Ideal for anterior teeth restoration.
iii) Pedo Jacket Crowns
Material: Made of tooth-colored copolyester material
filled with resin.
Characteristics:
Left on the tooth after polymerization instead of being removed.
Available in only one shade.
Cannot be trimmed easily.
Usage: Suitable for anterior teeth where aesthetics are
a priority.
iv) Fuks Crowns
Description: These crowns consist of a stainless steel
shell sized to cover a portion of the tooth, with a polymeric coating made
from a polyester/epoxy hybrid composition.
Advantages: Provide a durable and aesthetic option for
restoration.
v) New Millennium Crowns
Material: Made from laboratory-enhanced composite resin
material.
Characteristics:
Bonded to the tooth and can be trimmed easily.
Very brittle and more expensive compared to other options.
Usage: Suitable for anterior teeth requiring esthetic
restoration.
vi) Nusmile Crowns
Indication: Indicated when full coverage restoration is
needed.
Characteristics: Provide a durable and aesthetic
solution for primary teeth.
vii) Cheng Crowns
Description: Crowns with a pure resin facing that makes
them stain-resistant.
Advantages:
Less time-consuming and typically requires a single patient visit.
Usage: Suitable for anterior teeth restoration.
viii) Dura Crowns
Description: Pre-veneered crowns that can be placed
even with poor moisture or hemorrhage control.
Challenges: Not easy to fit and require a longer
learning curve for proper placement.
ix) Pedo Pearls
Material: Aluminum crown forms coated with a
tooth-colored epoxy paint.
Characteristics:
Relatively soft, which may affect long-term durability.
Usage: Used for primary teeth restoration where
aesthetics are important.
Procoagulant Drugs
Pharmacology
Procoagulant Drugs:
Desmospressin Acetate
• Is a synthetic analogue of the pituitary antidiuretic hormone (ADH).
• Stimulates the activity of Coagulation Factor VIII
• Use for treatment of hemophilia A with factor VIII levels less than or equal to 5%, treatment of hemophilia B or in clients who have factor VIII antibodies. Treatment of severe classic von Willebrand's disease (type I) and when an abnormal molecular form of factor VIII antigen is present. Use for type IIB von Willebrand's disease.
Blastomycosis (North American Blastomycosis; Gilchrist's Disease)
General Pathology
Blastomycosis (North American Blastomycosis; Gilchrist's Disease)
A disease caused by inhalation of mold conidia (spores) of Blastomyces dermatitidis, which convert to yeasts and invade the lungs, occasionally spreading hematogenously to the skin or focal sites in other tissues.
Pulmonary blastomycosis tends to occur as individual cases of progressive infection
Symptoms are nonspecific and may include a productive or dry hacking cough, chest pain, dyspnea, fever, chills, and drenching sweats. Pleural effusion occurs occasionally. Some patients have rapidly progressive infections, and adult respiratory distress syndrome may develop.
Amino acids
Biochemistry
Amino acids
Proteins are linear polymers of amino acids. Participate in virtually every biological process. Perform diverse functions:
1. Enzymes: catalyze all reactions in living organisms
2. Storage and transport
3. Structural
4. Mechanical work ( flagella, muscles, separation of chromosomes)
5. Decoding information (translation, transcription, DNA replication)
6. Cell-signalling (hormones and receptors)
7. Defence (antibodies)
Surgical Considerations for the Submandibular and Parotid Glands
Oral and Maxillofacial SurgerySurgical Considerations for the Submandibular and Parotid Glands
When performing surgery on the submandibular and parotid glands, it is
crucial to be aware of the anatomical structures and nerves at risk to minimize
complications. Below is an overview of the key nerves and anatomical landmarks
relevant to these surgical procedures.
Major Nerves at Risk During Submandibular Gland Surgery
Hypoglossal Nerve (CN XII):
This nerve is responsible for motor innervation to the muscles of
the tongue. It lies deep to the submandibular gland and is at risk
during surgical manipulation in this area.
Marginal Mandibular Nerve:
A branch of the facial nerve (CN VII), the marginal mandibular nerve
innervates the muscles of the lower lip and chin. It runs just deep to
the superficial layer of the deep cervical fascia, below the platysma
muscle, making it vulnerable during submandibular gland surgery.
Lingual Nerve:
The lingual nerve provides sensory innervation to the anterior
two-thirds of the tongue and carries parasympathetic fibers to the
submandibular gland via the submandibular ganglion. It is located in
close proximity to the submandibular gland and is at risk during
dissection.
Anatomical Considerations for Parotid Gland Surgery
Parotid Fascia:
The parotid gland is encased in a capsule of parotid fascia, which
provides a protective layer during surgical procedures.
Facial Nerve (CN VII):
The facial nerve is a critical structure to identify during parotid
gland surgery to prevent injury. Key landmarks for locating the facial
nerve include:
Tympanomastoid Suture Line: This is a reliable
landmark for identifying the main trunk of the facial nerve, which
lies just deep and medial to this suture.
Tragal Pointer: The nerve is located about 1 cm
deep and inferior to the tragal pointer, although this landmark is
less reliable.
Posterior Belly of the Digastric Muscle: This
muscle provides a reference for the approximate depth of the facial
nerve.
Peripheral Buccal Branches: While following
these branches can help identify the nerve, this should not be the
standard approach due to the risk of injury.
Submandibular Gland Anatomy
Location:
The submandibular gland is situated in the submandibular triangle of
the neck, which is bordered by the mandible and the digastric muscles.
Mylohyoid Muscle:
The gland wraps around the mylohyoid muscle, which is typically
retracted anteriorly during surgery to provide better exposure of the
gland.
CN XII:
The hypoglossal nerve lies deep to the submandibular gland, making
it important to identify and protect during surgical procedures.
Transient structures during tooth development
Dental Anatomy
Transient structures during tooth development
Enamel knot: Thickening of the internal dental epithelium at the center of the dental organ.
Enamel cord: Epithelial proliferation that seems to divide the dental organ in two.
Review the role of these two structures
Enamel niche: It is an artifact that is produced during section of the tissue. It occurs because the dental organ is a sheet of proliferating cells rather than a single strand. It looks like a concavity that contains ectomesenchyme.
Changes in Plaque pH After Sucrose Rinse
PeriodontologyChanges in Plaque pH After Sucrose Rinse
The pH of dental plaque is a critical factor in the development of dental
caries and periodontal disease. Key findings from
various studies that investigated the changes in plaque pH following
carbohydrate rinses, particularly focusing on sucrose and glucose.
Key Findings from Studies
Monitoring Plaque pH Changes:
A study reported that changes in plaque pH after a sucrose rinse
were monitored using plaque sampling, antimony and glass electrodes, and
telemetry.
Results:
The minimum pH at approximal sites (areas between teeth) was
approximately 0.7 pH units lower than that on buccal surfaces (outer
surfaces of the teeth).
The pH at the approximal site remained below resting levels for
over 120 minutes.
The area under the pH response curves from approximal sites was
five times greater than that from buccal surfaces, indicating a more
significant and prolonged acidogenic response in interproximal
areas.
Stephan's Early Studies (1935):
Method: Colorimetric measurement of plaque pH
suspended in water.
Findings:
The pH of 211 plaque samples ranged from 4.6 to 7.0.
The mean pH value was found to be 5.9, indicating a generally
acidic environment in dental plaque.
Stephan's Follow-Up Studies (1940):
Method: Use of an antimony electrode to measure in
situ plaque pH after rinsing with sugar solutions.
Findings:
A 10% solution of glucose or sucrose caused a rapid drop in
plaque pH by about 2 units within 2 to 5 minutes, reaching values
between 4.5 and 5.0.
A 1% lactose solution lowered the pH by 0.3 units, while a 1%
glucose solution caused a drop of 1.5 units.
A 1% boiled starch solution resulted in a reduction of 1.5 pH
units over 51 minutes.
In all cases, the pH tended to return to initial values within
approximately 2 hours.
Investigation of Proximal Cavities:
Studies of actual proximal cavities opened mechanically showed that
the lowest pH values ranged from 4.6 to 4.1.
After rinsing with a 10% glucose or sucrose solution, the pH in the
plaque dropped to between 4.5 and 5.0 within 2 to 5 minutes and
gradually returned to baseline levels within 1 to 2 hours.
Implications
The studies highlight the significant impact of carbohydrate exposure,
particularly sucrose and glucose, on the pH of dental plaque.
The rapid drop in pH following carbohydrate rinses indicates an
acidogenic response from plaque microorganisms, which can contribute to
enamel demineralization and caries development.
The prolonged acidic environment in approximal sites suggests that these
areas may be more susceptible to caries due to the slower recovery of pH
levels.