NEET MDS Synopsis
Emergency and Management in Dentistry
General Medicine
1. Anaphylaxis
- Adrenaline (epinephrine) injection 1:1000, 1 mg/ml
- Intramuscular adrenaline (0.5 ml of 1 in 1000 solution)
- Repeat at 5 minutes if needed
2. Hypoglycaemia
- Oral glucose solution/tablets/gel/powder
- Glucagon injection 1 mg Intramuscular
- Proprietary non-diet drink or 5 g glucose powder in water
3. Acute exacerbation of asthma
- (Beta-2 agonist) Salbutamol aerosol inhaler 100 mcg/activation
- Salbutamol aerosol Activations directly or up to six into a spacer
4. Status epilepticus
- Buccal or intranasal midazolam 10 mg/ml
5. Angina
- Glyceryl trinitrate spray 400 mcg/metered activation
6. Myocardial infarct
- Dispersible aspirin 300 mg
ANAEMIA
General Pathology
ANAEMIA
Definition. Reduction of the hemoglobin level below the normal for the age and sex of the patient
Classification
1. Blood loss anaemia:
- Acute.
- Chronic (results in iron deficiency).
2. Deficiency anaemia:
- Iron deficiency.
- Megaloblastic anaemia-BI2 and Folic acid deficiency.
- Protein deficiency.
- Scurvy-Vitamin C deficiency.
3. Marrow dysfunction:
- Aplastic anaemia.
- Marrow infiltration.
- Liver failure.
- Renal failure.
- Collagen diseases.
4 Increased destruction (Heamolysis)
- Due to corpuscular defects.
- Due to extra corpuscular defects
Acute tubular necrosis
General Pathology
Acute tubular necrosis
Characterized by impaired kidney functions due to the destruction of the renal tubule epithelium.
Caused by a variety of conditions that lead to ischemia of the renal tubules, usually resulting from renal tubular injury or problems with vascular flow. It can also be induced by ingesting toxins or drug-related toxicity (e.g., gentamicin).
The most common cause of acute renal failure.
Is a reversible condition, although it can be fatal.
Hormones of the Hypothalamus
Physiology
The hypothalamus is a region of the brain. It secretes a number of hormones.
Thyrotropin-releasing hormone (TRH)
Gonadotropin-releasing hormone (GnRH)
Growth hormone-releasing hormone (GHRH)
Corticotropin-releasing hormone (CRH)
Somatostatin
Dopamine
All of these are released into the blood, travel immediately to the anterior lobe of the pituitary, where they exert their effects.
Two other hypothalamic hormones:
Antidiuretic hormone (ADH) and
Oxytocin
travel in neurons to the posterior lobe of the pituitary where they are released into the circulation.
Distoangular Impaction
Oral and Maxillofacial SurgeryDistoangular Impaction
Distoangular impaction refers to the position of a tooth,
typically a third molar (wisdom tooth), that is angled towards the back of the
mouth and the distal aspect of the mandible. This type of impaction is often
considered one of the most challenging to manage surgically due to its
orientation and the anatomical considerations involved in its removal.
Characteristics of Distoangular Impaction
Pathway of Delivery:
The distoangular position of the tooth means that it is situated in
a way that complicates its removal. The pathway for extraction often
requires significant manipulation and access through the ascending ramus
of the mandible.
Bone Removal:
A substantial amount of distal bone removal is necessary to access
the tooth adequately. This may involve the use of surgical instruments
to contour the bone and create sufficient space for extraction.
Crown Sectioning:
Once adequate bone removal has been achieved, the crown of the tooth
is typically sectioned from the roots just above the cervical line. This
step is crucial for improving visibility and access to the roots, which
can be difficult to see and manipulate in their impacted position.
Removal of the Crown:
The entire crown is removed to facilitate better access to the
roots. This step is essential for ensuring that the roots can be
addressed without obstruction from the crown.
Root Management:
Divergent Roots: If the roots of the tooth are
divergent (spreading apart), they may need to be further sectioned into
two pieces. This allows for easier removal of each root individually,
reducing the risk of fracture or complications during extraction.
Convergent Roots: If the roots are convergent
(closer together), a straight elevator can often be used to remove the
roots without the need for additional sectioning. The elevator is
inserted between the roots to gently lift and dislodge them from the
surrounding bone.
Surgical Technique Overview
Anesthesia: Local anesthesia is administered to ensure
patient comfort during the procedure.
Incision and Flap Reflection: An incision is made in the
mucosa, and a flap is reflected to expose the underlying bone and the
impacted tooth.
Bone Removal: Using a surgical bur or chisel, the distal
bone is carefully removed to create access to the tooth.
Crown Sectioning: The crown is sectioned from the roots
using a surgical handpiece or bur, allowing for improved visibility.
Root Extraction:
For divergent roots, each root is sectioned and removed
individually.
For convergent roots, a straight elevator is used to extract the
roots.
Closure: After the tooth is removed, the surgical site
is irrigated, and the flap is repositioned and sutured to promote healing.
Considerations and Complications
Complications: Distoangular impactions can lead to
complications such as nerve injury (especially to the inferior alveolar
nerve), infection, and prolonged recovery time.
Postoperative Care: Patients should be advised on
postoperative care, including pain management, oral hygiene, and signs of
complications such as swelling or infection.
Paget Disease
General Pathology
Paget Disease (Osteitis Deformans)
This unique bone disease is characterized by repetitive episodes of exaggerated, regional osteoclastic activity (osteolytic stage), followed by exuberant bone formation (mixed osteoclastic-osteoblastic stage), and finally by exhaustion of cellular activity (osteosclerotic stage). The net effect of this process is a gain in bone mass; however, the newly formed bone is disordered and lacks strength. Paget disease usually does not occur until mid-adulthood but becomes progressively more common thereafter. The pathognomonic histologic feature is a mosaic pattern of lamellar bone (likened to a jigsaw puzzle) due to prominent cement lines that haphazardly fuse units of lamellar bone. (Fig. 12-5) The axial skeleton and proximal femur are involved in the majority of cases. In patients with extensive disease, hypervascularity of the marrow spaces can result in high-output congestive heart failure. Cranial nerves impingement also occurs and can lead to head ache and auditory disturbances. Rarely Paget disease is complicated by bone sarcoma (usually osteogenic).
Structural Divisions of the nervous system
PhysiologyStructural Divisions of the nervous system:
1) Central Nervous System (CNS) - the brain and spinal cord.
2) Peripheral Nervous System (PNS) - the nerves, ganglia, receptors, etc
Sutures for Periodontal Flaps
PeriodontologySutures for Periodontal Flaps
Suturing is a critical aspect of periodontal surgery, particularly when
managing periodontal flaps. The choice of suture material can significantly
influence healing, tissue adaptation, and overall surgical outcomes.
1. Nonabsorbable Sutures
Nonabsorbable sutures are designed to remain in the tissue until they are
manually removed. They are often used in situations where long-term support is
needed.
A. Types of Nonabsorbable Sutures
Silk (Braided)
Characteristics:
Excellent handling properties and knot security.
Provides good tissue approximation.
Applications: Commonly used in periodontal
surgeries due to its ease of use and reliability.
Nylon (Monofilament) (Ethilon)
Characteristics:
Strong and resistant to stretching.
Less tissue reactivity compared to silk.
Applications: Ideal for delicate tissues and areas
requiring minimal tissue trauma.
ePTFE (Monofilament) (Gore-Tex)
Characteristics:
Biocompatible and non-reactive.
Excellent tensile strength and flexibility.
Applications: Often used in guided tissue
regeneration procedures and in areas where long-term support is needed.
Polyester (Braided) (Ethibond)
Characteristics:
High tensile strength and good knot security.
Less pliable than silk.
Applications: Used in situations requiring strong
sutures, such as in flap stabilization.
2. Absorbable Sutures
Absorbable sutures are designed to be broken down by the body over time,
eliminating the need for removal. They are often used in periodontal surgeries
where temporary support is sufficient.
A. Types of Absorbable Sutures
Surgical Gut
Plain Gut (Monofilament)
Absorption Time: Approximately 30 days.
Characteristics: Made from sheep or cow
intestines; provides good tensile strength initially but loses
strength quickly.
Applications: Suitable for soft tissue
approximation where rapid absorption is desired.
Chromic Gut (Monofilament)
Absorption Time: Approximately 45 to 60 days.
Characteristics: Treated with chromium salts to
delay absorption; retains strength longer than plain gut.
Applications: Used in areas where a longer
healing time is expected.
Synthetic Absorbable Sutures
Polyglycolic Acid (Braided) (Vicryl, Ethicon)
Absorption Time: Approximately 16 to 20 days.
Characteristics: Provides good tensile strength
and is absorbed predictably.
Applications: Commonly used in periodontal and
oral surgeries due to its handling properties.
Dexon (Davis & Geck)
Characteristics: Similar to Vicryl; made from
polyglycolic acid.
Applications: Used in soft tissue approximation
and ligation.
Polyglycaprone (Monofilament) (Maxon)
Absorption Time: Similar to Vicryl.
Characteristics: Offers excellent tensile
strength and is absorbed more slowly than other synthetic options.
Applications: Ideal for areas requiring longer
support during healing.