NEET MDS Synopsis
INFLAMMATION
General Pathology
INFLAMMATION
Response of living tissue to injury, involving neural, vascular and cellular response.
ACUTE INFLAMMATION
It involves the formation of a protein .rich and cellullar exudate and the cardinal signs are calor, dolor, tumour, rubor and function loss
The basic components of the response are
Haemodynamic changes.
Permeability changes
Leucocyte events.
1. Haemodynamic Changes :
Transient vasoconstriction followed by dilatation.
Increased blood flow in arterioles.
More open capillary bed.
Venous engorgement and congestion.
Packing of microvasculature by RBC (due to fluid out-pouring)
Vascular stasis.
Change in axial flow (resulting in margination of leucocytes)
.2. Permeability Changes:
Causes.
Increased intravascular hydrostatic pressure.
Breakdown of tissue proteins into small molecules resulting in
increased tissue osmotic pressure.
Increased permeability due to chemical mediators, causing an
immediate transient response. .
Sustained response due to direct damage to microcirculation.
3. White Cell Events:
.Margination - due to vascular stasis and change in axial flow.
Pavementing - due to endothelial cells swollen and more sticky.
Leucocytes more adhesive.
Binding by a plasma component
Emigration - of leucocytes by amoeboid movement between endhothe1ial cells and beyond the basement membrane. The passive movement of RBCs through the gaps created during emigration is called diapedesis
Chemotaxis - This is a directional movement, especially of polymorphs and monocytes towards a concentration gradient resulting in aggregation of these cells at the site of inflammation. .Chemotactic agents may be:
Complement components. (C3and C5 fragments and C567)
Bacterial products.
Immune complexes, especially for monocyte.
Lymphocytic factor, especially for monocyte.
Phagocytosis - This includes recognition, engulfment and intracellular degradation. It is aided by .Opsonins., Specific antibodies., Surface provided by fibrin meshwork.
Functions of the fluid and cellular exudate
1. Dilution of toxic agent.
2. Delivers serum factors like antibodies and complement components to site of inflammation.
3. Fibrin formed aids In :
Limiting inflammation
Surface phagocytosis
Framework for repair.
4. Cells of the exudate:
Phagocytose and destroy the foreign agent.
Release lytic enzymes when destroyed, resulting in extracellular killing of organisms- and digestion of debris to enable healing to occur
Vestibuloplasty
Oral and Maxillofacial SurgeryVestibuloplasty
Vestibuloplasty is a surgical procedure aimed at deepening
the vestibule of the oral cavity, which is the space between the gums and the
inner lining of the lips and cheeks. This procedure is particularly important in
prosthodontics and oral surgery, as it can enhance the retention and stability
of dentures by increasing the available denture-bearing area.
Types of Vestibuloplasty
Vestibuloplasty (Sulcoplasty or Sulcus Deepening Procedure):
This procedure involves deepening the
vestibule without the addition of bone. It is primarily focused on
modifying the soft tissue to create a more favorable environment for
denture placement.
Indications:
Patients with shallow vestibules that may compromise denture
retention.
Patients requiring improved aesthetics and function of their
prostheses.
Technique:
The procedure typically involves the excision of the mucosa and
submucosal tissue to create a deeper vestibule.
The soft tissue is then repositioned to allow for a deeper
sulcus, enhancing the area available for denture support.
Labial Vestibular Procedure (Transpositional Flap Vestibuloplasty
or Lip Switch Procedure):
This specific type of vestibuloplasty
involves the transposition of soft tissue from the inner aspect of the
lip to a more favorable position on the alveolar bone.
Indications:
Patients with inadequate vestibular depth who require additional
soft tissue coverage for denture support.
Cases where the labial vestibule is shallow, affecting the
retention of dentures.
Technique:
A flap is created from the inner lip, which is then mobilized
and repositioned to cover the alveolar ridge.
This procedure increases the denture-bearing area by utilizing
the soft tissue from the lip, thereby enhancing the retention and
stability of the denture.
The flap is sutured into place, and the healing process allows
for the integration of the new tissue position.
Benefits of Vestibuloplasty
Increased Denture Retention: By deepening the vestibule
and increasing the denture-bearing area, patients often experience improved
retention and stability of their dentures.
Enhanced Aesthetics: The procedure can improve the
overall appearance of the oral cavity, contributing to better facial
aesthetics.
Improved Function: Patients may find it easier to eat
and speak with well-retained dentures, leading to improved quality of life.
Considerations and Postoperative Care
Healing Time: Patients should be informed about the
expected healing time and the importance of following postoperative care
instructions to ensure proper healing.
Follow-Up: Regular follow-up appointments may be
necessary to monitor healing and assess the need for any adjustments to the
dentures.
Potential Complications: As with any surgical
procedure, there are risks involved, including infection, bleeding, and
inadequate healing. Proper surgical technique and postoperative care can
help mitigate these risks.
MANDIBULAR CENTRAL INCISORS
Dental Anatomy
MANDIBULAR CENTRAL INCISORS
These are the first permanent teeth to erupt, replacing deciduous teeth, and are the smallest teeth in either arch
Facial Surfaces:-The facial surface of the mandibular central incisor is widest at the incisal edge. Both the mesial and the distal surfaces join the incisal surface at almost a 90° angle. Although these two surfaces are nearly parallel at the incisal edge, they converge toward the cervical margin. The developmental grooves may or may not be present. When present, they appear as very faint furrows.
Lingual: The lingual surface has no definite marginal ridges. The surface is concave and the cingulum is minimal in size.
Proximal: Both mesial and distal surfaces present a triangular outline.
Incisal: The incisal edge is at right angles to a line passing labiolingually through the tooth reflecting its bilateral symmetry.
Root Surface:-The root is slender and extremely flattened on its mesial and distal surfaces.
Superior Constrictor Muscle
AnatomySuperior Constrictor Muscle
Origin: Hamulus, pterygo-mandibular raphe, and
mylohyoid line of the mandible.
Insertion: Median raphe of the pharynx.
Nerve Supply: Vagus nerve via the pharyngeal plexus.
Arterial Supply: Ascending pharyngeal artery, ascending
palatine artery, tonsillar branch of the facial artery, and dorsal branch of
the lingual artery.
Action: Constricts the wall of the pharynx during
swallowing.
Ridge Augmentation
Oral and Maxillofacial SurgeryRidge Augmentation Procedures
Ridge augmentation procedures are surgical techniques used to increase the
volume and density of the alveolar ridge in the maxilla and mandible. These
procedures are often necessary to prepare the site for dental implants,
especially in cases where there has been significant bone loss due to factors
such as tooth extraction, periodontal disease, or trauma. Ridge augmentation can
also be performed in conjunction with orthognathic surgery to enhance the
overall facial structure and support dental rehabilitation.
Indications for Ridge Augmentation
Insufficient Bone Volume: To provide adequate support
for dental implants.
Bone Resorption: Following tooth extraction or due to
periodontal disease.
Facial Aesthetics: To improve the contour of the jaw
and facial profile.
Orthognathic Surgery: To enhance the results of jaw
repositioning procedures.
Types of Graft Materials Used
Ridge augmentation can be performed using various graft materials, which can
be classified into the following categories:
Autografts:
Bone harvested from the patient’s own
body, typically from intraoral sites (e.g., chin, ramus) or extraoral
sites (e.g., iliac crest).
Advantages: High biocompatibility, osteogenic
potential, and lower risk of rejection or infection.
Disadvantages: Additional surgical site, potential
for increased morbidity, and limited availability.
Allografts:
Bone grafts obtained from a human donor
(cadaveric bone) that have been processed and sterilized.
Advantages: No additional surgical site required,
readily available, and can provide a scaffold for new bone growth.
Disadvantages: Risk of disease transmission and
potential for immune response.
Xenografts:
Bone grafts derived from a different
species, commonly bovine (cow) bone.
Advantages: Biocompatible and provides a scaffold
for bone regeneration.
Disadvantages: Potential for immune response and
slower resorption compared to autografts.
Alloplasts:
Synthetic materials used for bone
augmentation, such as hydroxyapatite, calcium phosphate, or bioactive
glass.
Advantages: No risk of disease transmission,
customizable, and can be designed to promote bone growth.
Disadvantages: May not integrate as well as natural
bone and can have variable resorption rates.
Surgical Techniques
Bone Grafting:
The selected graft material is placed in the deficient area of the
ridge to promote new bone formation. This can be done using various
techniques, including:
Onlay Grafting: Graft material is placed on top
of the existing ridge.
Inlay Grafting: Graft material is placed within
the ridge.
Guided Bone Regeneration (GBR):
A barrier membrane is placed over the graft material to prevent soft
tissue infiltration and promote bone healing. This technique is often
used in conjunction with grafting.
Sinus Lift:
In the maxilla, a sinus lift procedure may be performed to augment
the bone in the posterior maxilla by elevating the sinus membrane and
placing graft material.
Combination with Orthognathic Surgery:
Ridge augmentation can be performed simultaneously with orthognathic
surgery to correct skeletal discrepancies and enhance the overall facial
structure.
MCQs Paediatrics 1
Paediatrics
1.cleft palate is best repaired
1) Soon after birth B
2) At one month
3) At 6-8 months
4) Between 12-18 months
Ans 4
Cleft lip repair should be done between 3-6 months of age.
2. Intra-osseous access for drugs and fluid administration is recommended for paediatric group up to the age of
1) <one year
2) <4 yeats
3) <6 years
4) Up to 12 years
Ans. 3
3. Which of the following is a true statement regarding congenital diaphragmatic hernia (CDH)
1) Common on right side
2) Associated with pulmonary hypoplasia
3) Present with recurrent vomiting at birth
4) Baby benefited with bag mask ventilation
Ans. 4
CHD is common on left side by which gastric contents herniate to thoracic cavity , Bag mask ventilation in these babies leads to gastric distension which may further compress the lungs and increase mediastinal shift.
Agranulocytosis
General Pathology
Agranulocytosis. Severe neutropenia with symptoms of infective lesions.
Drugs. are an important cause and the effect may be due to .
-Direct toxic effect.
-Hypersensitivity.
Some of the 'high risk drugs are.
-Amidopyrine.
-Antithyroid drugs.
-Chlorpromazine, mapazine.
-Antimetabolites and other drugs causing pancytopenia.
Bloodpicture: Neutropenia with toxic granules in neutrophils. Marrow shows decrease in granulocyte precursors with toxic granules in them.
Zygomatic Bone Reduction
General SurgeryZygomatic Bone Reduction
When performing a reduction of the zygomatic bone, particularly in the
context of maxillary arch fractures, several key checkpoints are used to assess
the success of the procedure. Here’s a detailed overview of the important
checkpoints for both zygomatic bone and zygomatic arch reduction.
Zygomatic Bone Reduction
Alignment at the Sphenozygomatic Suture:
While this is considered the best checkpoint for assessing the
reduction of the zygomatic bone, it may not always be the most practical
or available option in certain clinical scenarios.
Symmetry of the Zygomatic Arch:
Importance: This is the second-best checkpoint and
serves multiple purposes:
Maintains Interzygomatic Distance: Ensures that
the distance between the zygomatic bones is preserved, which is
crucial for facial symmetry.
Maintains Facial Symmetry and Aesthetic Balance:
A symmetrical zygomatic arch contributes to the overall aesthetic
appearance of the face.
Preserves the Dome Effect: The prominence of
the zygomatic arch creates a natural contour that is important for
facial aesthetics.
Continuity of the Infraorbital Rim:
A critical checkpoint indicating that the reduction is complete. The
infraorbital rim should show no step-off, indicating proper alignment
and continuity.
Continuity at the Frontozygomatic Suture:
Ensures that the junction between the frontal bone and the zygomatic
bone is intact and properly aligned.
Continuity at the Zygomatic Buttress Region:
The zygomatic buttress is an important structural component that
provides support and stability to the zygomatic bone.
Zygomatic Arch Reduction
Click Sound:
The presence of a click sound during manipulation can indicate
proper alignment and reduction of the zygomatic arch.
Symmetry of the Arches:
Assessing the symmetry of the zygomatic arches on both sides of the
face is crucial for ensuring that the reduction has been successful and
that the facial aesthetics are preserved.