NEET MDS Synopsis
Modified Gingival Index
PeriodontologyModified Gingival Index (MGI)
The Modified Gingival Index (MGI) is a clinical tool used to assess the
severity of gingival inflammation. It provides a standardized method for
evaluating the health of the gingival tissues, which is essential for diagnosing
periodontal conditions and monitoring treatment outcomes. Understanding the
scoring criteria of the MGI is crucial for dental professionals in their
assessments.
Scoring Criteria for the Modified Gingival Index (MGI)
The MGI uses a scale from 0 to 4 to classify the degree of gingival
inflammation. Each score corresponds to specific clinical findings:
Score 0: Absence of Inflammation
Description: No signs of inflammation are present
in the gingival tissues.
Clinical Significance: Indicates healthy gingiva
with no bleeding or other pathological changes.
Score 1: Mild Inflammation
Description:
Slight change in color (e.g., slight redness).
Little change in texture of any portion of the marginal or
papillary gingival unit, but not affecting the entire unit.
Clinical Significance: Suggests early signs of
gingival inflammation, which may require monitoring and preventive
measures.
Score 2: Mild Inflammation (Widespread)
Description:
Similar criteria as Score 1, but involving the entire marginal
or papillary gingival unit.
Clinical Significance: Indicates a more widespread
mild inflammation that may necessitate intervention to prevent
progression.
Score 3: Moderate Inflammation
Description:
Glazing of the gingiva.
Redness, edema, and/or hypertrophy of the marginal or papillary
gingival unit.
Clinical Significance: Reflects a moderate level of
inflammation that may require active treatment to reduce inflammation
and restore gingival health.
Score 4: Severe Inflammation
Description:
Marked redness, edema, and/or hypertrophy of the marginal or
papillary gingival unit.
Presence of spontaneous bleeding, congestion, or ulceration.
Clinical Significance: Indicates severe gingival
disease that requires immediate intervention and may be associated with
periodontal disease.
Clinical Application of the MGI
Assessment of Gingival Health:
The MGI provides a systematic approach to evaluate gingival health,
allowing for consistent documentation of inflammation levels.
Monitoring Treatment Outcomes:
Regular use of the MGI can help track changes in gingival health
over time, assessing the effectiveness of periodontal treatments and
preventive measures.
Patient Education:
The MGI can be used to educate patients about their gingival health
status, helping them understand the importance of oral hygiene and
regular dental visits.
Research and Epidemiological Studies:
The MGI is often used in clinical research to evaluate the
prevalence and severity of gingival disease in populations.
ADRENOCORTICAL TUMORS
General Pathology
ADRENOCORTICAL TUMORS
Functional adenomas are commonly associated with hyperaldosteronism and with Cushing syndrome, whereas a virilizing neoplasm is more likely to be a carcinoma. Determination of of the functional status of a tumor is based on clinical evaluation and measurement of the hormone or its metabolites. In other words, functional and nonfunctional adrenocortical neoplasms cannot be distinguished on the basis of morphologic features.
Patholgical features
Adrenocortical adenomas
- They are generally small, 1 to 2 cm in diameter.
- On cut surface, adenomas are usually yellow to yellow-brown due to presence of lipid within the neoplastic cells
- Microscopically, adenomas are composed of cells similar to those populating the normal adrenal cortex. The nuclei tend to be small, although some degree of pleomorphism may be encountered even in benign lesions ("endocrine atypia"). The cytoplasm ranges from eosinophilic to vacuolated, depending on their lipid content.
Adrenocortical carcinomas
These are rare and may occur at any age, including in childhood.
- Carcinomas are generally large, invasive lesions.
- The cut surface is typically variegated and poorly demarcated with areas of necrosis, hemorrhage, and cystic change.
- Microscopically, they are composed of well-differentiated cells resembling those of cortical adenomas or bizarre, pleomorphic cells, which may be difficult to distinguish from those of an undifferentiated carcinoma metastatic to the adrenal.
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.
Drugs Used in Diabetes -Biguanides
Pharmacology
Biguanides
metformin
Mechanism
↓ gluconeogenesis
appears to inhibit complex 1 of respiratory chain
↑ insulin sensitivity
↑ glycolysis
↓ serum glucose levels
↓ postprandial glucose levels
Clinical use
first-line therapy in type II DM
Toxicity
no hypoglycemia
no weight gain
lactic acidosis is most serious side effect
contraindicated in renal failure
Microbes in Periodontics
PeriodontologyMicrobes in Periodontics
Bacteria Associated with Periodontal Health
Primary Species:
Gram-Positive Facultative Bacteria:
Streptococcus:
S. sanguis
S. mitis
A. viscosus
A. naeslundii
Actinomyces:
Beneficial for maintaining periodontal health.
Protective or Beneficial Bacteria:
Key Species:
S. sanguis
Veillonella parvula
Corynebacterium ochracea
Characteristics:
Found in higher numbers at inactive periodontal sites (no
attachment loss).
Low numbers at sites with active periodontal destruction.
Prevent colonization of pathogenic microorganisms (e.g., S.
sanguis produces peroxide).
Clinical Relevance:
High levels of C. ochracea and S. sanguis are
associated with greater attachment gain post-therapy.
Microbiology of Chronic Plaque-Induced Gingivitis
Composition:
Roughly equal proportions of:
Gram-Positive: 56%
Gram-Negative: 44%
Facultative: 59%
Anaerobic: 41%
Predominant Gram-Positive Species:
S. sanguis
S. mitis
S. intermedius
S. oralis
A. viscosus
A. naeslundii
Peptostreptococcus micros
Predominant Gram-Negative Species:
Fusobacterium nucleatum
Porphyromonas intermedia
Veillonella parvula
Haemophilus spp.
Capnocytophaga spp.
Campylobacter spp.
Pregnancy-Associated Gingivitis:
Increased levels of steroid hormones and P. intermedia.
Chronic Periodontitis
Key Microbial Species:
High levels of:
Porphyromonas gingivalis
Bacteroides forsythus
Porphyromonas intermedia
Campylobacter rectus
Eikenella corrodens
Fusobacterium nucleatum
Actinobacillus actinomycetemcomitans
Peptostreptococcus micros
Treponema spp.
Eubacterium spp.
Pathogenic Mechanisms:
P. gingivalis and A. actinomycetemcomitans can
invade host tissue cells.
Viruses such as Epstein-Barr Virus-1 (EBV-1) and human
cytomegalovirus (HCMV) may contribute to bone loss.
Localized Aggressive Periodontitis
Microbiota Characteristics:
Predominantly gram-negative, capnophilic, and anaerobic rods.
Almost all localized juvenile periodontitis (LJP) sites harbor A.
actinomycetemcomitans, which can comprise up to 90% of the total
cultivable microbiota.
COMPOSITE RESINS -Solution Liners (Varnishes)
Dental Materials
Solution Liners (Varnishes)
Applications
o Enamel and dentin lining for amalgam restorations
o Enamel and dentin lining for cast restorations that are used with non adhesive cements
o Coating over materials that are moisture sensitive during setting
Components of copal resin varnish
o 90% solvent mixture (e.g., chloroform, acetone, and alcohol)
o 10% dissolved copal resin
Reaction
Varnish sets physically by drying Solvent loss occurs in 5 to 15 seconds (a film forms the same way as drying fingernail polish)
Manipulation
Apply thin coat over dentin. enamel. And margins of the cavity preparation Dry lightly with air for 5 seconds Apply a second thin coat Final thickness is 1 to 5 µ.m
Properties
o Physical
Electrically insulating barrier that prevents shocks. Too thin to be thermally insulating. Decreases degree of percolation attributable to thermal expansion
o Chemical
Forms temporary barrier that prevents microleakage into dentinal tubules until secondary dentin formation occurs. Decreases initial tendency for electrochemical corrosion
o Mechanical
Very weak and brittle film that has limited lifetime
Film adheres to smear layer
Malignant Diseases of Skin
General Pathology
Malignant Diseases of Skin
1. Bowen's disease refers to a carcinoma in situ on sun-exposed skin or on the vulva, glans a penis, or oral mucosa which has an association, in some cases, with a visceral malignancy.
2. Skin cancers associated with ultraviolet light damage include basal cell carcinoma, squamous cell carcinoma, and malignant melanoma.
3. A basal cell carcinoma is the MC malignant tumor of the skin and occurs on sunexposed, hair-bearing surfaces.
- Locally aggressive, infiltrating cancers arising from the basal cell layer of the epidermis and infiltrate the underlying superficial dermis.
- they do not metastasize
- BCC are commonly located on the face on the inner aspect of the nose, around the orbit and the upper lip where they appear as raised nodules containing a central crater with a pearly-colored skin surface and vascular channels.
- microscopically, they have cords of basophilic staining cells originating from the basal cell layer infiltrating the dermis.
- they commonly recur if they are not totally excised, because they are frequently multifocal.
- the basal cell nevus syndrome is an autosomal-dominant disorder characterized by the development of basal cell carcinomas early in life with associated abnormalities of bone, skin, nervous system, eyes, and reproductive system.
CARDIAC GLYCOSIDES
Pharmacology
CARDIAC GLYCOSIDES
Cardiac glycosides (Digitalis)
Digoxin
Digitoxin
Sympathomimetics
Dobutamine
Dopamine
Vasodilators
α-blockers (prazosin)
Nitroprusside
ACE-inhibitors (captopril)
Pharmacology of Cardiac Glycosides
1. Positive inotropic effect (as a result of increase C.O., the symptoms of CHF subside).
2. Effects on other cardiac parameters
1) Excitability
2) Conduction Velocity; slightly increased in atria & ventricle/significantly
reduced in conducting tissue esp. A-V node and His-Purkinje System
3) Refractory Period; slightly ^ in atria & nodal tissue/slightly v in ventricles
4) Automaticity; can be greatly augmented - of particular concern in ventricle
3. Heart Rate
-Decrease due to 1) vagal stimulation and 2) in the situation of CHF, due to improved hemodynamics
4 Blood Pressure
-In CHF, not of much consequence. Changes are generally secondary to improved cardiac performance.
-In the absence of CHF, some evidence for a direct increase in PVR due to vasoconstriction.
5. Diuresis
-Due primarily to increase in renal blood flow as a consequence of positive inotropic effect (increase CO etc.) Possibly some slight direct diuretic effect.
Mechanism of Action of Cardiac Glycosides
Associated with an interaction with membrane-bound Na+-K+ ATPase (Na-K pump).
Clinical ramifications of an interaction of cardiac glycosides with the Na+ K pump.
I. Increase levels of Ca++, Increase therapeutic and toxic effects of cardiac glycosides
II. Decrease levels of K+ , Increase toxic effects of cardiac glycosides
Therapeutic Uses of Cardiac Glycosides
CHF
CHF accompanied by atrial fibrillation
Supraventricular arrhythmias