Investigations In Dentistry Question And Answers

Investigations In Dentistry Question And Answers

Question 1. Write short note on exfoliative cytology.
Answer. Exfoliative cytology is the microscopic study of cells obtained from the surface of an organ or lesion after suitable staining.

The procedure of Exfoliative Cytology

• Surface of lesion is cleaned by removing all debris and mucin.
• Gentle scrapping is done on the surface of lesion with metal cement spatula or a moistened tongue blade for several times.
• Thus, material present on the surface of lesion adhere or collected at the border of instrument.
• Collected material is than evenly spread over a microscopic slide and is immediately fixed with 95% of alcohol.
• Slide is than air dried and is stained by a special stain called as PAP stain (Papanicolaou stain).

Findings in Exfoliative Cytology

Class 1 (Normal): It indicates that only normal cells are present in the smear.

Class 2 (Atypical): It indicates the presence of minor cellular atypia.

Class 3 (Intermediate): This is in between cytology that separate cancer from noncancer diagnosis, the cells which display wideratypia are suggestive of cancer. Biopsy is recommended for further diagnosis.

Class 4 (Suggestive of Cancer): It indicates that in the lesion, there is presence of few cells with malignant characteristic. Biopsy is mandatory.

Class 5 (Positive of Cancer): The cells exhibit definite features of malignancy. Biopsy is mandatory.

Read And Learn More: Oral Medicine Question And Answers

Indication of Exfoliative Cytology

Exfoliative cytology is establishing in diagnosis of following oral lesion:

• Herpes simplex and herpes zoster.
• Pemphigus vulgaris.
• Pemphigoid.
• Squamous cell carcinoma.
• Aphthous ulcer.

Question 2. Write short note on Paget’s test.
Answer. This is a type of a fluctuation test.

• This is used for the examination of the swelling.
• This test is performed by simply pressing the swelling at the center. The swelling containing fluid will be softer at the center than its periphery while solid swelling will be firmer at center than its periphery. It is called Paget’s test.
• This test is used in case of very small swelling which cannot accommodate two fingers.

Question 3. Write short note on toluidine blue staining.
Or
Write short note on toluidine blue test.
Or
Write short note on vital stain in diagnostic modality of oral cancer.
Answer. Vital staining as diagnostic modality for oral cancer consists of:

1. Toluidine blue method

2. Lugol’s Iodine

Toluidine Blue Staining

• Toluidine blue staining as topical application recently aids in the diagnosis of oral cancer and potentially malignant lesions.
• This method shows good sensitivity and has low false negative rate.
• Only a single discretion is present that dorsum of the tongue always stain positively because of the retention of dye in crevice between papillae.
• Toluidine blue demonstrates dysplasia and the early malignant lesion which should not be recognize clinically.

Toluidine Blue Staining Mechanism of Action

• DNA binding: Since dye is acidophilic, metachromatic nuclear dye of thiazine group which selectively stain the acidic tissue components mainly nucleic acids i.e. DNA and RNA. Dysplastic cells consist of more DNA as compared to normal cells. So dysplastic cells retain more dye.
• Intracellular canal: Malignant epithelium consists of intracellular canals which are wider as compared to normal epithelium and they facilitate the penetration of dye.
• Effect on normal epithelium: As the epithelial surfaces stain blue after applying 1% toluidine blue solution but stain get vanished away when 1% acetic acid is applied to the normal epithelial surface.
• Effect on the benign ulcer: Benign ulcers show uptake of dye at the margins which malignancy or dysplasia show diffuse marginal pattern.

Toluidine Blue Staining Composition

Toluidine blue kit is available as 3 component system. First kit consists of 1% toluidine blue 10 mL solution. Second and third kit consists of 1% acetic acid as pre and post rinsing solution

• Toluidine blue: 1 g
• Acetic acid: 10 cc
• 100% Alcohol: 4.19 cc
• Distill water: 86 cc
• pH: 4.5.

Toluidine Blue Staining Technique

• Rinse mouth with water for two times for at least 20 seconds each.
• Ask patient to rinse the mouth with 1% acetic acid for 20 seconds.
• Dry the lesional area by gauze.
• Paint the area with 1% toluidine blue by cotton swab.
• Ask the patient to rinse the mouth with acetic acid followed by rinsing with water.
• Positive area show blue colored staining.
• Repeat the test for 1 to 2 weeks and advice the patient to go for biopsy of the positive area.

Lugol’s Iodine Test

• Lugol’s iodine should not be retained in dysplastic or malignant cells but it get retained in normal squamous epithelial cells.
• Toluidine blue application along with Lugol’s iodine provides an advantage. Toluidine blue stains the dysplastic epithelium while Lugol’s iodine stains the normal epithelium.
• Lugol’s iodine is less sensitive to identify oral premalignant and dysplastic diseases but is of greater specificity.

Lugol’s Iodine Contents

• Iodine: 2 grams
• Potassium iodide: 4 grams
• Distilled water: 100 cc

Lugol’s Iodine Mechanism of Action

• Lugol’s iodine gives brown black stain when iodine reacts with glycogen. Removal of iodine can be done by removing fixation in alcohol and formaldehyde.
• Effect on proliferating epithelium: Content of glycogen is inversely proportional to degree of keratosis which suggest role of glycogen in keratinization. If in case proliferating epithelium is present and it is poorly stained or unstained.
• Effect on inflammatory tissue: Since degree of inflammation and glycogen content has direct relation which leads to dark brown staining.

Question 4. Write short note on serum alkaline phosphatase.
Answer. Alkaline phosphatases are a group of enzymes found primarily in the liver (isoenzyme ALP-1) and bone (isoenzyme ALP-2). They are also produced in small amount by cells lining the intestines (isoenzyme ALP-3), the placenta, and the kidney (in the proximal convoluted tubules).

It helps in removing phosphate groups from many types of molecules, including nucleotides, proteins, and alkaloids.

Alkaline Phosphatase Test

• Alkaline phosphatase levels are usually measured in blood, and the procedure is that of a routine blood test. It is recommended to give blood after 8–l0 hours of fasting, as food can cause transient increase in ALP levels. About 5 mL of blood is sufficient for this test.
• Certain medications may interfere with test results, and hence it is recommended to inform your physician about every other medication being consumed before the test.

Normal Values of Serum Alkaline Phosphatase

• Normal levels of ALP are in the range of 25–100 units per liter (U/L) for persons aged 15 or more, < 350 U/L for children aged 1–12 < 500 U/L for boys 12–15.
• Children have higher ALP levels as there is a lot of bone growth taking place in them. A low level of ALP in children is indicative of malnutrition.

Elevation of Alkaline Phosphatase Levels

Levels of ALP can increase due to both normal physiological conditions or in certain disease states.

Alkaline Phosphatase Levels In Normal Physiology:

• ALP levels are high in the first three months of life. It again increases during puberty and reaches normal levels only by the age of 18–20 years.
• Men generally have a higher ALP levels till around the age of 50. After menopause, the situation reverses and women tend to have higher ALP levels.
• Apart from puberty and post—menopause, also causes high placental ALP levels in women.
• Higher intestinal ALP levels are known to occur in persons having blood group B and O.
• Use of tobacco or an increase in blood sugar causes transient increase in ALP levels.

Alkaline Phosphatase Levels In Disease states:

• Liver and bile diseases: Elevated ALP levels are known to occur in conditions such as liver cirrhosis, stone or tumor in the gall bladder, tumor in the liver, cholestasis, cholecystitis, cholangitis, hepatitis and fatty liver syndrome.
• Bone diseases: Diseases affecting the bones, such as osteo-malacia, Paget’s disease, Vitamin D deficiency or hyperparathyroidism can cause elevated ALP levels.
• Other syndromes: ALP levels get elevated during the healing phase of cardiac or splenic infarctions, or in cancers of the breast, colon, ovary, and cervix or prostrate.

Lowered Alkaline Phosphatase Level

The following conditions or diseases may lead to reduced levels of alkaline phosphatase:

• Hypophosphatasia, an autosomal recessive disease
• Postmenopausal women receiving estrogen therapy because of osteoporosis
• Men with recent heart surgery, malnutrition, magnesium deficiency, hypothyroidism, or severe anemia
• Children with achondroplasia and cretinism
• Children after a severe episode of enteritis
• Pernicious anemia
• Aplastic anemia
• Chronic myelogenous leukemia
• Wilson’s disease.