PGCEE MDS 2022: Vasoconstrictor in local anesthetic (LA) solution:

 # Vasoconstrictor in local anesthetic (LA) solution:

a) Reduces toxic effects of LA solution. 

b) Decreases depth & duration of LA. 

c) Increases bleeding. 

d) Has no effect on efficacy of LA solution.

The correct answer is A. Reduces toxic effects of LA solution.

Vasoconstrictors are drugs that constrict blood vessels and thereby control tissue perfusion. They are added to local anesthetic solutions to oppose the inherent vasodilatory actions of the local anesthetics. Vasoconstrictors are important additions to a local anesthetic solution for the following

reasons:

1. By constricting blood vessels, vasoconstrictors decrease blood flow (perfusion) to the site of drug administration.

2. Absorption of the local anesthetic into the cardiovascular system is slowed, resulting in lower

anesthetic blood levels.

3. Local anesthetic blood levels are lowered, thereby decreasing the risk of local anesthetic toxicity.

4. More local anesthetic enters into the nerve, where it remains for longer periods, thereby increasing (in some cases significantly, in others minimally) the duration of action of most local anesthetics.

5. Vasoconstrictors decrease bleeding at the site of administration; therefore they are useful when increased bleeding is anticipated (e.g., during a surgical procedure).

PGCEE MDS 2022: In winter's WAR line, Amber line represents the:

 # In winter's WAR line, Amber line represents the:

a) Relative depth of the III molar

b) Point of application of the elevator

c) Bone level covering the impacted tooth

d) Axial inclination of the impacted tooth relative to Second molar

The correct answer is C. Bone level covering the impacted tooth.

Winter's lines include 3 imaginary lines that are drawn on the radiographs.

• White line

• Amber line

• Red line

White Line: It is drawn touching the occlusal surfaces of 1st and 2nd molars and is extended posteriorly over the 3rd molar region. It indicates the difference in occlusal level of 2nd and 3rd molars.

Amber Line: It is drawn from the crest of interdental bone between 1st and 2nd molars and extends posteriorly distal to 3rd molar or to the ascending ramus. It indicates the amount of alveolar bone covering the impacted tooth and the portion of tooth that is not covered by the bone.

Red line: It is drawn perpendicular from the amber line to an imaginary point of application of elevator.

It indicates the depth of the tooth in the bone and the difficulty encountered in removing of the tooth.

PGCEE MDS 2022: Gracey’s curette no 15/16 is used for:

 # Gracey’s curette no 15/16 is used for:

A. Anterior teeth

B. Premolars

C. Mesial surface of posterior teeth

D. Distal surface of posterior teeth

The correct answer is C. Mesial surface of posterior teeth. 

Double-ended Gracey curettes are paired in the following manner:

Gracey #1-2 and 3-4: Anterior teeth

Gracey #5-6: Anterior teeth and premolars

Gracey #7-8 and 9-10: Posterior teeth: facial and lingual

Gracey #11-12: Posterior teeth: mesial

Gracey #13-14: Posterior teeth: distal 

Recent additions to the Gracey curette set have been the Gracey #15-16 and 17-18. The Gracey #15-16 is a modification of the standard #11-12 and is designed for the mesial surfaces of posterior teeth. It consists of a Gracey #11-12 blade combined with the more acutely angled #13-14 shank. When the clinician is using an intraoral finger rest, it is often difficult to position the lower shank of the Gracey #11-12 so that it is parallel with the mesial surfaces of the posterior teeth, especially on the mandibular molars. The new shank angulation of the Gracey #15-16 allows better adaptation to posterior mesial surfaces from a front position with intraoral rests. If alternative fulcrums, such as extraoral or opposite-arch rests, are used, the Gracey #11-12 works well and the new #15-16 is not essential.

PGCEE MDS 2022: Jug handle view is another name for:

 # Jug handle view is another name for:

a. occipitomental view 

b. submentovertex view 

c. lateral cephalogram 

d. lateral oblique view

The correct answer is B. Submentovertex view.

Submentovertex projection or jug handle view: 

 The image receptor is positioned parallel to the patient’s transverse plane and perpendicular to the midsagittal and coronal planes. To achieve this position, the patient’s neck is extended as far backward as possible, with the canthomeatal line forming a 10-degree angle with the image receptor.

PGCEE MDS 2022: Treatment of mushroom poisoning :

 # Treatment of mushroom poisoning :

A. Atropine

B. Pilocarpine

C. Adrenaline

D. Quinidine

The correct answer is A. Atropine.

A mixture of signs and symptoms can occur with muscarinic poisoning from medications or mushrooms. Manifestations may vary even among persons who ingested mushrooms grown in the same patch and gathered at the same time. Confusion can occur if mushroom poisoning is attributed to a suspected species rather than to the toxin suggested by signs and symptoms. Accurate diagnosis depends on clinical suspicion and recognition of muscarinic manifestations, notably diaphoresis, salivation, bladder cramping, diarrhea, and difficulty with visual accommodation. Muscarinic toxicity due to medications necessitates an adjustment in drug dosage. In mushroom poisoning that produces primarily muscarinic effects, atropine is the treatment of choice. 

PGCEE MDS 2022: Collum angle is seen in:

 # Collum angle is seen in:

a) Class I bimaxillary protrusion

b) Class II div 1

c) Class II div 2 

d) Class III

The correct answer is C. Class II div 2.

The angle which is formed by the intersection of the long axes of the crown and root angulation is called Collum angle. It is decreased in Class II Div 2 cases. Due to this reason the crown appears to be lingual from the long axis of the roots in class II div 2 cases. Collum angle has been confused with interincisal angle. Interincisal angle is decreased in Class II div 1 and increased in class II div 2.

PGCEE MDS 2022 : Most suitable antiarrhythmic drug for counteracting ventricular extrasystoles due to digoxin toxicity

 # The most suitable antiarrhythmic drug for counteracting ventricular extrasystoles due to digoxin toxicity is :

A. Lignocaine

B. Quinidine

C. Verapamil

D. Amiodarone

The correct answer is A. Lignocaine.

The primary treatment of digoxin toxicity is digoxin immune fab, which is an antibody made up of anti-digoxin immunoglobulin fragments. This antidote has been shown to be highly effective in treating life-threatening signs of digoxin toxicity such as hyperkalemia, hemodynamic instability, and arrhythmias. Fab dose can be determined by two different methods. First method is based on the amount of digoxin ingested whereas the second method is based on the serum digoxin concentration and the weight of the person.

Other treatment that may be used to treat life-threatening arrhythmias until Fab is acquired are magnesium, phenytoin, and lidocaine. Magnesium suppresses digoxin-induced ventricular arrhythmias while phenytoin and lidocaine suppresses digoxin-induced ventricular automaticity and delay afterdepolarizations without depressing AV conduction. In the case of an abnormally slow heart rate (bradyarrhythmias), Atropine, catecholamines (isoprenaline or salbutamol), and/or temporary cardiac pacing can be used.

USES OF LIDOCAINE

Lidocaine is safe if given by slow i.v. injection; is used to suppress VT and prevent VF. It is ineffective in atrial arrhythmias. Because of rapidly developing and titratable action it is a good drug in the emergency setting, e.g. arrhythmias following acute MI or during cardiac surgery. In acute MI, i.v. infusion of lidocaine can prevent VF, but a metaanalysis has shown that it fails to improve survival; may even increase short term mortality. Therefore, lidocaine is no longer administered prophylactically to all MI patients, but may be used in selected cases, and to treat ventricular arrhythmias when they occur. Efficacy of lidocaine in chronic ventricular arrhythmia is poor, but it suppresses VT due to digitalis toxicity, for which it is used because it does not worsen A-V block.