NEET-PG 2012 - Dental PYQs Practice Questions

Q: Stability of alveoli is maintained by:

Reduced surface tension by surfactant. ***Reduced surface tension by surfactant*** - **Surfactant** (a mixture of lipoproteins) reduces the **surface tension** at the air-liquid interface within the alveoli, preventing their collapse at the end of expiration. - This reduction in surface tension helps to maintain the **stability** and patency of the smaller alveoli, preventing them from emptying into larger ones. *Compliance of the lungs* - **Compliance** refers to the distensibility of the lungs and chest wall, indicating how easily they can be stretched. - While pulmonary compliance is important for easy breathing, it does not directly maintain the stability of individual alveoli in preventing their collapse. *Negative intrapleural pressure* - **Negative intrapleural pressure** helps to keep the lungs expanded by creating a vacuum between the visceral and parietal pleura, pulling the lungs outwards. - This pressure prevents the lung as a whole from collapsing but does not directly prevent the collapse of individual alveoli due to surface tension. *Residual air in alveoli* - **Residual volume** is the amount of air remaining in the lungs after a maximal exhalation. - While residual air prevents the complete collapse of the lungs, it is surface tension reduction by surfactant that specifically maintains the stability of individual alveoli against collapse forces. [Practice more Dental PYQs on OnCourse]

Q: What is the forensic method of identification that utilizes lip prints?

Cheiloscopy. ***Cheiloscopy*** - **Cheiloscopy** is the scientific study of lip prints for human identification, based on the unique patterns of furrows on the human lips. - These patterns are considered individual and permanent, making them useful in forensic investigations. *Dactylography* - **Dactylography** is the study of fingerprints, which involves analyzing the unique patterns of ridges and furrows on the fingertips for identification. - It is one of the most widely used and reliable methods for personal identification in forensic science, but does not involve lip prints, *Poroscopy* - **Poroscopy** is a forensic technique that involves the examination of the pores on the ridges of fingerprints. - It is used to individualize fingerprints when there is insufficient ridge detail, but it focuses on pores, not lip prints. *Trichology* - **Trichology** is the scientific study of hair and scalp. - In forensics, it involves analyzing hair samples to determine characteristics such as origin, race, and presence of toxins, but not lip prints. [Practice more Dental PYQs on OnCourse]

Q: Brutonian lines on gums are seen in poisoning with which of the following substances?

Lead. ***Lead*** - **Brutonian lines**, also known as **Burton's lines**, are a classic sign of chronic lead poisoning, appearing as a blue or blue-black line along the gum margin. - This discoloration is caused by the reaction of circulating lead with sulfur ions released by oral bacteria, forming lead sulfide deposits in the gingival tissue. *Mercury* - Mercury poisoning can cause **gingivitis**, **stomatitis**, and excessive salivation, but typically not the distinct Burton's lines. - A characteristic feature of chronic mercury poisoning is often **erected tremor** and **erethism** (changes in mood and irritability). *Arsenic* - Chronic arsenic poisoning can lead to **hyperkeratosis** and **hyperpigmentation** of the skin (rain drop pigmentation), as well as **peripheral neuropathy**. - It does not typically cause the specific gingival discoloration seen in lead poisoning. *Zinc* - Zinc intoxication is relatively rare and often results from excessive ingestion of zinc-containing supplements or industrial exposure. - Symptoms usually include **nausea, vomiting, diarrhea**, and sometimes **copper deficiency**, but not gum line discoloration. [Practice more Dental PYQs on OnCourse]

Q: What percentage of oral cancer cases is attributed to tobacco use?

70% of cases. ***90%*** - Nicotine is a significant contributor to **oral cancer**, with studies indicating it is responsible for about **90%** of cases [1]. - Its carcinogenic effects are amplified when combined with other risk factors such as **tobacco** and **alcohol** use [1]. *40%* - This percentage underestimates nicotine's role in oral cancer development, which is much higher. - Key studies suggest that the impact of nicotine alone is much greater than **40%**, highlighting its pivotal role in carcinogenesis. *60%* - This estimate also falls short, as the consensus in oncology is that nicotine significantly contributes even beyond **60%**. - Oral cancer risk is further elevated when nicotine is consumed in conjunction with other **carcinogens** [1], rather than just being limited to a single contribution. *10%* - This figure drastically underrepresents nicotine's involvement, as it is a major causative agent in oral cancer. - The **10%** suggestion implies minimal risk, contradicting clinical evidence that strongly supports a far greater role for nicotine. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Lung, pp. 738-739. [Practice more Dental PYQs on OnCourse]

Q: What is the first permanent tooth to erupt?

First molar. ***First molar*** - The **first molars** are typically the first permanent teeth to erupt, usually around **6 years of age**. - They erupt distal to the primary second molars and are not preceded by primary teeth, making them crucial for establishing the **occlusion**. *First premolar* - **First premolars** typically erupt later, between **10 and 11 years of age**, replacing the primary first molars. - Their eruption is part of the **exchange of primary teeth** for permanent successors. *Second premolar* - The **second premolars** erupt even later, usually between **11 and 12 years of age**, replacing the primary second molars. - They are also involved in the **replacement of primary teeth**, not the initial permanent eruption. *Second molar* - **Second molars** erupt much later than the first molars, typically between **11 and 13 years of age**, distal to the first molars. - They are part of the **later stages of permanent dentition development**. [Practice more Dental PYQs on OnCourse]

Question 1

Stability of alveoli is maintained by:

Accepted Answer

Reduced surface tension by surfactant

Answer

Negative intrapleural pressure

Answer

Residual air in alveoli

Answer

Compliance of the lungs

Question 2

What is the forensic method of identification that utilizes lip prints?

Accepted Answer

Cheiloscopy

Answer

Trichology

Answer

Dactylography

Answer

Poroscopy

Question 3

Brutonian lines on gums are seen in poisoning with which of the following substances?

Accepted Answer

Lead

Answer

Mercury

Answer

Zinc

Answer

Arsenic

Question 4

What percentage of oral cancer cases is attributed to tobacco use?

Accepted Answer

70% of cases

Answer

60% of cases

Answer

10% of cases

Answer

40% of cases

Question 5

What is the first permanent tooth to erupt?

Accepted Answer

First molar

Answer

First premolar

Answer

Second premolar

Answer

Second molar

Question 6

Which of the following conditions is NOT associated with delayed dentition?

Accepted Answer

Cystic fibrosis

Answer

Down syndrome

Answer

Congenital hypothyroidism

Answer

Rickets

Question 7

Epulis arises from -

Accepted Answer

Gingiva

Answer

Enamel

Answer

Root of teeth

Answer

Pulp

Question 8

Kennedy phenomenon is seen in:

Accepted Answer

Gunshot injury

Answer

Burns

Answer

Contusion

Answer

Road traffic accident

Question 9

The primary indication for enucleation in pediatric patients is:

Accepted Answer

Retinoblastoma

Answer

Panophthalmitis

Answer

Acute congestive glaucoma

Answer

None of the options

NEET-PG 2012 — Dental