Dentosphere : World of Dentistry

 # Three days after the onset of myocardial infarction which enzyme level has the best predictive value? A. Serum CPK B. Serum LDH C. Serum SGOT D. Serum SGPT The correct answer is  B. Serum LDH Lactate dehydrogenase (LDH) levels rise 12-24 hours after myocardial infarction (MI), peak at 48-72 hours (around day 3), and remain elevated for 7-14 days, providing the highest diagnostic sensitivity and predictive value for confirming MI at this late stage. In contrast, creatine phosphokinase (CPK) peaks early (12-24 hours) and normalizes by day 3, making it less useful then; serum glutamic-oxaloacetic transaminase (SGOT/AST) peaks at 24-48 hours and declines by day 3-4; and serum glutamic-pyruvic transaminase (SGPT/ALT) is primarily liver-specific with minimal cardiac relevance. The LDH-1 isoenzyme is particularly specific for cardiac tissue damage.

 # Which of the following is an occupational disease of dentist? A. Syphilis B. HIV C. HBV D. All of the above The correct answer is D. All of the above Dentists face occupational risks from bloodborne pathogens due to exposure via needlestick injuries, cuts, splashes, or aerosols during procedures. HBV (hepatitis B virus) is highly transmissible and a major concern, with vaccination recommended. HIV (human immunodeficiency virus) has lower infectivity but remains a risk. Syphilis (Treponema pallidum) can spread through contact with infectious oral lesions or blood. OSHA and CDC guidelines classify all three as occupational hazards for dental professionals, emphasizing universal precautions, PPE, and post-exposure protocols to mitigate transmission.

 # Ideal period for surgical correction of maxilla and mandible: A. Early growth spurts B. Mid growth spurts C. Late growth spurts D. After cessation of growth spurts The correct answer is D. After cessation of growth spurts. Orthognathic surgery for correcting maxillary and mandibular discrepancies is ideally performed after skeletal growth has ceased to minimize postoperative relapse due to residual growth. This typically occurs in late adolescence or early adulthood (around 16-18 years for females and 18-21 years for males), once pubertal growth spurts are complete and facial bones have stabilized. Earlier interventions during active growth phases (options A-C) risk instability and require potential revisions. Preoperative orthodontics (12-18 months) aligns teeth for optimal surgical outcomes, followed by postoperative orthodontics for refinement. 

 # Mother presents with a 2 month old baby having ulceration of tongue in relation to erupted tooth in mandibular incisor region. Treatment:  A. Extraction B. Prescribe local anesthetic gel C. Radiograph to confirm presence of deciduous tooth followed by rounding of incisal edges D. Counsel mother and recall The correct answer is C. Radiograph to confirm presence of deciduous tooth followed by rounding of incisal edges This case likely involves Riga-Fede disease, a traumatic ulceration of the tongue caused by the sharp incisal edges of a natal or neonatal tooth (typically a mandibular primary central incisor) in an infant. At 2 months old, tooth eruption is premature, so confirming it's a deciduous tooth via radiograph is essential to rule out anomalies like supernumerary teeth. The primary treatment is conservative: smoothing or rounding the incisal edges to eliminate the trauma source, allowing the ulcer to heal spontaneously (often within 1-4 weeks). Extraction (option A) i...

 # In comparison with the permanent mandibular canine, the permanent maxillary canine in the same mouth: a) Has a shorter root b) Is wider mesiodistally c) Is narrower mesiodistally d) Has a less pronounced cingulum The correct answer is b) Is wider mesiodistally The permanent maxillary canine is wider mesiodistally than the permanent mandibular canine in the same mouth, with typical crown measurements of about 7.5 mm for the maxillary canine compared to 7.0 mm for the mandibular canine. In contrast, the maxillary canine has a longer root (around 17 mm versus 16.5 mm for the mandibular), and its cingulum is more developed and prominent on the lingual surface than the mandibular canine's.

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