Dentosphere : World of Dentistry

 # Thumb sucking is considered as emotional disturbance according to which psychological study? A. Classical conditioning B. Operant conditioning C. Freudian theory D. Pavlov Theory The correct answer is C. Freudian theory. In Freudian psychoanalytic theory, thumb sucking is viewed as an oral-stage fixation or regression, stemming from unresolved emotional conflicts or disturbances during infancy, where sucking provides instinctual gratification but persists as a self-soothing mechanism indicative of underlying anxiety or unmet needs. This contrasts with classical conditioning (Pavlov's theory, option D) focused on stimulus-response associations, operant conditioning (option B) on reinforcement of behaviors, and lacks direct ties to emotional disturbance in those frameworks. Modern views often see it as normal self-soothing, but Freud's perspective pathologizes prolonged habits as symptomatic of psychosexual development issues.

 # Keen’s approach is used to elevate zygomatic arch: A. Extraorally B. Intraorally C. Transbuccally D. Percutaneous route The correct answer is  B. Intraorally Keen’s approach is a closed reduction technique for isolated zygomatic arch fractures, performed via an intraoral incision in the maxillary buccal vestibule (upper gingival sulcus), allowing indirect elevation with a Rowe's disimpaction forceps or similar instrument inserted through the incision to access and lift the depressed arch. This method minimizes visible scarring, avoids facial nerve risk, and prevents external incisions, though it requires careful closure to avoid complications like oroantral fistula. It contrasts with extraoral approaches (e.g., Gillies temporal), percutaneous stab incisions (e.g., for screws), or transbuccal punctures.

 # Growth of maxilla in the vertical direction is due to: A. Growth of alveolus B. Growth of sutures C. Growth of cranial base D. Growth of synchondrosis The correct answer is  B. Growth of sutures Vertical growth of the maxilla occurs primarily through inferior displacement facilitated by bone apposition and remodeling at the circum-maxillary sutures (e.g., fronto-maxillary, zygomatico-maxillary, and spheno-maxillary sutures), allowing the maxilla to elongate downward while adapting to surrounding structures like the expanding nasal septum and orbital contents. This mechanism accounts for the majority of vertical maxillary development from infancy through adolescence, with contributions from alveolar apposition around erupting teeth but not as the primary driver. Cranial base growth (via synchondroses) contributes indirectly by providing anteroposterior expansion that influences displacement, but sutural growth is the direct enabler of vertical changes, as supported by class...

 # Which is added as an additional parameter in five characteristics of Ackerman-Proffit Classification? A. Curve of Spee B. Esthetic line of occlusion C. Smile arc D. Smile line The correct answer is  B. Esthetic line of occlusion The Ackerman-Proffit classification evaluates malocclusion using Angle's anteroposterior relationships plus five key characteristics—alignment (perimeter/crowding), transverse relationship (arch width discrepancies), vertical relationship (open/deep bite), overjet (incisor protrusion), and midline deviation (asymmetry)—often visualized via a Venn diagram for comprehensive diagnosis. To enhance esthetic analysis, the esthetic line of occlusion is incorporated as an additional parameter, assessing the curved alignment of the maxillary incisor edges relative to the lower lip during smiling or repose, which helps predict treatment outcomes for facial harmony beyond functional aspects. This addition addresses limitations in purely skeletal classificatio...

 # Gene therapy targeting the germ-line is: A. Heritable B. Non heritable C. Sometimes heritable D. Unrelated to heritability The correct answer is:  A. Heritable Germ-line gene therapy involves modifying DNA in germ cells (sperm, ova, or their precursors), which integrate into the genome and are transmitted to future generations, making the genetic changes heritable. This contrasts with somatic gene therapy, which targets non-reproductive cells and is non-heritable (option B). Option C is incorrect as heritability is inherent to germ-line targeting, and option D is irrelevant since heritability is the defining feature. Ethical and regulatory concerns limit germ-line therapy in humans, but the biological principle remains clear.

 # A 9 year old boy visited OPD for soreness in the mouth. He had history of juvenile diabetes mellitus and was on insulin therapy. On intraoral examination, a large white scrapable lesion was noted on the soft palate. Raw erythematous areas with bleeding spots were seen after scraping the lesion. What is the most likely diagnosis to be? A. Diphtheria B. Oral Thrush C. White Spongy Nevus D. Vincent’s stomatitis E. Chronic Hyperplastic Candidiasis The correct answer is  B. Oral Thrush Oral thrush (pseudomembranous candidiasis) is the most likely diagnosis, characterized by white, creamy plaques on mucosal surfaces like the soft palate that scrape off easily, revealing underlying erythematous, raw tissue prone to bleeding—directly matching the presentation. Juvenile diabetes mellitus predisposes to this via hyperglycemia impairing immune response and promoting Candida albicans overgrowth, common in children on insulin. Diagnosis is clinical, confirmed by microscopy if needed (h...

 # Which of the following is an accessory cusp found on a mandibular molar? A. Protostylid B. Cusp of Carabelli C. Dens Evaginatus D. Paramolar cusp The correct answer is A. Protostylid The protostylid is a supernumerary accessory cusp located on the mesiobuccal surface of mandibular molars, often appearing as a pit, groove, or distinct tubercle that can vary in expression from mild to pronounced. In contrast, the cusp of Carabelli (option B) is an accessory feature on the mesiolingual surface of maxillary first molars; dens evaginatus (option C) typically presents as an occlusal tubercle on premolars (especially mandibular second premolars), though it can rarely affect molars; and the paramolar cusp (option D), also known as Bolk's cusp, is primarily an extra tubercle on the buccal surface of maxillary molars. 

 # 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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