Dentosphere : World of Dentistry

 # The proximal segment of mandibular angle fracture usually displaced in which direction ? a. Anterior and superior b. Posterior and inferior c. Inferior only d. Posterior and superior The correct answer is A. Anterior and superior. Fractures of angle of mandible are influenced by the pull of medial pterygoid, masseter and temporalis muscles, which displace the ramus in superior and anterior direction. This is a liorizontally unfavorable fracture.

# Golden period for treatment of open wound is?  A. 2 hrs  B. 4 hrs C. 6 hrs  D. 8 hrs  The correct answer is B. 4 hours. In the first 4 hours after a breach in an epithelial surface and underlying connective tissues, there is delay in the mobilisation of host defences. This period is called 'decisive period' and during this period bacterial colonisation and established infection can begin. It is logical that prophylactic antibiotics will be most effective during this time.

   # Tessier classification used for  A. Isolated cleft palate  B. Facial cleft  C. TMJ internal disorder  D. White lesion of oral mucosa  The correct answer is B. Facial cleft. Dr. paul Tessier, the father of the field of craniofacial surgery, developed a classification system for craniofacial clefts that is the most widely used of those available today.

 # Rhytidectomy is associated with which nerve involvement?  A. Great auricular nerve  B. Auriculotemporal nerve  C. Marginal mandibular nerve  D. Sympathetic plexus around ICA  The correct answer is A. Greater auricular nerve. Rhytidectomy is a surgical procedure meant to counteract the effects of time on the aging face. In the rhytidectomy procedure (also known as a “face-lift”), the tissues under the skin are tightened and excess facial and neck skin are excised. Rhytidectomy literally means wrinkle (rhytid-) removal (-ectomy). The great auricular nerve, which supplies sensation to the skin of the ear and nearby skin is the most commonly injured in a rhytidectomy.

 # The probability of rejecting the null hypothesis when it is true: A. Type 1 error B. Type 2 error C. Power of a statistical test D. Level of significance The correct answer is A. Type I error. In statistical hypothesis testing, a type I error is the mistaken rejection of an actually true null hypothesis (also known as a "false positive" finding or conclusion; example: "an innocent person is convicted"), while a type II error is the failure to reject a null hypothesis that is actually false (also known as a "false negative" finding or conclusion; example: "a guilty person is not convicted"). Much of statistical theory revolves around the minimization of one or both of these errors, though the complete elimination of either is a statistical impossibility if the outcome is not determined by a known, observable causal process. By selecting a low threshold (cut-off) value and modifying the alpha (α) level, the quality of the hypothesis test can be ...

#  The immunoglobulin which is produced first by the fetus in response to infection is: A. IgG B. IgA C. IgM D. IgD The correct answer is C. IgM. Phylogenetically, IgM is the oldest immunoglobulin class. It is also the earliest immunoglobulin to be synthesized by the fetus beginning by about 20 weeks of age. As it is not transported across the placenta, the presence of IgM in the fetus or newborn indicates intrauterine infection and its detection is useful in the diagnosis of congenital infections such as syphilis, rubella, HIV infection and toxoplasmosis. 

 # Normal submandibular salivary gland in sialograph shows a. Tree in winter appearance b. Bush in winter appearance c. Herb in winter appearance d. Shrub in winter appearance The correct answer is B. Bush in Winter Appearance. Normal sialographic appearances of the submandibular gland These include: • The main duct is of even diameter (3-4 mm wide) and should be filled completely and uniformly. • This gland is smaller than the parotid, but the overall appearance is similar with the branching duct structure tapering gradually towards the periphery — the so-called bush in winter appearance.