Dentosphere : World of Dentistry

COLLEGE OF MEDICAL SCIENCES. TEACHING HOSPITAL BHARATPUR            Dec-Jan 2019-2020 Level: IV BDS                                                                                                                            Exam: Send up Subject: Orthodontics                                                                                                              Time: 2 h...

COLLEGE OF MEDICAL SCIENCES. TEACHING HOSPITAL BHARATPUR            Dec-Jan 2019-2020 Level: IV BDS                                                                                                                            Exam: Send up Subject: Periodontics                                                                                                              Time: 2 h...

COLLEGE OF MEDICAL SCIENCES. TEACHING HOSPITAL BHARATPUR            Dec-Jan 2019-2020 Level: IV BDS                                                                                                                            Exam: Send up Subject: Pedodontics                                                                                                              Time: 2 hr...

COLLEGE OF MEDICAL SCIENCES. TEACHING HOSPITAL BHARATPUR           Dec-Jan 2019-2020 Level: IV BDS                                                                                                                            Exam: Send up Subject: Oral Medicine                                                                                                               Ti...

# The most common bone cancer is (AlIMS 94, AIPG 99) a) Osteosarcoma b) Metastatic bone cancer c) Multiple myeloma d) Squamous cell carcinoma The correct answer is: B. Metastatic bone cancer. Metastatic cancers are most common cancers in bone. Multiple myeloma is the common primary bone tumor, whereas the common inherent bone cell tumor is osteogenic sarcoma or osteosarcoma.

# Bifid ribs, multiple radiolucent lesions of the jaws, multiple basal cell nevi and falx ceribri calcification are found in (Man 98, 97) a) Basal cell nevus syndrome b) Sturge weber syndrome c) Horner syndrome d) Hereditary internal polyposis The correct answer is A. Basal cell nevus syndrome. Basal cell nevus syndrome is also called as Gorlin Goltz syndrome. Horner's syndrome is characterized by miosis, ptosis and anhidrosis over face due to interruption of sudomotor and vasomotor control. Hereditary intestinal polyposis is seen in Peutz-Jeghers syndrome.

# Which of the following tumors is most aggressive? (AIPG 91, AIIMS2004) a) Ameloblastoma b) Odontoma c) Odontogenic myxoma d) Fibrocarcinoma The answer is C. Odontogenic myxoma ODONTOGENIC MYXOMAS Aggressive, intraosseous neoplasms derived from embryonic odontogenic mesenchyme probably arise from the dental papilla or follicular mesenchyme. Nearly all lesions are found in the tooth bearing areas of maxillary and mandibular bone. Mandibular lesions are commonly found in the premolar-molar area. The lesions often produce multilocular radiolucency with a "soap bubble' or "honey comb" appearance in the bone. Thin and extremely delicate septa of bone are often seen to course through the radiolucent area and produce a "spider- web" like or "tennis racket" like appearance.  (Ref: Shafer's Textbook of oral pathology 7h ed., p 299)

# Obesity, genetic profile, and aging all contribute to the development of Type II diabetes. Of the following, which is the most important additive factor for these three conditions in the development of Type II diabetes? A. elevated hepatic ketogenesis B. elevated pancreatic glucagon secretion C. impaired renal clearance of glucose D. muscle resistance to insulin Answer: D - Muscle resistance to insulin is the most important additive factor for these three conditions in the development of Type II diabetes. The progressive loss of skeletal muscle sensitivity to insulin leads to increased rates of visceral cell lipolysis and pancreatic beta-cell compensation.

# # All of cranial nerve have parasympathetic outflow except : A. 5th nerve B. 7th nerve C. 3rd neve D. 9th nerve The correct answer is A. 5th nerve Cranial nerves having parasympathetic now are 3,7,9 and 10. Preganglionic parasympathetic neuron cell bodies are located in certain cranial nerve nuclei of the brain stem and in the grey matter of the second to fourth sacral segments of the spinal cord. Efferent fibres, which are myelinated, emerge from the CNS only in cranial nerves III, VII, IX, and X and in the second to fourth sacral spinal nerves. Preganglionic parasympathetic neurons are cholinergic.  The only cranial nerve which arises on the dorsal aspect   -       Trochlear The cranial nerve with longest intracranial coarse              -        Abducent The cranial nerve with longest coarse                      ...

# ___________most often refer pain to the temporal region, while _________most often refer pain the ear. A. Maxillary second premolars, mandibular molars B. Maxillary molars, mandibular molars C.  Maxillary second premolars, mandibular premolars D. Maxillary molars, mandibular premolars The correct answer is A. Maxillary second premolars, mandibular molars. If careful diagnosis does not reveal the affected tooth, other teeth and related anatomic structures become suspect. Pulpitis in one tooth may cause pain in other areas - the pain is referred. Site of Pain Referral                              Pulp of Tooth Causing Pain Forehead region                                    Maxillary incisors Nasolabial area                      ...

# Which of the following statements is TRUE? (MAN-95) a) The hydrolysis of lactose yields glucose and galactose b) The hydrolysis of maltose yields glucose and fructose c) The hydrolysis of sucrose yields only glucose d) All of the above statements are true The correct answer is A. The hydrolysis of lactose yields glucose and galactose Carbohydrate Products Maltose 2 glucose units Sucrose 1 glucose + 1 fructose Lactose Galactose + glucose Starch Water soluble amylose and a water soluble amylopectin Inulin Polymer of fructose

# Advantage of chromic gut over plain is: A. Delayed resorption B. Increased strength C. Less irritation D. Less tissue reaction The correct answer is A. Delayed resorption. Chromic gut sutures consist of the plain gut that has been treated with chromium trioxide. This results in a delay in the absorption rate. Because retention of sutures beyond a few days is not recommended in endodontic surgery, the use of chromic gut sutures offers no advantage. Also, evidence indicates that plain gut is more biocompatible with oral soft tissues than is the chromic gut. The gut suture material is marketed in sterile packets containing isopropyl alcohol. When removed from the packet, the suture is hard and non-pliable because of its dehydration. Before using gut sutures should be hydrated by placing them into sterile, distilled water for 3 to 5 minutes. After hydration, the gut suture material will be smooth and pliable with manipulative properties similar to silk. ...

# Benzodiazepine antagonist is: A. Flumazenil B. Naloxone C. Furazolidone D. Dapsone The correct answer is A. Flumazenil Benzodiazepine act by enhancing presynaptic or postsynaptic inhibition through a specific receptor which is integral part of gabba receptor Cl-channel complex. Flumazenil is a BZD analogue which has little intrinsic activity but it competes with BZDs as well as inverse agonists for BZD receptor and reverses their depressant or stimulant effects respectively. Flumazenil is the drug of choice for benzodiazepine overdose.

# To prevent sensitivity caused by acid etching and to protect pulp in deep cavities, which of the following should be used? A. Calcium hydroxide liner B. ZnO liner C. Light cure GIC liner D. Lining with varnish The correct answer is A. calcium hydroxide liner Deep caries excavation close to the pulp, which may result in either an undetected pulpal exposure or a visible pulpal exposure, should be covered with a calcium hydroxide liner that can stimulate formation of dentin bridges (reparative dentin) over the exposure. For amalgam restorations, deep excavations not encroaching on the pulp should be covered with a glass-ionomer material that will contribute to thermal protection and provide mechanical protection from amalgam condensation forces at thicknesses of I to 1.5 mm or greater.

# Bonding of composite resins to tooth structure is by: (KAR-01) a) Covalent bond b) Ionic bond c) Mechanical d) Vander waal forces The correct answer is C. Mechanical Bonding of composites to tooth structure occurs by micromechanical retention. Acid etching creates micro porosities into which the resin penetrates resulting in resin tag formation. These tags penetrate to a depth of 5 - 10 µm but their lengths are dependent on the enamel etching time.

# The main advantage of composites over unfilled direct filling resin is their: (KAR-97) a) Higher solubility in saliva b) Lower modulus of elasticity c) Esthetic excellence d) Lower thermal co-efficient of expansion The correct answer is D. Lower coefficient of thermal expansion. Advantages of composites over unfilled resins: Lower coefficient of thermal expansion Low polymerization shrinkage Low water absorption High abrasive resistance Disadvantages of composites: Less color stability Less smooth finish than unfilled resins