Dentosphere : World of Dentistry

# Concept of cortical anchorage given by: a. Angle  b. Kingsley  c. Ricketts  d. Newton  The correct answer is C. Ricketts.  Rickets technique by intentionally bringing the buccal roots of the anchor teeth into contact with the cortical plates of bone thus increasing the anchorage value of such teeth. It should be appreciated that this process should be carried out with great care and precision since overzealous torque can produce root resorption or in extreme cases cortical perforation. (Brezniak& Wasserstein, 2008)

  # One of the following procedures falls under high bacteremia risk for infective endocarditis:  a. Post-operative suture removal  b. Intraligamentary and intra-osseous local anesthetics injections  c. Intracanal endodontic treatment  d. Placement/ removal of removable orthodontic appliances  The correct answer is B. Intraligamentary and intra-osseous local anesthetics injections. All dental procedures that involve manipulation of gingival tissue or the periapical region of teeth or perforation of the oral mucosa are the procedures for which endocarditis prophylaxis is reasonable. The following procedures and events do not need prophylaxis:  routine anesthetic injections through noninfected tissue,   taking dental radiographs,  placement of removable prosthodontic or orthodontic appliances,  adjustment of orthodontic appliances,  placement of orthodontic brackets,  shedding of deciduous teeth,  and bleeding from trau...

 Fenestration is a notable adverse effect associated with fixed orthodontic treatment. It refers to the formation of a window-like defect in the alveolar bone, where the root of a tooth becomes partially exposed due to the bone's resorption. This condition can occur when excessive or improperly directed orthodontic forces are applied, causing the tooth to move outside the limits of the alveolar bone housing. The main factors contributing to fenestration include: Excessive Force Application: Applying too much force during orthodontic treatment can lead to undue stress on the bone, resulting in resorption and fenestration. Unfavorable Tooth Movement: Moving teeth in directions that extend beyond the anatomical boundaries of the alveolar bone can cause this adverse effect. Pre-existing Bone Deficits: Patients with naturally thin or compromised alveolar bone are more susceptible to fenestration when undergoing orthodontic treatment. Fenestration above left maxillary canine in a fema...

 # The daily requirement of vitamin B12 is:  A. 0.25-0.67 mcg per day B. 3-5 mcg per day C. 0.5-0.7 mcg per day D. 1-2 mcg per day The correct answer is D. 1-2 mcg per day. Vitamin B12 plays a crucial role in maintaining healthy nerve function, supporting red blood cell production, and aiding in DNA synthesis. This range is in line with the daily recommended intake for vitamin B12 for most adults, which is typically around 2.4 mcg per day according to various health guidelines.

 # Organism most commonly seen in lung abscesses is:  A. Candida albicans  B. Herpes zoster virus  C. Oropharyngeal flora  D. Staphylococcus aureus (PSC KOSHI 2081) The correct answer is C. Oropharyngeal flora.  Lung abscesses are typically caused by aspiration of bacteria from the oropharyngeal flora. This flora includes a mix of aerobic and anaerobic bacteria normally found in the mouth and throat. When these bacteria are aspirated into the lungs, they can cause an infection leading to a lung abscess. While the other options listed can cause infections in the lungs, they are not the most common cause of lung abscesses: Candida albicans (A): This fungus is a common cause of opportunistic infections, but it is not the most common cause of lung abscesses. Herpes zoster virus (B): This virus causes shingles and can rarely lead to lung complications, but it is not a common cause of lung abscesses. Staphylococcus aureus (D): While this bacterium can cause pneum...

 # Tetany is caused by: A. Hyperglycemia  B. Hypocalcemia  C. Clostridium tetani  D. Low oxygen level The correct answer is B. Hypocalcemia. Tetany is a condition characterized by involuntary muscle contractions, cramps, and spasms. The primary cause of tetany is hypocalcemia, which is a low level of calcium in the blood. Calcium plays a crucial role in muscle contraction and nerve function. When calcium levels are low, nerves become hyperexcitable, leading to the uncontrolled muscle contractions seen in tetany. Hyperglycemia (A): High blood sugar levels are associated with diabetes, not tetany. Clostridium tetani (C): This bacterium causes tetanus, a different condition characterized by muscle stiffness and spasms. Low oxygen level (D): While low oxygen can cause various symptoms, it is not the primary cause of tetany. Reference:  Hypocalcemia and Tetany: Causes, Symptoms, and Treatment (webmd.com)

 # Intrusion of tooth is resisted by: A. Apical and interradicular fibers B. Oblique and horizontal fibers C. Alveolar crest and oblique fibers D. All Periodontal fibers The correct answer is C. Alveolar crest and oblique fibers. The principal fibers of periodontal ligament are arranged in six groups and are named according to their location and direction of attachment.  1. Transseptal group Location: These fibers run into the interproximal space over the crest of alveolar bone and get inserted in the cementum of neighboring tooth. Function: They have the innate capacity to reconstruct themselves in periodontal disease even there is destruction of the alveolar bone. This unique property of fibers is responsible for returning teeth to their original state after orthodontic therapy. 2. Alveolar crest group (apico-oblique) Location:  Cervical root to alveolar crest of alveolar bone proper Function:  Prevent extrusion and lateral tooth movements 3. Horizontal group Loca...