Dentosphere : World of Dentistry

 # Torque prescription for maxillary central incisor according to MBT in degrees is: A. 17 B. 10 C. -7 D. 0 The correct answer is A. 17. Torque in orthodontics refers to the buccopalatal crown-root inclination of a tooth. To implement torque, larger dimensional archwires are inserted and engaged into brackets. This generates an activating force as the wire is manipulated into the bracket slot. Torque is not directly “in the wire.” Instead, it results from torsion in an archwire when it interacts with a bracket slot. When the wire twists compared to the bracket slot, it creates a couple (a rotational force) that affects the tooth’s inclination. Torque is not related to the angle of the bracket slot or the axial inclination of the tooth. In orthodontic treatment, torque control is often required, especially for maxillary incisors. Proper torque helps achieve an ideal inter-incisal angle, adequate incisor contact, and sagittal adjustment of the dentition for an ideal occlusion. T...

 # Which cusp on a maxillary first molar has two ridges: one that forms part of a transverse ridge and the other that forms part of an oblique ridge? a. Mesiobuccal b. Mesiolingual c. Distobuccal d. Distolingual The correct answer is B. Mesiolingual.  The mesiolingual cusp has triangular ridge as well as buccal ridge as shown in the figure of right maxillary first molar. 

 # From which view are only two roots visible on a maxillary first molar? a. Mesial b. Distal c. Buccal d. Lingual The correct answer is A. Mesial. On both the maxillary first and second molars from the mesial view, two roots can be seen: the lingual root and the mesiobuccal root, which is considerably wider buccolingually than the hidden distobuccal root.  On the first maxillary molar, the convex buccal outline of the mesiobuccal root often extends a little buccal to the crown outline, but the apex of this root is in line with the tip of the mesiobuccal cusp.

 # The furcations are likely to be farthest away from the cervical portion of the tooth in which of the following teeth? A. Mandibular first molar B. Mandibular second molar C. Mandibular third molar D. Maxillary first molar The correct answer is C. Mandibular third molar.  Both maxillary and mandibular third molar roots are noticeably shorter than on firsts or seconds. They are very crooked, often curving distally, and more commonly fused most of their length resulting in a long root trunk with the furcation located only a short distance from the apices of the roots. 

 # What is the main purpose of miniplates in orthodontic practice? A. To manage skeletal discrepancy without dental adverse effects  B. To serve as an alternative anchorage system for mini-implants  C. To withstand torsional force  D. To anchor soft tissue to root apices The correct answer is: A. To manage skeletal discrepancy without dental adverse effects.  Miniplates are an alternative form of orthodontic TADs. They are anchored on skeletal bone using monocortical titanium screws and are indicated for orthopaedic traction to manage skeletal discrepancy without dental adverse effects. They can also be used as an alternative anchorage system when mini-implant insertion is unsatisfactory. While miniplates can be used as an alternative anchorage system, their primary purpose is not specifically to serve as an alternative to mini-implants. Unlike mini-implants, miniplates can resist various types of force applications and have a lower failure rate. They are able t...

 # Mr. Baburam Bhattarai brought his two children one female and one male for dental checkup. The female was 18-years-old & the male was 12 years old. Both had a skeletal class II growth pattern. The growth modification can be done only for the following:  A. Only in male  B. Only in female  C. In both the male & female  D. Cannot be done  The correct answer is A. Only in Male. Though the chronological age may be misleading and the status of growth has to be evaluated through CVM stages, growth modulation is possible in 12 year males and it's not possible in 18 year females. 

 # Prachanda, a 20-year-old boy went to his dentist with a complaint of spacing between his upper central incisors. On examination there was presence of mid line diastema. There was a high frenal attachment. Which test will the dentist do to confirm it?  A. Montoux test  B. Cotton test  C. Ganong’s test  D. Blanch test The correct answer is D. Blanch Test. To confirm the high frenal attachment in the presence of a midline diastema, the dentist would perform the Blanch test. This test involves lifting the lip and pulling it outward. If blanching (whitening) occurs in the soft tissue palatal to or between the central incisors, it indicates a high labial frenum attachment. Therefore, the correct answer is D. Blanch test.

 # Lesions within the basal ganglia produce the following signs except:  A. Hypotonia  B. Tremor  C. Hemiballisumus  D. Athetosis Lesions within the basal ganglia can lead to various motor disturbances. Let's analyze the given signs: 1. Hypotonia: This refers to reduced muscle tone or decreased resistance to passive movement. It is associated with basal ganglia dysfunction. 2. Tremor: Tremors are rhythmic, involuntary movements. Basal ganglia lesions can indeed cause tremors. 3. Hemiballismus: Hemiballismus is characterized by sudden, wild, and flinging movements of one side of the body. It specifically results from damage to the subthalamic nucleus within the basal ganglia. 4. Athetosis: Athetosis involves slow, writhing, and twisting movements, often affecting the hands and fingers. It is also associated with basal ganglia dysfunction. Given the options, the sign that is not directly associated with basal ganglia lesions is Hypotonia. Hypotonia is more common...

 # Perfusion of oxygen supply in a free flap can be correctly estimated by: a) Pulse oximetry  b) Laser Doppler flowmetry  c) Prick test  d) Fluroscopy The correct answer is B. Laser doppler flowmetry. Let's go through each option: a) Pulse oximetry: Pulse oximetry measures the oxygen saturation of hemoglobin in arterial blood non-invasively. However, it may not provide an accurate estimation of oxygen supply in a free flap because it only measures the oxygen saturation of blood and does not directly assess tissue perfusion. While it can indicate overall oxygenation status, it may not reflect the oxygen supply to a specific tissue like a free flap. b) Laser Doppler flowmetry: Laser Doppler flowmetry is a non-invasive technique used to measure tissue perfusion by detecting the movement of red blood cells. It can provide real-time information about blood flow in the microcirculation of tissues, including free flaps. Therefore, it is often used to monitor the perfusion ...

 # The teeth most likely to be transposed are: A. Mandibular Premolars and maxillary incisors B. Maxillary premolars and mandibular incisors C.  Maxillary molars and canines D. Mandibular molars and canines The correct answer is B. Maxillary premolars and mandibular incisors. Transposition is a rare positional interchange of two adjacent teeth. It occurs with a prevalence of approximately 0.3% and equally affects males and females. The teeth most likely to be transposed are mandibular incisors and maxillary premolars, and this usually occurs as a consequence of ectopic eruption. There appears to be a genetic component to this problem. In the early mixed dentition years, transposition can develop when distally directed eruption of the permanent mandibular lateral incisor leads to loss of the primary mandibular canine and primary first molar. If left untreated, this can result in a true transposition of the permanent lateral incisor and canine.

 # The first material used for orthodontic TADs was: A. Titanium B. Stainless Steel  C. Vitallium D. Nickel - Chromium The correct answer is C. Vitallium. To date, three types of materials have been used for orthodontic TADs: titanium alloy, stainless steel and vitallium. Vitallium was the first material used for orthodontic TADs. However, due to undesirable biocompatibility and a higher failure rate, vitallium was gradually replaced by titanium alloy. Stainless steel is also used for orthodontic mini-implants and recent evidence indicates that the success rate is similar between titanium alloy and stainless steel mini-implants. Nowadays, due to high biocompatibility of titanium, orthodontic TADs made of titanium alloy are most frequently used in clinical practice. Reference: Clinical Insertion Techniques of Orthodontic Temporary Anchorage Devices, Wiley Blackwell

 # Who first advocated the opening of mid palatal suture to expand the dental arch? Emerson C. Angell  B. Pierre Fauchard C. Edward H. Angle  D. Raymond Begg The correct answer is A. Emerson C. Angell. In 1860 Emerson C. Angell was probably the first person to advocate opening of the midline suture to provide space in the maxillary arch, because he took a very strong stand against extraction. Ref: Graber, 7th Edition