NEET MDS Shorts
50146
Orthodontics
SOLUTION The mandible is ossified in the fibrous membrane covering the outer surfaces of Meckel’s cartilages. These cartilages form the cartilaginous bar of the mandibular arch, and are two in number, a right and a left. Ossification takes place in the membrane covering the outer surface of the ventral end of Meckel’s cartilage , and each half of the bone is formed from a single center which appears, near the mental foramen, about the sixth week of fetal life. By the tenth week the portion of Meckel’s cartilage which lies below and behind the incisor teeth is surrounded and invaded by the membrane bone
16187
Oral PathologyCotton-wool appearance is pathognomonic of Pagets disease of bone. This radiographic appearance results from the irregular pattern of bone resorption and formation creating areas of mixed radiolucency and radiopacity resembling cotton wool. Osteosclerosis appears uniformly radiopaque, periapical cemental dysplasia shows various stages, and ossifying fibroma has a more uniform appearance.
79370
EndodonticsReversible pulpitis is a mild inflammation of the dental pulp that is typically relieved by the application of cold water or air. The transient pain is caused by the movement of fluid within the dentinal tubules when exposed to stimuli, which is consistent with the hydrodynamic theory of pain.
72056
PhysiologyThe acrosome in sperm contains enzymes that help in the penetration of the ovum during fertilization, facilitating the fusion of sperm and egg.
79521
PeriodonticsDuring activation of a scaling instrument, the facial surface of the blade and tooth surface should form an angle of > 45 but < 90 degrees.
32616
Dental Materials
Barium sulfate is added to Gutta Percha to enhance its radiographic visibility.
50491
Prosthodontics
Effects of loading on the abutment tooth and the surrounding structures. Widening of the periodontal ligament: When loads are
applied to a tooth, the periodontal ligament (PDL) experiences stress. This
can lead to a mild widening of the PDL space due to the mechanical loading
and adaptive responses of the tissues involved. Thus, this statement is
true. Increase in the density of the cortical plates: When
there is functional loading, the cortical bone surrounding the teeth can
adapt by increasing in density (a process known as bone remodeling).
Increased loads can stimulate bone formation, leading to denser cortical
plates. This statement is also true. Increase in the trabeculation of the alveolar bone:
Similar to the cortical plates, the trabecular (or cancellous) bone also
adapts to loads through a process of remodeling, often leading to increased
trabeculation during functional loading. This means denser and more
organized bone structure in response to the applied forces, which is true as
well. None of the above: Given that all the previous
statements can be considered true in the context of what happens when loads
are applied to the abutment tooth, the option "None of the above" suggests
that all of the listed outcomes can occur with loading on the abutment
tooth, making option 4 the correct choice. In summary, when loads are placed on the abutment tooth, all the mentioned
effects (widening of the periodontal ligament, increase in the density of the
cortical plates, and increase in the trabeculation of the alveolar bone) are
valid responses to mechanical stress. Therefore, the answer 4 (None of the
above) is correct because there are no false statements among the listed
outcomes.
76595
Radiology
Tomography is a diagnostic imaging method that is often referred to as basic
"sectional" or "slice" radiography. It involves taking a series of
two-dimensional images of a specific area or "slice" of the body, using a narrow
beam of radiation that passes through the body from multiple angles. These
images are then combined to create a detailed, cross-sectional view of the
internal structures, allowing for the visualization of the body without the
superimposition of structures outside the area of interest. This technique is
particularly useful for diagnosing conditions that may not be apparent on
standard X-rays.
Explanation of the other options:
1) Othopantomography: This is a type of panoramic radiography used to capture a
wide-angle view of the teeth, jaw, and other oral structures. While it does
produce an image of a "section" of the body, it is not typically referred to as
"sectional" or "slice" radiography in the same sense as tomography, as it does
not involve the same layering or cross-sectional approach.
2) Cephalogram: A cephalogram is a specific type of X-ray used in dentistry and
orthodontics to examine the soft tissues and bones of the face and head,
particularly the skull and jaw. It provides a two-dimensional, flat
representation of the head from the side view, and while it is a form of
radiography, it does not produce the layered or cross-sectional images that are
characteristic of tomography.
14414
Oral SurgeryFor mandibular tooth extraction, the occlusal plane should be parallel to the floor when the mouth is wide open. This positioning provides optimal access, proper force direction, and ergonomic advantage for the operator during mandibular extractions.
64145
State PSC PYQThe technique records stress-bearing areas in functional form, non-stress-bearing areas in anatomic form, and helps obtain maximum peripheral extension. Recording non-stress-bearing areas in functional form is NOT one of its objectives.