Dentosphere : World of Dentistry

 # A 3 year old patient has extensive vesicles on lip, tongue, oral mucous membrane. After 2-4 days vesicles rupture at followed by pseudo membrane formation and also some dermal lesions are seen. What will be the diagnosis?  a. Herpetic stomatitis  b. Erythema multiforme  c. ANUG  d. Steven-Johnson Syndrome  The correct answer is B. Erythema multiforme.  Erythema multiforme (EM) is acute, self‐limited, inflammatory mucocutaneous disease that manifests on the skin and often oral mucosa, although other mucosal surfaces, such as the genitalia, may also be involved. It represents a hypersensitivity reaction to infectious agents (majority of cases) or medications. In general, EM is classified as EM minor if there is less than 10% of skin involvement and there is minimal to no mucous membrane involvement, whereas EM major has more extensive but still characteristic skin involvement, with the oral mucosa and other mucous membranes affected.

 # Three inherent characteristics of a radiographic film: a. density, distortion, contrast  b. sharpness, contrast, density  c. definition, sharpness, penumbra  d. distortion, detail, sharpness  The correct answer is: B. Sharpness, contrast, density. Image quality describes the subjective judgment by the clinician of the overall appearance of a radiograph. It combines the features of density, contrast, latitude, sharpness, resolution, and perhaps other parameters.

 # Use of intensifying screen is: a. to decrease scattered radiation  b. to decrease patient radiation  c. to increase contrast  d. to increase number of photons striking the anode filament  The correct answer is B. To decrease patient radiation. The presence of intensifying screens creates an image receptor system that is 10 to 60 times more sensitive to x-rays than the film alone. Consequently, the use of intensifying screens substantially reduces the dose of x radiation to the patient. Intensifying screens are used with films for virtually all extraoral radiography, including panoramic, cephalometric, and skull projections.

 # Digital radiography differs from conventional in: a. X-rays not used  b. Rays other than X-rays are used  c. Radiation receptors are different  d. No hard copy is formed  The correct answer is C. Radiation receptors are different. Digital image receptors encompass numerous different technologies and come in many different sizes and shapes. Numerous different and sometimes confusing names are in use to identify these receptors in medicine and dentistry. The most useful distinction is that between two main technologies: (1) solid-state technology and (2) photostimulable phosphor (PSP) technology. Although  solid-state detectors can be subdivided further, these detectors have in common certain physical properties and the ability to generate a digital image in the computer without any other external device. In medicine, the use of solid-state detectors is referred to as digital radiography. In dentistry, intraoral solid-state detectors are often called senso...

 # Tzanck smear test is used in the diagnosis of : a. Pemphigus  b. ANUG  c. Aphthous disease  d. Lichen planus  The correct answer is A. Pemphigus. Pemphigus as an entity is characterized microscopically by the formation of a vesicle or bulla entirely intraepithelially, just above the basal layer producing the distinctive suprabasilar ‘split’. Prevesicular edema appears to weaken this junction, and the intercellular bridges between the epithelial cells disappear. This results in loss of cohesiveness or acantholysis, and because of this, clumps of epithelial cells are often found lying free within the vesicular space. These have been called ‘Tzanck cells’ and are characterized particularly by degenerative changes which include swelling of the nuclei and hyperchromatic staining. These changes are particularly obvious in cytologic smears taken from early, freshly opened vesicles. 

 # A flat, circumscribed discoloration of skin or mucosa that may vary in size and shape is referred to as:  a. epulis  b. macule  c. nodule  d papule  The correct answer is B. Macule. Macules: These are lesions that are flush with the adjacent mucosa and that are noticeable because of their difference in color from normal skin or mucosa. They may be red due to increased vascularity or inflammation, or pigmented due to the presence of melanin, hemosiderin, and foreign material (including the breakdown products of medications). A good example in the oral cavity is the melanotic macule. Papules: These are lesions raised above the mucosal surface that are smaller than 1.0 cm in diameter (some use 0.5 cm for oral mucosal lesions). They may be slightly domed, or flat‐topped. Papules are seen in a wide variety of diseases, such as the yellow‐white papules of pseudomembranous candidiasis. Plaques: These are raised lesions that are greater than 1 cm in diameter; ...

 # Bismuth intoxication is manifested as:  a. Pigmentation in areas of inflammation  b. Burtonian line  c. Gingiva  d. Blackish line in the mucosa  The correct answer is D. Blackish line in the mucosa. Oral Manifestations: Bismuth pigmentation of the oral mucosa, particularly of the gingiva and buccal mucosa, is the most common oral feature of bismuth therapy and is reported to occur in a high proportion of patients receiving preparations containing the metal. The pigmentation appears as a ‘bismuth line’, a thin blue-black line in the marginal gingiva which is sometimes confined to the gingival papilla. There may also be the same type of pigmentation of the buccal mucosa, the lips, the ventral surface of the tongue, or in any localized area of inflammation such as around partially erupted third molars or around the periphery of an ulcer as an anachoretic phenomenon.