Which of the following is a property of biofilms and is of clinical signifcance?

 Which of the following is a property of biofilms and is of clinical signifcance?

a. Facilitate stain formation.

b. Increase sensitivity to antibiotics.

c. Extremely tolerant of antimicrobial agents.

d. Enhance the development of halitosis.

The correct answer is C. Extremely tolerant of antimicrobial agents.

The term biofilm describes relatively undefinable microbial community associated with a tooth surface or any other hard non-shedding material. Biofilms are ubiquitous and are found in oral cavity, the bottom of boats and docks, inside pipes, rocks in streams, catheters, hip and voice prosthesis and contact lenses.

Biofilm bacteria exhibit stronger resistance (1000 to 1500 times) to biocides and antimicrobial agents than do their planktonic counterpart. Following hypothesis may help to explain the increased resistance to antimicrobials.

1. The exopolysaccharide of the biofilm matrix may inhibit the diffusion of antimicrobial agents.

2. The physiological differences among biofilm bacteria leave only a part of biofilm bacteria susceptible to growth dependent antibiotics.

3. The genetic changes occurring in transition from planktonic to biofilm bacteria make the biofilm bacteria insensitive to various biocides and antimicrobial agents.

4. Slower rate of growth of organisms due the nutrient limitation may also contribute to the resistance to antimicrobial agents by biofilm bacteria. 

5. Extracellular enzymes such as β–lactamase, formaldehyde dehydrogenase become concentrated in extracellular matrix, thus inactivating some antibiotics.

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Herpes simplex type 1 virus can be transmitted in dentistry by which of the following?

 # Herpes simplex type 1 virus can be transmitted in dentistry by which of the following? 

a. Sharps injury. 

b. Contact with skin. 

c. Inhalation of infected droplets. 

d. Contact of infected material with skin or eyes 

The correct answer is D. Contact of infected material with skin or eyes.

It is estimated that out of the 80 known herpes viruses, at least eight are known to infect human beings. The herpes viruses that are known to cause infection in humans are herpes simplex virus (HSV 1 and 2), varicella zoster virus (VZV), cytomegalovirus (CMV), Epstein-Barr virus (EBV), human herpes virus 6 (HHV-6), human herpes virus 7 (HHV-7) and human herpes virus 8 (HHV-8). These viruses are usually transmitted from host to host by direct contact or through saliva and genital secretions. Herpes viruses are shed in the saliva of asymptomatic hosts.

Which of the following structures are closely related in time of development and sometimes have related malformations?

 # Which of the following structures are closely related in time of development and sometimes have related malformations? 

a. Ear and tongue. 

b. Palate and tongue. 

c. Palate and face. 

d. Face and ears. 

The correct answer is C. Palate and Face.

The human face develops early in gestation, during the fourth through seventh weeks, and the palatal processes begin to close during the eighth week. These two structures are closely related in time of development and sometimes have related malformations. 

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The condition involved with an unerupted tooth or impacted tooth is:

 # The condition involved with an unerupted tooth or impacted tooth is:

A. Dentigerous cyst

B. Mural ameloblastoma

C. Adenomatoid odontogenic tumor

D. All of the above

The correct answer is D. All of the above.

Dentigerous cyst is always associated initially with the crown of an impacted, embedded or unerupted tooth. A dentigerous cyst may also be found enclosing a complex compound odontoma or involving a supernumerary tooth. The most common sites of this cyst are the mandibular and maxillary third molar and maxillary cuspid areas.

Adenomatoid Odontogenic Tumors are seen in a rather narrow age range, between 5 and 30 years, with most cases appearing in the second decade. Females are more commonly affected than males. Lesions often appear in the anterior portion of the jaws, more often in the anterior maxilla, generally in association with the crowns of impacted teeth. 

HSV-2 virus resides in:

 # HSV-2 virus resides in:

A. Basal ganglia

B. Stellate ganglia

C. Lumbosacral ganglion

D. Otic ganglion

The correct answer is C. Lumbosacral region.

It is now well established that the HSV does not remain latent at the site of the original infection in the skin or oral mucosa. Instead, the virus reaches nerve ganglia supplying the affected areas, presumably along nerve pathways, and remains latent there until reactivated. The usual ganglia involved are the trigeminal for HSV-1 and the lumbosacral for HSV-2. Viral DNA can be demonstrated in these ganglia. Unfortunately, this incorporation of viral DNA into host DNA ensures a lifelong infection beyond the reach of antibody, cell mediated immune responses or chemotherapy.

The tongue of a patient deviates to one side whenever he sticks his tongue out. The cranial nerve that may be damaged is:

 # The tongue of a patient deviates to one side whenever he sticks his tongue out. The cranial nerve that may be damaged is:

A. Trigeminal nerve

B. Vagus nerve

C. Facial nerve

D. Hypoglossal nerve

The correct answer is D. Hypoglossal nerve.

HYPOGLOSSAL NERVE

Hypoglossal nerve is the twelfth cranial nerve. It supplies the muscles of the tongue. The hypoglossal nerve is tested clinically by asking the patient to protrude his/her tongue. Normally, the tongue is protruded straight forwards. If the nerve is paralysed, the tongue deviates to the paralysed side. 

Which of these is a pseudocyst?

 # Which of these is a pseudocyst?

A. Nasolabial cyst

B. Globulomaxillary cyst

C. Traumatic cyst

D. Radicular cyst

The correct answer is C. Traumatic cyst.

Traumatic cyst is also called as Solitary bone cyst, hemorrhagic cyst, extravasation cyst, unicameral bone cyst, simple bone cyst, idiopathic bone cavity. The traumatic cyst is a pseudo cyst (lacks an epithelial lining) and an uncommon lesion comprises about 1% of all jaw cysts. It occurs in other bones of the skeleton as well.