Dentosphere : World of Dentistry

 # Distraction osteogenesis is preferred over a traditional osteotomy:  A. When a large advancement is needed  B. When a small advancement is needed  C. When exacted interdigitation of the occlusion is needed  D. When the treatment needs to be done in a very short period of time  The correct answer is A.  When a large advancement is needed. Distraction osteogenesis is preferred over traditional osteotomies when large skeletal movements are required and the associated soft tissue cannot adapt to the acute changes and stretching that results. Larger movements may be at increased risk of some relapse; this is particularly true in a patient with a cleft palate, where there is significant soft tissue scarring from previous surgeries.

 # At which of the following locations are perikymata usually found? a. Cervix of the crown. b. Apex of the root. c. Cusp tips. d. Deposited throughout the crown. The correct answer is A. Cervix of the crown. Perikymata are transverse, wave-like grooves, believed to be the external manifestations of the striae of Retzius. They are continuous around a tooth and usually lie parallel to each other and to the cementoenamel junction. Ordinarily there are about 30 perikymata per millimeter in the region of the cementoenamel junction, and their concentration gradually decreases to about 10 per millimeter near the occlusal or incisal edge of a surface. Their course usually is fairly regular, but in the cervical region it may be quite irregular. The terms perikymata and imbrication lines are used without distinction to the surface structures of ridges or grooves. To avoid confusion in the usage of these terms it has been suggested that the terms perikymata or imbrication lines be suffixed b...

 # Bones that are small, irregularly shaped, and found along sutures are called  a. Parietal.  b. Wormian.  c. Temporal.  d. Zygomatic.  The correct answer is B. Wormian bone. Wormian bones, also known as intrasutural bones or sutural bones, are extra bone pieces that can occur within a suture (joint) in the skull. These are irregular isolated bones that can appear in addition to the usual centres of ossification of the skull and, although unusual, are not rare. They occur most frequently in the course of the lambdoid suture, which is more tortuous than other sutures. They are also occasionally seen within the sagittal and coronal sutures. A large wormian bone at lambda is often called an Inca bone (Os Incae), due to the relatively high frequency of occurrence in Peruvian mummies. Another specific Wormian bone, the pterion ossicle, sometimes exists between the sphenoidal angle of the parietal bone and the great wing of the sphenoid bone. They tend to vary i...

 # Which certification is required for dentists that provide general anesthesia?  a. Basic life support (BLS).  b. Emergency medical training (EMT).  c. Cardiopulmonary resuscitation (CPR).  d. Advanced cardiac life support (ACLS).  The correct answer is D. Advanced cardiac life support (ACLS). Dentists that provide general anesthesia must be certifed in ACLS for their licensure; BLS certifcation is inadequate. Many states mandate, and the current standard of care necessitates, certifcation in ACLS training for dentists providing general anesthesia.  ACLS: For healthcare professionals who either direct or participate in the management of cardiopulmonary arrest or other cardiovascular emergencies and for personnel in emergency response What does this course teach? Basic life support skills, including effective chest compressions, use of a bag-mask device, and use of an AED Recognition and early management of respiratory and cardiac arrest Recogniti...

 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...

 # 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?  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.  CLICK HERE FOR MORE MCQs