Center of resistance of maxilla is at:

 # Center of resistance of maxilla is at:

A. Point A

B. Palatal suture

C. Above the roots of premolar

D. Maxillary tuberosity

The correct answer is C. Above the roots of  premolar.

In theory, the movement of the maxilla can be controlled in the same way as a single tooth is controlled: by managing forces and moments relative to the center of resistance of the jaw. In practice, it is difficult to analyze exactly where the center of resistance and center of rotation of the maxilla might be, but they are above the teeth and most likely above the premolar teeth. Directing the line of force closer to the center of resistance is another major reason for including an upward direction of pull for most children who have headgear force to the maxilla.

Reference: Contemporary Orthodontics, Proffit

Age of closure of sphenooccipital synchondrosis is:

 # Age of closure of sphenooccipital synchondrosis is:

a) 6 years 

b) 12 years

c) 18 years 

d) 25 years

The correct answer is C. 18 years.

The spheno-occipital synchondrosis (also known as the basiocciput or basicranial synchondrosis) is the synchondrosis between the basisphenoid and basiocciput bones, which together when joined form the clivus. When fused, the synchondrosis is often called the spheno-occipital suture - this is a misnomer - as anatomically it is not a suture.

Fusion of the spheno-occipital synchondrosis initiates in girls at 12-13 years, and in boys at 14-15 years and is complete by 17-18 years. Fusion begins superiorly and progresses inferiorly, and also starts at the inner surface of the skull base proceeding towards the ectocranial surface.

Purpose of the post treatment retention of an orthodontic case is:

 # Purpose of the post treatment retention of an orthodontic case is:

A. To allow bony changes

B. To prevent tongue thrusting

C. To encourage the space closure

D. To let the patient get used to the new functional position of the teeth

The correct answer is D. To let the patient get used to the new functional position of the teeth

The purpose of post-treatment retention of an orthodontic case is to let the patient get used to the new functional position of the teeth. After completing orthodontic treatment, the teeth are in a new position, and the surrounding bone and soft tissues need time to adapt to this new position. During the retention period, the teeth are held in place while the surrounding structures adjust to the new position of the teeth. This helps to ensure the long-term stability of the treatment results. The retention period also allows the patient to become accustomed to the new position of their teeth and develop new habits such as proper oral hygiene practices and speech patterns.

In determining the psychological prognosis for a complete denture patient, one of the most valuable aids is which of the following?

 # In determining the psychological prognosis for a complete denture patient, one of the most valuable aids is which of the following?

A. A classification of the ridge relation

B. An evaluation of the  resorption of the ridges

C.  An evaluation of the patient’s occupational background

D. An evaluation of the patient’s present  dentures and attitudes

The correct answer is D. An evaluation of the patient’s present  dentures and attitudes

An evaluation of the patient’s present dentures and attitudes is one of the most valuable aids in determining the psychological prognosis for a complete denture patient. This is because the patient's previous experiences with dentures can greatly influence their attitude towards wearing dentures again. If the patient had a positive experience with their previous dentures, they are more likely to have a positive attitude towards wearing new dentures. On the other hand, if the patient had a negative experience with their previous dentures, they may be more resistant to wearing new dentures and have a more negative attitude towards the treatment. Therefore, evaluating the patient's present dentures and attitudes can help the clinician anticipate any potential difficulties and plan an appropriate treatment approach to ensure a successful outcome.

MCQs on Protein Metabolism - Biochemistry MCQs

# Tertiary structure of proteins is maintained by all except:
A. H2 bond
B. Hydrophobic
C. Ionic bond
D. Disulphide bond
E. None of the above

# Which of the following is a derived protein?
A. Protamines
B. Peptones
C. Prolamines
D. Lactalbumin

Which of the following is the general term for the complex microbial community that develops on the tooth surface?

 # Which of the following is the general term for the complex microbial community that develops on the tooth surface? 

a. Calculus. 

b. Saliva. 

c. Dental plaque. 

d. Dental stain. 

The correct answer is C. Dental Plaque. 

Dental plaque is the general term for the complex microbial community that develops on the tooth surface. Plaque is a soft, sticky film that forms on the teeth and can lead to dental caries and gum disease if not removed through proper oral hygiene practices, such as brushing and flossing. Calculus (also known as tartar) is a hard mineral deposit that can form on the teeth when plaque is not removed, and it can contribute to gum disease. Saliva is a fluid that helps to protect the teeth and oral tissues from infection, but it is not the same as dental plaque. Dental stain refers to discoloration of the teeth that can be caused by various factors, such as smoking, drinking coffee or tea, or poor oral hygiene.

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 

Herpes simplex type 1 virus can be transmitted in dentistry through direct contact with infected oral secretions or lesions, such as through contaminated instruments or gloves, or through accidental exposure to infected material during dental procedures. It is important for dental healthcare personnel to use standard precautions, such as wearing gloves and eye protection, to minimize the risk of transmission of herpes simplex virus and other infectious agents. Sharps injury and inhalation of infected droplets are not routes of transmission for herpes simplex virus, and while contact with skin may be a route of transmission, contact with infected oral secretions or lesions is a more likely mode of transmission in a dental setting.