MCQs in Orthodontics - Biomechanics of Tooth Movement

# 'Torque' in orthodontics refers to:
A. The change in mesiodistal inclination of teeth
B. The change in labiolingual inclination of teeth
C. The rotation of teeth
D. None of the above

# Resorption in case of ideal orthodontic tooth movement should be:
A. Undermining
B. Frontal
C. Indirect
D. Necrotic

# In orthodontic tooth movement which is involved:
A. Osteoblast
B. Osteoclast
C. Both A and B
D. None

MCQs on Dental Cements- Dental Materials MCQs

# Fluoride rich materials include:
A. Silicate cement
B. Glass ionomer cement
C. Poly carboxylate cement
D. All of the above

# Glass ionomer cements are composed of:
A. Alumina silicate powder and phosphoric acid
B. Aluminosilicate powder and polyacrylate
C. Zinc oxide powder and phosphoric acid
D. Zinc oxide powder and polyacrylate Liquid

# Which one of the following dental cement accelerates the formation of reparative dentin?
A. Eugenol
B. Calcium hydroxide
C. Zinc oxide
D. Silica

# Minimum thickness for type I zinc phosphate cement should be:
A. 15 microns
B. 25 microns
C. 50 microns
D. 100 microns

The bone of tooth socket is called:

 # The bone of tooth socket is called:

A. Alveolar process

B. Alveolus

C. Gomphosis

D. Cancellous bone

The correct answer is A. Alveolar process.

The bone of the tooth socket is called the Alveolar process.

Here’s a brief explanation of the terms:

Alveolar process: The bony ridge in the jaw that contains the sockets (alveoli) for the teeth.

Alveolus: Refers specifically to the individual tooth socket itself.

Gomphosis: The fibrous joint between a tooth and its socket.

Cancellous bone: A type of bone tissue that is spongy and found within the alveolar process, but it is not specifically the term for the socket.

So the correct answer is A. Alveolar process.

Number of surfaces of an anterior tooth is:

 # Number of surfaces of an anterior tooth is:

A. 5

B. 3

C. 4

D. 6

The correct answer is C. 4.

The number of surfaces of an anterior tooth is typically 4. Anterior teeth, which include incisors and canines, generally have the following surfaces:

1. Facial (or Labial): The surface facing the lips.
2. Lingual: The surface facing the tongue.
3. Mesial: The surface closest to the midline of the dental arch.
4. Distal: The surface farthest from the midline.

Therefore, the correct answer is C. 4.

Universal tooth numbering system was given by:

 # Universal tooth numbering system was given by:

A. ADA in 1968

B. WHO adopted

C. Adolph Zsigmondy

D. Palmer

The correct answer is A. ADA in 1968.

The Universal Tooth Numbering System, developed by the American Dental Association (ADA) in 1968, is a standardized method used primarily in the United States for identifying and labeling teeth. Here’s a detailed breakdown of its components and significance:

Overview of the System

Numbering Convention:

• The system assigns a unique number to each tooth, starting from the upper right third molar (tooth #1) and moving across the upper arch to the upper left third molar (tooth #16).
• The numbering then continues with the lower left third molar (tooth #17) and goes across the lower arch to the lower right third molar (tooth #32).
• This creates a simple, sequential numbering system that allows for easy identification of each tooth.

Tooth Types:

The system includes all types of teeth: incisors, canines, premolars, and molars.

For example, incisors are numbered as follows:

Upper right central incisor: #7

Upper left central incisor: #9

Similarly, for molars:

Upper right first molar: #3

Lower left first molar: #19

Importance of the System

Communication:

The Universal Tooth Numbering System facilitates clear communication among dental professionals. By using a standardized number for each tooth, practitioners can avoid confusion that may arise from differing naming conventions.

Record Keeping:

This system is particularly useful for patient records, treatment planning, and documentation. It allows dentists to efficiently reference specific teeth during consultations, procedures, and follow-ups.

Education:

Dental students and practitioners benefit from learning this system as it is widely used in clinical practice. Mastery of tooth numbering is crucial for accurate diagnosis and treatment.

Alternatives to the Universal System

While the Universal Tooth Numbering System is prevalent in the U.S., other countries may use different systems, such as:

• FDI World Dental Federation Notation: This system uses a two-digit code where the first digit represents the quadrant and the second digit represents the tooth within that quadrant.
• Palmer Notation: This method employs a symbol to indicate the quadrant and numbers to denote the teeth within that quadrant.

Conclusion

The Universal Tooth Numbering System established by the ADA has become an integral part of dental practice in the U.S. Its simplicity and efficiency help streamline communication and improve the overall quality of dental care.

What is the area of biopsy of an ulcer?

 # What is the area of biopsy of an ulcer?

A. Center of ulcer 

B. Edge of ulcer 

C. Adjacent mucosa 

D. Margins of ulcer

The correct answer is B. Edge of ulcer.

The edge of the ulcer is the preferred site for biopsy because it is most likely to contain a mixture of both the pathological tissue and relatively healthy tissue, making it easier to assess the nature of the lesion. The center of the ulcer may contain necrotic tissue, which can obscure diagnosis, while adjacent mucosa and margins might not provide the necessary diagnostic material.

While the terms "edge" and "margin" may seem similar, in the context of ulcer biopsy, they refer to different areas:

Edge of the ulcer: This refers to the transitional zone where the ulcerated tissue meets the adjacent normal or mildly affected tissue. It contains a mix of pathological changes (inflammation, dysplasia, or neoplastic transformation) and some relatively intact tissue. This makes it ideal for biopsy because it provides a clearer picture of the disease process.

Margin of the ulcer: This term typically refers to the boundary or outer rim of the ulcer where the surrounding tissue is largely unaffected or healthy. A biopsy from the margin might miss the abnormal cellular changes that are occurring in the active disease area.

In summary, the edge includes both ulcerated and transitioning tissue, making it more useful for diagnosis, whereas the margin is often farther out in the healthier tissue, which may not show the necessary pathological changes.

Posterior triangle of neck is subdivided into two parts by which muscle?

 # Posterior triangle of neck is subdivided into two parts by which muscle?

A. Sternocleidomastoid

B. Superior belly of Omohyoid

C. Inferior belly of Omohyoid

D. Pulley of Trapezius

The correct answer is C. Inferior belly of Omohyoid.

The posterior triangle of the neck is divided into two smaller triangles: the occipital triangle and the subclavian (supraclavicular) triangle. This division is created by the inferior belly of the omohyoid muscle.

Here’s a breakdown of the other options:

A. Sternocleidomastoid: Forms the anterior border of the posterior triangle, but does not subdivide it.

B. Superior belly of Omohyoid: Lies more anteriorly and is not involved in subdividing the posterior triangle.

D. Pulley of Trapezius: The trapezius muscle forms the posterior boundary of the posterior triangle but does not subdivide it.