MCQs in Orthodontics - Orthodontic Growth and Development Assessment

# Which of the following terms describes an increase in the number of cells?
A. Hypertrophy
B. Maturation
C. Accretion
D. Hyperplasia

# The concept that growth occurs along an axis from head to tail is known as which growth pattern?
A. Anteroposterior
B. Proximodistal
C. Somatic
D. Cephalocaudal

# According to Scammons' curves, which tissue system exhibits the most rapid growth during the first few years of life, followed by a plateau?
A. Genital system
B. General body growth
C. Lymphoid system
D. Neural system

# Which theory of craniofacial growth posits that growth occurs primarily due to adaptive responses of the skeletal tissues to functional demands of surrounding soft tissues and spaces?
A. Sutural theory
B. Servosystem theory
C. Cartilage theory
D. Functional Matrix Theory

# The primary mechanism for the increase in size of the cranial vault after birth is:
A. Surface remodeling on the external surface of the vault
B. Endochondral ossification at the cranial base
C. Appositional growth at the condylar cartilage
D. Intramembranous bone formation at the sutures

# Which cranial base synchondrosis typically fuses last, continuing to contribute to anteroposterior cranial base growth into late adolescence?
A. Pterygomaxillary synchondrosis
B. Spheno-ethmoidal synchondrosis
C. Intersphenoid synchondrosis
D. Spheno-occipital synchondrosis

# Forward and downward growth of the maxilla primarily occurs through:
A. Appositional growth at the alveolar processes
B. Endochondral ossification within the maxilla itself
C. Direct bone formation at the midpalatal suture
D. Bone deposition at the maxillary sutures and surface remodeling

# Which of the following is the primary mechanism for the growth of the mandible during childhood?
A. Intramembranous ossification of the corpus
B. Endochondral ossification at the condylar cartilage
C. Growth at the symphysis
D. Sutural growth at the posterior border of the ramus

# According to Lavergne and Gasson's classification, which type of mandibular rotation refers to the rotation of the basal bone relative to the cranial base?
A. Intramatrix rotation
B. Matrix rotation
C. Total rotation
D. Alveolar rotation

# A patient with a high Frankfort-Mandibular Plane Angle (FMA) and a tendency towards an anterior open bite often exhibits which of Tweed's growth patterns?
A. Type A (Average/Mesofacial)
B. Type B (Horizontal/Brachyfacial)
C. Type C (Vertical/Dolichofacial)
D. Type D (Unclassified)

# Which pharyngeal arch gives rise to the muscles of mastication and the maxilla/mandible?
A. First pharyngeal arch
B. Second pharyngeal arch
C. Third pharyngeal arch
D. Fourth pharyngeal arch

# The primary palate develops from the fusion of which embryonic structures?
A. Two lateral palatine processes
B. Nasal septum and palatal shelves
C. Frontonasal prominence and mandibular prominences
D. Two medial nasal prominences and two maxillary prominences

# At what approximate gestational age does the fusion of the secondary palate typically begin?
A. Week 4
B. Week 6
C. Week 7-8
D. Week 10

# The primary driving force for the elevation of the palatal shelves during secondary palate formation is widely attributed to:
A. Rapid bone growth within the shelves
B. Tongue growth pushing the shelves upward
C. Intrinsic mesenchymal turgor pressure due to hyaluronic acid accumulation
D. Muscle contractions within the shelves

# Programmed cell death (apoptosis) plays a crucial role in the fusion of the palatal shelves by eliminating which specific tissue?
A. Nasal septal cartilage
B. Medial edge epithelium (MEE)
C. Mesenchymal cells of the shelves
D. Oral epithelial cells on the superior surface

# Which of the following maternal conditions during pregnancy is a known environmental factor that increases the risk of cleft palate?
A. Maternal anemia
B. Use of certain anticonvulsant medications (e.g., phenytoin)
C. Maternal hypothyroidism
D. Excessive intake of Vitamin C

# The neonatal line in enamel and dentin is formed as a result of:
A. Physiological stress associated with birth
B. Genetic predisposition for enamel hypoplasia
C. Trauma during eruption of primary teeth
D. Pre-natal systemic illness

# Which of the following conditions would typically lead to a thinner or less distinct neonatal line?
A. Diabetic mother
B. Low birth weight
C. Elective Caesarean section delivery
D. Asphyxia in the newborn

MCQs on Cephalometric Parameters and Malocclusion

# Which of the following cephalometric parameters suggest skeletal class III malocclusion? 1. ANB is less than 0 degree 2. SNA= 84 degrees 3. SNB=82 degrees 4. Wit’s appraisal shows point A before point B 5. FMA is 40 degrees
A. 2, 4 and 5
B. 1, 4 and 5
C. 3, 4 and 5
D. 1 and 3

# A patient presents with anterior crowding as a result of large size of teeth in comparison to the base of mandible. This will be classified as:
A. Tertiary crowding
B. Secondary crowding
C. Third degree crowding
D. Primary crowding

# Which of the following cephalometric angles is primarily used to assess the anteroposterior position of the maxilla relative to the cranial base?
A. FMA
B. SNB
C. ANB
D. SNA

# A patient with a skeletal Class II malocclusion typically exhibits which of the following characteristics?
A. Prognathic mandible
B. ANB angle greater than 4°
C. Retrognathic maxilla
D. Point B anterior to Point A on Wit's appraisal

# Which cephalometric parameter assesses the vertical relationship between the Frankfort Horizontal plane and the mandibular plane?
A. FMA
B. Y axis
C. Facial angle
D. SN-GoGn

# What is the normal average value for the SNA angle in a Caucasian population?
A. 86°
B. 78°
C. 82°
D. 90°

# A high FMA angle (e.g., 30° or more) is often associated with which facial growth pattern?
A. Anteroposterior growth pattern
B. Horizontal growth pattern
C. Vertical growth pattern
D. Neutral growth pattern

# Which of the following describes a normal skeletal Class I relationship according to cephalometric analysis?
A. Wit's appraisal with point B anterior to point A
B. ANB angle between 0° and 4°
C. ANB angle of 5°
D. SNA=80° and SNB=76°

Which of the following cephalometric parameters suggest skeletal class III malocclusion?

 # Which of the following cephalometric parameters suggest skeletal class III malocclusion?

1. ANB is less than 0 degree

2. SNA= 84 degrees

3. SNB=82 degrees

4. Wit’s appraisal shows point A before point B

5. FMA is 40 degrees (INICET 2025)

A. 1, 4 and 5

B. 1 and 3

C. 2, 4 and 5

D. 3, 4 and 5

The correct answer is B. 1 and 3. 

Explanation:

• 1. ANB is less than $$\begin{gathered} 0 \\ degrees: \end{gathered}$$ A negative ANB angle indicates that point B (mandible) is anterior to point A (maxilla), which is a classic sign of skeletal Class III malocclusion.

• 3. SNB=$$\begin{gathered} 82 \\ degrees \end{gathered}$$: While the average SNB is around 80 degrees, an SNB of 82 degrees indicates a more protrusive mandible relative to the cranial base, which is consistent with a Class III tendency (especially if SNA is normal or reduced). In contrast, SNA=84 degrees (option 2) suggests a protrusive maxilla, which is typically seen in Class II, not Class III.

• 4. Wit’s appraisal shows point A before point B: This indicates a Class II skeletal relationship, where the maxilla is anterior to the mandible. For Class III, point B would be anterior to point A.

• 5. FMA is $$\begin{gathered} 40 \\ degrees \end{gathered}$$: FMA (Frankfort Mandibular Plane Angle) indicates the vertical growth pattern. A high FMA (40 degrees is significantly high) suggests a vertical growth pattern or an open bite tendency, but it does not directly indicate a sagittal Class III relationship.

A patient presents with anterior crowding as a result of large size of teeth in comparison to the base of mandible. This will be classified as:

 # A patient presents with anterior crowding as a result of large size of teeth in comparison to the base of mandible. This will be classified as: (AIIMS PG 2020)

A. Primary Crowding

B. Secondary Crowding

C. Tertiary crowding

D. Third degree crowding

The correct answer is A. Primary Crowding.

Explanation:

Primary Crowding refers to crowding that arises due to a disproportion between the size of the teeth and the size of the jawbones. In this case, the patient has large teeth relative to a smaller mandible, leading to anterior crowding. This is often genetic in origin and present even before all permanent teeth have erupted.

Secondary Crowding typically develops later, often due to factors like premature loss of primary teeth, leading to mesial migration of posterior teeth and a reduction in arch length for the erupting permanent teeth.

Tertiary Crowding (also known as late adult crowding) usually occurs in late adolescence or early adulthood, often involving the lower anterior teeth, and its exact etiology is multifactorial but can involve late mandibular growth, mesial drift, and eruption of third molars.

Third-degree crowding is not a standard classification of crowding etiology; rather, crowding is often quantified as mild, moderate, or severe, sometimes with degrees (e.g., in millimeters of discrepancy), but not as "first, second, or third degree" in terms of cause.