1
Angle’s Class I molar relationship is defined as:
A) MB cusp of upper 1st molar anterior to buccal groove of lower 1st molar
B) MB cusp of upper 1st molar posterior to buccal groove of lower 1st molar
C) MB cusp of upper 1st molar coincides with buccal groove of lower 1st molar
D) Distal cusp of upper molar aligns with lower molar
C) MB cusp of upper 1st molar coincides with buccal groove of lower 1st molar
ANB angle assesses:
A) Vertical growth
B) Mandibular plane angle
C) Sagittal skeletal relationship
D) Dental inclination
C) Sagittal skeletal relationship
Serial extraction is mainly indicated in:
A) Spacing cases
B) Severe crowding
C) Open bite
D) Crossbite
B) Severe crowding
Normal value of SNA angle is approximately:
A) 72°
B) 82°
C) 92°
D) 102°
B) 82°
Nance holding arch is used for:
A) Distalization
B) Space maintenance in maxilla
C) Expansion
D) Intrusion
B) Space maintenance in maxilla
The most stable orthodontic tooth movement is:
A) Tipping
B) Rotation
C) Translation
D) Intrusion
C) Translation
The center of resistance of a single-rooted tooth is located:
A) At apex
B) At CEJ
C) Mid-root area
D) Crown center
C) Mid-root area
Rapid maxillary expansion primarily opens:
A) Zygomatic suture
B) Frontonasal suture
C) Midpalatal suture
D) Pterygomaxillary suture
C) Midpalatal suture
Bolton analysis evaluates:
A) Skeletal discrepancy
B) Tooth size discrepancy
C) Arch length
D) Vertical pattern
B) Tooth size discrepancy
The most reliable indicator of skeletal maturity is:
A) Chronological age
B) Dental eruption
C) Height
D) CVM (Cervical vertebral maturation)
D) CVM (Cervical vertebral maturation)
Proclination of incisors increases:
A) Interincisal angle
B) Facial convexity
C) Overbite
D) SNB angle
B) Facial convexity
The ideal force for tipping a tooth is approximately:
A) 5–10 g
B) 35–60 g
C) 150–200 g
D) 300 g
B) 35–60 g
The interincisal angle in normal occlusion is approximately:
A) 110°
B) 120°
C) 130°
D) 135
C) 130°
The most common cause of relapse after rotation correction is:
A) Occlusal trauma
B) Periodontal fibers
C) Root resorption
D) Caries
B) Periodontal fibers
Reverse pull headgear is mainly used in:
A) Class I
B) Class II
C) Class III
D) Open bite
C) Class III
The primary cellular mediator responsible for osteoclast differentiation during orthodontic tooth movement is:
A) BMP-2
B) RANKL
C) Osteocalcin
D) TGF-beta
B) RANKL
The regional acceleratory phenomenon (RAP) peaks approximately:
A) Immediately after force application
B) 1 week
C) 1–2 months
D) 6 months
C) 1–2 months
In corticotomy-assisted orthodontics, tooth movement acceleration is primarily due to:
A) Reduced friction
B) Direct bone removal
C) Increased force levels
D) Transient osteopenia
D) Transient osteopenia
In finite element analysis of orthodontic movement, stress concentration is highest:
A) At cervical and apical areas
B) Uniformly distributed
C) At incisal edge
D) Only at apex
A) At cervical and apical areas
The biologic lag phase during orthodontic tooth movement is mainly due to:
A) Decreased osteoblast activity
B) Hyalinized periodontal ligament undergoing undermining resorption
C) Reduced blood flow in pulp
D) Cementoblast apoptosis
B) Hyalinized periodontal ligament undergoing undermining resorption
A TAD placed between maxillary second premolar and first molar fails repeatedly despite adequate technique. The most probable anatomical reason is:
A) Thin buccal cortical bone
B) Thick gingiva
C) High bone turnover
D) Wide periodontal ligament
A) Thin buccal cortical bone
Which cytokine balance determines osteoclast activation during orthodontic movement?
A) IL-1 / BMP ratio
B) RANKL / OPG ratio
C) TGF-β / Osteocalcin ratio
D) TNF-α / Collagen ratio
B) RANKL / OPG ratio
Heavy continuous forces produce delayed tooth movement because:
A) Increased osteoblast activity
B) Extensive PDL necrosis and undermining resorption
C) Reduced RANKL expression
D) Immediate cortical perforation
B) Extensive PDL necrosis and undermining resorption
The most accurate predictor of post-treatment stability in open bite correction is:
A) Overcorrection
B) Retention duration
C) Control of vertical growth pattern
D) Bracket prescription
C) Control of vertical growth pattern
In adults, rapid maxillary expansion without surgery results mainly in:
A) Parallel skeletal expansion
B) Pure dental tipping
C) Anterior suture opening only
D) Stable orthopedic change
B) Pure dental tipping