Ortho Final Questions

Synchondroses are thin, soft tissue between adjacent bones (mark all that apply):
a. capable of active, independent growth
b. have only one periosteum & connective tissue
c. filled with cartilage
d. have direct ossification

a. capable of active, independent growth
c. filled with cartilage

Which of the following are main steps in the conversion of cartilage into bone (endochondral ossification):
1. invasion of blood vessels into cartilage
2. multiplication of cartilage cells
3. degeneration of cartilage cells
4. replacement of cartilage cells by osteoblasts
5. formation of bone matrix by osteoblasts

ALL TRUE

The mandible grows by (mark all that apply):
a. apposition and remodeling resorption at the ramus
b. pulled away from skull by growth of soft tissues
c. endochondral replacement at condyles
d. pulled from behind by lengthening the cranial base

a. apposition & remodeling at the ramus
b. pulled away from skull by growth of soft tissues
c. endochondral replacement at condyles

Mandibular condyle (mark all that apply):
a. has independent growth that is controlled genetically
b. have a growth cartilage that is involved in growth
c. is the site of growth
d. is the center of growth

b. have a growth cartilage that is involved in growth
c. is the site of growth

Which of the synchondroses fuses at birth?
a. intra-sphenoidal
b. spheno-occipital
c. sphenoethmoidal

a. intra-sphenoidal

Mevin Moss was a dentist-anatomist from Columbia University who recommended in 1970:
a. the Sutural Growth Theory that states that cell divisions that occur at sutures are the driving force of bone growth
b. the Functional Matrix Theory that states that growth of the brain provides the force to separate bone
c. the Cartilage Growth Theory/Nasal Septum Theory that states that the determinant of craniofacial growth, even in areas distant from the cartilage locations, is the growth of cartilages

b. the Functional Matrix Theory that states that growth of the brain provides the force to separate bone

TRUE or FALSE: the secretion of extracellular material is the most important cellular activity for the growth of the craniofacial skeleton

TRUE

Bone (mark all the applies):
a. grows under tension
b. grow in length at the epiphyseal plate
c. grows under pressure
d. is tension adapted
e. increase in the diameter by appositional growth

a. grows under tension
b. grow in length at the epiphyseal plate
d. is tension adapted
e. increase in the diameter by appositional growth

In which decade of life is facial growth completed?
a. fifties or later
b. teens
c. thirties
d. forties
e. twenties

a. fifties or later

Growth, most the time, will refer to (mark all that apply):
a. change
b. increase in number
c. increase in size
d. increase in complexity

a. change
b. increase in number
c. increase in size

Development is primarily used to refer to (mark all that apply):
a. increase in number
b. increase in size
c. change
d. gaining cell specialization
e. increase in complexity

d. gaining cell specialization
e. increase in complexity

TRUE OR FALSE: growth pattern refers to the predictable changes in body proportions over time as the individual grows

TRUE

The maxilla (A) grows faster than the mandible during adolescent growth because (B) it's closer to the brain and more influenced by neural growth than the mandible is
a. A & B true, related
b. A & B true, unrelated
c. A true, B false
d. A false, B true

d. A false, B true

TRUE or FALSE: growth of a long bone occurs in the growth plate

TRUE

TRUE or FALSE: growth of long bone occurs in a layer of periosteum adjacent to bone surface

TRUE

TRUE or FALSE: growth of long bone occurs in bone marrow

FALSE

TRUE or FALSE: osteoclasts are bone cells responsible for bone stability

FALSE

TRUE or FALSE: osteoclasts are bone cells responsible for synthesizing of specific bone matrix components

FALSE

TRUE or FALSE: osteoclasts are bone cells responsible for bone resorption

TRUE

TRUE or FALSE: osteoclasts are bone cells responsible for sensory input during adaptation of bone to mechanical factors

FALSE

Which of the following is NOT characteristic of the face of a newborn infant?
a. face is longer than it is broad
b. short, small nose
c. mandible with no teeth
d. lack of chin prominence

a. face is longer than it is broad

Embryonic period (mark all that apply):
a. is also called organogenesis period
b. is from 3-8 weeks of gestation
c. is period when embryo is most sensitive teratogens
d. is period when functions of organ develop
e. is from 9-22 weeks of gestation

a. is also called organogenesis period
b. is from 3-8 weeks of gestation
c. is period when embryo is most sensitive teratogens

Development of the face begins in _______ week of gestation
a. 4th
b. 3rd
c. 7th
d. 12th

a. 4th

TRUE or FALSE: almost all of the tissue of the face & neck originate from ectoderm

TRUE

If a child has a chronologic age of 10 but a bone maturation age of 12. What is her dental age most likely to be?
a. 10
b. 12
c. 8
d. 14

b. 12

(A) Acute febrile illness in a child leaves a mark in the teeth forming at the time because (B) growth of dentin and cementum stops during feverish episodes
a. A & B true, unrelated
b. A & B true, related
c. A false, B true
d. A true, B false

a. A & B true, unrelated

In fetal and postnatal growth, what is meant by "cephalocaudal gradient of growth"?
a. head grows faster than trunk & limbs
b. trunk & limbs grow faster than head
c. cephalic structures are more important for growth
d. caudal structures are more important for growth

b. trunk & limbs grow faster than head

At what stage do lymphoid tissues reach their maximum development?
a. pre-adolescence
b. adolescence
c. post-adolescence
d. infancy

a. pre-adolescence

The adolescent growth spurt is characterized by sexual differences (mark all that apply)
a. timing
b. duration
c. rate
d. cognitive changes
e. sexual orientation

a. timing
b. duration
c. rate

Major contributors to variability of growth:
a. timing of adolescence
b. nutrition
c. birth order

a. timing of adolescence

More space in the pharyngeal area is provided during adolescence by (mark all that apply):
a. decrease in size of adenoids
b. forward movement of the tongue as the mandible grows
c. backward remodeling of the posterior pharyngeal wall

a. decrease in size of adenoid
b. forward movement of the tongue as mandible grows

The adolescent period of life is mediated by sex hormones (A) controlled through hypothalamic area of the brain (B) and the pituitary gland (C)
a. all true
b. A true, B & C false
c. all false
d. A & B false, C true

a. all true

What percentage of a normally distributed population is within two standard deviations of the mean?
a. 66
b. 75
c. 95
d. 55

c. 95

When considering physical growth & development, which term refers to qualitative changes (functional abilities), the gradual advancement in skills needed to be able to function?
a. differentiation
b. development
c. growth
d. maturity

b. development

What is the best way(s) of assessing growth and, in particular, the pubertal growth spurt of a patient for possible timing of orthodontic treatment (growth modification treatment)?
a. skeletal age - lateral cephalometric radiograph
b. development age
c. chronological age
d. dental age

a. skeletal age - lateral cephalometric radiograph

Dental age is determined by:
a. amount of development of permanent teeth
b. which primary teeth have exfoliated
c. which teeth are erupted
d. amount of resorption of roots of primary teeth
e. all of the above

e. all of the above

When considering the rate of growth of a child - which statement is CORRECT?
a. rate of growth is the same through infancy, childhood, adolescence, and going into adulthood
b. rate of growth declines in infancy rapidly, increases in childhood, significantly increases in adolescence, and declines into adulthood
c. rate of growth declines in infancy rapidly, slightly declines in childhood, significantly increases in adolescence, and increases into adulthood
d. rate of growth declines in infancy rapidly, slightly declines in childhood, significantly increases in adolescence, and decreases going into adulthood

d. rate of growth declines in infancy rapidly, slightly declines in childhood, significantly increases in adolescence, and decreases going into adulthood

When considering growth & development in girls & boys:
a. there is a gender variation between girls & boys - girls tend to start the pubertal growth spurt later than boys and achieve complete growth earlier than boys
b. there is a gender variation between girls & boys - girls tend to start the pubertal growth spurt earlier than boys and achieve complete growth earlier than boys
c. there is no difference in growth & gender variation between girls & boys
d. there is a gender variation between girls & boys - girls tend to start their pubertal growth spurt earlier than boys & achieve greater physical size than boys
e. there is a gender variation between girls & boys - girls tend to start the prepubertal growth spurt later than boys & achieve a lesser physical size compared to boys

b. there is a gender variation between girls & boys - girls tend to start the pubertal growth spurt earlier than boys and achieve complete growth earlier than boys

When considering Scammon Systemic Growth Curves for the growth of the maxilla & mandible, which statement is INCORRECT?
a. maxillary growth spurt is closely associated with the neural growth curve
b. mandibular growth curve is closely associated with the somatic general growth curve
c. the reason why the facial profile begins more convex then straightens as a child growing into adulthood is associated with the difference in rate & timing of the maxillary & mandibular growth curves
d. the reason why the facial profile begins straight & then becomes more convex as a child growing into adulthood is associated with the difference in the rate & timing of the maxillary & mandibular growth curves

d. the reason why the facial profile begins straight and then becomes more convex as a child growing into adulthood is associated with the difference is the rate & timing of the maxillary & mandibular growth curves

Eruption sequence of primary teeth
a. start tooth - #e, #d, #c, #b, #a - last tooth
b. start tooth - #d, #e, #c, #b, #a - last tooth
c. start tooth - #e, #b, #d, #c, #a - last tooth
d. start tooth - #d, #e, #b, #c, #a - last tooth
e. start tooth - #e, #d, #b, #c, #a - last tooth

e. start tooth - #e, #d, #b, #c, #a - last tooth

Eruption hematoma. Which statement is INCORRECT?
a. it is an accumulation of fluid or blood in the follicular sac
b. self-limiting on rupture during gingival emergence
c. asymptomatic
d. dark blue/black coloration to swelling
e. usually requires surgical treatment

e. usually requires surgical treatment

Anatomy of Primary Teeth - which is INCORRECT?
a. primary teeth crowns are shorter than permanent teeth crowns
b. primary teeth pulp horns are closer to the surface of the tooth than pulp horns in permanent teeth
c. primary teeth enamel and dentin are thinner than permanent teeth enamel and dentin
d. primary teeth roots are longer and slenderer in relation to crown size compared to permanent teeth
e. primary teeth have less cervical constriction than permanent teeth

e. primary teeth have less cervical constriction than permanent teeth

In a complete primary dentition we see primate spaces. These are positioned and measure in the upper dental arch:
a. distal to the upper primary canine tooth and usually is 1mm
b. mesial to the upper primary lateral incisor tooth and usually is 4mm
c. mesial to the upper primary canine tooth and usually is 4mm
d. distal to the upper primary canine and usually is 4mm
e. mesial to the upper primary canine tooth and usually 1mm

c. mesial to the upper primary canine tooth & usually is 4 mm

Evaluation of the Primary Complete Dentition - incisal overjet and overbite. Which answer is CORRECT?
a. incisal overbite is the vertical overlap of the anterior teeth and measured in % or mm
b. incisal overbite is the horizontal relationship of the anterior teeth and measured in %
c. incisal overbite is the vertical overlap of the anterior teeth and measured in degrees
d. incisal overjet is the horizontal relationship of the anterior teeth measured in %
e. incisal overjet is the vertical overlap of the anterior teeth and measured in % or mm

a. incisal overbite is the vertical overlap of the anterior teeth and measured in % or mm

Complete Primary Dentition - Molar Relationship: when classifying the primary molar relationship, which relationship is not described/classified?
a. exaggerated distal step
b. distal step
c. flush terminal plane
d. mesial step
e. exaggerated mesial step

a. exaggerated distal step

A mesial step primary molar classification will usually produce a ______ permanent molar relationship in the permanent dentition.
a. Class III
b. Class II
c. Class I
d. ½ unit class II
e. ½ unit class III

c. Class I

TRUE OR FALSE: in a complete primary dentition, the Class I canine relationship is best described as the cusp tip of the maxillary primary canine is in the same vertical plane as the distal surface of the mandibular primary canine tooth.

TRUE

In the early mixed dentition, between the ages of 6 to 9 yrs of age, the permanent upper central and lateral incisor teeth start to erupt into the mouth. At this stage, all the statements below are correct, EXCEPT:
a. the upper incisor teeth may well look splayed apart
b. there may be an upper midline diastema present
c. there is an "incisor liability", the 4 maxillary permanent incisors are 2mm larger than the primary incisor teeth
d. there is an increase in the intercanine width due to transverse skeletal growth of the maxilla
e. the upper splayed teeth spaces are likely to close when the upper permanent canine teeth erupt and come into the mouth

c. there is an "incisor liability", the 4 maxillary permanent incisors are 2 mm larger than the primary incisor teeth

The Leeway Space is the tooth size differential between primary canine and molars and their permanent successor teeth. Which of the following statements is CORRECT?
a. The Leeway Space is the same amount of space in both arches
b. The Leeway Space is estimated to be 0.9mm in the maxillary arch and 1.7mm in the mandibular arch
c. The Leeway Space is estimated to be 1.7mm in the maxillary arch and 1.7mm in the mandibular arch
d. The Leeway Space is estimated to be 0.9mm per quadrant in the maxillary arch and 1.7mm per quadrant in the mandibular arch
e. The Leeway Space is estimated to be 1.7mm per quadrant in the maxillary arch and 0.9mm per quadrant in the mandibular arch

d. The Leeway Space is estimated to be 0.9 mm per quadrant in the maxillary arch & 1.7 mm in the mandibular arch

TRUE OR FALSE: primary tooth eruption starts at age 6 months and typically completes at age 4

FALSE

TRUE OR FALSE: primary dentition is typically associated with crowding in the dental arch

TRUE

TRUE OR FALSE: the primary forces acting on the teeth as they erupt into the mouth are the muscles of the tongue & muscles of mastication

TRUE

TRUE OR FALSE: the dental arch growth continues in the permanent dentition, especially posterior

TRUE

TRUE OR FALSE: the mixed dentition typically ranges from 6 years to 10 years of age

FALSE

TRUE OR FALSE: the primary force on the teeth in the dental arches comes from the muscles of mastication, the tongue, and includes erupting permanent teeth

TRUE

TRUE OR FALSE: the primate spaces typically remain open

FALSE

TRUE OR FALSE: the amount of growth is moderate & steady until puberty

TRUE

In the mixed dentition phase, in a non-intact dentition, where there has been premature loss of a primary molar...
a. there will usually be no space loss in the dental arch
b. the amount of space loss will be independent of the eruption phases of the adjacent teeth/active eruption
c. the amount of space loss will be dependent on the eruption phases of the adjacent teeth/active eruption
d. there is no increased potential to dental arch crowding in the permanent dentition

c. the amount of space loss will be dependent on the eruption phases of the adjacent teeth/active eruption

In the Intact Dentition, during the mixed dentition phase of development...
a. the lower first permanent molar tooth erupts upright on its own
b. the lower first permanent molar tooth erupts using the distal surface of the second deciduous/primary molar tooth, without rotation
c. the lower first permanent molar tooth erupts and rotates around its mesial root, using the distal surface of the second deciduous/primary molar tooth
d. the erupting lower first permanent molar tooth produces a distal force

b. the lower first permanent molar tooth erupts using the distal surface of the second deciduous/primary molar tooth, without rotation

What is the correct eruption sequence for the permanent dentition in the upper right quadrant of the dental arch?
a. start tooth - #3, #7, #8, #5, #4, #6 - last tooth
b. start tooth - #3, #8, #7, #4, #5, #6 - last tooth
c. start tooth - #3, #8, #7, #5, #4, #6 - last tooth
d. start tooth - #3, #8, #7, #5, #6, #4 - last tooth
e. start tooth - #8, #3, #7, #5, #4, #6 - last tooth

c. start tooth - #3, #8, #7, #5, #4, #6 - last tooth

If the upper right second deciduous/primary molar tooth is lost earlier than it should be (extracted due to caries)...
a. there will be no effect on the eruption of the upper right first permanent molar tooth
b. the upper right first permanent molar tooth will tip mesially
c. the upper right first permanent molar tooth will tip mesially and rotate around its mesial/buccal root
d. the upper right first permanent molar tooth will tip mesially and rotate around its palatal root
e. the upper right first permanent molar tooth will tip distally and rotate around its palatal root

d. the upper right first permanent molar tooth will tip mesially & rotate around its palatal root

Which would be an undesirable quality (incorrect statement) of a space maintainer?
a. it should be passive
b. durable and cleansable
c. not interfere with the occlusion
d. should be able to be activated to cause tooth movement
e. not interfere with the eruption of the teeth
f. should be adjustable to fit the mouth post extraction

d. should be able to be activated to cause tooth movement

Which diagnostic record is not routinely taken as part of standard orthodontic diagnostic records?
a. photographs
b. radiograph - lateral Cephalogram
c. clinical examination
d. radiograph - panoramic radiograph (pano)
e. bone scan
f. study models - plaster cast or digital

e. bone scan

When evaluating a patient's physical growth and assessing the cervical vertebral maturation, which phase is most ideal to carry out optimal orthodontic treatment or mandibular growth modification?
a. CVM 5
b. CVM 1 to 2
c. CVM 4 to 5
d. CVM 2 to 3
e. CVM 4

d. CVM 2 to 3

When orthodontically evaluating a patient's tooth-lip relationship, at mini esthetic level, the ideal amount of incisor display and gingival display should be:
a. on full smile - show 70 to 100% incisal display and 4mm gingival display for females and males
b. on full smile - show 40 to 60% incisal display and 0mm gingival display
c. on full smile - show 70 to 100% incisal display and 6mm gingival display for females
d. on full smile - show 70 to 100% incisal display and 1 to 2 mm gingival display for females
e. on full smile - show 100% incisal display and 4mm gingival display for females and males

d. on full smile - show 70 to 100% incisal display & 1-2 mm gingival display for females

A patient with a significant posterior divergent facial profile is likely to have:
a. Skeletal I jaw relationship
b. Skeletal II jaw relationship
c. Skeletal III jaw relationship
d. divergent facial profile does not give you any indication of skeletal relationship

b. Skeletal II jaw relationship

A patient with a significant convex facial profile is likely to have a:
a. Skeletal III jaw relationship
b. Skeletal I jaw relationship
c. Skeletal II jaw relationship
d. a convex facial profile will not give you an indication of skeletal relationship

c. Skeletal II jaw relationship

When orthodontically evaluating a patient's tooth-lip relationship at the mini esthetic level, the ideal amount of incisal show at repose should be:
a. 0 mm
b. 1 to 2 mm
c. 3 to 4 mm
d. 4 to 5 mm
e. 6 to 7 mm

b. 1 to 2 mm

The smile arc is:
a. the contour of the upper anterior teeth gingival margins relative to the curvature of the upper lip on social or posed smile
b. the contour of the upper anterior teeth incisal edges relative to the curvature of the upper lip on social or posed smile
c. the contour of the upper anterior teeth gingival margins relative to the curvature of the lower lip on social or posed smile
d. the contour of the upper anterior teeth incisal edges relative to the curvature of the lower lip on social or posed smile
e. the contour of the upper anterior teeth incisal edges relative to the curvature of the upper lip on social or posed smile

d. the contour of the upper anterior teeth incisal edges relative to the curvature of the lower lip on social or posed smile

When evaluating the dental appearance of the upper anterior teeth, the micro esthetics of the teeth are:
a. the width of the upper central incisor should be the same as the anatomical crown height
b. the width of the upper central incisor should be half the height of the anatomical crown height
c. the width of the upper central incisor should be a quarter the height of the anatomical crown height
d. the width of the upper central incisor should be 4/5th's the height of the anatomical crown height
e. the width of the upper central incisor should be 1/3rd the height of the anatomical crown height

d. the width of the upper central incisor should be 4/5 the height of the anatomical crown height

The Golden Proportion of the upper front teeth should be:
a. starting from the upper central incisor tooth width as your reference - the lateral incisor tooth width should be approx. 60% smaller than the central incisor & the canine tooth width should be approx. 60% smaller than the lateral incisor tooth width
b. starting from the upper central incisor tooth width as your reference - the lateral incisor tooth width should be approx. 40% smaller than the central incisor & the canine tooth width should be approx. 40% smaller than the lateral incisor tooth width
c. starting from the upper central incisor tooth width as your reference - the lateral incisor tooth width should be approx. 80% smaller than the central incisor & the canine tooth width should be approx. 80% smaller than the lateral incisor tooth width

a. starting from the upper central incisor tooth width as your reference - the lateral incisor tooth width should be approx. 60% smaller than the central incisor & the canine tooth should be approx. 60% smaller than the lateral incisor tooth width

Cephalometric analysis of a lateral cephalogram for orthodontic treatment allows the clinician to:
a. evaluate the upper jaw to the cranial base
b. evaluate the lower jaw to the upper jaw (and visa versa)
c. evaluate the lower jaw to cranial base
d. determine the position of the teeth to the jaws
e. determine the position of the teeth to the cranial base and facial soft tissues
f. All of the above

f. all of the above

Cephalometric Landmark - Sella (S). Which is the INCORRECT answer?
a. sella is located by visual inspection
b. sella is a landmark point of a bilateral anatomical structure
c. sella is the geometric center of the pituitary fossa
d. sella is used in many important cephalometric analyses
e. sella is a landmark point and not an angle or linear measurement

b. sella is a landmark point of a bilateral anatomical structure

TRUE OR FALSE: the cephalometric measurement of an individual person is compared to a derived set of norms to help determine a cephalometric diagnosis for that patient

TRUE

TRUE OR FALSE: different norms are used for patients from different ethnic backgrounds

TRUE

Lateral cephalometric analysis can help to determine: which statement is INCORRECT?
a. if teeth need to be extracted as part of an orthodontic treatment plan
b. if a patient requires surgery rather than orthodontic treatment without surgery
c. if a single jaw or both jaws are required for surgery to correct the malocclusion of the teeth
d. to ensure confirmation or otherwise, of the clinical orthodontic examination of the skeletal relation and inclination of the upper and lower front teeth
e. if a patient requires maxillary arch expansion

e. if a patient requires maxillary arch expansion

In the early mixed dentition, there can be crowding in the lower incisor region. As the dentition progresses, the crowding may resolve. This is by several means: which is the INCORRECT answer?
a. labial positioning of the lower permanent incisor teeth, which gains 1-2 mm additional space
b. increase in the width of the lower dental arch between the canine teeth
c. repositioning of the permanent canine teeth - they move slightly distally into the primate space
d. the lower permanent incisors intrude relative to the position of the primary incisor teeth
e. there is an increase in the circumference of the lower anterior permanent teeth when they erupt

d. the lower permanent incisors intrude relative to the position of the primary incisor teeth

Leeway space and Molar Drift. Which is the CORRECT statement?
a. mesial step in the primary dentition will most likely lead to a Class II molar relationship in the permanent dentition
b. distal step in the primary dentition will most likely lead to a Class III molar relationship in the permanent dentition
c. mesial step in the primary dentition will most likely lead to a Class I molar relationship in the permanent dentition
d. the Leeway space does not have any effect on the resulting permanent dentition molar relationship
e. flush terminal plane in the primary dentition will most likely lead to a full unit Class II molar relationship in the permanent dentition

c. mesial step in the primary dentition will most likely lead to a Class I molar relationship in permanent dentition

In carrying out a mixed dentition arch length analysis, there are four analyses that can be carried out. Which is the INCORRECT answer?
a. direct measurement - measurement used of erupted teeth and unerupted teeth on a radiograph
b. indirect measurement
c. estimation from proportionality table/Moyer's Prediction Table
d. Johnston-Tanaka analysis
e. Hixon-Oldfather analysis

b. indirect measurement

Using the Direct Measurement method space analysis in the mixed dentition - which statement is INCORRECT?
a. you can use erupted contra-lateral teeth to estimate width of unerupted teeth
b. accuracy is fair to good - depends on the quality of the radiograph
c. lower permanent canine and both premolar teeth need at least 36 mm spacing per quadrant
d. indicates amount of crowding present
e. can use measurements taken from erupted teeth and unerupted teeth on a periapical radiograph

c. lower permanent canine & both premolar teeth need at least 36 mm spacing per quadrant

When considering treatment in the mixed dentition, the goals you should consider are:
a. mixed dentition treatment should not be too long
b. mixed dentition treatment should have specific aims for intervention and be time limited
c. precise tooth movement is essential if a second phase of treatment is anticipated
d. A & B only are correct
d. all statements are correct

d. A & B only are correct

Examples of orthodontic treatment in the mixed dentition include: which statement is INCORRECT?
a. maxillary expansion
b. stopping a finger or thumb sucking habit
c. correction of an anterior crossbite
d. correction of a protrusive maxilla
e. correction of a protrusive mandible
f. correction of a deep bite

e. correction of a protrusive mandible

Space can be created in a moderate to severe mixed dentition dental arch. Which is the INCORRECT answer?
a. procline lower incisors
b. distalize upper molars
c. serial extraction
d. retrocline lower incisors
e. expand the dental arch

d. retrocline lower incisors

Serial extraction is carried out in the mixed dentition. Which is an INCORRECT indication for treating a patient by serial extraction?
a. thin attached tissue labial to the lower incisors (thin gingival phenotype)
b. the skeletal pattern should be ideally class I
c. dental classification should ideally be class I incisor and class I molar relationship
d. crowding of 2.5mm in each dental arch
e. dentoalveolar protrusion

d. crowding of 2.5 mm in each dental arch

The Serial Extraction Sequence is below - which statement is INCORRECT?
a. the patient is in the mixed dentition with moderate to severe crowding & it is anticipated they will require the loss of permanent premolar teeth as part of their definitive orthodontic treatment in the future
b. extraction of primary incisor teeth if lower permanent incisor crowding is moderate to severe
c. extraction of primary canines to facilitate the second premolars to erupt first
d. extraction of the first primary molar teeth when ½ to ¾ root formation of first premolar teeth have occurred
e. extract the first premolar teeth, second primary molar teeth exfoliate normally, and permanent canine and second premolar teeth erupt into the arch

c. extraction of primary canines to facilitate the second premolars to erupt first

When considering the Stress/Strain curve of a material, (orthodontic archwire) the ultimate tensile strength-maximum stress of a material is when: which is the CORRECT answer?
a. 0.1% of deformation of the material occurs
b. the material reaches its proportional limit
c. Hookes Law is obeyed
d. the maximum amount of Stress-Strain a material can withstand while being pulled before necking occurs
e. the material exhibits elastic properties below the proportional limit for the material

d. the maximum amount of Stress-Strain a material can withstand while being pulled before necking occurs

NiTi Orthodontic archwires special properties are: Which are the CORRECT two statements?
a. they do not have superelastic properties
b. they do have shape memory properties
c. they do have superelastic properties
d. they do not have shape memory properties

b. they do have shape memory properties
c. they do have superelastic properties

When considering the interpretation of a NiTi orthodontic archwire Stress-Strain curve/graph: which is INCORRECT?
a. the graph represents a plot of stress (force) against strain (extension) when a NiTi orthodontic archwire is tied into an orthodontic bracket
b. the graph represents a Hysteresis Loop
c. the area of the graph below the loading plateau and above the unloading plateau represents the energy stored in the orthodontic archwire when it is deflected into an orthodontic bracket
d. the stress-strain curve for stainless steel archwire shows the same typical stress-strain pattern as NiTi
e. the graph represents the superelasticity of the NiTi archwire material

d. the stress-strain curve for stainless steel archwire shows the same typical stress-strain pattern as NiTi

When considering a force on a tooth, which factors need to be considered: which is the INCORRECT answer?
a. the magnitude of the force
b. the line of action of the force
c. the sense or direction of the force
d. can be defined as when a force is applied to an object, it will move the object in the opposite direction to the force applied
e. the point of application of the force

d. can be defined as when a force is applied to an object, it will move the object in the opposite direction to the force applied

Which statement/principle is INCORRECT?
a. the center of resistance for an object, in free space, is the same as the center of the mass of the object
b. the center of resistance is a point through which an applied force must pass for a free object to move in a linear way without rotation
c. the center of resistance of an object is the point of concentrated resistance to movement of that object
d. when an object is partially restrained, (root of tooth in bone) the center of resistance of the object (root of tooth) for moving will remain unchanged
e. if the applied force on a tooth does not pass through its center of resistance, a moment is created

d. when an object is partially restrained, (root of tooth in bone) the center of resistance of the object (root of tooth) for moving will remain unchanged

When a force is applied to the clinical crown of a tooth, with a healthy alveolar bone around the root, a moment will occur. This means: which is the CORRECT answer?
a. the tooth will tip forwards in the direction of the force
b. the tooth will translate forwards in the direction of the force
c. the tooth will extrude
d. the tooth will tip and translate forwards in the direction of the force
d. the tooth will tip forwards in the direction of the force and extrude

d. the tooth will tip & translate forwards in the direction of the force

When considering couple forces placed on a tooth, they can be classified as First, Second and Third Order. Which of the below statements are CORRECT?
a. couple in the second order is an in-out directional movement and a third order movement is a mesiodistal movement
b. couple in the second order is a mesiodistal movement and a third order is a labio-lingual movement
c. couple in the first order is an in-out movement and a third order is a mesio-distal movement
d. couple in the second order is a labio-lingual movement and a third order is a mesio-distal movement

b. a couple in the second order is a mesiodistal movement & a third order is a labio-lingual movement

When considering the optimal force to apply to an upper permanent central incisor tooth for intrusion, it should be in the range of: which is the CORRECT answer?
a. 30 to 60 grams
b. 150 to 200 grams
c. 50 to 100 grams
d. 10 to 20 grams
e. 70 to 120 grams

d. 10 to 20 grams

There are several types of cell in the periodontal ligament (PDL). These include:
a. undifferentiated cells (pluripotent mesenchymal cells)
b. osteoclasts
c. neural and vascular cells
d. fibroblasts
e. osteoblasts
f. B, D and E are correct
g. all of the above

g. all of the above

Characteristics of cells in the PDL. Which is the CORRECT statement?
a. fibroblasts are multinuclear cells derived from the hematopoietic stem cells
b. osteoclasts are multinuclear cells derived from the hematopoietic stem cells
c. osteoblasts main function is to produce extracellular matrix and express collagen
d. osteoblasts main function is to dissolve mineral and breakdown the underlying organic matrix
e. osteoclasts produce osteoid which is type I collagen

b. osteoclasts are multinuclear cells derived from the hematopoietic stem cells

Characteristics of osteoclast cells. Which statement is CORRECT?
a. their differentiation pathway is common to macrophages and dendritic cells
b. their main function is to dissolve mineral and degrade the underlying organic matrix
c. they are multinuclear cells
d. they originate from the hemopoietic stem cell population
e. B & C are correct
f. B, C, & D are correct
g. all of the above

g. all of the above

The response of the periodontium to NORMAL function when an orthodontic force is applied is:
a. during normal mastication of food, the forces generated between teeth are heavy and intermittent
b. < 1 sec - PDL fluid incompressible and alveolar bond bends causing a piezoelectric signal in the bone
c. 1 to 2 sec - PDL fluid is expressed and tooth moves in the PDL space
d. 3 to 5 sec - PDL fluid expressed, the PDL tissues are compressed, and immediate pain is experienced
e. the PDL is designed to resist/adjust to short duration light and heavy forces; as orthodontic treatment forces are generally of longer duration, the result of this type of light/continuous force produces a very different physiological response
f. all statements are correct except E
g. all statements are correct

g. all statements are correct

In the Bioelectric Theory, which statement is INCORERCT?
a. piezo-electric currents help general maintenance of the skeleton
b. when pressure is applied to bone cells, they deform and produce a flow of electric current called piezoelectricity
c. piezo-electric currents help the skeleton undergo adaptation to functional demands placed upon it
d. The Bioelectric Theory is the MAIN theory that underlies how teeth/roots move through bone under the influence of orthodontic forces
e. piezoelectric signals are generated when the alveolar bone is flexed which causes changes in the local bone metabolism in that area

d. The Bioelectric Theory is the MAIN theory that underlies how teeth/roots move through bone under the influence of orthodontic forces

When considering the Pressure-Tension theory and the cells involved in areas of tension and compression in the PDL: which are the CORRECT statements (mark all that apply)
a. osteoblasts respond to pressure and build bone
b. osteoclasts respond to tension and remove bone
c. osteoblasts respond to tension and build bone
d. osteoclasts respond to pressure and remove bone

c. osteoblasts respond to tension & build bone
d. osteoclasts respond to pressure & remove bone

In the Pressure-Tension Theory, when a LIGHT orthodontic force is applied to a tooth/root against bone: which is the INCORRECT statement?
a. tooth movement will occur after 2 to 3 days
b. there will be differentiation of osteoclasts within the PDL
c. hyalinization or sterile necrosis of the bone will occur
d. process is called frontal resorption
e. process is called direct bone resorption

c. hyalinization or sterile necrosis of the bone will occur