Orthodontics Exam 1 Questions With Verified Correct Answers Newest Update
Orthodontics Exam 1 Questions With
Verified Correct Answers Newest
Update
Genetic factors influence what aspects of malocclusion? - ANSWER ✔ - Tooth Size, Shape, and Number
Class III malocclusion
_____ Factors are what mostly influence malocclusion-They alter what 3 things? - ANSWER ✔ -
Environmental factors
Tooth position, jaw size and location
What are the 3 Mechanical/functional hypotheses for changes in occlusion? - ANSWER ✔ - Habits
Interferences with normal breathing
Decreased muscle strength and activity
_____ is the most common form of malocclusion treated by orthodontists. Formula? - ANSWER ✔ - -
Crowding/Spacing
-Tooth size - Arch length discrepancy (TSALD) = [arch perimeter - tooth size]
How is Incisor Alignment/Irregularity measured? - ANSWER ✔ - Irregularity Index; sum of *Linear
displacement* of 5 anterior anatomic contact points = degree of irreg
Is TSALD or Incisor irregularity a better measurement of Crowding? - ANSWER ✔ - TSALD is a better
measure of crowding
_____ mm or more needs to be fixed
_____% of the population has a problem with ______ incisor irregularity.
_____% have a Severe problem with incisor irregularity - ANSWER ✔ - 4-4.5mm
, Orthodontics Exam 1 Questions With Verified Correct Answers Newest Update
40%, *Mandibular*
17%
What age is there a decrease of irregularity?
Increase? - ANSWER ✔ - - mixed-early permanent dentition (9/10 - 12/13)
- Early permanent to early adulthood (12/13 - 19/20)
As individuals age the arch length _____ and TSALD ___
Males experience greater amounts of crowding due to _____ compared to females - ANSWER ✔ -
Decreases, increases
Increased growth
In the Richardson 1999 study what was the change in crowding when measured from 13 to 18 years of
age?
What was the change in 1st molar movement?
What is the trend in crowding rate with older individuals? - ANSWER ✔ - -Crowding increase by ≈2.3 mm
-1st molars moved Forward ≈ 2mm per side
As individuals get older the change in crowding becomes less (crowding rate is greatest in the teens and
tapers off with age: stabilizes in late 20s)
On average what happens to Incisor Irregularity during Postretention of nonextraction orthodontic
treatment?
How much for extraction studies?
For nontreated individuals? - ANSWER ✔ - Average 1.9 mm increase in Incisor irregularity
2.2 mm for extraction studies
2.3mm
T/F
Most post-treatment crowding is due to the orthodontic treatment. (why)
The Mandibular arch is more susceptible to crowding. - ANSWER ✔ - 1st False: Not due to treatment:
physiological
2nd True
, Orthodontics Exam 1 Questions With Verified Correct Answers Newest Update
What are 2 factors to consider in malocclusion? - ANSWER ✔ - - Growth changes (create or eliminate
space)
- Dentoalveolar compensation
How are Class I relationships typically achieved during development?
Which has a greater influence? - ANSWER ✔ - -Late mesial shift after loss of 2nd primary molars
-Greater forward growth of the Mandible than the Mx (has a greater influence)
Flush terminal plane causes what occlusion? - ANSWER ✔ - CI and sometimes CII (abnormal
growth/insufficient space)
_____ is a major risk factor for a child developing crowding of the Permanent dentition. - ANSWER ✔ -
Lack of Space in the primary dentition
Closed contacts = lost space
Leeway space produces about _____ mm of space per side
How is the space maintained?
What has greater migration: molar or incisor? - ANSWER ✔ - 2.5 mm
Dental appliance
Molar
How does the Arch Perimeter change through development and in Maxilla and Mandible? - ANSWER ✔ -
Increase during Early mixed dentition
Decrease during Late mixed dentition
Maxilla: Overall Slight Increase in perimeter (≈0.5mm)
Mandible: Overall Decrease in perimeter (≈4mm)
T/F
Patient Age is the most influential factor contributing to incisor irregularity or malalignment.
3rd Molars cause clinically significant increases in anterior crowding.
Orthodontics Exam 1 Questions With
Verified Correct Answers Newest
Update
Genetic factors influence what aspects of malocclusion? - ANSWER ✔ - Tooth Size, Shape, and Number
Class III malocclusion
_____ Factors are what mostly influence malocclusion-They alter what 3 things? - ANSWER ✔ -
Environmental factors
Tooth position, jaw size and location
What are the 3 Mechanical/functional hypotheses for changes in occlusion? - ANSWER ✔ - Habits
Interferences with normal breathing
Decreased muscle strength and activity
_____ is the most common form of malocclusion treated by orthodontists. Formula? - ANSWER ✔ - -
Crowding/Spacing
-Tooth size - Arch length discrepancy (TSALD) = [arch perimeter - tooth size]
How is Incisor Alignment/Irregularity measured? - ANSWER ✔ - Irregularity Index; sum of *Linear
displacement* of 5 anterior anatomic contact points = degree of irreg
Is TSALD or Incisor irregularity a better measurement of Crowding? - ANSWER ✔ - TSALD is a better
measure of crowding
_____ mm or more needs to be fixed
_____% of the population has a problem with ______ incisor irregularity.
_____% have a Severe problem with incisor irregularity - ANSWER ✔ - 4-4.5mm
, Orthodontics Exam 1 Questions With Verified Correct Answers Newest Update
40%, *Mandibular*
17%
What age is there a decrease of irregularity?
Increase? - ANSWER ✔ - - mixed-early permanent dentition (9/10 - 12/13)
- Early permanent to early adulthood (12/13 - 19/20)
As individuals age the arch length _____ and TSALD ___
Males experience greater amounts of crowding due to _____ compared to females - ANSWER ✔ -
Decreases, increases
Increased growth
In the Richardson 1999 study what was the change in crowding when measured from 13 to 18 years of
age?
What was the change in 1st molar movement?
What is the trend in crowding rate with older individuals? - ANSWER ✔ - -Crowding increase by ≈2.3 mm
-1st molars moved Forward ≈ 2mm per side
As individuals get older the change in crowding becomes less (crowding rate is greatest in the teens and
tapers off with age: stabilizes in late 20s)
On average what happens to Incisor Irregularity during Postretention of nonextraction orthodontic
treatment?
How much for extraction studies?
For nontreated individuals? - ANSWER ✔ - Average 1.9 mm increase in Incisor irregularity
2.2 mm for extraction studies
2.3mm
T/F
Most post-treatment crowding is due to the orthodontic treatment. (why)
The Mandibular arch is more susceptible to crowding. - ANSWER ✔ - 1st False: Not due to treatment:
physiological
2nd True
, Orthodontics Exam 1 Questions With Verified Correct Answers Newest Update
What are 2 factors to consider in malocclusion? - ANSWER ✔ - - Growth changes (create or eliminate
space)
- Dentoalveolar compensation
How are Class I relationships typically achieved during development?
Which has a greater influence? - ANSWER ✔ - -Late mesial shift after loss of 2nd primary molars
-Greater forward growth of the Mandible than the Mx (has a greater influence)
Flush terminal plane causes what occlusion? - ANSWER ✔ - CI and sometimes CII (abnormal
growth/insufficient space)
_____ is a major risk factor for a child developing crowding of the Permanent dentition. - ANSWER ✔ -
Lack of Space in the primary dentition
Closed contacts = lost space
Leeway space produces about _____ mm of space per side
How is the space maintained?
What has greater migration: molar or incisor? - ANSWER ✔ - 2.5 mm
Dental appliance
Molar
How does the Arch Perimeter change through development and in Maxilla and Mandible? - ANSWER ✔ -
Increase during Early mixed dentition
Decrease during Late mixed dentition
Maxilla: Overall Slight Increase in perimeter (≈0.5mm)
Mandible: Overall Decrease in perimeter (≈4mm)
T/F
Patient Age is the most influential factor contributing to incisor irregularity or malalignment.
3rd Molars cause clinically significant increases in anterior crowding.
