Class 1 Malocclusion
Class 1 Malocclusion
Questions and Answers
- 1.
What is the skeletal relationship in class1 malocclusion? (3)
- A.
Class 2
- B.
Class 1
- C.
Class 2 with incisial retroclination
- D.
Class 2 with incisal proclination
- E.
Class 3 with incisal proclination
Correct Answer(s)
B. Class 1
C. Class 2 with incisial retroclination
E. Class 3 with incisal proclinationExplanation
The correct answer is Class 1, Class 2 with incisal retroclination, and Class 3 with incisal proclination. This means that the skeletal relationship in class 1 malocclusion can vary, with some individuals having a normal skeletal relationship (Class 1), some having a Class 2 skeletal relationship with retroclination of the incisors, and some having a Class 3 skeletal relationship with proclination of the incisors. This indicates that the malocclusion is not solely determined by the skeletal relationship but also by the position of the incisors.Rate this question:
-
- 2.
What is the ANB in class 1
- A.
1-5%
- B.
5-10%
- C.
2-4%
- D.
2-6%
- E.
4-5%
Correct Answer
C. 2-4%Explanation
The ANB in class 1 refers to the Angle of the Nasal Bone, which is a measurement used in orthodontics to assess the relationship between the upper and lower jaws. The correct answer, 2-4%, indicates that in class 1, the angle between the nasal bone and the base of the skull should fall within the range of 2-4%.Rate this question:
-
- 3.
What is the main complaint regarding class 1?
- A.
Difficulty eating
- B.
Goofy appearance
- C.
Crowding
- D.
Crossbite
- E.
Fluorosis
Correct Answer
C. CrowdingExplanation
The main complaint regarding class 1 is crowding. Crowding refers to the condition where there is not enough space in the mouth for all the teeth to properly align. This can lead to overlapping or crooked teeth, which can cause difficulty in cleaning and maintaining oral hygiene. Crowding can also affect the appearance of the smile and may require orthodontic treatment to correct.Rate this question:
-
- 4.
Which of these does not cause crowding in class 1
- A.
Tooth size and number discrepency
- B.
Arch size discrepency
- C.
High caries risk
- D.
Displaced and Impacted teeth
- E.
Premature loss of deciduous/permanent teeth
Correct Answer
C. High caries riskExplanation
High caries risk refers to an increased likelihood of developing tooth decay. While tooth size and number discrepancy, arch size discrepancy, displaced and impacted teeth, and premature loss of deciduous/permanent teeth can all contribute to crowding in class 1, high caries risk does not directly cause crowding in class 1.Rate this question:
-
- 5.
What should be extracted to alleviate mild crowding in class 1?
- A.
All 3's
- B.
Upper 4's
- C.
Lower 5's
- D.
All 5's
- E.
All 4's
Correct Answer
D. All 5's -
- 6.
What should be extracted to alleviate moderate to sever crowding in class 1?
- A.
Lower 5's
- B.
Upper 4's and lower 5's
- C.
All 4's
- D.
Lower 6's
- E.
All 5's
Correct Answer
C. All 4'sExplanation
To alleviate moderate to severe crowding in class 1, all 4's should be extracted. This implies that students who are in the fourth grade should be moved to a different class or grade level in order to reduce the overcrowding. By doing so, the class size will be reduced and create a more manageable learning environment for the students.Rate this question:
-
- 7.
What can cause spacing in class 1? (2)
- A.
Missing teeth
- B.
Tilting of teeth
- C.
Impacted teeth
- D.
Small teeth in relation to arches
- E.
Bulbous cingulum
Correct Answer(s)
A. Missing teeth
D. Small teeth in relation to archesExplanation
Spacing in class 1 can be caused by missing teeth and small teeth in relation to arches. Missing teeth create gaps between the teeth, resulting in spacing. Additionally, if the teeth are smaller in size compared to the arches, there may not be enough space to accommodate all the teeth, leading to spacing issues.Rate this question:
-
- 8.
What effect can full and everted lips have regarding class 1?
- A.
Goofy teeth
- B.
Bimaxillary proclination
- C.
Unilateral crossbite
- D.
Scissor bite
- E.
Bimaxillary retroclination
Correct Answer
B. Bimaxillary proclinationExplanation
Full and everted lips can have an effect on class 1 by causing bimaxillary proclination. Bimaxillary proclination refers to the forward positioning of both the upper and lower jaws, resulting in protrusion of the teeth. When the lips are full and everted, they may exert pressure on the teeth and jaws, pushing them forward and causing the condition of bimaxillary proclination. This can lead to an improper bite and alignment of the teeth, which may require orthodontic treatment to correct.Rate this question:
-
- 9.
What is the molar relationship with class 1?
- A.
MB cusp U6 lies in fissure of L7
- B.
DP Cusp U6 occludes with Lingual cusp L7
- C.
ML cusp U6 occludes with MB cusp L6
- D.
MB cusp U6 occludes with MB groove L6
- E.
MB cusp L6 occlude with MB groove U6
Correct Answer
D. MB cusp U6 occludes with MB groove L6Explanation
The correct answer is MB cusp U6 occludes with MB groove L6. This means that the mesiobuccal cusp of the upper first molar occludes with the mesiobuccal groove of the lower first molar.Rate this question:
-
- 10.
When is lower labial crowding most apparent in class 1?
- A.
Mid - late teens
- B.
Under 10
- C.
Young adulthood
- D.
Middle age
- E.
Over 70
Correct Answer
A. Mid - late teensExplanation
Lower labial crowding is most apparent in the mid to late teens. This is because during this stage of development, the permanent teeth have fully erupted and settled into their positions. As the jaw continues to grow and develop, there may not be enough space for all the teeth, leading to crowding. This is particularly noticeable in the lower front teeth, known as the lower labial area. In younger children, the primary teeth are still present and the jaw is still growing, while in young adulthood and middle age, the jaw has typically finished growing and any crowding issues would have been addressed earlier.Rate this question:
-
- 11.
Why does labial crowding occur?
- A.
Heavy bite
- B.
Proclined upper incisors
- C.
Intercanine width decreases after 9
- D.
Poor OH
- E.
Sugar rich diet
Correct Answer
C. Intercanine width decreases after 9Explanation
Labial crowding occurs when there is a decrease in intercanine width after the age of 9. This means that the space between the canines becomes narrower, leading to overcrowding of the front teeth. This can happen due to various reasons such as the eruption of permanent teeth, growth of the jaw, or changes in the surrounding tissues. When the intercanine width decreases, there is not enough space for the teeth to align properly, causing them to become crowded and misaligned.Rate this question:
-
- 12.
Which of these is not a reason for any missing upper incisor? (2)
- A.
Trauma
- B.
Extraction due to dilaceration
- C.
Heavy bite
- D.
Congenitally absent
- E.
Crossbite
Correct Answer(s)
C. Heavy bite
E. CrossbiteExplanation
The correct answer is "Heavy bite, Crossbite". A heavy bite refers to excessive force applied on the teeth, which can lead to tooth damage or loss. A crossbite is a misalignment of the upper and lower teeth, causing them to bite down on the wrong side. Both heavy bite and crossbite can potentially cause damage to the upper incisors, leading to their loss. Trauma, extraction due to dilaceration, and congenital absence are all valid reasons for missing upper incisors.Rate this question:
-
- 13.
What percentage of caucasians may have absent lateral incisors?
Correct Answer(s)
2%
2 percentExplanation
The correct answer is 2% or 2 percent. This means that out of the total population of caucasians, approximately 2% may have absent lateral incisors. This could be due to genetic factors or other dental conditions that result in the absence of these teeth. It is important to note that this percentage may vary among different populations and individuals.Rate this question:
- 14.
Which of these is not an option for managing missing upper laterals?
- A.
Implants
- B.
Bridge
- C.
Denture
- D.
Close space by moving canine anteriorly
- E.
Move central distally and create mid line diastema
Correct Answer
E. Move central distally and create mid line diastemaExplanation
Moving the central distally and creating a midline diastema is not an option for managing missing upper laterals. This option involves shifting the position of the central incisors, which may not be suitable for managing missing laterals. Instead, options such as implants, bridges, dentures, or closing the space by moving the canine anteriorly are more commonly used methods to manage missing upper laterals.Rate this question:
-
- 15.
Which of these is not a reason for lower labial crowding
- A.
Decreased intercanine width after age 9
- B.
Mesial migration of posterior teeth
- C.
Erupting third molars
- D.
Forward growth of mandible in conjunction with soft tissue pressures
- E.
Thumb sucking
Correct Answer
E. Thumb suckingExplanation
Thumb sucking is not a reason for lower labial crowding. Lower labial crowding refers to the misalignment or overcrowding of the lower front teeth. The other options listed in the question can contribute to lower labial crowding. Decreased intercanine width after age 9, mesial migration of posterior teeth, erupting third molars, and forward growth of the mandible in conjunction with soft tissue pressures can all lead to lower labial crowding. However, thumb sucking does not directly cause lower labial crowding.Rate this question:
-
- 16.
What may have an influence on your choice to open or close a space?
- A.
Caries risk
- B.
OH
- C.
Inclination of adjacent teeth
- D.
Opposing dentition
- E.
Tetracycline staining
Correct Answer
C. Inclination of adjacent teethExplanation
The inclination of adjacent teeth refers to their alignment and position in relation to the space in question. If the adjacent teeth are inclined or tilted in a way that closing the space would negatively impact their alignment or function, it may influence the decision to keep the space open. On the other hand, if the adjacent teeth are properly aligned and closing the space would improve their alignment or function, it may influence the decision to close the space.Rate this question:
-
- 17.
Which teeth are most commonly displaced? (2)
- A.
Canines
- B.
Upper incisors
- C.
Lower incisors
- D.
Premolars
- E.
Molars
Correct Answer(s)
A. Canines
D. PremolarsExplanation
Canines and premolars are the teeth that are most commonly displaced. Displacement of teeth refers to the abnormal positioning or movement of teeth within the mouth. Canines, also known as the "eye teeth," are particularly prone to displacement due to their longer roots and position at the corners of the dental arch. Premolars, which are located between the canines and molars, can also be easily displaced. Displacement of these teeth can occur due to various factors such as genetics, trauma, overcrowding, or abnormal growth patterns.Rate this question:
-
- 18.
Which of these options may be utilised in the management of displaced teeth? (3)
- A.
Extraction of primary tooth and space maintenance
- B.
Extraction of teeth adjacent to diplaced tooth
- C.
Exposure of displaced tooth and application of orthodontic traction
- D.
Extraction of tooth if severly displaced
- E.
Hemisection of displaced tooth
Correct Answer(s)
A. Extraction of primary tooth and space maintenance
C. Exposure of displaced tooth and application of orthodontic traction
D. Extraction of tooth if severly displacedExplanation
Extraction of primary tooth and space maintenance is a viable option for managing displaced teeth because it allows for the proper alignment of the permanent tooth. By removing the primary tooth and maintaining the space, the permanent tooth has a chance to erupt in the correct position.
Exposure of displaced tooth and application of orthodontic traction is another option for management. This involves surgically exposing the displaced tooth and attaching an orthodontic appliance to guide it back into its correct position.
Extraction of tooth if severely displaced is a necessary option when the tooth is severely displaced and cannot be realigned.
Hemisection of displaced tooth is not mentioned as a management option and therefore is not applicable in this context.Rate this question:
-
- 19.
What is the main cause of crowding?
- A.
Small arch
- B.
Oversized teeth
- C.
Too many teeth
- D.
Lack of space for permanent tooth to erupt
- E.
Midline diastema
Correct Answer
D. Lack of space for permanent tooth to eruptExplanation
The main cause of crowding in teeth is the lack of space for permanent teeth to erupt. When there is not enough space in the jaw for the new teeth to come in properly, they may grow in misaligned or crowded positions. This can lead to overlapping or crooked teeth.Rate this question:
-
- 20.
Which teeth are commonly implicated in crowding?
- A.
1,3,5,8
- B.
2,3,4,6
- C.
2,3,5,8
- D.
2,4,6,8
- E.
3,5,6,7
Correct Answer
C. 2,3,5,8Explanation
The teeth that are commonly implicated in crowding are numbers 2, 3, 5, and 8.Rate this question:
-
- 21.
How may you manage crowding due to a lack of space for a permanent tooth to erupt? (4)
- A.
Active tooth movement
- B.
Retain deciduous teeth
- C.
Extract retained deciduous teeth
- D.
Extract supernumeries
- E.
Remove any pathology e.g. dentigerous cyst
Correct Answer(s)
A. Active tooth movement
B. Retain deciduous teeth
D. Extract supernumeries
E. Remove any pathology e.g. dentigerous cystExplanation
To manage crowding due to a lack of space for a permanent tooth to erupt, several approaches can be taken. Active tooth movement can be employed to guide the permanent tooth into the correct position. Retaining deciduous teeth can help create space for the permanent tooth to erupt by maintaining the existing tooth structure. Extracting supernumerary teeth, which are extra teeth that can cause crowding, can also alleviate the issue. Additionally, removing any pathology such as a dentigerous cyst can help create space for the permanent tooth to erupt properly.Rate this question:
-
- 22.
In which malocclusion can bimaxillary proclination not occur?
- A.
Class 2 div 1
- B.
Class 3
- C.
Class 2 div 2
- D.
Class 1
Correct Answer
C. Class 2 div 2Explanation
Bimaxillary proclination refers to the protrusion of both the upper and lower jaws. In Class 2 div 2 malocclusion, the upper jaw is retrognathic (retruded) and the lower jaw is prognathic (protruded). This means that the upper jaw is positioned further back than normal, making it unlikely for bimaxillary proclination to occur. Therefore, bimaxillary proclination cannot occur in Class 2 div 2 malocclusion.Rate this question:
-
- 23.
What is bimaxillary proclination?
- A.
Rapid growth of the maxilla
- B.
Buccal scissor bite
- C.
Maxillary overgrowth
- D.
Proclined upper and lower incisors
- E.
Retroclined upper and lower incisors
Correct Answer
D. Proclined upper and lower incisorsExplanation
Bimaxillary proclination refers to the condition where both the upper and lower incisors are proclined, meaning they are inclined forward. This can occur due to various factors such as genetics, habits like thumb sucking, or abnormal growth patterns of the jaws. Proclined incisors can affect the overall appearance of the face and may lead to problems with proper alignment of the teeth and bite. Treatment options for bimaxillary proclination may include orthodontic braces or other orthodontic appliances to correct the position of the incisors and improve the overall alignment of the teeth.Rate this question:
-
- 24.
What is the cause of bimaxillary proclination?
- A.
Tight strap like lips
- B.
Full and evert lips
- C.
Presence of supernumeries
- D.
Tilted anterior teeth
- E.
Crowding labially
Correct Answer
B. Full and evert lipsExplanation
Full and evert lips can cause bimaxillary proclination. Bimaxillary proclination refers to the forward positioning of both the upper and lower jaws. When the lips are full and everted, they push the teeth and jaws forward, leading to bimaxillary proclination. This can result in an increased overjet (horizontal distance between the upper and lower teeth) and protrusion of the lips.Rate this question:
-
- 25.
When might a class 1 malocclusion mistakenly be diagnosed as a class 2 div 1
- A.
When sunil is the operator
- B.
Bimaxillary proclination
- C.
In severe crowding
- D.
In severe spacing
- E.
When deciduous teeth are retained
Correct Answer
B. Bimaxillary proclinationExplanation
A class 1 malocclusion might mistakenly be diagnosed as a class 2 div 1 when there is bimaxillary proclination. Bimaxillary proclination refers to the forward positioning of both the upper and lower jaws, causing the upper front teeth to protrude significantly. This can create an appearance similar to a class 2 div 1 malocclusion, where the upper front teeth are protruded and the lower front teeth are retruded. Therefore, if a dentist or orthodontist observes bimaxillary proclination without considering other factors, they may misdiagnose the malocclusion as a class 2 div 1 instead of a class 1.Rate this question:
-
- 26.
What is the management for bimaxillary proclination?
- A.
Upper and lower removeable appliances
- B.
Extracts 5's
- C.
Retrocline incisors with fixed appliances
- D.
Alleviate labial crowding
- E.
Retrocline upper incisors
Correct Answer
C. Retrocline incisors with fixed appliancesExplanation
The management for bimaxillary proclination involves retroclining the incisors with fixed appliances. Bimaxillary proclination refers to the protrusion of both the upper and lower jaws, which can result in an excessive forward position of the incisors. Retroclining the incisors means moving them backward, which helps to correct the protrusion and improve the alignment of the teeth. Fixed appliances, such as braces, are used to apply controlled forces to gradually move the teeth into the desired position. This treatment approach aims to alleviate the labial crowding and improve the overall alignment of the teeth and jaws.Rate this question:
-
- 27.
When is tx for bimaxillary proclination likely to fail?
- A.
If soft tissues can adapt to new incisor positions
- B.
When lip seal is competent
- C.
When lip seal is incompetent but with good muscle tone
- D.
Lipseal grossly incompetent and unstable
Correct Answer
D. Lipseal grossly incompetent and unstableExplanation
The correct answer is when the lip seal is grossly incompetent and unstable. This means that if the lips are unable to properly seal and stabilize the position of the teeth, the treatment for bimaxillary proclination is likely to fail. The lips play a crucial role in maintaining the alignment of the teeth, and if they are unable to provide the necessary support, the treatment may not be successful.Rate this question:
-
- 28.
What is the incisor relationship for class 1
- A.
Lower incisors edges occlude or lie immediately posterior to the cingulum plateau of upper incisors
- B.
Upper Incisors proclined
- C.
Upper and lower incisors in edge to edge occlusion
- D.
Lower incisors buccal to upper incisors
Correct Answer
A. Lower incisors edges occlude or lie immediately posterior to the cingulum plateau of upper incisorsExplanation
The correct answer is "Lower incisors edges occlude or lie immediately posterior to the cingulum plateau of upper incisors." This means that when the person bites down, the edges of their lower incisors come into contact with or are positioned just behind the rounded area on the back of the upper incisors called the cingulum plateau. This is known as a class 1 incisor relationship.Rate this question:
-
Quiz Review Timeline +
Our quizzes are rigorously reviewed, monitored and continuously updated by our expert board to maintain accuracy, relevance, and timeliness.
-
Current Version
-
Mar 21, 2023Quiz Edited by
ProProfs Editorial Team -
Dec 09, 2009Quiz Created by
Spatel
Back to top