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Flashcards in Ortho Deck (92)
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1
Q

When will a flush terminal plane primary occlusion become class one if it does NOT have a primate space?

A

during the late mesial shift

2
Q

What is the incidence of supernumerary teeth?

A

3.6% (10:1 more common in maxilla, boys more than girls)

3
Q

Describe flush terminal plane

A

the distal surfaces of primary second molars are flush

4
Q

What is the incidence of congenitally missing second molars and maxillary lateral incisors?

A

4% - most frequent besides third molars

Incidence of supernumerary teeth is 3.6%

5
Q

Mesial step occlusal - 15% incidence, usually results in Class ___ occlusion?

A

one

6
Q

Marie-Sainton syndrome: cleidocranial dysplasia or osteodentin dysplasia or mutational dysostosis: large fontanelles; SMALL nasal sinus; no clavicles; maintain the primary dentition until age 15. MAny supernumerary teeth. What type of bone malformation occurred?

A

Intramembranous ossification disorder (endochondrial = achondroplasia)

7
Q

What are the leeway spaces for maxilla and mandible?

A

maxilla: 0.9 mm per quad
mandible: 1.7 mm per quad

8
Q

If the canine overlaps NOT beyond the lateral incisor’s midline long axis, successful repositioning is approximate ___%?

A

85-90%

9
Q

If the canine overalps beyond the lateral incisor’s long axis, what is the % chance of successful repositioning?

A

60%

10
Q

Consult the orthodontist BEFORE removing lower canines, especially if patient is _______________

A

brachyfacial/a deep bite case

11
Q

What type of maxillas are associated with digit habits, mouth breathing patterns, and primary canine interference (canines are vertically oriented)

A

Constricted maxillas

12
Q

Define class 2 div 1:

A

maxillary anterior teeth are (1) PROCLINED and a (2) large overjet is present

13
Q

What appliance is being described: fixed palatal arch wire from E’s with distalization elastics to bonded button on first molar to treat ectopical eruption of 6 year molars

A

Haltermann appliance

14
Q

Erupting premolars will move through __ mm of bone in 4-5 months

A

1 mm

15
Q

What is an ideal primary dentition occlusion?

A

FTP or mesial step with class one canines

Baume type one arch with generalized spacing

2mm OJ, 2 mm OB (30-50% OB)

16
Q

What is the goal of maxillary expansion?

A

correct transverse discrepancy and eliminate functional shift

17
Q

Average FMA?

A

26 degrees

18
Q

Primary spacing affects crowding outcomes predictors into the mixed dentition. What % chance of crowding with crowded primary teeth?

A

100% with incisor crowding

19
Q

What is the treatment for an anterior open bite with extra oral habit?

A

4-6 yo - try a rewards program

8-10 yo: crib appliance for 6 months

20
Q

T/F: Loss of a primary molar before 7 years results in delayed eruption of premolars. Loss of a primary molar after 7 years will lead to an accelerated eruption of the premolar

A

True

21
Q

T/F: Most of the space loss occurs in the first 6 months after an extraction. Erupting premolars will move through 1 mm of bone in 4-5 months

A

True

22
Q

What class relationship can occur from distal end or end-on-end primary relationship?

A

Class II

23
Q

What is the % chance of incisor crowding when spacing is less than 3 mm?

A

20%

24
Q

Mixed dentition analysis: Moyers, Nance, and Tanaka Johnson all use what measurement as the standard?

A

mesiodistal width of the mandibular permanent incisors

25
Q

What is the priority for space management for brachyfacial/deep bite patients?

A

prioritize arch development/expansion

Dolichofacial/open bite - extraction is more likely

26
Q

Average IMPA?

A

90-94 degrees

27
Q

What is the formula for the mandible using Tanaka Johnson?

A

(1/2)x(combined mesiodistal width of all 4 mandibular incisors+10.5)

28
Q

In any mixed dentition analysis, the most careful estimate will only be accurate within __ mm

A

2 mm

29
Q

What is more common, labial or palatal displacement of the canines?

A

MEsiolabial displacement of #6,11 affects up to 10% of children. Palatal displacement of maxillary canines is much less common affecting only 1-2% of the population with a predilection for females (3:1 - palatal displacement of 6,11)

30
Q

What % of pediatric primary dentitions have non-spaced dentitions?

A

1/3 (Baume type II)

Note: Spacing in arches is related to BASAL ARCH SIZE rather than tooth mass differences

31
Q

What % of children have bilateral posterior crossbite?

A

2-3%

32
Q

What % of children with a non-nutritive sucking habit will discontinue between the ages of 24-48 months of age?

A

50%. Digit habits can last longer than pacifier habits, both produced similar effects if they persist beyond 4 years of age

33
Q

What is typically the last tooth to erupt in the primary dentition

A

Upper second molars: A, J

34
Q

What is the primate space?

A

Distal of lower canines to mesial of mand first primary molar
Mesial of upper canines to distal of lateral incisor

35
Q

What is the priority for space management for dolichofacial/open bite patients?

A

Extraction is more likely

brachyfacial/deep bite patients: prioritize arch development/expansion

36
Q

BQ: Ectopic eruption of first molars. incidence?

A

2-3% in maxillary arch, rare in mandibular arch. 66% self correct except in CLP where only 22% self correct

37
Q

What are some treatment considerations of ectopic eruption of first permanent molars?

A

1) Elastic separators

2) Fixed palatal arch wire from E’s with distalization elastics to bonded button on first molar (Haltermann appliance)

38
Q

75% of occlusal relationships in the primary dentition are what?

A

Flush terminal plane, most shift to class one but some shift to class two

39
Q

What is the maxillary leeway space?

A

0.9 mm per quadrant (1.8 mm total)

Eruption: 6-1-2-4-5-3-7

40
Q

What terms describe counter-clockwise rotation of the face?

A

Hypodivergent/Brachyfacial

41
Q

What is the combined mesiodistal width of primary canines, first, and second molars?

A

Leeway space of Nance: 1.5 mm total maxilla; 1.5 mm both sides mandible

42
Q

Digit habits can last longer than pacifier habits, both produced similar effects if they persist beyond ___ years of age

A

4 years. Anterior open bite, posterior crossbite, increased overjet, high vaulted palate, possible class II relation, distorted incisor eruption

43
Q

BQ: What is the most common ankylosed tooth?

A

mandibular first molars

44
Q

Average ANB?

A

2-4 degrees

45
Q

What is the incidence of congenitally missing permanent teeth?

A

4%, no gender differences (2% are maxillary laterals)

46
Q

Average SNA?

A

80-82 degrees

47
Q

FMA of 31 degrees: Brachyfacial or dolichofacial

A

Dolichofacial

48
Q

Primary spacing affects crowding outcomes predictors into the mixed dentition. What % chance of crowding with no spacing?

A

50% with incisor crowding

49
Q

Define functional posterior cross bite

A

shift of the mandible on closure. This masks bilateral maxillary constriction and makes it appear to be unilateral crossbite, even though the crossbite is bilateral and a product of bilateral maxillary constriction

50
Q

What is the treatment for a functional crossbite?

A

Removable hawley with finger springs, fixed palatal rigid archwire with finger springs, labial archwire with edgewise brackets

51
Q

Non-nutritive sucking habit: Which is more critical, duration or force of strength of force?

A

NNS: Duration of force rather than magnitude

52
Q

What class occlusion is being described: functional cross bite with lingually displaced upper incisors complicated by anterior shift of the mandible that exaggerates cross bite discrepancy

A

pseudo class 3

53
Q

BQ: Ankylosed teeth: list them from most common to least

A

lower first molars -> upper first molars -> lower second molars -> upper second molars

54
Q

What % of mesiodens are single?

A

80%

20% are more than one

55
Q

Distal step primary molar class relationship usually results in which permanent molar relationship?

A

Class 2 or end on end class 2 molar relationship

56
Q

What occurs when there is an early mesial shift in a FTP class occlusion?

A

first permanent molars erupt in end on relationship and class 1 relationship is achieved by EARLY mesial shift

57
Q

Moyer’s probability chart has what level of probability?

A

75%; the advantage of moyer’s mixed dentition analysis is that it does NOT require a radiograph

58
Q

What is recommended ortho wise after extracting primary canines to prevent lingual collapse of lower incisors, increased overjet, deepened bite, and loss of arch length?

A

Placement of LLHA

59
Q

2/3 of ectopically erupting 1st permanent molars self-correct. After what age do they rarely self correct?

A

7

60
Q

Primary spacing affects crowding outcome predictors into the mixed dentition. What is the % chance of incisor crowding with spacing of 3-6mm?

A

No transitional crowding

61
Q

T/F: Small maxillary laterals, lateral with a pronounced distal inclination, non-mobile primary canines, eruptive building of canines are all signs of maxillary canine eruptive displacement

A

True - remove primary canines whenthe permanent canines #6,11 have about 2/3 root structure

62
Q

What is the goal of maxillary expansion? (2 things)

A

1) Correct transverse discrepancy

2) Eliminate functional shift

63
Q

What class relationship can occur from excessive mesial step with crossbite?

A

Class III

64
Q

When is the best time to extract #C and H?

A

Remove primary canines when the permanent canines have about 2/3 root structure. Note: if canine overlaps beyond the lateral incisors long axis, successful reposition is approximately 60%

65
Q

What is the Leeway space of Nance?

A

the combined mesiodistal width of primary canines, first and second molars

maxilla: 1.5 mm
mandible: 1.5 mm both sides

66
Q

Where is space loss most significant?

A

maxillary arch after loss of A or J

67
Q

T/F: FMA less than 21 - vertical deficiency?

A

true

68
Q

Bilateral posterior crossbite is associated with what type of skeletal vertical growth pattern?

A

Dolichofacial

RPE, Haas, sutural expansion. W-arch/quad helix = slow and low force

69
Q

What is the term for a shift of the mandible on closure. This masks bilateral maxillary constriction and makes it appear to be unilateral crossbite, even though the crossbite is bilateral and a product of bilateral maxillary constriction

A

Functional crossbite - greater than 90% of primary dentition crossbites express a functional shift in their occlusion pattern

70
Q

Space loss is most severe in which arch after loss of second molars?

A

maxillary arch

71
Q

What class relationship are mesial step canines?

A

Class I relationship

72
Q

What age is the permanent dentition generally complete?

A

Age 12 - Maxilla: 6, 1, 2, 4, 5, 3, 7

73
Q

What are the risks of removing lower primary canines?

A

lingual collapse of incisors -> increased overjet, loss of arch length, bite deepening

74
Q

Define class 2 div 2

A

maxillary central incisors are retroclined and a deep overbite exists, lateral proclined

75
Q

In what class of occlusion is lateralization of canines emphasized?

A

Class II occlusion

76
Q

Describe a skeletal class 3 relationship

A

1) Prognathic mandible
2) Retrognathic maxilla
3) Typically involves all anterior teeth in crossbite
4) Proclined upper, retroclined lowers

77
Q

What is the average mandibular incisor crowding?

A

1.0mm to 1.6mm

After 8-9, there are no future arch dimensional changes to compensate for crowding/ malalignment in the lower anterior segment

78
Q

T/F: 60-70% of malalignments are from early loss of primary tooth

A

True

79
Q

What are the primate spaces located?

A

Maxilla: Lateral to canine
Mandible: Canine to first primary molar
simian or anthropoid spaces or meyers or ebners spaces

80
Q

Erupting premolars will move through 1 mm of bone in ___ months

A

4-5 months

81
Q

If crowding is excessive (3-4mm), develop a plan to develop the arch (not serial extraction)

A

disk canines 1-2 mm each

82
Q

What are the simian or anthropoid spaces also known as?

A

Primate spaces = meyers or ebners space

83
Q

What would the treatment for managing space be if more than 4 mm of space needs to be gained?

A

Extract primary canines

Disc 1-2 mm of mesial buccal of primary canines if less than 3-4 mm of space needed

84
Q

Which tooth is the best predictor of sagittal relationship into the permanent dentition?

A

Canine

85
Q

What is the mandibular leeway space?

A

1.7 mm per quadrant (3.4 mm total)

Eruption: 6-1-2-3-4-5-7

86
Q

There are case reports of second premolar tooth germs developing as late as__ years of age

A

10

87
Q

When do you consider cessation therapy for non-nutritive sucking habits?

A

prior to eruption of permanent anterior teeth, around age 5,6 if the NNS habit persists

88
Q

What is the formula for the maxilla using Tanaka Johnson?

A

(1/2)x(combined mesiodistal width of all 4 mandibular incisors+11)

89
Q

T/F: Primary teeth erupt on average from 8 months (lower incisors) to 30 months (upper second molars) with a S.D. of 3 months. Sequence of both arches is the same: A B D C E

A

True

90
Q

What % of primary dentition exhibits generalized spacing?

A

2/3 (66%) Baume type one

91
Q

What % of mesiodens are palatal?

A

90%

75% require surgical intervention as they do not erupt on their own

92
Q

Primary spacing affects crowding outcomes predictors into the mixed dentition. What % chance of crowding with spacing less than 3 mm?

A

20% with incisor crowding