Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Ortho > Lecture 2 > Flashcards

Lecture 2 Flashcards

1
Q

why is it important to have a good understanding of the sequence and biology of dental eruption when treating orthodontic patients?

A

because many orthodontic problems are related to abnormal dental development and eruption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

the first stage of eruption of the permanent teeth is seen at what age? what is it characterized by?

A
  • 6 years old
  • characterized by the near-simultaneous eruption of the mandibular central incisors, mandibular first molars, and maxillary first molars
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is characterized by dental age 8?

A
  • eruption of the maxillary lateral incisors

- the mandibular lateral incisors and maxillary central incisors have typically erupted between age 6 and age 8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

at what age do most ortho patients receive phase 1 orthodontic treatment if it is necessary?

A

dental age 8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is characterized by dental age 11?

A

more or less simultaneous eruption of the:

  • mandibular canines
  • mandibular first premolars
  • maxillary first premolars
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is typically considered the best stage of development to start full orthodontic treatment or phase II orthodontic treatment?

A

dental age 11

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is characterized by dental age 12?

A

eruption of the remaining succedaneous teeth:

  • maxillary canine
  • maxillary second premolars
  • maxillary and mandibular second molars a few months later (these teeth will typically erupt during the full orthodontic treatment, and are incorporated into the orthodontic treatment as they erupt
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is characterized by dental age 15?

A
  • roots of all permanent teeth (except 3rd molars) are complete
  • crown formation of 3rd molars often has completed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are the two phases of tooth eruption?

A
  1. pre-emergent eruption (eruption of the tooth until it emerges into the mouth)
  2. post-emergent eruption (eruption of a tooth after it has broken through gingival tissues
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

the post-emergent eruption phase is further characterized by what two periods?

A
  1. juvenile post-emergent eruption

2. adult post-emergent eruption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what supports the idea that metabolic activity within the PDL is necessary for tooth eruption to begin and continue?

A

the eruptive movement of the tooth begins soon after the root begins to form, and the roots are seen emerging from the dental follicle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are the two processes necessary for pre-emergent eruption to occur?

A
  1. there must first be resorption of bone and the primary tooth roots, overlying the crown of the erupting tooth
  2. next, there must be a propulsive mechanism to move the tooth in the direction where the overlying path has been cleared
    - these two mechanisms normally operate in concert with each other
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is an example of a condition that interferes with the resorptive process of pre-emergent eruption?

A

cleidocranial dysplasia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are the characteristic features of cleidocranial dysplasia?

A
  • underdeveloped or absent clavicles
  • delayed closing of the fontanelles of the skull bones
  • bulky forehead, hypertelorism, and midfacial hypoplasia
  • dental abnormalities
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are the dental abnormalities associated with cleidocranial dysplasia?

A
  • delayed loss of the primary teeth
  • delayed appearance of the secondary teeth
  • unusually shaped, peg-like teeth
  • misalignment of the teeth and jaws
  • supernumerary teeth which are sometimes accompanied by cysts in the gums
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

the failure of tooth eruption is thought to be caused by a failure of migration of the permanent teeth toward the oral cavity, which is thought to be caused by ___

A

defects in the osteoclastic and resorptive activity in the alveolar bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

cleidocranial dysplasia is caused by a mutation in the ___ gene, a member of the ___ family of transcription factors located on chromosome ___

A
  • core binding factor alpha 1 (CBFA1)
  • RUNX
  • 6p21
  • the CBFA1 gene is responsible for the initial osteoblastic differentiation and osteogenesis to form skeletal structures
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what are the contributing factors for failure of eruption of permanent teeth in children with cleidocranial dysplasia?

A
  • abnormal resorption of both the overlying bone and primary teeth
  • presence of multiple supernumerary teeth can impede eruption
  • fibrotic gingiva
  • cleidocranial dysplasia patients are an example of a defect in a patient’s ability to remove the overlying structures during tooth eruption, which causes delayed eruption or the impaction of the involved teeth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

if the mechanical obstruction of eruption is removed in patients with cleidocranial dysplasia, what may happen to the teeth?

A

they may erupt spontaneously and can often be brought into the arch with orthodontic force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

T or F:

the rate of bone resorption and the rate of tooth eruption are controlled physiologically by the same mechanism

A

false
-this means that the tooth’s occlusal eruptive movement does not control the dissolution of the overlying bone and/or primary teeth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

completion of the crown does what two things in the eruption process?

A
  1. signals for the resorption of overlying bone and primary tooth too begin
  2. removes the inhibition of the genes that are necessary for root formation, causing root formation to begin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

T or F:
it has been shown that a tooth will continue to grow and form the tooth’s root regardless of whether the overlying bone and primary teeth are removed

A

true

  • therefore, it would seem clear that resorption of the overlying bone and primary tooth is the rate-limiting factor in pre-emergent eruption
  • if the overlying bone and primary tooth removal is delayed, then pre-emergent eruption will also be delayed or prevented, but root formation will typically continue
23
Q

normally, the rate of eruption is such that the ___ area where root formation begins remains in the same place, with the crown typically moving occlusally

A

-apical

24
Q

if eruption is mechanically blocked, what happens to the proliferating apical area?

A

it will move in the opposite direction, causing a distortion of the root in an abnormal direction (called a dilaceration)

25
Q

T or F:
it has been shown that after a tooth has had its apical area removed (apicoectomy), the tooth cannot continue to erupt on its own

A

false
-it can continue to erupt on its own, which shows that proliferation of cells associated with lengthening of the root is not an essential part of the propulsive eruption mechanism

26
Q

if a tooth’s root formation is complete on an impacted tooth, can the tooth still erupt?

A

yes, but some situations may require surgical orthodontic eruption

27
Q

T or F:

the precise mechanism through which the propulsive force in pre-emergent eruption is generated remains unknown

A

true

28
Q

active formation of the root is not necessary for what two processes?

A
  • continued clearance of an eruption path above the tooth

- propulsive movement of a tooth along the eruption path

29
Q

___ is a condition characterized by non-syndromic eruption failure of permanent teeth in the absence of mechanical obstruction, indicating that there is a defect in the propulsive mechanism of tooth eruption

A

primary failure of eruption (PFE)

30
Q

typically in PFE patients, the more anterior/posterior teeth are, the more frequently they are affected

A
  • posterior

- 1st and 2nd molars are more frequently affected than the premolars and canines

31
Q

in PFE patients, if a tooth in a further ___ position presents with an eruption disturbance, the ___ teeth are usually, but not always, affected as well

A
  • anterior

- posterior

32
Q

in PFE patients, what happens to the affected teeth?

A

they resorb the alveolar bone above the crown, but then the teeth erupt only partially or fail to erupt at all

33
Q

T or F:

both deciduous and permanent teeth can be affected in patients with PFE

A

true

34
Q

is PFE typically seen as being symmetrical or asymmetrical?

A

asymmetrical, and primarily non-ankylosed teeth tend to become ankylosed as soon as orthodontic forces are applied

35
Q

when does the juvenile phase of post-emergent eruption begin?

A

once the tooth emerges into the mouth

36
Q

what is the juvenile post-emergent spurt?

A

the stage of relative rapid eruption from the time a tooth first penetrates the gingiva until it reaches the occlusal level

37
Q

instrumentation shows that the majority of tooth eruption occurs only during the critical period between what time of day? what does this cyclic rhythm of eruption correlate with?

A
  • between 8PM and 1AM
  • it correlates with the cyclic release of growth hormone, which probably plays a role in post emergent juvenile tooth eruption
38
Q

experiments with the application of pressure against an eruption premolar suggest that eruption is stopped by a force applied for only ___

A

1-3 minutes

39
Q

what forces oppose the eruption of teeth?

A
  • chewing forces

- soft tissue forces

40
Q

which forces controls tooth eruption the most and why?

A

-soft tissue pressure are probably more important in controlling tooth eruption than the heavy pressures that occur during chewing, because eruption typically occurs between 8PM and 1AM, during which most patients occlusal activities are not very active

41
Q

T or F:
light pressures of long duration are more important in producing orthodontic tooth movement than heavy intermittent pressures like chewing

A

true

42
Q

are multiple teeth typically involved in ankylosis?

A

no, typically only one tooth is involved, but primary first and second molars can commonly both be seen to be ankylosed

43
Q

how can you tell if a second primary molar is ankylosed?

A

look for a step between the first permanent molar and the second primary molar

44
Q

how can you tell if a posterior openbite is caused by lateral tongue thrust?

A
  • can involve multiple teeth, caused by the pressure of the tongue preventing the eruption of the teeth as the maxilla and mandible grow, creating a posterior openbite
  • you can typically see the patient pressing or resting the tongue in the openbite space
  • scalloped tongue
45
Q

what are 3 possible scenarios for an openbite?

A
  • primary failure of eruption
  • ankylosis
  • lateral tongue thrust
46
Q

what are the treatment options if an adult tooth undergoes ankylosis during post-emergent eruption?

A
  • extraction (with possible implant)
  • crowns
  • surgery (luxation or corticotomy and bone grafting)
47
Q

in what case is ankylosis especially problematic?

A

when the permanent tooth is missing underneath the ankylosed primary tooth

48
Q

if there is an adult tooth underneath the ankylosed primary tooth, do you HAVE to extract the ankylosed tooth?

A

not always, but the adult tooth will typically have a delayed eruption, which can be problematic

49
Q

when is extraction of a primary ankylosed tooth recommended?

A
  • if the primary tooth drops below the height of contour of the adjacent teeth
  • you want to extract in this case even if there is not a permanent tooth underneath the ankylosed tooth
  • EXT of the primary ankylosed tooth in this case helps prevent periodontal and bone defects to the adjacent teeth and helps stop bone loss in the extraction site, which will typically require an implant later
50
Q

other than extraction, what are two other options for an ankylosed primary tooth, in the case where the permanent tooth is missing underneath?

A
  • build up the primary tooth to place it into occlusion

- leave the primary tooth in place as it is

51
Q

T or F:

eruption of teeth stops in adulthood

A

false

teeth continue to erupt at an extremely slow rate during adult life

52
Q

the eruption mechanism remains active throughout life. what demonstrates this?

A

if a permanent tooth’s opposing tooth is lost at any age, a tooth can begin to erupt again, causing occlusal interferences

53
Q

what might happen if extreme wear occurs and eruption rate is unable to compensate?

A

the vertical dimension of the face decreases

54
Q

typically, the wear of the teeth is compensated by ___

A

additional eruption

Ortho (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions