3rd class Flashcards
When does mand perm 1st molar erupt?
6 yrs
When does max perm 1st molar erupt?
6 1/4 yr
When does mand perm CI erupt?
6 1/4 yr
When does max perm CI erupt?
7 1/4 yr
When does mand perm LI erupt?
7 1/2 yr
When does max perm LI erupt?
8 1/4 yr
When does mand perm canine erupt?
10 1/2 yr
When does mand perm 1st PM erupt?
10 1/2 yr
When does mand perm 2nd PM erupt?
11 1/4 yr
When does mand perm 2nd molar erupt?
12 yr
When does mand perm 3rd molar erupt?
20 yr
When does max perm canine erupt?
11 1/2 yr
When does max perm 1st PM erupt?
10 1/4 yr
When does max perm 2nd PM erupt?
11 yr
When does max perm 2nd molar erupt?
12 1/2 yr
When does max perm 3rd molar erupt?
20 yr
Once the root is ____ % completed, it can handle hardware used as space maintainers
50%
When the second primary molars are lost, the first permanent molars move forward (mesially) relatively rapidly, into the ________
Leeway space.
When the second primary molars are lost, the first permanent molars move ______ (in what direction) relatively rapidly, into the Leeway space.
forward (mesially)
This movement (molars moving mesially) _______ both arch length and arch circumference, which are related but not the same thing, and are commonly confused.
decreases
Majority of the Leeway space is used by _____ mvmnt of
the molars.
mesial movement
Both _______, and _________ tend to
decrease during the transition of the molars moving mesially into the leeway space
arch length (L) and arch circumference (C)
Because of the incisor liability, a normal child will go through a
transitory stage of mandibular incisor crowding at age ____ to _____
•Even if there will eventually be enough room to accommodate all the
permanent teeth in good alignment.
8 to 9.
In other words, a period when the mandibular incisors are
slightly crowded is a normal developmental stage, and by the
time the ____ teeth erupt, space is once again adequate
under normal conditions.
canine
Does the jaw grow in the posterior or anterior segment?
Posterior portion of jaw
What are the 3 sources where extra space in A-P dimension of mandible comes from?
- Increase in the width of the dental arch.
- Labial positioning of the permanent incisors.
- Repositioning of mandibular canines.
As growth continues, the teeth erupt in what 2 directions?
Upward and outward
The increase in arch width is about ___ mm on average
2 mm
More width is gained in the which arch? , and more is gained by boys than girls.
Maxillary arch
More width is gained in the maxillary arch than in the
mandibular, and more is gained by which gender?
Boys
Do girls or boys have a greater liability to incisor crowding particularly mandibular incisor crowding?
Girls
The primary incisors tend to be quite ______
upright
As the permanent incisors replace them, the perm teeth lean slightly
_____ (in what direction), which arranges them along the arc of a larger circle.
forward
Although this change is also small (proclination of perm incisors), it contributes __ to __ mm
of additional space in the average child.
1 to 2 mm
As the permanent incisors erupt, the canine teeth not widen in what 2 directions into the primate space?
Out and back
As the permanent incisors erupt, the canine teeth not only widen out
slightly but move slightly back into the ____ space
primate space.
How much space is the backward and outward movement of the erupting mandibular canines, how much space is created?
1 mm
From a profile view, the molar surface lie on the arch or
circle which, continued posteriorly touched the anterior
border of mandibular condyle.
- concave in mand; convex in max
Curve of spee
•From frontal view, it is the mediolateral curve
that contacts the buccal and lingual cusp tips on
each side of the arch.
Curve of Wilson
In ortho, do you want the curve of spee or not?
No
In contrast to the anterior teeth, the
permanent premolars are _____ than the
primary teeth they replace.
smaller
Lower E is __ mm larger than the second premolar.
2 mm
Upper E is __ mm larger.
1.5 mm
Lower D is slightly larger than the 1st premolar. Only
contributes an extra ____ mm.
0.5 mm
Upper D is almost ___ mm larger than the first premolar.
equal/ 0 mm
Mandibular arch contains about ___ mm
of what is called Leeway space per quadrant
2.5
Maxillary arch has a Leeway Space
about ___ mm on the average per quadrant
1.5 mm
•In mixed dentition with primate spaces, eruption force of the 1st permanent molar is sufficient to push primary 1st and 2nd molars forward to close the primate space. •This space closure due to eruption force of 1st permanent molar called \_\_\_\_\_\_
Early
Mesial Shift.
•In mixed dentition with primate spaces, eruption force of the \_\_\_\_\_\_ tooth is sufficient to push primary 1st and 2nd molars forward to close the primate space. •This space closure due to eruption force of 1st permanent molar called Early Mesial Shift.
1st permanent molar
•When no spaces exist, the erupting 1st permanent molar is not able to move mesially. •In these cases when the primary molars exfoliate the permanent molars migrate mesially to use up the Leeway Space.
Late Mesial Shift
When primary second molars are lost, both the maxillary and mandibular molars tend to shift mesially into the leeway space, but the ____ molar normally moves mesially more than its maxillary counterpart.
mandibular
The flush terminal plane can lead to end on the relationship
of permanent molars or can lead to Class __ permanent molar
occlusion with forward growth of mandible.
Class I
The mesial step can lead to Class I permanent molar
relationship and with forward growth of mandible can lead
to Class __ molar relationship.
Class III
The distal step can lead to Class __ permanent molar
relationship and with forward growth of mandible can lead to
end on occlusion of permanent molars.
Class II
If a child has a flush terminal plane molar relationship,
about ___ mm of movement of the lower molar
forward relative to the upper molar is required for a
smooth transition to a Class I molar relationship.
3.5 mm
About ___ of this distance can be obtained from the leeway
space, which allows greater mesial movement of the mandibular
than the maxillary molar.
half
The other half of the 3.5 mm needed to turn flush terminal plane into class I occlusion not supplied by leeway space is supplied by \_\_\_\_\_ of the lower jaw, carrying the lower molar with it.
differential growth
_____ quantifies the amount of needed space (crowding/
spacing) within the arches estimating the severity of space
discrepancy.
Space analysis
•Tanaka and Johnston analysis is a mixed dentition analysis which allows one to estimate the space available in an arch for the permanent teeth to erupt. •All you need to do is to measuring the \_\_\_ width of what teeth?
MD width of all lower incisors.
