Development/Eruption Flashcards
When do primary maxillary central incisors erupt? When are they shed?
Erupt 8-12 months Shed 6-7 yrs
When do primary maxillary lateral incisors erupt? When are they shed?
Erupt 9-13 months Shed 7-8 yrs
When do primary maxillary canines erupt? When are they shed?
Erupt 16-22 months Shed 10-12 yrs
When do primary maxillary first molars erupt? When are they shed?
Erupt 13-19 months Shed 9-11 yrs
When do primary maxillary second molars erupt? When are they shed?
Erupt 25-33 months Shed 10-12 yrs
When do primary mandibular central incisors erupt? When are they shed?
Erupt 6-10 months Shed 6-7 yrs
When do primary mandibular lateral incisors erupt? When are they shed?
Erupt 10-16 months Shed 7-8 yrs
When do primary mandibular canines erupt? When are they shed?
Erupt 17-23 months Shed 9-12 yrs
When do primary mandibular first molars erupt? When are they shed?
Erupt 14-18 months Shed 9-11 yrs
When do primary mandibular second molars erupt? When are they shed?
Erupt 23-31 months Shed 10-12 yrs
What are succedaneous teeth?
Permanent teeth that replace exfoliated deciduous teeth
Describe how the root of anterior and posterior teeth are divided into thirds
Apical third (root tip) Middle third Cervical third
Describe how the crown of anterior and posterior teeth are divided into thirds
-incisal/occlusal, middle, cervical -mesial, middle, distal -labial/buccal, middle, lingual
Name the 6 line angles found in anterior teeth
- Mesiolabial
- Distolabial
- Mesiolingual
- Distolingual
- Labioincisal
- Linguoincisal
Name the 8 line angles found in posterior teeth
- Mesiobuccal
- Distobuccal
- Mesiolingual
- Distolingual
- Mesio-occlusal
- Disto-occlusal
- Bucco-occlusal
- Linguo-occlusal
Name the 4 point angles found in anterior teeth
- Mesiolabioinscisal
- Distolabioincisal
- Mesiolinguoincisal
- Distolinguoincisal
Name the 4 point angles found in posterior teeth
- Mesiobucco-occlusal
- Distobucco-occlusal
- Mesiolinguo-occlusal
- Distobucco-occlusal
What are mamelons and in which teeth are they found?
- Small bumps on the incisal ridge of maxillary and mandibular central and lateral incisors (permanent only)
- Ridge wears into an edge over time, so mamelons are more common in children than adults
Name the depression outlined by the colored lines, and name the protrusion circled in green
Lingual fossa and cingulum
What are 4 ways that maxillary lateral incisors exhibit variation?
- Peg shaped laterals sometimes seen
- May be missing
- May have a palato-radicular groove-see
- May see a large pointed tubercle
What is perikymata?
parallel ridges formed by cyclic deposition of enamel
What 3 characteristics can chronolgy play a role in?
form, color, and arrangements
what 3 teeth are anomolies most often seen in?
maxillary laterals, third molars, and mandibular 2nd premolars
when does enamel hypoplasia develop?
during enamel formation
Name the amount of time it takes for primary crown formation to continue after birth for the centrals, laterals, canines, 1st molars, and 2nd molars
centrals - 3 months
laterals - 4 months
canines - 8.5 months
1st molars - 7 months
2nd molars - 10.5 months
Is the cementum of permanent teeth thicker or thinner than that of primary teeth?
thicker in permanent teeth
When does root formation occur in relation to crown formation?
root formation occurs after crown formation
What is a function of continued root formation in relation to eruption?
continued root formation aids in the tooth erupting and contacting opposites
what happens to the roots of primary teeth in the absense of a permanent successor?
the root may only partially resorb, possibly resultng in prolonged retention of the primary tooth
what happens to alveolar bone height during development in relation to formation of teeth?
the alveolar bone height will increase to accomodate the increasing length of the teeth
Name the sequence of eruption of the primary teeth
1) central incisor
2) lateral incisor
3) 1st molar
4) canine
5) 2nd molar
around what age is the emergence of primary dentition usually completed?
around 30 months
what event marks the beginning of mixed dentition? what event marks the end?
the emergence of the mandibular 1st permanent molar marks the beginning of mixed dentition, and the loss of the last primary tooth marks the end (around 11-12 years of age)
T or F:
permanent teeth do not begin eruptive movement until the crown is completed
true
considering 1st molars are not succedaneous teeth (they do not have primary teeth as predecessors), how is their eruption guided?
by the distal surface of the primary 2nd molars
T or F:
the premature loss of primary teeth due to caries does not effect the development of permanent dentition
false
T or F:
the premature loss of primary teeth leads to a lack of space for permanent teeth
true
T or F:
premature loss of primary teeth may lead to occlusion, loss of arch length, and crowding
true
what are developmental lobes?
centers of formation of permanent teeth; there are 4 lobes in each tooth
T or F:
follicles of developing incisors and canines are labial to deciduous roots
false
they are lingual to deciduous roots
in relation to primary molars, where are follicles of permanent premolars located?
in the bifurcation of deciduous roots
what do permanent incisors, canines, and premolars have in common?
they are all succedaneous teeth; they take place of their primary predeccessors
in general, do teeth in the mandibular arch emerge before or after those of the maxilla?
before
T or F:
size of teeth are not genetically or racially determined
false
what does pulp get smaller with age?
due to deposition of secondary dentin
4 types of cementoenamel junction
1) enamel overlaps cementum
2) end to end
3) gap exposing dentin
4) cementum overlaps enamel
T or F:
while teeth are forming, very little environmental influences will affect teeth
true, BUT:
tetracycline can cause brown-bluish color, and fluoride can either make enamel less susceptible to caries or cause fluorosis (excess fluoride)
T or F:
mandibular incisors have the smallest mesiodistal dimensions of all teeth
true
in what direction is masticatory stress in the mandibular central?
labio-lingual direction
T or F:
mandibular central incisor root is wide mesiodistal and narrow labiolingual
false
the root is narrow mesiodistal and wide labiolingual
is the length of the mandibular central incisor root longer than the maxillary central incisor?
it is as long, and sometimes longer than the maxillary central incisor
T or F:
in the mandibular central incisor, the mesial cervical line curvature is almost 1/2 the length of the crown
false
curvature is almost 1/3 the length of the crown
what is an important identification mark to separate the mandibular central and lateral incisors?
the mandibular central incisor’s incisal edge is almost at right angles with labiolingual bisecting line
T or F:
in the mandibular central incisor, the labiolingual dimension is always greater than the mesiodistal dimension
true
T or F:
in mandibular central incisor roots, two canals may be present
true
the root section is often ribbon-like, and sometimes two canals may be present
relative to the mandibular central incisor, is the mandibular lateral incisor root longer or shorter?
longer
in the mandibular lateral incisor, why does the crown appear to be twisted from an incisal view?
the incisal edge is curved to follow the curvature of the arch
at what age is the peak attack of caries most common?
around age 13 when there are only about 5% of primary teeth left
after primary teeth are completely finished, about how long is it before tooth resorption begins?
1-2 years
T or F:
primary teeth are usually more yellow than permanent teeth
false
primary teeth are less pigmented than permanent teeth, giving them a whiter appearance
describe characteristics of roots of primary molars
they are longer and flare more so that permanent premolars can develop between them
compare enamel, dentin, and pulp of primary teeth to permanent teeth
enamel in primary teeth is thin with a consistent depth
dentin in thin
pulp horns are high and chamber is large
compare the mesiodistal vs cervicoincisal measurements in maxillary central incisors of primary and permanent dentition
primary dentition:
mesioincisal length is longer than cervicoincisal length
permanent dentition:
mesioincisal length is shorter than cervicoincisal length
T or F:
cervical ridges are more pronounced in permanent maxillary central incisors than in primary maxillary central incisors
false
cervical ridges are more pronounced in primary maxillary central incisors
T or F:
the primary maxillary lateral incisor’s mesiodistal length is shorter than its cervicoincisal length
true
which primary tooth has an appearance of a tooth on steroids?
maxillary canine
what is the purpose of the primary mandibular central incisor labiolingual measurement being only 1mm smaller than that of the primary maxillary central incisor?
for strength
