Development and Anatomy of Primary Dentition (Lecture 5) Flashcards
What is the primary dentition?
§ Dentition before the eruption of _____ 
§ What else are the primary teeth called?
§ _____ (comes from a Latin word “deciduus” which means fall off) teeth
§ Baby teeth
§ _____ teeth
§ When do primary teeth emerge in the mouth?
§ Between the ages of _____
permanent teeth
deciduous
milk
6 months and 2 years
Humans are _______
diphyodont, have two sets of teeth
Although replaced by the succedaneous teeth, primary teeth play a very important role for the proper _______ and _______ of the permanent teeth
position
occlusion
How many are the primary teeth? § Twenty (20) §10 maxillary and 10mandibular teeth § In each arch: § \_\_\_\_\_\_\_ incisors § \_\_\_\_\_\_\_ cuspids (canines) § \_\_\_\_\_\_\_ molars
4
2
4
Primary Dentition
§ No _______
§ Primary molars are replaced by _______
§ Permanent molars have no _______ and erupt _______ to primary molars
primary premolars
premolars
predecessors
distal
Palmer vs. Federation Dentaire International Numbering System
L shaped dictates location for palmer
quadrants dictate dentaire (1-4 for permanent, 5-7 for primary, then 51 etc.)
When does the development of primary teeth start?
_______ weeks in ____
When does calcification of the primary teeth start?
____ in utero
How much of the crown of primary teeth has formed at birth?
____ (approximately)
By when the enamel formation has been completed for all primary teeth?
By ____ of age
6-8 weeks, utero
14-20th week
1/2-5/6
12 months
Stages of development (eruption) of the dentition Birth - 6 months: \_\_\_ 6 months - 2.5 years: \_\_\_ 2.5 years - 6 years: \_\_\_\_ 6 - 12 years: \_\_\_\_\_ > 12 years: \_\_\_\_\_
edentulous arches eruption of primary teeth full primary dentition mixed dentition permanent dentition
Birth -6 months of age
___ usually visible at birth
What is an exception?
___ or ___ teeth
no teeth
natal -> present at birth
neonatal -> erupt 30 days of birth
Natal and Neonatal Teeth q Natal teeth q \_\_\_ at birth q Neonatal teeth q Erupt within \_\_\_ after birth q May be \_\_\_ teeth q More likely early eruption of \_\_\_ q Unknown why they occur; superficial position of the tooth germ, associated with a \_\_\_
present 30days extra primary teeth (85%) hereditary factor
When does the eruption of the primary teeth start? Which is the first primary teeth to erupt?Does eruption of primary teeth happen earlier in boys or girls?
§ ___ of age -> First primary tooth erupts
§ ___
§ Boys and girls have similar eruption times for ___ (in contrast to ___ teeth: girls do erupt their permanent teeth ___ than boys)
6-10 months mandibular central incisor primary permanent earlier
Calcification of roots normally is completed by age ___- Active eruption occurs when ___ of the root is formed - Usually erupt in ___
3-4 years
2/3
erupts
7+4
Explain
7 months is starting point 11 months = 4 erupted teeth 15 months = 8 erupted 19 months = 12 erupted 23 months = 16 erupted 27 months = 20 erupted
Sequence of Eruption of Primary Teeth
___ before maxillary
§ ___ to back except ___ before canine
mandibular
front
1st primary molar
3 years
§ Primary teeth in ___
occlusion
3 1⁄2 years
§ All primary teeth in ___ and ___ completed
occlusion
roots
Spacing in primary dentition
§ ___ spacing
§ interdental spacing mostly in the ___ area of the mouth
§ Primate spacing
§ Distal to the ___
§ Distal to upper ___
§ ___ (than the rest of interdental) spaces
generalized
anterior
lower primary canine
primary lateral incisor
wider
Primate Spaces
• Naturally occurring spaces in the primary dentition
• Maxillary: between the ___ and ___
• Mandibular: between the ___ and ___
lateral
canine
canine
molar
§ SPACED
§ ___ of primary dentitions: spaced
§ ___ of primary dentition: non spaced
§ Once established, arches ___ spaced or non- spaced over the course of primary dentition
2/3
1/3
remain
Does primary spacing affects crowding outcome into the permanent dentition? Spacing >= 6mm = \_\_\_ Spacing 3-6 mm = \_\_\_ Spacing < 3 mm = \_\_\_ No spacing = \_\_\_ Crowded primary = \_\_\_
no crowding 20% crowding 50% crowding 66% crowding 100% with incisor crowding
Molar relationship § Defined by the mesiodistal relation between the \_\_\_ surfaces of the upper and lower \_\_\_ (terminal plane) § 3 types § \_\_\_ terminal plane § \_\_\_ step terminal plane § \_\_\_ step terminal plane
distal second primary molars flush mesial distal
Flush terminal plane
§ The upper and lower distal surface of the second primary molars are in the ___ plane
same vertical
Mesial step terminal place
§ Distal surface of the lower second primary molar is more ___ to the ___ surface of the upper second primary molar
Step is defined by ___
mesial
distal
mandibular primary molar
Distal step terminal plane
§ Distal surface of the lower second primary molar is more ___ to the ___ surface of the upper second primary molar
distal
distal
Canine (cuspid) Relationship
§ Mesial stepà___
§ Distal stepà___
§ Excessive mesial stepà___
§ Class I: the tip of the max primary canine is in the ___ as the distal surface of the mandibular primary canine
§ Class II: the tip of the max. primary canine is ___ to distal surface of the mandibular primary canine
§ Class III: the tip of the max. primary canine is ___ to the distal surface of the mandidbular primary canine
class I class II class III same plane mesial distal
Overjet and Overbite § Ideal § Overjet: \_\_\_ § Overbite: \_\_\_ § \_\_\_ in primary dentition § may indicate \_\_\_ § \_\_\_ or open bite § may be evidence for a habit i.e., \_\_\_
0-4mm 10-40% excessive overbite skeletal malocclusion excessive overjet thumbsucking
