6. Development of Dentition and Occlusion Flashcards
What are the three different stages of eruption
invagination of dental lamina
- Tooth buds
- Emergence
What is the average age of eruption of first tooth
7.5 months
Most people have complete primary dentition by ages -
2-3 y.o
(Males/Females) get their primary teeth faster but (males/females) get their permenant dentition faster
males…females
Sequence of erupt goes from front to back with exception of _ in the primary teeth
canines
Which come in first for the primary teeth (lower/uppers) with the exception of
lowers… lateral incisors
Where are the primate space locations for the maxillary and mandibular arches
- Maxillary= lateral and canine
- Mandibula= canine and first moalr
Describe flush terminal plane, distal and mesial step
- Flush= maxillary and mandibular 2nd molars are flush (mandibular however is slightly anterior)
- Distal step= Manidbular 2nd molar is distal to the maxillary
- Mesial step= Manidbular 2nd molar is mesial to the maxillary
T/F the terminal plane remains constant in the deciduous dentition
t
T/F Kids with flush terminal plane have max. overbite and oj
f- minimal
For kids with flush terminal plane. The permenant 1st molars with initially erupt in what orientation relatin to one another
cusp to cusp
Distal step favors what class of occlusion
Angles II
Mesial step favors what angle’s class of occlusiom
I or class III (if severe)
Permenant eruption is accelerated if
- Long standing periapical abcess present
- Late extraction of primary molar
Permenant eruption is delayed when
- Congenital absence permenant follice
- Early extraction of primary moalr
What is incisor liability
the size difference (MD) between the primary and permenant incisors
Factors favoring tooth alignment are
- Intercanine arch width growth
- Intercanine arch length increase (anterior permenant incisor placement)
- Favorable size ratio variation
labially positioning incisors will (increase/decrease) arch length
increase
Increase in canine arch widths for males and femalse are esentially complete when
- Male= 10
- Female= 8.5-9
Maxillary and mandibular incisor liability numbers are
Maxillary= 7.6 mm Mandibular= 6 mm
What is leeway space
size differential between primary and permenant posterior teeth
- Deciduous and permenant canines
- Primary 1st moalr and permenant 1st PM
- Primary 2nd molar and permenant 2nd PM
What is the difference between Early mesial drift and late mesial drift
Early= spaced deciduous teeth Late= no deciduous spacing
Permenant teeth pierce ridge at _ root formation
2/3
Permenant teeth pierce gingival margin at _ root formation
3/4
Increase in age –> (increase/decrease) in arch width and (increase/decrease) in arch length
increase… decrease
How is arch length measured
- Horizontal line drawn from mesial of permenant 1st molars
- Vertical line measured from that line to the labial incisors
Arch circumference is (greater/less) at an older age compared to younger age
less
T/F Skeletal growth increments not accurately predicted but space for tooth alignment is well predicted
t
Signs of malocclusion
- Lack of spacing in primary teeth
- Crowding of incisors in mixed dentition
- Premature loss of deciduous canines (esp unilateral)
Premature loss in arch length may be a result of
- ectopic eruption
- Blocked out maxillary canines or mandibular 2nd PMs (due to early eruption of 2nd molars)
