Development of the dentition Flashcards
In a newborn, what shape are the upper gum pads?
Rounded
In a newborn, what shape are the lower gum pads?
‘U’ shaped.
If a child is born with a tooth, what’s this called?
A natal tooth
What are the 3 classes of jaw relationship? Explain each class.
Skeletal class 1: Mandible 2-3mm posterior to the maxilla.
Skeletal class 2: Mandible retruded relative to the maxilla.
Skeletal class 3: Mandible protruded relative to the maxilla.
What is the order of eruption for deciduous teeth?
a,b,d,c,e.
At what age should all of the deciduous teeth have erupted by?
3
Is spacing desirable in the deciduous dentition?
Yes
At what age is there a mixed dentition?
6-13
What are the first permanent teeth to erupt?
Lower 1 or 6.
A mixed dentition has 2 stages A and B; Explain what erupts at each stage.
A: 6-8.5
First permanent molars and incisors.
B: 10-12.5
Canines, premolars and second molars.
How does the dentition accommodate permanent incisors.
Spacing in the deciduous dentition.
Permanent teeth more proclined.
What is the rule about teeth that lie proximally to one another?
The proximal tooth comes in 6 months after the tooth.
What is the rule regarding central and lateral incisors?
Central must come before lateral.
What are supernumerary teeth?
Extra teeth that come in-between the the deciduous and permeant dentition.
List and explain the bite classifications.
Anterior cross bite: Some anterior teeth lie in front of the lower and some lie behind the lower.
Increased overjet: Upper teeth project forwards.
Reversed overjet: Lower teeth lie in front of the upper teeth.
Posterior crossbite: Some upper posterior teeth lie in front of the lower and some lie behind. (mixed)
What is the order of eruption for both upper and lower stage B?
Upper: 4,5,3.
Lower: 3,4,5.
Where does arch length increase?
Length increases after/Posterior to the first deciduous molar.
What is leeway space?
The difference in size between the deciduous and permanent dentition.
What is the leeway space of the maxilla?
1.5mm
What is the leeway space of the mandible?
2.5mm
What is the ideal static occlusion?
Incisors slightly proclined.
Lower incisal edge in contact with upper cingulum.
Overbite 2-4mm.
In ideal static occlusion; what are the points of contact for some molars?
Mesiobuccal cusp of upper permanent molars occlude the buccal groove of mandibular first molar.
List and explain the 3 incisor classifications.
Class 1: Lower incisal edges occlude the cingulum of the upper incisors.
Class 2 division 1: Lower incisal edges lie posterior to the cingulum.
Class 2 division 2: Upper centrals are retroclined.
Class 3: Lower incisal edges lie anterior to the cingulum of the upper incisors.
