2 - Development of the Dentition Flashcards
Eg pt has unerupted, delayed eruption of upper canine - could cause resorption of u central or lateral incisor
Or
Growth modification for pt who has severe underlying skeletal problem - if referred at correct time, at start of pubertal growth spurt - then can do this.
Concept of ideal vs normal occlusion
What is ideal occlusion?
Ideal occlusion = Andrew’s six keys:
- Correct molar relationship - (anteriorposteriorly class 1 and molars interdigitate well in buccal segments)
- Correct crown angulation - mesial/distal tilt
- Correct crown inclination - labiolingual inclination
- No rotations
- Tight contacts
- Flat occlusal plane - so not deep overbite or anterior open bite
What is normal occlusion?
What is malocclusion
Development of deciduous dentition
1- when do deciduous teeth develop from and until
2- calcification begins when?
3- when is root formation complete after eruption?
4- when do maxillary and mandibular A-E erupt?
Ideal positions for Deciduous dentition :
(4)
What 3 things should we have at the completion of deciduous dentition?
Deciduous incisor relationship
Explain feature of lower gum pad at birth
Is overbite normal at first and what happens over the next few years?
At 5 years what occurs?
What variations often occur on ‘ideal’ deciduous incisor relationship
Overbite and overjet often depend on degree of thumb sucking
anterior open bite on left image
increased overjet on right image
Spacing between incisors - deciduous dentition
1- what is the increase in intercanine width during time deciduous incisors present?
2- If deciduous incisors are not spaced what happens to permanent dentition:
3- If crowded deciduous incisors what happens to permanent dentition:
4- How much spacing is needed in the lower arch to ensure permanent incisors are aligned?
1- 1-2mm increase in intercanine width during time deciduous incisors present
2- if deciduous incisors not spaced -> crowded permanent incisors
3- if crowded deciduous incisors -> severely crowded permanent incisors
4- in lower arch only if > 6mm spacing of deciduous incisors will permanent incisors be aligned
End to end E relationship
1- Ideal E relationship
2- Variations of E relationship
1- Es should be vertically on top of each other
2-
Class I Es -> class I 6s or class III 6s
Class II Es -> class II 6s
Class III Es -> very rare as mandible lags behind maxilla at this stage
Problems arising during development of deciduous dentition
Abnormalities in tooth tissue ratio leads to
Abnormalities in number of teeth could lead to: (3)
Abnormalities in tooth form or position leads to:
What can occur due to thumb sucking?
Also leads to increase in overjet and anterior open bite
Incisor retrusion leads to:
Posterior crossbite could be caused by?
What 2 problem could we detect in deciduous dentition
Development of the permanent dentition
1- starts at what age?
2- calcification dates
3- root formation:
4- what age do mandibular and maxillary 1-7 erupt?
If disruption eg illness at the time of the calcification may reflect in teeth being affected eg hypoplasia -if at birth could affect 6s as they calcify at this time
Take 1
