Flashcards in CFD10 : Dental chronology Deck (31)
What is eruption?
tooth moves from bone into the mouth into occlusion
what forms first out of the crown and the roots?
what is calcification?
hard tissue appearing in the developing tooth
why learn dental chronology?
– calcification start
– crown complete
– root completion
what is visible radiographically?
why is learning eruption important?
-assess correct "dental age"
-detect abnormalities in eruption
Describe the gum pads at brith.
– over A‐D’s at birth
– separated by tongue
– usually +ve Over Jet
– u.e. teeth crowded
– rapid growth in 1st year
When does tooth development start in deciduous dentition?
6 weeks i.u
when do tooth germs form in deciduous dentition?
3rd-4th month i.u
when does the first deciduous tooth erupt?
when is the deciduous dentition complete?
2.5 years (approx)
What is the order of deciduous eruption?
-6 months - lower A's
-7 months - upper A's
-7 months - lower B's
-8 months- Upper B's
-12-16 months - Ds
-16-20 months - C's
-20-30 months - E's
why do D's erupt before C's?
stabilise the occlusion
when is initial calcification (in -utero) of deciduous dentition?
-3-4.5 months - A's
-4.5 months - B's
-5 months - C's
-5 months - D's
-6 months - E's
when is crown completion of deciduous dentition?
-4 months - A's
-4.5-5 months - B's
-9 months - C's
- 6 months - D's
-10-12 months - E's
when does root completion of deciduous dentition occur?
1- 1.5 years after eruption
what is the variation in eruption ?
Note - much variation in eruption dates e.g A's can appear as late as 1 year old
what are deciduous dentition features?
-to (approx) 6 years
-frequently incisor spacing
-anthropoid (primate) spaces
-flush distal edges of E's
-permanent dentition developing
what are anthropoid or primate spaces?
bigger spaces between the upper A and the C and the lower C and D
what is attrition?
teeth are worn down , lower teeth drift forward and produce medial step
when does eruption of permanent dentition commence?
-start of the mixed dentition
what happens when permanent teeth erupt?
deciduous teeth start to be shed
Do you have to lose all deciduous teeth for permanent teeth to come in?
No - difference in accessional and successional teeth
what permanent tooth erupts first?
usually 6’s erupt first then lower 1’s
What is the order of permanent eruption?
-6-7 years- 6s
-6-7 years - lower 1's
-7-8 years - lower 2's
-7-8 years - upper 1's
-8-9 years - upper 2's
-9-10 years - lower 3's
-10-12 years - 4's
-10-12 years - 5's
-11-12 years - upper 3's
-12-13 years - 7's
-17-21 years - 8's
what can u feel high in the sulcus upper the C?
what is the 1st signs of calcification?
-1st signs of calcification :
6's - around birth or just before
7's- 2.5 - 3.5 years
8's - 7-9 years (upper) , 8-10 years (lower)
-rest of teeth during first 2 years
when are the crown completion of permanent dentition?
-1's and 2's - 4-5 years
-3's - 6-7 years
-4's - 5-6 years
-5's - 6-7 years
-6's - 2.5-3 years
-7's - 7-8 years
-8's - 12-16 years
when does root completion in permanent dentition occur?
2-3 years after eruption