lecture 8 Flashcards
what are the 3 dental arch measurements
arch width
arch perimeter
intercanine distance
arch length (Depth) is measure at
this is measured at the midline to a tangent touching the distal surfaces of the second primary molars
what are the arch length changes with incisors erupt
lose arch length in lower
gain arch length in upper
how is arch width measured
between cusps of canines in transverse plane
and
between occlusal grooves of second primary molars (permanent first molars in mixed dentition)
arch width somewhat changes from primary to mixed dentition in lower arch. it grows until
girls=
boys=
girls= 10-11
boys= 11-12
(+3-4mm)
this is measured from distal surface of the second primary molar around the arch over the contact points and incisal edges in a smoothed curve
arch perimeter
where do the permanent first molars erupt
distal of the primary dentition
permanent tooth eruption (dental sac) does what to primary roots
resorbs them
when the primary tooth root is totally resorbed, the primary tooth exfoliates and
the permanent tooth erupts
when does the permanent tooth stop erupting
when it reaches the occlusal plane
tooth replacement variability in:
1
2
3
4
- sequence
- timing
- position
- numbers
congenitally missing teeth is rare and is ___% of the population
3-5
most frequent missing tooth
lateral incisor of upper
then mandibular second premolar
then max central incisor
fusion of part of the root of a primary tooth to the underlying bone, which stops the tooth from erupting
ankylosis
what is usually the treatment of ankylosis
monitor teeth (50% of time self correct)
if fail to exfoliate, extract tooth to avoid damages to permanent dentition
