permanent dentition Flashcards
variabilty in eruption sequence
More so than deciduous dentition, the
sequence is VARIABLE
gender differences in eruption sequence
Girls are ahead of boys in calcification and
except for the third molars, girls are ahead of boys
by an average of 5-6 months in the eruption
pattern
lower arch sequence of eruption
lower arch eruption times
maxillary eruption sequence
why would you extract the primary canine
to redirect secondary eruption path
maxillary eruption times
timing of eruption consistentcy within a dentition
Timing is consistent within a dentition –children who erupt any
tooth early or late tend to acquire others early or late
eruption of both sides coordinated?
Both sides should erupt at the same time- approximately
different eruption sequences explain what crowding?
Different eruption sequences explain most frequently crowded teeth:
maxillary cuspids to the labial with small arches and mandibular second bicuspid with impacted second molars
Local influences which hasten permanent tooth
eruption
localized pathosis: periapical lesions (abscess), pulpitis and pulpotomy? of a primary molar)
if the primary tooth is extracted during active eruption of permanent tooth
(more than 2/3 of the root formed)
Local influences which slow permanent tooth
eruption
When a primary tooth is extracted before active eruption of permanent tooth (i.e. before root formation)
arch width change in maxilla
increased/decreased?
tied to?
The increases are tied to alveolar process growth (both dental eruption and vertical process growth)
both canine and PM erupt buccally which increases width
when does arch width change
occurs during general growth “spurts”
arch width changes in maxilla vs mandible
different for maxilla and mandible: divergent maxillary process translates into more arch width growth (mandible is convergent)
dental factors of arch width changes
• Dental Eruption
▪ wider placement of the permanent teeth
▪ apposition of alveolar bone to support these teeth will result in increase in arch width
intercanine distance in mixed dentition stage
will see increase during this time
intercanine distance in perm dentition stage
will stop increase on mandible and decrease by .5mm on maxilla
overall larger on maxilla
maxillary intercanine distance will increase during:
➢increases occur during growth spurts
➢increases occur during eruption of incisors
➢large increase occurs during eruption of the cuspids
intercanine distance after canine eruption
NO SIGNIFICANT INCREASES IN INTERCANINE
WIDTH OCCUR IN EITHER THE MAXILLA OR
MANDIBLE AFTER THE ERUPTION OF PERMANENT
CANINES.
when canines erupt they bring?
bone, can be used for treatment planning
does arch perimeter change in perm dentition
yes
Variations in Dimensional changes in the Dental Arches
➢changes are quite variable
➢different for males and females
➢different for maxillary and mandibular arches (maxillary easy to expand/more bone, mandible with less expansion and bone)
max arch perimeter changes
variable?
sexes?
Variable(depends on pattern of tooth eruption)
Not difference between sexes
Factors which limit loss of maxillary arch perimeter include:
greater labial angulation of incisors, greater increases in arch width and smaller leeway space
the curve of spee with development
flat in primary dentition, begins to curve slightly with perm eruption due to differences in the anterior and posterior eruption times
curve allows for dynamic mandible movement
could become too curved with development
third molars
- Prophylactic extraction of impacted teeth is a reasonable option.
- Extraction of third molars to avoid orthodontic relapse has a weak correlation, likely just an association
