1occlusion development stages
gum pad: birth to 6-7mo
prim dent: until age 6
mixed dent: until last deciduous tooth leaves
perm dent: adult
2overbite
amt of vertical coverage of mand teeth by max
vary from edge-edge to 40%
3overjet
horizontal distance between max and mand teeth
vary from 0-4m
4all prim teeth are usually erupted by when
30mo
5sequence of primary dent eruption
centrals, laterals, 1m, k9, 2m
6spaces for prim dent
usually seen and desirable to make room for perm dent
7does prim dent display occlusal wear
yes bc interarch relationship of prim dent is edge to edge
8occlusal classification for prim dent
based on relationship between 2m in sagittal plane: flush terminal plane, mesial step, distal step
9what occl class do most children have
flush or 1mm+ mesial step
10flush terminal plane
2Ms are in line with each other
11mesial step
mandibular 2M more mesial than max 2m
12distal step
mand 2m more distal than max 2m
13what causes failure of eruption of permanent teeth
trauma, supernumerary, early loss of primary tooth with scar tissue
14midline diastema of mixed dent is most frequent at age
6
15in mixed dentition, crowded arches can show
premature loss of primary canine
loss of space for perm canines
16leeway space
diff between MD widths of primary canines,1m 2m and MD width of successors
diff should be POSITIVE! accomodates size of perma teeth
17leeway space averages
max 1.3mm
mand 3.1mm
18what usually erupts first into leeway space
molar, helps attain class I
19arch width change in mixed dent
intercanine and intermolar width inc
20arch length change in mixed dent
dec slightly due to loss of leeway space and centrals uprighting