23 terms

Dental Anatomy module IV

What is derived from mesoderm?
dentin, pulp, cementum, peridontal ligament, some aveolar bone
Enamel organ
enamel-derived from Ectoderm
Dental papilla
mesoderm cells which form the dentin and pulp
Dental Sac
mesoderm cells which forms cementum, periodontal ligament, and alveolar bone
Dental lamina
-1st sign of tooth formation
-stratified squamous epithelium thickens into underlying connective tissue
Enamel organ
-part of Dental lamina that forms enamel
-derived from ectoderm
Enamel organ goes through 3 stages
bud, cap, bell
inital budding from dental lamina at 10 thickened areas in each arch
-root formation=6 weeks
-deepedy parts of buds become slightly concave the
-the concavity of the cap grows
***-Stratum Intermedium layer appears
Successional lamina
-extends off dental lamina for perm tooth development
-Goes through bud, cap, bell stage
-perminant teeth that follow primary teeth
Primate space
-for secondary teeth
-found mesial to Max. primary canines
-found distal to mand. canines
-ALL primates have this space
Leeway space
-the difference between the space that deciduous(primary) molars
-larger in size
-take up a lot of space so when perminent replacements, which are smaller, have pleny of room when they erupt
Mesial drift
molars continuing to move mesially (forward) after eruption
Has 2 effects:
-spaces b/w primary teeth are closed as the perm. 1st molars push primary molard together
-if primary teeth lost early or interproximal decay is present and is not restored, the perm. molar will move mesially and fill that space
Characteristics of Primary teeth
-Constricted occlusal table
-Short root trunks
-Roots flare apically
-Large pulp chambers
-Enamel thin and consistent depth
Primary Occlusion
-Flush terminal plane
-Distal step
-Mesial step
Flush terminal plane
distal surfaces of Primary 2nd molars are even w/ each other
Distal step
-the mand. molars are more distal than max. molars
-Angles class II
Mesial step
-the mand. molars are more mesial than max. molars
-Angles class III
-majority of children
Eruption dates primary teeth
Mand 1st molar-> 6-7yrs (Nonsuccedaneous)
Max. 1st molar-> (Nonsuccedaneous)
Mand central-> 7-8yrs
Max central
Mand lateral 8-9yrs
Max lateral
Mand canine-> 9-10yrs
Mand 1st premolar-> 10-12yrs
Max 1st premolar
Max 2nd premolar
Max canine->11-12yrs
Mand 2nd premolar
Mand 2nd molar-> 12-13yrs (Nonsuccedaneous)
Max 2nd molar-> (Nonsuccedaneous)
Mand 3rd molar-> 17-22yrs-> (Nonsuccedaneous)
Max 3rd molar-> (Nonsuccedaneous)
perm teeth that does NOT replace deciduous teeth
Ex: perm molar, Max 2nd premolar
perm teeth that take the place of deciduous teeth
Mand canine
comes in 3 yrs later than max canines