CH. 8 Oral embryology and histology Flashcards
Embryology
Study of prenatal development through the stages of birth
Histology
Study of structure and function of tissues
Three periods of prenatal development
- preimplantation
2.embryonic
3.Fetal
Most critical stage of prenatal development and why
Embryonic. The stage where all major structures in the body begin to form
When does preimplantation occur
Beginning of the 2nd week to the 8th week
When does the fetal period occur
From the 9th week until birth
The THREE primary embryonic layers
1.ectoderm (outer layer)
2.mesoderm (middle layer)
3. Endoderm (inner layer)
Antibiotic a pregnant woman should not take and what does it cause
Tetracycline. It causes stain to the babies teeth.
What can developmental disturbances be caused by?
Environmental and genetic factors
When does facial development occur?
Between the 5th and 8th week
When does the first sign of tooth development occur?
when the embryo is 5-6 weeks old
When are all primary teeth developed?
17th week
Teratogens
Adverse environmental influences that cause birth defects (drugs, alcohol, exposure to xray)
Resorption
Removal/dissolving of bone
Deposition
process of adding new bone
Osteoblasts
cells responsible for new bone formation
Osteoclasts
cells responsible for the process of removing bone
Anodontia
Absence of one or more teeth
Supernumery teeth
Development of extra teeth
Macrodontia
Abnormally large teeth
Microdontia
Abnormally small teeth
Dens in dente
A tooth that grows into another tooh
Germination
when a single bud splits and forms two teeth
when two teeth develop from one tooth bud
when tooth germ try to divide
Fusion
Two teeth fusing together. The union of two adjacent tooth germs
