Head and Neck Anatomy Flashcards
NBDHE
what is the origin and formation of teeth
odonotgensis
what are the three layers of the human embryo?
- ectoderm
- mesoderm
- endoderm
epithelial linings of internal organs (stomach, intestines)
endoderm
forms skeletal and muscular systems, organs
mesoderm
outer covering of the body; lining of the oral cavity and enamel, nervous tissue
ectoderm
what week does development of the face begin?
week 3 with the formation of the stomodeum
what do the dentin, cementum, and pulp form from?
underlying connective tissue (AKA ectomesenchyme)
the primitive mouth later becomes what?
oral and nasal cavities
what does tooth enamel form from?
ectoderm lining the stomodeum
what stage is being described?
ectoderm lining the stomodeum gives rise to the oral epithelium and dental lamina
initiation stage
what stage is being described?
dental lamina grows into underlying mesenchyme (connective tissue) in 20 different places
BUD stage
what stage is being described?
enamel organ develops from the dental lamina and will produce enamel. the dental papilla arises from connective tissue (ectomesenchyme) and produces the pulp and dentin. the dental sac surrounds developing tooth and becomes the PDL, cementum, and alveolar bone
CAP stage
what stage is being described?
cells increase in number and form a bell shape. enamel organ has four distinct layers and the inner enamel epithelium becomes ameloblasts and the basement membrane separates the IEE from the dental papilla. odontoblasts from the dental papilla form dentin. the greatest extent of differentiation occurs at this stage
BELL stage
layer by layer formation of tooth structure
apposition stage
tooth tissues fully mineralize with hydroxyapatite and the hydroxyapatite is crystallized calcium phosphate
maturation stage
four layers of enamel condensed together after the production of enamel. most of this is lost after eruption
reduced enamel epithelium
remaining part of the REE after the tooth erupts
junctional epithelium
what is the importance of Hertwig’s epithelial root sheath?
- used as the “blueprint” for the root outline
- dissolves after root formation
when considering muscles of mastication, which are responsible for elevation?
- masseter
- temporalis
- medial pterygoid
when considering muscles of mastication, which are responsible for depression?
lateral pterygoid
when considering muscles of mastication, which are responsible for protrusion?
lateral pterygoid
when considering muscles of mastication, which are responsible for retrusion?
termporalis
when considering muscles of mastication, which are responsible for lateral shift?
lateral pterygoid
which movement of the TMJ elevates and depresses the mandible?
rotational or hinge movement
