57 terms

Review of the embryonic development of the face, oral cavity, and teeth

Beginning of Ch. 5 Developmental Disorders
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Terms in this set (...)

developmental disorder
a failure or disturbance that occurs during division, multiplication and differentiation of cells may result in a lack, excess, or deformity of a body part.
inherited disorders
caused by an abnormality in the genetic makeup (genes and chromosomes) of an individual and transmitted from parent to offspring through the egg or sperm.
congenital disorder
can be inherited or developmental; most causes are unknown; present at birth
proliferation and differentiation
provides numerous possibilities for errors or defects in development
what is the most common location for developmental defects.
the head and neck region because of its intricate sequence and pattern of development.
How can developmental defects be identified?
clinically, radiographically, biopsy, or histologically
If no treatment is indicated, do you record developmental anomalies observed clinically and radiographically and do you inform the patient about the anomalies?
yes
During the _____ week, ectoderm infolds to form the stomodeum, the primitive oral cavity.
third
What is the primitive oral cavity called?
stomodeum
What is above the stomodeum?
the frontal process
what is below the stomodeum?
the first brachial arch
What does the first racial arch divide into?
2 maxillary processes and the mandibular process
invagination
infolding
what does the maxillary process give rise to?
the upper part of the cheeks, the lateral portions of the upper lip, and part of the palate
What does the mandibular process give rise to?
the lower part of the cheeks, the mandible, and part of the tongue
Two pits that mark the future of the most that develop on the surface of the frontal process are:
olfactory pits
The olfactory pits divide the frontal process into 3 parts:
median nasal process, the right lateral nasal process, and the left lateral nasal process.
What forms the sides of the nose?
the lateral nasal processes
what forms the center and tip of the nose and later grows downward between the maxillary processes to a pair of bulges called the globular process?
the median nasal process
What forms from the globular process?
the premaxilla
where does the nasal septum arise from?
the median nasal process
What 3 components make a Y shaped pattern and forms the maxilla?
the lateral palatine processes and the premaxilla.
What does the body of the tongue form from?
The first branchial arch
What does the base of the tongue form from?
the second and third brachial arches.
primitive stomodeum
a shallow depression in the embryonic surface
odontogenesis
tooth development
When does tooth development begin place?
in about the fifth week of life
What does odontogenesis involve?
the ectoderm and the ectomesenchyme
What does odontogenesis begin with?
with formation of a band of ectoderm in each jaw called the primary dental lamina
____ small knoblike proliferations develop on the primary dental lamina in each jaw.
10
What do the 10 knoblike proliferations on the primary dental lamina extend in to?
the underlying mesenchyme
What do the 10 knoblike proliferations on the primary dental lamina become?
the early enamel organ for each primary tooth.
What are the 3 parts of the tooth germ?
the enamel organ, the dental papilla, and the dental sac
the enamel organ produces:
enamel
the dental papilla forms:
the dental pulp
the dental sac provides:
cells that form cementum, the periodontal ligament, and alveolar bone.
Is cementum formed before, during, or after the crown is complete?
after
What part of the tooth germ forms from the ectoderm?
the enamel organ
What part of the tooth germ forms from the mesoderm?
the dental papilla and the dental sac
Ameloblasts form
enamel
odontoblasts form:
dentin
Do the permanent, or succedaneous, enamel organs form during, before, or after the enamel organs of primary teeth form.
during
formation of dental hard tissues occur during the ____ month of gestation.
5th
dentinogenesis is:
the formation of dentin
What is the first mineralized tissue to appear?
dentin
When dentin begins to form, the mesenchymal tissue within the tooth germ is called:
the dental papilla
after dentin is formed, the dental papilla is called the:
dental pulp
When does the enamel matrix begin to form?
shortly after dentin
When does mineralization and maturation of enamel occur?
following the formation of the enamel matrix
Amelogenesis is:
the formation of enamel
___% of enamel volume is occupied by hydroxyapatite crystals.
90
Cementogenesis is:
the formation of cementum
does cementogenesis occur before, after or during crown formation.
after
What proliferates to shape the root of the tooth and induces the formation of the root dentin?
Hertwig epithelial root sheath
What must happen to the cells of the Hertwig epithelial root sheath before cementum can be produced.
they must break away from the root surface
Very little ______ is produced until the tooth has erupted and is in occlusion and functioning.
cementum
Root length is not completed until __-__ years after the tooth erupts into the oral cavity.
1-4