Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
116 Cards in this Set
- Front
- Back
Weeks of orofacial development Structures of orofacial development |
4 -12 palate, nasal septum, nasal cavity and tongue |
|
Palatal Development |
Starts in week 5 - week 12 2 structures - primary & secondary palate 3 stages Forms from fusion of different structures |
|
Primary Palate starts in what week with what structure? |
Starts in week 5 Formation of the intermaxillary segment |
|
Intermaxillary segment |
Result of fusion of medial nasal processes Is a wedge shaped mass inside stomodeum Develops into floor of nasal pits & nasal septum Located between the maxillary process Gives rise to primary palate |
|
Primary palate |
Starts week 5 Triangular mass Serves as a partial separation between oral & nasal cavities Later it will be the anterior 1/3 AKA premaxillary portion of the maxilla |
|
Premaxillary portion of maxilla location |
Anterior to the incisive foramen & contains maxillary incisor teeth |
|
Secondary Palate Formation week and structure |
Week 6 when maxillary processes give rise to palatal shelves AKA lateral palatine processes |
|
Growth and surrounding tissue of secondary palate |
Grow inferior ad deep with in stomodeum along both sides of developing tongue that moves out of the way. Grow vertical, then flip to grow horizontally upward. Shelves elongate, move medially, and fuse. |
|
Secondary palate gives rise to |
Posterior 2/3 of the hard palate. Maxillary canines and posterior teeth. Soft palate Uvula |
|
Fusion of lateral palatine processes |
Median palatine raphe (tissue) median palatine suture (bone) |
|
Completion of palate occurs in what week when this happens |
In the 12th week When the primary and secondary palates fuse at which time bone has begun to form in anterior hard palate. This separates oral and nasal cavities. |
|
In the soft palate during completion |
mesenchyme from 1st & 2nd branchial arches migrate to form palatal muscles |
|
Incisive foramen |
A small canal at the junction of the primary & secondary palates |
|
Bony fusion of hard palate is completed when |
1 year after birth why thumb sucking is an issue. |
|
Cleft Palate |
Failure of shelves (lateral palatine processes) to fuse. Hereditary or Environmental. 1/2500 births. Females. With or without cleft lip. |
|
Cleft Uvula |
AKA incomplete cleft palate. Mildest of cleft palate. 2% of births. Native Americans 10%. Ranges in varying degrees. |
|
Nasal Cavity and Septum happen in what weeks with this occurrence |
Week 5-12 same as palate With fusion of medial nasal processes |
|
Nasal Palate and Nasal Septum fusion begins and ends in what weeks |
Starts week 9 and completes in week 12. Results in paired nasal cavity completely separate from oral cavity. |
|
Nasal septum increases vertical length sevenfold in what weeks |
Weeks 10 to birth |
|
Tongue Development happens in what weeks |
Weeks 4-8 |
|
Tongue is developed from what |
first 4 branchial arches |
|
1st branchial arch |
body |
|
2nd, 3rd, & 4th baranchial arches |
Base |
|
Grooves between the arches are eliminated by what |
Fusion Growth Migrating and Merging of mesenchyme into the grooves. |
|
Body of the tongue begins in what week with what occurance |
4th week With tuburculum impar or median tongue swelling is a triangular median swelling at midline on the floor of primitive pharynx on mandibular arch (1st). |
|
Lateral lingual swellings (1) OR distal tongue buds |
Oval swellings on each side of the tuberculum impar. (2) From mesenchyme of 1st baranchial arch |
|
Body formed when |
lateral swellings grow and merge |
|
Median lingual sulcus formed |
with/ at fusion of lateral swellings Sulcus frees tongue from the floor of mouth except for lingual frenum |
|
Base of tongue |
from copula swellings |
|
Copula swellings (3) |
Posterior to lateral lingual swellings. |
|
Copula comes from |
the fusion of mesenchyme of the 3rd & 4th branchial arches. |
|
Copula overgrows |
the 2nd arch (hyoid) to form base of the tongue. |
|
Epiglottic swelling (4) |
Posterior to copula From 4th branchial arch Gives rise to most posterior portion of the tongue. |
|
Completion of tongue in what week with what occurance |
8th week When lateral lingual swellings and copula fuse to complete tongue at the sulcus terminalis (landmark of fusion). |
|
Foramen cecum |
Posterior to the sulcus terminalis The beginning of the thyrolglossal duct |
|
tyroglossal duct |
Origin and pathway for the thyroid gland into the neck. After migration,duct disappears. |
|
After 8 weeks of tongue development |
Tongue swellings have fused and moves anterior to avoid interference with palatal formation.
|
|
Tongue at Birth |
is in oral cavity proper |
|
Age 4 |
Base and epiglottis descend into the oropharynx |
|
Tongue between birth and puberty |
doubles in length, width, and thickness |
|
Tongues nerves |
innervated by various cranial nerves due to each branchial arch having its own nerve |
|
Papilla |
Lingual papilla - end of week 8 Then circumvallate and foliate lingual papilla near branch of glossopharyngeal nerve. Then Fungiform near cord tympani of facial nerve. Last filiform papilla in weeks 10-11 LC FOFUFI |
|
Taste buds |
week 11-13 From interaction between cells of tongue and nerve cells of facial & glossopharyngeal nerves |
|
Ankyloglossia |
Tongue -tied Lingual frenum is short and toward the apex. Restricts movement, but may stretch over time. |
|
Odentogenesis |
Development of teeth. Many stages. No definite beginning or end. |
|
Stages of odentogenesis |
Initiation Stage Bud Stage Cap Stage Bell Stage Apposition Maturation |
|
Developmental process of teeth |
IPDMM Overlapping and continual One dominant in each stage |
|
Development begins |
mandibular anterior first Maxillary anterior then posterior Not all teeth develop at the same time. |
|
Development of primary teeth |
Embryonic & Fetal periods |
|
Development of permanent teeth |
Start in fetal period but odontogenesis continues years after birth |
|
TEETH HAVE LONGEST DEVELOPMENT PERIOD OF ANY OTHER ORGAN IN THE BODY |
fetal - 21 years (3rd molar) |
|
Initiation Stage |
Weeks 6-7 Mesenchyme interacts with ectoderm to initiate odontogenesis |
|
Dental arches |
oral epithelium from ectoderm in 2 horse-shoe shaped bands of tissue at the surface of stomodeum. |
|
Ectomesenchyme |
Deep to oral epithelium. Derived from migrating neural crest cells. |
|
Basement membrane |
Separates the oral epithelium and ectomesenchyme |
|
Dental Lamina |
Composed of a strand of oral epithelium that grows deeper into the ectomesenchyme |
|
Formation |
Starts at midline the progress to posterior. Why anterior teeth develop first. |
|
Bud Stage |
8 weeks Proliferation ONLY, cellular structure does not change. |
|
Buds |
When dental lamina undergoes proliferation. Oval masses that penetrate ectomesenchyme. 10 buds per arch that develop into tooth germs. Give rise to teethand surrounding tissues |
|
Teeth are |
ectodermal & mesenchymal |
|
Space with no buds |
dental lamina thickens and disintegrates as oral mucosa lines the oral cavity |
|
Cap Stage |
9-10 weeks Proliferation, Differentiation, and morphogenesis Dental Lamina grows to cap shape |
|
Predominant process in cap stage is |
Morphogenesis Due to formation of primordium or the tooth germ |
|
Enamel Organ |
Depression in deepest part of bud. Originated from from ectoderm. Innermost part gives tooth its forms i.e. cusps |
|
Ectomesenchymal mass |
Is deep to the bud. Lies within the cap concavity. |
|
Dental Papilla |
inner mass of ectomesenchyme Gives rise to dentin and pulp (mesenchymal origin) |
|
Dentinoenamel Junction |
basement membrane between enamel organ ad dental papilla |
|
Dental sac/ dental follical |
Remaining mass around the cap. Gives rise to periodontium (cementum, PDL, Aveolar bone which is mesenchymal originated) |
|
Dental sac and enamel organ |
separated by basement membrane |
|
Tooth germ |
End of cap stage. Formed by enamel organ, dental papilla, and dental sac. |
|
Initiation in anterior for permanent dentition begins |
10th week Cap stage of primary dentition Appear as an extension of the dental lamina into the ectomesenchyme lingual to primary tooth germs. |
|
Sight of origin for initiation of permanent dentition |
Successional dental lamia |
|
Permanent molars develop from |
A Posterior extension of the dental lamina Distal to the dental lamina of the primary second molar |
|
Bell Stage |
4th Stage Weeks 11-12 PDM (proliferaion, differentiation, morphogenesis) Differentiation to FULLEST extent creating 4 types of cells |
|
4 types of cells |
Outer Enamel Epithelium (OEE) Inner Enamel Epithelium (IEE) Stellate reticulum (wave/net) Stratum intermedium *these cells transform cap to bell |
|
OEE |
outer layer of enamel organ that protects it during enamel formation |
|
IEE |
inner layer of cells that differentiate into ameloblasts |
|
ameloblasts |
enamel secreting cells |
|
Stellate reticulum & stratum intermedium |
layers between the OEE & IEE to help support enamel production |
|
Bell Stage Dental papilla |
differentiates into 2 layers inner cells- pulp outer cells- odontoblasts dentin secreting |
|
Bell stage dental sac |
increases collagen fibers later becomes cementum, PDL, and bone |
|
Apposition & Maturation |
Final stages of odontogenesis |
|
Matrix |
enamel, dentin, cementum in successive layers Partially calcified frame work for later calcification. |
|
Maturation |
when tissues are fully mineralized time period depend on tooth involved |
|
During apposition |
induction occurs between enamel and msenchyme of dental papilla and dental sac. Critical interaction by basement membrane for the formation of enamel, dentin, and cementum. |
|
Enamel and coronal dentin production includes formation of |
Preameloblasts Odontoblasts Dental Matrix Ameloblasts DEJ Enamel Matrix |
|
Preameloblasts |
Elongated cells formed from differentiation of IEE cells. Induce dental papilla cells to differentiate in to denti-forming cells (odontoblasts). Differentiate into ameloblasts (enamel secreting) |
|
Repolarization
|
Occurs during differentiation
Nuclei migrate away from basement membrane. Important in change of IEE cells into preameloblasts |
|
Odontoblasts |
Preameloblast cells induce outer dental papilla to differentiate to odontoblast. Also Repolarize Secrete before enamel matrix formation- dentin thicker |
|
Dentinogenesis |
repolarized cells line up in a mirror image Formation of predentin |
|
Basement membrane of preameloblasts & predentin disintegrates |
After formation of predentin Allows preameloblasts to come in contact with predentin (induction) Mineralizes and becomes DEJ |
|
Induction of preameloblast & predentin |
Preameloblasts become ameloblasts and begin amelogenesis (making enamel matrix) |
|
Tomes' Process |
Where enamel is secreted Angled part of ameloblast facing basement menbrane |
|
Odontoblastic Processes |
extensions left by the odontoblasts in the predentin asthey move away from basement membrane |
|
Dental tube |
mineralized tube that contains odontoblastic process |
|
Root Development takes place when |
After crown formation and eruption starts |
|
Cervical Loop |
Responsible for root formation. Most cervical part of enamel organ. Consists of IEE & OEE Grows deep into sac Moves away from the crown to enclose more dental papilla to form HERS |
|
Hertwig's epithelial Root Sheath (HERS) |
Functions to shape the root (curved, straight, single, multiple) Induce dentin formation in the root to be continuous with coronal dentin
|
|
Root Dentin Formation |
Formed by induction and differentiation of the outer dental papilla cells into odontoblasts that produce dentin. Process similar to enamel and dentin formation under influence of IEE. |
|
Absent of enamel on roots because |
it lacks the stellate reticulum and stratum intermedium layers. |
|
Epithelial rests of Malassez form when and are what? |
After basement membrane and HERS disintegrates. Cells locate in the mature PDL and CAN become cystic. |
|
Cementum and Pulp Formation |
. |
|
cementogenesis |
apposition of cementum occurs when the HERS disintegrates. Allows undifferentiated cells to contact newly formed root dentin creating immature cementoblasts. |
|
Cementoid |
Cementum matrix layed by cementoblasts. Induced by undifferendiated cells contacting dentin. |
|
Cementocyte |
Formed when cementocyte is trapped in the matrix its producing. |
|
DCL formed |
Dentinocemental junction formed when cementocytes mature and calcify cementum. |
|
Central dental papilla form what and when? |
Form the pulp at the same time as DCL formation. |
|
Multirooted Teeth |
. |
|
Premolars and molars start as |
single root |
|
Root trunk divides when |
During differential growth of the HERS |
|
the cervical loop does what when? |
Forms long extensions during enamel formation to correspond with with number of roots. |
|
Single cervical opening does what |
divides into 2 or 3 openings from extensions Development continues as a single root would Then pulpal surface will undergo dentinogenesis |
|
PDL & aveolar bone development |
. |
|
PDL is derived from and made of what |
Derived from ectomesenchyme of dental sac next to newly formed cementum. Made of collagen fibers form into bundles to attach cementum to alveolar bone. |
|
PDL fibers |
Sharpey's fibers Shock absorbers |
|
Alveoli |
socket tooth sits in. From ectomenchymal mineralization of dental sac. |