Orofacial Structures & Tooth Development

Front 1

Weeks of orofacial development

Structures of orofacial development

Back 1

4 -12

palate, nasal septum, nasal cavity and tongue

Front 2

Palatal Development

Back 2

Starts in week 5 - week 12

2 structures - primary & secondary palate

3 stages

Forms from fusion of different structures

Front 3

Primary Palate starts in what week with what structure?

Back 3

Starts in week 5

Formation of the intermaxillary segment

Front 4

Intermaxillary segment

Back 4

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

Front 5

Primary palate

Back 5

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

Front 6

Premaxillary portion of maxilla location

Back 6

Anterior to the incisive foramen & contains maxillary incisor teeth

Front 7

Secondary Palate Formation week and structure

Back 7

Week 6

when maxillary processes give rise to palatal shelves AKA lateral palatine processes

Front 8

Growth and surrounding tissue of secondary palate

Back 8

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.

Front 9

Secondary palate gives rise to

Back 9

Posterior 2/3 of the hard palate.

Maxillary canines and posterior teeth.

Soft palate

Uvula

Front 10

Fusion of lateral palatine processes

Back 10

Median palatine raphe (tissue)

median palatine suture (bone)

Front 11

Completion of palate occurs in what week when this happens

Back 11

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.

Front 12

In the soft palate during completion

Back 12

mesenchyme from 1st & 2nd branchial arches migrate to form palatal muscles

Front 13

Incisive foramen

Back 13

A small canal at the junction of the primary & secondary palates

Front 14

Bony fusion of hard palate is completed when

Back 14

1 year after birth

why thumb sucking is an issue.

Front 15

Cleft Palate

Back 15

Failure of shelves (lateral palatine processes) to fuse.

Hereditary or Environmental.

1/2500 births.

Females.

With or without cleft lip.

Front 16

Cleft Uvula

Back 16

AKA incomplete cleft palate.

Mildest of cleft palate.

2% of births.

Native Americans 10%.

Ranges in varying degrees.

Front 17

Nasal Cavity and Septum happen in what weeks with this occurrence

Back 17

Week 5-12 same as palate

With fusion of medial nasal processes

Front 18

Nasal Palate and Nasal Septum fusion begins and ends in what weeks

Back 18

Starts week 9 and completes in week 12.

Results in paired nasal cavity completely separate from oral cavity.

Front 19

Nasal septum increases vertical length sevenfold in what weeks

Back 19

Weeks 10 to birth

Front 20

Tongue Development happens in what weeks

Back 20

Weeks 4-8

Front 21

Tongue is developed from what

Back 21

first 4 branchial arches

Front 22

1st branchial arch

Back 22

body

Front 23

2nd, 3rd, & 4th baranchial arches

Back 23

Base

Front 24

Grooves between the arches are eliminated by what

Back 24

Fusion

Growth

Migrating and

Merging of mesenchyme into the grooves.

Front 25

Body of the tongue begins in what week with what occurance

Back 25

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).

Front 26

Lateral lingual swellings (1)

OR

distal tongue buds

Back 26

Oval swellings on each side of the tuberculum impar. (2)

From mesenchyme of 1st baranchial arch

Front 27

Body formed when

Back 27

lateral swellings grow and merge

Front 28

Median lingual sulcus formed

Back 28

with/ at fusion of lateral swellings

Sulcus frees tongue from the floor of mouth except for lingual frenum

Front 29

Base of tongue

Back 29

from copula swellings

Front 30

Copula swellings (3)

Back 30

Posterior to lateral lingual swellings.

Front 31

Copula comes from

Back 31

the fusion of mesenchyme of the 3rd & 4th branchial arches.

Front 32

Copula overgrows

Back 32

the 2nd arch (hyoid) to form base of the tongue.

Front 33

Epiglottic swelling (4)

Back 33

Posterior to copula

From 4th branchial arch

Gives rise to most posterior portion of the tongue.

Front 34

Completion of tongue in what week with what occurance

Back 34

8th week

When lateral lingual swellings and copula fuse to complete tongue at the sulcus terminalis (landmark of fusion).

Front 35

Foramen cecum

Back 35

Posterior to the sulcus terminalis

The beginning of the thyrolglossal duct

Front 36

tyroglossal duct

Back 36

Origin and pathway for the thyroid gland into the neck.

After migration,duct disappears.

Front 37

After 8 weeks of tongue development

Back 37

Tongue swellings have fused and moves anterior to avoid interference with palatal formation.

Front 38

Tongue at Birth

Back 38

is in oral cavity proper

Front 39

Age 4

Back 39

Base and epiglottis descend into the oropharynx

Front 40

Tongue between birth and puberty

Back 40

doubles in length, width, and thickness

Front 41

Tongues nerves

Back 41

innervated by various cranial nerves due to each branchial arch having its own nerve

Front 42

Papilla

Back 42

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

Front 43

Taste buds

Back 43

week 11-13

From interaction between cells of tongue and nerve cells of facial & glossopharyngeal nerves

Front 44

Ankyloglossia

Back 44

Tongue -tied

Lingual frenum is short and toward the apex.

Restricts movement, but may stretch over time.

Front 45

Odentogenesis

Back 45

Development of teeth.

Many stages.

No definite beginning or end.

Front 46

Stages of odentogenesis

Back 46

Initiation Stage

Bud Stage

Cap Stage

Bell Stage

Apposition

Maturation

Front 47

Developmental process of teeth

Back 47

IPDMM

Overlapping and continual

One dominant in each stage

Front 48

Development begins

Back 48

mandibular anterior first

Maxillary anterior

then posterior

Not all teeth develop at the same time.

Front 49

Development of primary teeth

Back 49

Embryonic & Fetal periods

Front 50

Development of permanent teeth

Back 50

Start in fetal period but odontogenesis continues years after birth

Front 51

TEETH HAVE LONGEST DEVELOPMENT PERIOD OF ANY OTHER ORGAN IN THE BODY

Back 51

fetal - 21 years (3rd molar)

Front 52

Initiation Stage

Back 52

Weeks 6-7

Mesenchyme interacts with ectoderm to initiate odontogenesis

Front 53

Dental arches

Back 53

oral epithelium from ectoderm in 2 horse-shoe shaped bands of tissue at the surface of stomodeum.

Front 54

Ectomesenchyme

Back 54

Deep to oral epithelium.

Derived from migrating neural crest cells.

Front 55

Basement membrane

Back 55

Separates the oral epithelium and ectomesenchyme

Front 56

Dental Lamina

Back 56

Composed of a strand of oral epithelium that grows deeper into the ectomesenchyme

Front 57

Formation

Back 57

Starts at midline the progress to posterior.

Why anterior teeth develop first.

Front 58

Bud Stage

Back 58

8 weeks

Proliferation ONLY, cellular structure does not change.

Front 59

Buds

Back 59

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

Front 60

Teeth are

Back 60

ectodermal & mesenchymal

Front 61

Space with no buds

Back 61

dental lamina thickens and disintegrates as oral mucosa lines the oral cavity

Front 62

Cap Stage

Back 62

9-10 weeks

Proliferation, Differentiation, and morphogenesis

Dental Lamina grows to cap shape

Front 63

Predominant process in cap stage is

Back 63

Morphogenesis

Due to formation of primordium or the tooth germ

Front 64

Enamel Organ

Back 64

Depression in deepest part of bud.

Originated from from ectoderm.

Innermost part gives tooth its forms i.e. cusps

Front 65

Ectomesenchymal mass

Back 65

Is deep to the bud.

Lies within the cap concavity.

Front 66

Dental Papilla

Back 66

inner mass of ectomesenchyme

Gives rise to dentin and pulp (mesenchymal origin)

Front 67

Dentinoenamel Junction

Back 67

basement membrane between enamel organ ad dental papilla

Front 68

Dental sac/ dental follical

Back 68

Remaining mass around the cap.

Gives rise to periodontium (cementum, PDL, Aveolar bone which is mesenchymal originated)

Front 69

Dental sac and enamel organ

Back 69

separated by basement membrane

Front 70

Tooth germ

Back 70

End of cap stage.

Formed by enamel organ, dental papilla, and dental sac.

Front 71

Initiation in anterior for permanent dentition begins

Back 71

10th week

Cap stage of primary dentition

Appear as an extension of the dental lamina into the ectomesenchyme lingual to primary tooth germs.

Front 72

Sight of origin for initiation of permanent dentition

Back 72

Successional dental lamia

Front 73

Permanent molars develop from

Back 73

A Posterior extension of the dental lamina

Distal to the dental lamina of the primary second molar

Front 74

Bell Stage

Back 74

4th Stage

Weeks 11-12

PDM (proliferaion, differentiation, morphogenesis)

Differentiation to FULLEST extent creating 4 types of cells

Front 75

4 types of cells

Back 75

Outer Enamel Epithelium (OEE)

Inner Enamel Epithelium (IEE)

Stellate reticulum (wave/net)

Stratum intermedium

*these cells transform cap to bell

Front 76

OEE

Back 76

outer layer of enamel organ that protects it during enamel formation

Front 77

IEE

Back 77

inner layer of cells that differentiate into ameloblasts

Front 78

ameloblasts

Back 78

enamel secreting cells

Front 79

Stellate reticulum & stratum intermedium

Back 79

layers between the OEE & IEE to help support enamel production

Front 80

Bell Stage Dental papilla

Back 80

differentiates into 2 layers

inner cells- pulp

outer cells- odontoblasts dentin secreting

Front 81

Bell stage dental sac

Back 81

increases collagen fibers

later becomes cementum, PDL, and bone

Front 82

Apposition & Maturation

Back 82

Final stages of odontogenesis

Front 83

Matrix

Back 83

enamel, dentin, cementum in successive layers

Partially calcified frame work for later calcification.

Front 84

Maturation

Back 84

when tissues are fully mineralized

time period depend on tooth involved

Front 85

During apposition

Back 85

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.

Front 86

Enamel and coronal dentin production includes formation of

Back 86

Preameloblasts

Odontoblasts

Dental Matrix

Ameloblasts

DEJ

Enamel Matrix

Front 87

Preameloblasts

Back 87

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)

Front 88

Repolarization

Back 88

Occurs during differentiation

Nuclei migrate away from basement membrane. Important in change of IEE cells into preameloblasts

Front 89

Odontoblasts

Back 89

Preameloblast cells induce outer dental papilla to differentiate to odontoblast.

Also Repolarize

Secrete before enamel matrix formation- dentin thicker

Front 90

Dentinogenesis

Back 90

repolarized cells line up in a mirror image

Formation of predentin

Front 91

Basement membrane of preameloblasts & predentin disintegrates

Back 91

After formation of predentin

Allows preameloblasts to come in contact with predentin (induction)

Mineralizes and becomes DEJ

Front 92

Induction of preameloblast & predentin

Back 92

Preameloblasts become ameloblasts and begin amelogenesis (making enamel matrix)

Front 93

Tomes' Process

Back 93

Where enamel is secreted

Angled part of ameloblast facing basement menbrane

Front 94

Odontoblastic Processes

Back 94

extensions left by the odontoblasts in the predentin asthey move away from basement membrane

Front 95

Dental tube

Back 95

mineralized tube that contains odontoblastic process

Front 96

Root Development takes place when

Back 96

After crown formation and eruption starts

Front 97

Cervical Loop

Back 97

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

Front 98

Hertwig's epithelial Root Sheath (HERS)

Back 98

Functions to shape the root (curved, straight, single, multiple)

Induce dentin formation in the root to be continuous with coronal dentin

Front 99

Root Dentin Formation

Back 99

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.

Front 100

Absent of enamel on roots because

Back 100

it lacks the stellate reticulum and stratum intermedium layers.

Front 101

Epithelial rests of Malassez form when and are what?

Back 101

After basement membrane and HERS disintegrates.

Cells locate in the mature PDL and CAN become cystic.

Front 102

Cementum and Pulp Formation

Back 102

.

Front 103

cementogenesis

Back 103

apposition of cementum occurs when the HERS disintegrates.

Allows undifferentiated cells to contact newly formed root dentin creating immature cementoblasts.

Front 104

Cementoid

Back 104

Cementum matrix layed by cementoblasts.

Induced by undifferendiated cells contacting dentin.

Front 105

Cementocyte

Back 105

Formed when cementocyte is trapped in the matrix its producing.

Front 106

DCL formed

Back 106

Dentinocemental junction formed when cementocytes mature and calcify cementum.

Front 107

Central dental papilla form what and when?

Back 107

Form the pulp at the same time as DCL formation.

Front 108

Multirooted Teeth

Back 108

.

Front 109

Premolars and molars start as

Back 109

single root

Front 110

Root trunk divides when

Back 110

During differential growth of the HERS

Front 111

the cervical loop does what when?

Back 111

Forms long extensions during enamel formation to correspond with with number of roots.

Front 112

Single cervical opening does what

Back 112

divides into 2 or 3 openings from extensions

Development continues as a single root would

Then pulpal surface will undergo dentinogenesis

Front 113

PDL & aveolar bone development

Back 113

.

Front 114

PDL is derived from and made of what

Back 114

Derived from ectomesenchyme of dental sac next to newly formed cementum.

Made of collagen fibers form into bundles to attach cementum to alveolar bone.

Front 115

PDL fibers

Back 115

Sharpey's fibers

Shock absorbers

Front 116

Alveoli

Back 116

socket tooth sits in.

From ectomenchymal mineralization of dental sac.