Eruption and Shedding of Teeth

_______Phase:

-   Includes all movement of primary & permanent teeth from ______to ______completion, and movement is within the tooth crypts. Phase ends with root______.

Preeruptive

initiation

crown

formation

Developing crowns respond to:

o   ______ ______of neighboring crowns

o   Changes to____  and ____as they grow and mature

o   Lengthening of jaws causes ___and ___ movement

Position changes

maxilla

mandible

mesial

distal

Early,  permanent incisors develop _____to the primary incisors

lingual

_______ ______move to be positioned within the roots of the primary molars

Permanent premolars

Permanent maxillary molars have a __ tilt, permanent mandibular molars have a __ tilt

distal

mesial

______ ______Phase:

-   Begins with root formation and ends with _____ _____

Prefunctional Eruptive

occlusal contact

Root formation

o   Requires space for root_____

o   Starts with proliferation of _____

o   This starts formation of root____  and ____ tissue

o   Root formation also causes an _____fibrous tissue of the follicle

elongation

Hertwig’s epithelial root sheath

dentin

pulp

increase

Prefunctional Eruptive Phase

Movement in ____or ____direction through the bony crypt

o   Occurs to develop space for _____ ______

o   Reduced enamel epithelium and oral epithelium _______and then fuse

incisal

occlusal

enlarging roots

proliferate

The tip of the crown _____the fused epithelial layer

o   Enamel is covered at this point with developmental ___ ____

penetrates

primary cuticle

____/____movement continues until contact with the opposing tooth occurs

 Occlusal/incisal

Clinical crown – extends from cusp tip to _________ ___________

gingival attatchment

Anatomic crown – extends from cusp tip to ______

cemento-enamel-junction

Tissue Changes

o   Overlying the teeth

§  Dental follicle changes to form an_____ ______

§  ____tissue, _____and ____fragment

§  Area forms an_____  triangle – the eruption pathway

§  ____ _____– follicular fibers guide teeth to complete eruption

eruptive pathway

Connective, blood vessels,nerves

inverted

Gubernacular cord

Teething

• First tooth erupts into mouth around _____of age: mandibular ____ ____

• Many parents will tell you that teething is associated w fussiness, fever, diarrhea, and increased salvation in their child

• 6-8 months

• central incisors

__________ release enzymes to destroy cells, nerves, vessels

Macrophages

Bone loss w/ aid of _____remodel _____

osteoclasts/osteoblasts

alveolus

Permanent anterior teeth have eruption paths_____  to _____anterior teeth

·  Evidenced by foramina in ______regions 

lingual

primary

incisal

  _____resorption of primary teeth similar to bone resorption

Foramina on the _____ aspect of the primary incisors facilitate 

Dentin

palatal

Hard tissue resorption

o   ______ →  Osteoblasts →  Fusion to form __________

O Monocytes undergo fusion to form  _____

o   Separate mineral from collagen matrix via ______ in lacunae

o   Ruffled border of _____ increase efficiency

O ____ and _____ remodel collagen fibers 

Monocytes

Multinucleated Osteoclasts

multinucleated osteoclasts

hydrolytic enzymes

osteoclasts

Fibroblasts,fibroclasts

Two phases

§  – mineral separated from collagen

§  – ingestion/dissolution of minerals by osteoclasts

§  Fibroblast-fibroclast cells_____  collagen fibers

Extracellular

Intracellular

destroy

_____ molars move through bone (no overlying primary teeth)

§  Reduced _____epithelium contacts _____ epithelium – these fuse

§  Fused epithelium also fuses with developmental ____

§  Epithelium ruptures, forms attached ____

§  Clinical crown appears and erupts into ____

Permanent

enamel

oral

cuticle

gingiva

occlusion

Overlying the teeth/ Tissue Changes 

§  Increase in____ ____ area corresponds to length of eruption of the crown

§  _____form collagen around root apex, become attached to the root via fibers adhering to _____

§  A _____ (bony) ladder forms between the roots – increases in density

§  ______ (dense bone) forms around apex and adjacent alveolar bone

root apex

Fibroblasts

cementum

trabecular

Cortical

• Trauma has more favorable outcomes in younger patients because their _____are open 

-More  _____

-Improved____

apices

vascular

healing

Functional Eruptive Phase:

-   Starts when teeth move into functional _____ with opponents (opposing teeth)

-   Root canal space____ due to maturation of the root dentin

-   ____ completion continues even after functional occlusion achieved

o   Primary teeth – ____years

o   Permanent teeth – _____years

-   _____ ____increases and ____ ____ fibers orient to mature state

o   Fibers stabilize and ____ ____ provide nutrients

-   _____ continues to be deposited throughout life

occlusion

narrows

Root

1 – 1.5

2  to 3

Bone density

periodontal ligament

teeth, blood vessels

Cementum

Causes of Tooth Eruption

-   Root growth (along with periodontal ligament/alveolar bone modifications)**

-   Pulpal p’ressure

-   Cell proliferation

-   Increased vascularity

-   Enzymatic degradation

-   Tooth thought to move from an area of increased pressure to decreased pressure

Humans are _____– two dentitions

diphyodont

_____ dentition - functions from about 2-6 years of age

Primary

______dentition – functions from about 6-12

mixed

 ______Dentition- after shedding of last primary tooth at 12 years

Permanent

Degeneration of the pulp

o   Loss of_____ , _____trunk degeneration, ____ _____density decrease

o   The child does not feel pain due to ____and the tooth becomes non-responsive to _____pain as it nears exfoliation

#Nerve fibers organize into a ____ ____in the pulp chamber of the primary tooth 

o   Once roots are resorbed, tooth held in only by the ___ _____

           

cells,nerve,blood vessel

resorption

pulpal

parietal plexus

oral epithelium