Tooth Eruption

Question 1

Incisors pre-eruptive phase

Answer 1

Early, permanent tooth develops lingual to the incisal level of it Later -As primary erupts permanent positioned lingual to and apical 1/3 of the root of the primary tooth

Question 2

Premolars Pre-Eruptive Phase

Answer 2

Permanent premolar is lingual to primary molar Permanent premolar shifts to be enclosed within the roots of the primary premolars

Question 3

Molars Pre-eruptive Phase

Answer 3

Molars have no primary teeth to succeed Upper/Maxillary molars have their occulosal surfaces slanted toward the distal Lower/Mandibular molars have their suface slanted toward the mesial

Question 4

Pre-eruptive Functional Phase: Root formation

Answer 4

Proliferation of epithelial root sheath (lengthens) Leads to root dentin being formed and pulp

Question 5

Fusion of what leads to the formation of the junctional epithelium?

Answer 5

Reduced enamel epithelium fuses with epithelial layer—>Junctional Epithelium

Question 6

What is occuring during the painful process of teething in babies?

Answer 6

Zone of degenerating connective tissue fibers appears over the tooth

Nerve fibers break into pieces

Osteoclasts help resorb bone as tooth pushes through

Question 7

Gabernacular Cord

What is it and function

Answer 7

In eruption pahway follicular cells develop a gubernacular cord directed toward mucose

believed to help guide tooth in eruption

Question 8

Eruption summary 7 steps

Answer 8

1. Pre-eruptive phase tooth crown approaches oral epithelium
2. Contact of reduced enamel epithelium including developmental cuticle and oral epithelium
3. Fusion of reduced enamel epithelium and oral epithelial
4. Thinning of fused epithelial
5. Rupture of oral epithelium, formation of attached gingiva and emergence
6. Crown appearance into oral cavity (prefunctional phase)
7. Tooth erupting into functional occlusion

Question 9

Fundic Region

Location

Composed of

Answer 9

• Located cervical to developing root
• Filled with fibroblasts, some form strands that mature into calcified trabeculae
• Trabeculae form bony ladder

Question 10

Bony Ladder

Function

Answer 10

Delicate bony ladder becomes more dense as additional plates form

Helps in tooth eruption

Bony plates remain until teeth are in functional occlusion

Question 11

Functional Eruptive Stage

Answer 11

• Occurs after teeth are in occlusion and functioning
• Height of alveolar process increases
• Fundic alveolar plates resorb so roots can form to apex
• Root canal narrows
• Primary roots take 1-1.5 yrs
• Permanent roots take 2-3

Question 12

Primary Dentition

Answer 12

20 primary

In each quadrant

• 2 incisors (central and lateral)
• 1 canine
• 2 molars (1st and 2nd)