Ch 2 Dev't & Eruption of Teeth Prelim review

Question 1

Dentists sees not only clinical crowns but also:

Answer 1

• number
• shape
• size
• position
• coloration
• angulations of teeth
• outlines of roots
• occlusal contacts
• esthetics
• evidence of function and parafunction
• phonetics

Question 2

Foundation of diagnosis:

-form of tooth related:

Answer 2

• to accept patient’s concern that a cosmetic problem is present and needs correction, requires dentist to transform patient’s idea of esthetics into reality by ortho and cosmetic restorative dentistry.
• position and angulation in arch.
• appreciation for esthetics of tooth form and coloration is a requirment

Question 3

Variability

Answer 3

• Know normal morphology and morphological variability

- variety in sequences of eruption depend on population sampled.

Question 4

• Enamel hypoplasia

- hypocalcification

Answer 4

• all quantitative defects of enamel thickness
• opacities are qualitative defects
• chronologies and location of defect determines when,how,and cause.

Question 5

Sequence of emergence of primary teeth

Answer 5

CI, LI, 1M, C, 2M

Question 6

Emergence through alveolar crest

Answer 6

-when approx. 2/3 root is formed

Question 7

Emergence through cavity

Answer 7

-when approx. 3/4 root is formed

Question 8

Neuromuscular Dev’t-Primary Dentition

Answer 8

• completed by 30 mo
• increased intercanine width
• ^size in both jaws in sagittal
• ^vertical direction of facial skeleton
• splanchno remains small
• @ age 8, width mandible = width neurocran.
  - Dent arch complete, occlusion is functional

Question 9

Transitional (mixed) dentition

*crown must complete 1st before erupt

Answer 9

-1st begins w/ emerg/erupt of Man 1permM and ends w/ loss of last primary tooth = 11-12 years

Question 10

Permanent dentition

Answer 10

• 32 teeth, completed 18-25 years
• follicles of developing incisors and canine are lingual to deciduous roots
• developing premolars are within bifurication of primary molar roots
• mandibular permanent grows faster > max perm

Question 11

Succedaneous

Answer 11

-Permanent incisors, canines, and premolars

Question 12

size of teeth

Answer 12

• genetically determined, racial differences

- gender-sized dimorphism

Question 13

Dental pulp

Answer 13

• connective tissues organ containing a # of structures like arteries, veins, lymphatic sys, and nerves
• to form dentin of tooth
• bcomes smaller as tooth is completed

Question 14

Types of junctions

Answer 14

1. enamel over-lapping cementum
2. end-to-end approximating junction
3. absence of connecting enamel and cementum, so that dentin is external part of root.
4. over-lapping of enamel by cementum

Question 15

Probing

Answer 15

• to determine level of periodontal support, position of gingival margin, and attachment of CEJ
• to probe level of attachment of fibers to tooth in presence of periodontal diseases.
• location and nature of CEJ have clinical sig, not just morphology
• should be able to envision CEJ of each tooth

Question 16

Dental age assessment

Answer 16

• based on which teeth have erupted and
• the number of teeth at each chronological age
• the amount of resorption of the roots of primary teeth
• stages of the formation of crown and roots
• dev’t of permanent teeth
• can reflect assessment of physiological age comparable to age based on skeletal dev’t, weight, or height

Question 17

Types of chronologies

Answer 17

-age of attainment: tooth emergence. to avoid damage to developing teeth during treatment.

• age prediction: based on being in a stage
• age in a stage of dev’t. used for assessing unknown ages of patients and for forensic and archeological app.

-maturity assessment: based on mean stage for age, where stages, rather than, subject ages, are averaged. age is known.

Question 18

Estimating time of Enamel Hypoplasia

Answer 18

ADF = ACF - (years of formation/crown height x distance of defect from CEJ)

• age at which the formation of the enamel hypoplasia occurred
• age at which crown is completedi

Question 19

Rule of “six” in dental dev’t

Answer 19

• 6 weeks in utero: Onset of dental dev’t
• 6 months old: emergence of the first primary tooth
• 6 years old: emergence of the first permanent tooth

Question 20

Stages of tooth formation

Answer 20

1. beginning calcification
2. crown completion
3. root completion

• Nolla-11 stages
• Gleiser and Hunt-14 stages

Question 21

• Resorption:

- Eruption:

Answer 21

• gradual physiologic root destruction by the underlying erupting permanent tooth
• continuous tooth movement from the dental bud to occlusal contact

Question 22

Rule of “fours” for permanent tooth dev’t (3rd Molars not included)

• at birth:
• at 4 years of age
• at 8 years
• at 12 years
• at 16 years

Answer 22

• four 1st molars have initiated calcification
• all crowns have initiated calcification
• all crowns are completed
• all crowns emerge
• all roots are complete

Question 23

Sequence of Eruption for Permanent

*mand tend to erupt before max

Answer 23

1. man M
2. man CI/LI
3. max central
4. max lateral
5. first premolar
6. man canine
7. second premolar
8. max canine
9. second molars
10. third molars

Question 24

Sequence of Eruption of Primary

Answer 24

1. CI
2. LI
3. First Molar
4. Canine
5. Second Molar

Question 25

systemic fluoride

Answer 25

Crowns take a few years to form once calcification has begun, therefore its impt to take through age 12 to protect all teeth.

Question 26

Points to remember

Answer 26

1. mand > max
2. tooth erupts when its root is about half-formed
3. the roots of primary teeth will complete about 1.5 years after eruption
4. roots of permanent teeth will complete about 2.5 years after eruption

Question 27

Clinical considerations:

• normal crown vs pathological crown
• roots
• Occlusal contacts
• gingiva

Answer 27

• size, shape, position, number, color
• outline
• function, parafunction, and phonetics
• appearance

Question 28

Malformations

Answer 28

• form ex: screw-driver shaped max incisors
• color
• arrangement
• structure of teeth ex: enamel hypoplasia