Postnatal Development of the Human Dentition Flashcards
During the 9-11 years of development (from 3-12/14 yrs of age), what should the dentist look out for need for intervention?
- Recognising developmental anomalies
- Recognising disruptions to the normal development of the dentition
What are the basic knowledge principles in post-natal dental development?
- Sequence and Timing of eruption
- Leeway space
- Root development and emergence of teeth
PLUS Observations of developing dental conditions
What observations should warrant investigations and/or treatment?
- Delayed (>6 months past normal range of eruption) and disturbance of eruption of permanent teeth (unilateral)
- Difference in occlusal plane between posterior and anterior teeth –> possible thumb sucking?
- Marked displacement of teeth (unilateral) eg. misalignment
- Prolonged retention of primary teeth (unilateral or bilateral)
- Premature loss of primary teeth (unilateral or bilateral)
What is the normal eruption sequence of Primary teeth?
A, B, D, C, E
At which stages is there an increase in arch length (depth) + width in a child’s jaw
Birth
6-8 months
9-10 months
24-30 months
30-72 months
At which stages is the arch length (depth) and width of a child stabilized?
10-14months
14-18 months
18-24 months
What is the eruption timing and sequence of children
Birth: NIL
6-8 months: 1/2 As (lower)
8-10 months: As
10-14 months: Bs
14-18 months: Ds
18-24 months: Cs
24-30 months: Es
30-72 months: NIL
What is the clinical advantage of having spaced deciduous dentition over the closed dentition?
Spaced dentition results in better outcome in permanent dentition eruption as it allows larger permanent dentition to erupt without problems.
What is the percentage of children with spaced deciduous dentition and closed deciduous dentition.
Spaced: 75%
Closed: 25%
What is the normal first three permanent teeth to erupt?
6, 1, 2
What is the eruption timing and sequence of the first 3 permanent dentitions?
5-6 yrs: 6s
6.2yrs: lower 1s start
7yrs: lower 1s completed, upper 1s start
7.3 yrs: lower 2s begins
8 yrs: upper 1s and lower 2s completed, upper 2s begins
8.5 yrs: upper 2s completed
What does an ectopic mesial eruption of #16 cause?
Tx?
External root resorption of E distal
Most self correcting (66%)
If severe then extract and preserve space.
What are the observations in the ectopic eruption of a molar?
Unilateral delayed eruption and difference in occlusal plane (E becomes overerupted)
What factors to consider to resolve impaction of teeth
- Root formation completion: incomplete = good potential for tooth eruption
- Curvature of root: Substantial root curvature makes proper tooth positioning impossible as it can hit cortical bone easily if it is tracked
What is the value of a CBCT
- Visualize the true extent of displacement
2.Stage of root formation and development of dilaceration - Ability to plan with oral surgeon best approach and position of attachment to be bonded to the crown
- Increased understanding from parents after visualization and explanation on severity of displacement