DEVELOPMENTAL ANOMALIES (14/15) Flashcards
Name the stages of tooth development
- Initiation
- Proliferation
- Histodifferentiation
- Morpho differentiation
- Apposition
- Calcification
- Eruption
Name the three different anomalies classifications
- Acquired
- Developmental
- Descriptive
What are the four sub-groups of descriptive classification of Anomalies
- number
- Structure
- Size & Shape
- Eruption and exfoliation
give examples of anomalies that lye under anomalies of structure
- Enamel anomalies ( Amelogenesis imperfecta, Hypoineralisation, Hypocalcification, Hypomaturation)
- Dentinogenesis imperfecta
- Dentine Dysplasia
- MIH
What is meant by Qualitative defect?
when the calcification and maturation of the structure are interrupted, it leads to a qualitative defect. The enamel is of normal thickness, but not fully mineralised so of poor quality, making it brittle, weak and prone to caries and sensitivity
What is meant by Quantitative defect?
This happens earlier in the tooth development than qualitative defect. It occurs when the matrix is not being laid down correctly, creating missing tooth structure.
Example is hypoplasia: Reduced quantity of enamel which results in small or irregularly shaped
teeth, which may be pitted, thinner or smaller in size
What is meant by Acquired anomalies
Anomalies that occur as a result of local or systemic insult and it is usually environmental.
How is Amelogenesis imperfecta caused
When a mutation in AMELX, ENAM, MMP20 AND FAM83H genes happens, the essential proteins that are responsible for normal tooth development (majority for enamel development) are not produced anymore, resulting in an abnormally thin enamel and soft and may have a yellow or brown colour
Is Amelogenesis imperfecta a qualitative or quantitative defect? and is it part of anomalies of structure or anomalies of shape and size?
-Amelogenesis imperfecta (AI) is a diverse collection of inherited diseases that exhibit quantitative or qualitative tooth enamel defects in the absence of systemic manifestations.
- it is part of anomalies of structure
what are different ways to diagnose amelogenesis imperfecta?
- Phenotype
- Family history
- Genetic C test
What are the 4 different Witkop’s classification of Amelogenesis Imperfecta
- Type I- Hypoplastic
- Type II- Hypomaturation
- Type III- Hypocalcified
- Type IV-Type IV- Hypomature-Hypoplastic + Taurodontism
What are the 4 different Witkop’s classifications of Amelogenesis Imperfecta
- Type I- Hypoplastic
- Type II- Hypomaturation
- Type III- Hypocalcified
- Type IV-Type IV- Hypomature-Hypoplastic + Taurodontism
Odontogenesis Imperfecta Facts
- Genetic or aquired?
- compared to amelogenesis imperfecta which one more common?
- This is less common.
1 in 6-8,000 while Amelo is 1 in 700 - A genetic condition affecting dentin genesis
- Autosomal Dominant
- Association with Osteogenesis imperfecta
What are the phenotypes of Dentinogenesis imperfecta?
- Short roots
- Cervical Constriction
- Grey, Blue, Opalescent
What genes associated with the three classifications of Dentinogenetic Imperfecta
- DI and OI: Col1A1 and Col1A2 (responsible for collagen formation), Associated with Osteogenesis imperfecta
- DII (mutations for gene for DSPP) - doesn’t include osteogenesis imperfecta
- DIII (mutations for gene for DSPP) Affect certain families
How many different type of Dentine Dysplasia and what is their phenotype
Type I:
- clinically normal, sharp, conical apical constrictions
Type II:
- translucent amber teeth
- ‘Rootless’
- Thistle shaped pulp chambers
- Abnormal primary teeth and normal permanent teeth
* 1:100000
Definition of MIH
Hypomineralisation of systemic origin of at least one first permanent molars and frequently associated with affected incisors”
Name 2 different types of anomalies of number
- Hypodontia
- Hyperdontia
- Is hyperdontia more common in primary or secondary dentition?
- Is it more common in male or female?
- more common in maxillary or mandible?
- Secondary
- male
- Maxillary (5:1)
What are the different terminology used when differentiating Hyperdontia be shape and by position?
By Position
- Mesiodens
- Paramolars/ distomolars
By Shape
- Supplemental: normal size and shape of the tooth
- Conical
- Tuberculate
- Odontome: don’t look like teeth