Anatomy - Outcome 14 Flashcards
Initiation
This process includes the dental lamina and bud stages, and affects the presence of absense of tooth bud.
Proliferation
Occurs during the bud, cap and bell stages, and influences the general size and proportions of the tooth germ.
Histodifferentiation
This process takes place from the advanced cap stage through the bell stage, and basically involves the formation of potential enamel and dentin-forming cells
Morphodifferentiation
The shape and size of the tooth are determined in this process, which happens during the budy, cap and bell stages. Thus a disturbance in morphodifferentiation may inffluence the size and shape of a tooth but have no effect on the enamel and dentin-forming process.
Apposition
The process is active during the bell stage, through the completion of the root, and involves the regular laying down of the enamel and dentin.
Maturation
Dental tissues fully mineralize
Most dental anomalies are caused by…
hereditary and congenital factors, developmental, or metabolic disturbances
Important factors influencing the final form of the anomaly, as well as which teeth are affected
The stages of development along with the length of the effect
Is permanent or primay teeth more prone to abnormality?
Permanent dentition is much more prone to abnormality than deciduous teeth. This is partially explained by the position of the permanent tooth bud on the dental lamina when compared to the primary tooth bud
Tooth anomalies may appear as variations in…
-number
-size
-shape (form)
-structure (calcification and apposition
Abnormal Number of Teeth - Reason
The presence of an abnormal number of teeth, either more or less than usual, is almost always the result of some type of disturbance during the initiation process (dental lamina and budy stage) of teooth develipment. The disturbance is most often hereditary in nature.
Anodontia
-complete absence of teeth or absense of a single tooth
-hereditary, hormonal, disease, radiation
-complete absence very rare
Hyperdontia
-supernumerary (extra tooth)
-extra bud from dental lamina
-does not resemble normal tooth
-mesiodens
-4th molar
-hereditary/syndromes
Abnormal Size of Teeth
-Normally the teeth of an individual vary in size directly with their general face and body size. Therefore, large, or small teeth, when found in this context, are not considered to be abnormal
- very rare for all the teeth to be abnormal in size
- Anomaly is usally limited to a single tooth, or a few teeth of the same type
- is thought to be the result of a disturbance during morphodifferentiation in the bell stage, with genetic etiologoy
Macrodontia (Gigantism)
-abnormal increase in tooth size
-one or more teeth
True Macrodontia
-rare
-all teeth
-pitutiary gigantism
False Macrodontia
-incomplete tooth splitting
-teeth fusing together
Microdontia (Dwarfism)
-abnormal decease in tooth size
-hereditary
-bilateral