31 - Anomalies in Tooth Structure + Dental Dysplasia Flashcards
What are the main structure anomalies?
Hypoplasia
Hypo-mineralisation
Hypo-Maturation
Hyper-Pigmentation
What is Hypoplasia
Its a defect due to enamel deficiency.
Causes: problems during enamel matrix formation, nutritional factors + fluorosis
Results in an abnormal thickness + shape of enamel
What is Hypo-Mineralisation?
It is a disturbance during enamel matrix mineralisation, which results in soft + poorly mineralised enamel.
The shape and thickness is normal
What is Hypo-Maturation?
This is a disturbance in enamel maturation.
It results in enamel that is clinically identical to Hypo-mineralised enamel
What is Hyper-Pigmentation?
Permanent pathological colouration from postponed pigments in tooth structure.
It CANNOT be removed with external cleaning
What are the main diseases that cause tooth anomalies?
Hereditary Dysplasia Congenital Dysplasia Acquired Dysplasia Amelogenesis imperfecta Icterus Gravis Neonatorum Turner's Teeth Fluorosis
What is Hereditary Dysplasia?
This can affect both dentitions and can cause: Hypo-Mineralisation Hypo-Maturation Hypoplasia This also includes genetic risk factors
What is Congenital Dysplasia
This mainly affects the primary teeth.
Causes:
Hypoplasia - via malnutrition of pregnant women in 2nd trimester, occurs in early toxicosis of pregnancy
Hypo-Mineralisation - via malnutrition of pregnant women, late toxicosis of pregnancy + rubella, corticosteroid treatment, and in premature infants
Hyper-Pigmentation - occurs after porphyria or taking tetracyclines
What is Acquired Dysplasia?
This is developed by 3 types of factors:
Exogenous, Endogenous + Local
They affect permanent dentition as they develop after birth and can be all 4 structural defects
ADs - Endogenous factors in childhood
Hemolytic disease of the newborn hypotrophy dyspepsia hypovitaminosis rickets frequent infections chronic diseases
ADs - Exogenous Factors
These are local factors acting after the birth of the child
They affect single teeth + only where they are acting factors locally
ADs - Local Factors
A chronic complication of untreated caries in a primary tooth affects permanent dentition. Trauma of primary tooth Local action of radiation Affect individual teeth Dysplasias are asymmetric
Mechanism of Development of Hypoplasia
Impairs the functions of ameloblasts:
- Affects the quality of the synthesised + secreted proteins
- Affects the amount of secreted matrix
Ways of impairment of the Ameloblasts
Defect in genetic information
Rubella in 1st trimester of pregnancy - directly injures ameloblasts
In premature infants - building cells are damaged
Congenital Allergies - inadequate Calcium (Ca) content in blood, increased acidity, impaired water + mineral metabolism
Rickets - disturbs entire metabolism - Mainly Ca/P
Toxic dyspepsia - loss of water, salts, Ca, K, Mg - building cells are damaged
When fluoride is taken in toxic doses, it damages the ameloblasts
Mechanisms for hypomineralisation
In the disturbed function of ameloblasts, a defective matrix that does not provide the correct mineralisation
They can act as factors disturbing the required amount of minerals at relatively properly formed matrix
