Dental Anomalies Flashcards
What happens in the enamel secretory phase?
Enamel matrix is produced and there is some initial mineralisation
What are the two stages to enamel development?
Secretory phase
Maturation phase
What happens in the enamel maturation phase?
The mineral content is increased
What are the stages of tooth development?
Initiation
Morphogenesis
Crytodifferentiation
Matrix secretion
What happens in the initiation phase?
Dental placode is produced
What happens in morphogenetic?
Bud stage leading to cap stage
The bud stage is where the enamel knot and enamel organ are formed and there is corned station of the ectomesenchyme forming the dental papilla
The cap stage the enamel organ starts to enclose the dental papilla and the internal and external epithelium form
What happens in Crytodifferentiation ? What is the cervical loop?
Bell stage
In the early bell stage you can see the EEE, IEE, SR, DL and bud for tooth
In the late bell stage the enamel and dentine of cusps and IEE and EEE fuse to form cervical loop.
Advanced bell stage IEE induces odontobalsst to differentiate and dentine formation induces Ameloblastic differentiation. Predintine is laid
Cervical loop forms hertwigs sheath to map out shape of root and when broken down centrum forms and remanants are epithelial cell rests of malassez
Defects in enamel can be caused by
Local or generalised factors
The local and gernalised causes of enamel defects can lead to which two categories?
Hypoplastic
Hypo mineralised
T/F
Hypoplastic enamel is thinner
Hypolplasia of enamel results from failure or maturation
T
F failure of normal volume of matrix produced
T/F
Hypo mineralised enamel results from failure of calcification
T
Severe hypominerlaistion leads to what?
Hypocalcification
Less severe enamel hypominerlaistion leads to what type of enamel defect?
Hypomaturation
What are the local causes of enamel defects?
Infection
Idiopathic
Irradiation
Trauma
What two things can lead to hypominerlaistion of the permanent tooth germ? And which teeth are most commonly affected?
Trauma and infection of primary tooth
Permanent maxillary incisors
Mandib and max premolars
What is the name of a tooth which is damaged by an infection to primary tooth?
Turner tooth
What are the two causes of generalised enamel defects?
Genetic
Environmental/chronological/systemic
T/F genetic diseases can affect the body and well as the teeth?
T
What is an example of a genetic tooth only disease?
AI
This is a generalised enamel defect affecting all or most teeth of the primary and permanent dentition
How can AI be inherited?
AD
AR
X linked
Sporadic
If AI has been inherited in an AD fashion, what would this mean ?
Each generation affected 50% chance of passing to kids M=F Primary and sedondary dentition affected Wide variety of presentations
If AI is inherited in an X linked fashion, what would this mean?
Males more severely and uniformly affected
Females show vertical grooves and ridges
If AI is inherited in an AR fashion, what does this mean?
Parents are close relatives eg first cousins
Enamel Hypoplasia and hypominerlaistion
Which type of inheritance of AI is rare?
AR
How can we classify AI?
Based on phenotype
What are the three phenotypic variations of AI?
Hypoplasia
Hypocalcification
Hypomaturation
How do you manage AI?
Severely affected teeth may need cast restorations and crowns
What are the genetic generalised caused of enamel defects?
Down’s syndrome
Ectodermal dysplasia
Epidermolysis bullosa
Occulo-dento-osseous dysplasia
What are the generalised (non teeth only) environmental causes of enamel defects? How will this appear clinically?
Prenatal: rubella, syphylis
Neonatal: prem birth, hypocalcaemia
Postnatal: measles,chicken pox, Vit a c d def, chemical agents eg fluoride
There will be a horizontal band that affects all the teeth that were developing at that time
How much fluoride intake would lead to fluorosis?
> 0.05mg/kg/day
Drinking water with more than 2ppm is associated with high risk
What are the problems will develop following fluorisis ?
Aesthetics
Thermal osmotic stimuli
Poor OH
Comprised occlusion
How can you distinguish between fluorisis and AI?
Fluorosis will show sings of chronological development whereas AI does not
Which enamel defect affects the molars and incisors?
MIH
What are the causes of dentine defects?
Genetic
Environmental
What are the genetic causes of dentine defects?
Dentinogenesis imperfecta
Dentinal dysplasia
Vitamin D resistant rickets
What are the environmental causes of dentine defects?
Drugs
Infection
Trauma
Deficiency
T/F
Dentinogenesis is AD inheritance
T
T/F DI only occurs in isolation?
F
It can occur in isolation but can also occur in association with Osteogenesis imperfecta
T/F DI only affects secondary teeth
F
Primary and secondary
What are the three types of DI?
Type 1: dental manifestations of OI
Type 2: classic hereditary opalescent dentine
Type 3: brandy wine isolate opalescent dentine
How do you manage DI?
Remove pain and infection
Protect posterior teeth from wear
Restore aesthetics
Prevention + OHI + diet advice
What is dentinal dysplasia?
AD disease which affects both dentitions
What are the features of dentinal dysplasia?
Normal enamel but atypical dentine with abnormal pulp morphology
What are the types of dentinal dysplasia ?
Type 1: Radicular type: short roots with almost absent pulp chamber
Type 2: coronal type that has enlarged pulps
What type of inheritance is vitamin D resistant rickets?
X linked
What skeletal features do people with vitamin D def rickets have?
Males
Short
Bowed legs
What dental features with people with vir D def rickets have?
Abscesses in the absence of caries
Large pulp space
Large amounts of inter globular dentine
Pulp horns may be exposed due to attrition
Can females be affected in Vit D def rickets?
Yes
They are heterozygous and they aare less severely affected with few dental anomalies
Which drugs may interfere with dentine formation?
Chemotherapy
Nutritional def
Cytotoxic drugs
Tetracycline
Which cementum defects are there?
Affected in many genetic disorders and the effect can be quite bad
Hyperxementosis; Periapical inflam, mechanical stimulation
Hypocementosis: cleidocrwnial dysplasia, hypophosphotasia
Which disease can affect all dental tissues?
Regional odontodysplasia
This is where the tooth germ development is arrested
Disturbances in eruption can be caused be…
Local and generalised factors
Name the three types of disturbances in eruption?
Premature
Delayed
Impacted
What are examples of premature tooth eruption?
Natal teeth
Neonatal teeth
What is a tooth that is presnt at birth?
Neonatal
What is a tooth that erupts after birth within the first month?
Neonatal
What is the prevelence of natal teeth?
1:2000-3000 live births
Which teeth are most commonly natal teeth?
Primary mandibular incisors
T/f natal teeth are usually supernumerary?
F
T/F neonatal and natal teeth are commonly mobile?
T because of limited root development
Which syndromes can natal and neonatal teeth be related to?
Pachyonychia
Ellis van crevald
Soto syndrome
How do you manage neonatal and natal teeth?
Monitor
Smooth edge
Or xla
When would you xla a neonatal or natal tooth and what technique would you perform?
If it is markedly loose
Use spencer wells forceps and use slight local curettage to remove the rest of the remnants of the developing tooth germ
What are the causes of delayed tooth eruption?
Local: traumatic displacement of tooth germ
Dilacerated permanent tooth
Presence of Supernumary or cyst
Impacted
Systemic Prematurity and low birth rate Downs and Turner syndrome Hypothyroidism and hypopituarism Hereditary gingivofibromatosis
What happens when teeth are impacted? And what are the causes?
They remain unerupted of partially erupted beyond normal eruption time
Cause: abnormal position of tooth germ, supernumerary, cyst, tumour
T/F impaction is rare in primary teeth?
T
Which teeth are most commonly impacted?
8’s
Mandib premolars
Max canines
Teeth can exfoliate…
Prematurely or
Delayed
What are the local and systemic causes of premature exfoliation?
Local: tooth: arch discrepancy
Systemic: hypophosphotasia, cyclic neutropenia, chronic perio
What are the local and systemic causes of delayed exfoliation?
Usually due to failure of eruption of permanent tooth
Local: infra occluded teeth
Gen: rare! Cherubim and cleidocranial dysplasia
How do you manage problems with exfoliation and eruption?
Refer to paediatric dentist
But make sure good medical history since some conditions very serious.
Infra occluded teeth can be different severities. What are they?
Mild: 1mm below occlusal place
Moderate: level with the contact point of one or more adjacent teeth
Severe: at level of interproximal gingival tissue of one or both adjacent teeth
What is infra occlusion caused by?
Fusion of the cementum to bone
Which teeth are most commonly affected by infraocclusion?
Primary molars
1.5-9%
How do you manage infraocclusion?
Monitor
Early extraction and space maintenance
Restore occlusal height
Xla when exfoliation unlikely
What is the prev of hypodontia in primary and secondary?
0.1-0.7 primary
2-9 perm
T/F Microdontia is more common in permanent dentition?
T
T/f microdontia is more common in Females?
T
Which teeth are most commonly microdeents?
8 and 2
T/f generalised Microdontia is common?
T
