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
what are the different treatment option for Hyperdontia
- Consider timing (as we may need to XLA some teeth so no drifting)
- Take images
- Watch and wait or removal of supernumerary (in case teeth adjacent are still developing to prevent any damage)
- Referral to paediatric or orthodontic department
What are the associated syndrome for Hyperdontia
- Cleidocranial Dysplasia
- Oral Facial Digital
- Gardner Syndrom (autosomal dominant)
What are the most common to lease common teeth for hypodontia?
8s>Lower 5s>Upper 2s>Upper 5s>Lower 1s
what is it called when no tooth erupt
Anodontia
what is it called when some teeth are missing (due to hypodontia) but some are present
Oligodontia
which teeth are rarely affected by hypodontia
- 1st incisor
- canine
- 6
- 7
Syndromes associated with Hypodontia?
- Trisomy 21 – hypo/oligodontia
- MSX1 – Witkop syndrome
- defect in PAX9 gene – missing molars
what genes associated with Hypodontia?
- MSX1
- PAX9
Ectodermal Dysplasia
- Disorder of ectoderm
- Affects teeth, hair, skin, sweat glands, nails
- Multiple patterns of inheritance Associated genes: EDA/EDAR/EDARADD and WNT10
– AR
– AD
– X-linked hypohidrotic ED (EDA
Name different anomalies of Size and shape
- microdontia
- macrodontia
- Dens invaginates
- Talon Cusp
what is the difference between Concrescence and fusion or germination tooth appearance
- Concrescence is the fusion of cementum so two teeth attach together from the root side
- Fusion or germination: when two clinical crowns look fused
- both of these result in macrodontia
which conditions assosiated with Microdontia
- Down syndrome
- Hypodontia
What is den’s invasion and its complications
- Dens invaginatus / dens in dente tooth
- problem with them is the build-up of plaque in between
infoldings in the incisal region or palatal region which can
lead to caries development and loss of vitality. because anatomy is hard, RCT is not possible
Den’s invasion treatment
- Prevention is better than cure
- Fissure seal prominent/deep palatal pits- EARLY!!
Talon Cusp treatment
- selective grinding (risk of pulpal exposure)
- removal and elective pulpotomy
name 3 different root anomalies
- Dilaceration: can be associated with Turner syndrome, high birth weights precocious puberty or endocrine abnormalities like hypothyroid or diabetes
- Additional roots
- Taurodontis: characterised by elongated pulp
name the 4 different types of anomalies of Eruption
- Premature Eruption
- Delayed Eruption
- Premature Exfoliation
- Delayed Exfoliation
what’s the difference between natal and neonatal teeth
natal: at birth
neo natal: within 30 days of birth
what are the problems associated with natal and prenatal teeth?
- Mobile – Risk of Aspiration
- Breast Feeding
- Riga-Fede Ulceration (under tongue)
what can be the cause of Delayed eruption? (associated conditions)
- Numbers
- Hypothyroidism
- Hypoparathyroidism
- Downs Syndrom
- Osteopetrosis
premature exfoliation facts
Premature exfoliation
* Before 5 years
* Generalised
* Irregular
* Preceded by mobility
Aetiology of premature exfoliation
Structural Defects
- Cementum
- Periodontal Ligament
- Alveolar Bone
Cellular Defects
- Neutrophils
- Numbers
- Quality
what is infra-occlusion
- delayed loss of teeth and position of teeth being lower than the rest of the occlusion
name some causes of Infra occlusion?
- Ankylosis
- Infraposition
- Submergence
- Arrested eruption
- Secondary retention
- Depression
- Impaction
- Buried tooth
- Reimpaction
- Suppressed eruption
- Incomplete eruption
which teeth affected more than the others by infra occlusion?
- primary molars> permanent
- Mandibular> Maxillary
- mandibular first primary molar affected most frequently
Aetiology of infra occlusion
- Familial tendency (Kurol 1981, Via 1964)
- Absence of permanent successor (Bjerklin et al 1992, Winter et al 1997)
- Ankylosis (Darling + Levers 1973, Kurol + Magnusson 1984)
- General theory: disturbance in periodontal ligament – leading to direct contact between
cementum or dentine and bone
Classification of Infra occlusion
- Slight: between occlusal surface and interproximal contact (less than 2mm)
- Moderate: within occluso-gingival margin of interproximal contact
- Severe: below the interproximal contact point
(for moderate and severe, refer for second opinion)
Treatment of infra occlusion
Monitor Unless
- Successor ectopic
- Successor absent
- Infraoccluding below gingival level (as can’t get cleaned possible cavities and perio problems)
