dental anomalies Flashcards
What 4 things are commonly affected by dental anomalies?
Number of teeth
Size and shape of teeth
Hard tissue defects
Eruption and exfoliation
Name 4 conditions associated with hypodontia
Any from:
- ectodermal dysplasia
- Down syndrome
- Cleft palate
- Hurler’s syndrome
- Incontinencia pigmentii
Name 4 problems commonly caused by hypodontia
Any from:
- abnormal shape - often cone shaped
- abnormal form
- infraocclusion
- deep overbite
- reduced lower face height
Describe the prevalence of supernumeraries
1.5-3.5% prevalence
Males:females 2:1
More common in maxilla
Higher frequency in Japan
Higher frequency in cleidocranial dysplasia
What are the 4 types of supernumeraries?
Conical (cone shaped)
Tubercular (barrel shaped, has tubercles)
Supplemental (looks like tooth of normal series)
Odontome (irregular mass of dental hard tissue, can be compound or complex)
What is the most common cause of delayed eruption of permanent incisors?
Supernumeraries
What is the prevalence of hypodontia?
6.3% in females
4.6% in males
0.9% in primary dentition
Which teeth are least likely to be missing?
First permanent molars
Upper central incisors
Describe microdontia, explain the prevalence and give an example
Smaller teeth than normal
2.5% prevalence, affects females more than males
Eg - peg shaped lateral incisor
Give 4 examples of anomalies of tooth size and shape
Any from:
- microdontia
- macrodontia
- odontomes
- taurodontism
- dilaceration
- accessory cusps
What is macrodontia and explain the prevalence?
Larger teeth than normal
Less than 1% for single teeth and 0.1% generalised
What is taurodontism and explain the prevalence?
Flame shaped pulp
6.3% prevalence in the UK
Give a common example of accessory cusps
Talon cusps
What is dens in dente and why must it be sealed?
A tooth within a tooth
The tooth inside has its own pulp system and RCT cannot be provided
What are the causes of short root anomaly?
Radiotherapy
Dentine dysplasias
Accessory roots
Describe the prevalence of short root anomaly
Mostly occurs on permanent maxillary incisors
2.5% incidence
15% of these also have short roots on canines and premolars
What is the danger of short root anomaly?
Very dangerous for orthodontic treatment
Give 3 examples of anomalies of enamel structure
Amelogenesis imperfecta
Environmental enamel hypoplasia
Localised enamel hypoplasia
Name 4 types of amelogenesis imperfecta
Hypoplastic
Hypocalcified
Hypomaturational
Mixed forms
Give 4 causes of environmental enamel hypoplasia
Any 4 from:
- systemic disease
- nutritional deficiency
- metabolic eg - rhesus incompatibility
- infection eg - measles
- trauma
- infection of primary tooth
What is the cause of localised enamel hypoplasia?
Trauma to primary teeth or infection of primary teeth
What are the different categories of hard tissue defects aetiologies?
Localised or generalised
What are the 2 causes of generalised hard tissue defects?
Environmental
Genetic factors
Describe the aetiology of fluorosis
Generalised and caused by environmental factors
Describe the aetiology of MIH
Generalised and caused by environmental factors
Associated with childhood illness and chronological hypomineralisation eg - liver or kidney failure
Give an example of a prenatal, neonatal and postnatal infection that can lead to a generalised environmental enamel defect
Prenatal - rubella
Neonatal - meningitis
Postnatal - measles
Describe the prevalence of amelogenesis imperfecta
Affects 1 in 14,000
Familial inheritance
Autosomal dominant, recessive and x-linked
What is used to diagnose amelogenesis imperfecta
Family history
Generally affects both dentitions but worse in permanent
Affects all teeth
Tooth size, structure and colour
Radiographs - fail to see changes in radiolucency between enamel and dentine
Describe the biology of the aetiology of amelogenesis imperfecta
Enamel formation needs multiple genes to transcribe the process of crystal growth and mineralisation
Gene mutations found involve the enamel ECM molecules amelogenin, enamelin and kallikrein 4
Describe hypoplastic AI
Enamel crystals do not grow to the correct length
Describe hypomineralised AI
Enamel crystals fail to grow in thickness and width
Describe hypomaturational AI
Enamel crystals grow incompletely in thickness or width but to normal length with incomplete internalisation
Give 4 dental problems patients with AI may experience
Any from:
- sensitivity
- caries and acid susceptibility
- poor aesthetics
- poor oral hygiene
- delayed eruption
- anterior open bite
What are the treatment options for AI?
Enhanced prevention
Composite veneers
Fissure sealants
Metal and ceramic onlays
SS crowns - later get replaced
Orthodontics - brackets often deboned but often required due to AOB
Name 4 systemic disorders associated with enamel defects
Any 4 from:
- Down syndrome
- Prader-Willi syndrome
- Porphyria
- Hurler’s syndrome
- Epidermolysis bullosa
- Tuberous sclerosis
- Pseudohypoparathyroidism
- incontinente pigmentii
Give 4 examples of anomalies of dentine structure
Dentinogenesis imperfecta
Dentine dysplasia
Odontodysplasia
Systemic disturbance - nutritional, metabolic, drugs
What is dentine dysplasia?
Normal crown morphology, amber radiolucency, pulpal obliteration and short constricted roots
What is Odontodysplasia?
Localised arrest in tooth development
Thin layers of enamel and dentine
Large pulp chambers
‘Ghost teeth’
What is the prevalence of dentinogenesis imperfecta?
Very rare, far rarer than AI
What are the 3 types of dentinogenesis imperfecta?
Type I
Type II
Brandywine
How is dentinogenesis imperfecta diagnosed?
Appearance
Family history
Associated osteogenesis imperfecta (wheelchair, multiple bone fractures)
Both dentitions
Affected
Radiographs - bulbous crowns and obliterated pulps (I and II)
Enamel loss - normal but quickly lost due to no connection at ACJ
Occult abscess - abscess forming without any disease
Describe the pulp chamber in DI
Huge pulps when tooth first erupts but quickly obliterated
What is type I DI associated with?
Osteogenesis imperfecta - child will have blue sclera of eye in stead of white and teeth will appear amber/translucí ent grey
What dental problems may patients with DI experience?
Poor aesthetics
Caries and acid susceptibility
Spontaneous abscess
Very poor prognosis
What are the treatment options for DI?
Enhanced prevention
Composite veneers
Overdentures
Removable prosthesis
SS crowns on posterior teeth
Composite on anterior teeth
Name 2 other hereditary dentine defects limited to dentine only
Dentinogenesis imperfecta type II
Fibrous dysplasia of dentine
Name 2 other hereditary dentine defects associated with a general disorder
Any 2 from:
- Osteogenesis imperfecta
- Ehlers-Danlos syndrome
- Rickets
- Hypophosphatasia
What are the main aims of treatment for tooth structure defects?
Enhanced prevention
Pain control
Restoration of lost tissue
Harness growth
Give examples of 2 anomalies of cementum
Cleidocranial dysplasia - no clavicle, patient can touch shoulders together - hypoplasia of cellular component of cementum
Hypophosphatasia - hypoplasia or aplasia of cementum, early loss of primary teeth
Name 3 signs of premature eruption of teeth
High birth weight
Precocious puberty (early)
Natal or neonatal teeth
Give 4 signs of delayed eruption of teeth
Any 4 from:
- Preterm and low birth weight
- Malnutrition
- Down syndrome
- Cleidocranial dysplasia
- Gingival hyperplasia - pseudodelayed eruption, so much gingivae that teeth don’t seem to be erupting
- infraocclusion
- double primary teeth
- hypodontia
- ectopic permanent successors
- following trauma
Name 4 causes of premature exfoliation
Any 4 from:
- trauma
- following pulpotomy
- Hypophosphatasia
- immunological deficiency eg - cyclic neutropenia
- Chediak-Higashi syndrome
- Hystiocytosis X
Describe the prevalence of infra-occlusion
Affects 1-9% of people
Lower first primary molar most common, can happen to second too
Congenital absence of premolar successor
Majority exfoliate by 11-12 but some are properly ankylosed
