Dental Anomalies Flashcards
What are the 4 different subsections of dental anomalies?
- number
- shape and size
- structure
- eruption and exfoliation
Provide examples of dental anomalies of number
- hypodontia
- hyperdontia/supernumerary
What is hypodontia?
congenitally missing teeth
What are the most common teeth to be missing in hypodontia?
- third molars
- 9-37% have >1 missing
- mandibular premolars
- 1.2-2.5%
- most commonly 5s
- maxillary lateral incisors
- 1-2%
- lower central incisor
- lateral coded for before central
- last tooth in the series is most likely to be missing
- lateral incisor
- second premolar
- third molar
What teeth are least likely to be missing?
- first permanent molars
- upper central incisors
What is Celtic Canine?
- absence of a maxillary canine
- very rare
- most common in Scotland/Ireland
What conditions may be associated with hypodontia?
- ectodermal dysplasia
- abnormal development of skin, nails, etc
- fine, sparse hair
- saddle shaped nose
- intolerance to sweating
- abnormal development of skin, nails, etc
- Down syndrome
- trisomy 21
- cleft palate
- Hurler’s syndrome
- IUDA deficiency
- lysosomal enzyme
- IUDA deficiency
- incontinentia pigmenti
- genodermatosis
- skin, eye, teeth, CNS abnormalities
- genodermatosis
What can pose a challenge when replacing the space left by a missing upper lateral incisor in a hypodontia patient?
- over-eruption of the lower canine
- if no tooth or retained primary
- must keep canine in position
What are the different dental management options for hypodontia?
- diagnosis
- removable prosthesis
- orthodontics
- composite build ups
- porcelain veneers
- bridges and implants
- preventative treatment
How can removable prosthesis be used for management of hypodontia?
- used until patient is old enough for definitive restoration
- space maintenance
- over denture
- placed over infraoccluded teeth
When can a definitive solution be considered for hypodontia patients?
- once growth is complete
- must be out of the mixed dentition
How can ortho be used to manage hypodontia patients?
- changing the size and location of spaces
How can composite build ups be used to manage hypodontia patients?
- teeth are commonly small and straight sided or cone shaped
- build up to traditional shape
How can porcelain veneers be used to manage hypodontia patients
- teeth are commonly small and straight sided or cone shaped
- veneer to traditional shape
- must wait until early 20s
- gingival margin settles at this age
How can bridges and implants be used to manage hypodontia patients?
- replacement of spaces
- definitive
- once fully grown
Why is preventative treatment so important for hypodontia patients?
- must prevent tooth loss
- already have reduced number of teeth
- considered high risk
- enhanced prevention route
What problems may present with dental management of hypodontia?
- abnormal tooth shape and form
- cone shaped
- straight sided
- small
- spacing
- submergence/infraocclusion
- occlusal problems
- deep overbite
- reduced LFH
What is the prevalence of hyperdontia?
1.5-3.5%
Is hyperdontia more common in males or females?
males
Is hyperdontia more common in the mandible or the maxilla?
maxilla
What condition may be associated with hyperdontia?
cleidocranial dysplasia
What are the 4 types of supernumerary teeth? Describe them
- conical
- cone shaped
- tuberculate
- barrel shaped
- has tubercles
- can have premolar like appearance
- supplemental
- looks like tooth of normal series
- most commonly lateral incisor
- supplemental usually smaller
- both usually erupt
- chose to keep one in better position
- odontome
- irregular mass of dental hard tissue
- complex
- compound
- irregular mass of dental hard tissue
What problem can supernumerary teeth cause?
most common cause of delayed eruption of permanent incisors, particularly upper lateral incisors
Provide examples of anomalies of tooth shape and size?
- microdont
- macrodontia
- double teeth
- odontomes
- taurodontism
- dilaceration
- accessory cusps
What is the prevalence of microdontia and what gender is more commonly affected?
- 2.5%
- more common in females
What is microdontia?
- reduced tooth size
- e.g. peg shaped lateral incisor
What is macrodontia?
- increased tooth size
What is the prevalence of microdontia?
- 1% for single teeth
- 0.1% for generalised
What are the two ways in which double teeth can form?
- germination
- one tooth splits into two
- fusion
- two teeth join to form one
What is taurodontism and what risks does it pose?
- flame shaped pulp
- bull horn appearance
- increased risk of pulp exposure
- normal clinical appearance
- larger pulp to expose during restoration
What is dilaceration?
- deviation or bend of the crown or root
- may or may not be caused by trauma
What are accessory cusps?
- extra cusps
- e.g. talon cusp
- can be labial or palatal
- e.g. talon cusp
How can peg shaped laterals be managed?
- commonly with composite build ups
How can talon cusps be managed?
- selective grinding
- small amount of tooth ground away
- fluoride applied
- encourage pulp to shrink
- disguise with composite
What is dens in dente and how are they managed?
- tooth within a tooth
- invaginations within teeth
- additional pulp system
- seal all areas
- prevent ingress of bacteria
- cannot perform RCT
Provide examples of anomalies of root structure
- short root anomaly
- dentine dysplasias
- accessory roots
Describe short root anomaly and its implications
- 2.5% incidence in permanent maxillary incisors
- 15% also have affected canines and premolars
- high risk of root resorption with ortho
- roots begin much shorter than average
Provide examples of anomalies in enamel structure
- amelogenesis imperfecta
- hypoplastic
- hypocalcified
- hypomaturational
- mixed forms
- environmental enamel hypoplasia
- systemic
- systemic diseases
- kidney failure
- liver failure
- nutritional
- deficiencies during development
- metabolic
- Rhesus incompatibility
- liver diseae
- infection
- measles
- systemic
- localised enamel hypoplasia
- trauma
- enamel lesions on permanent teeth
- result of trauma to primary teeth
- infection of primary teeth
- most commonly primary molars
- spots visible on premolars
- ask if any primary teeth extracted
- trauma
How does hypomineralised enamel form?
- secretory phase adequate
- correct enamel matrix
- mineralisation phase inadequate
- incorrect mineralisation
- white, brown or yellow patch appearance
How does hypoplastic enamel form?
- secretory phase inadequate
- insufficient enamel matrix
- mineralisation phase adequate
- correct mineralisation
- chunks of enamel missing but good quality
How can hard tissue defects be categorised?
- aetiology
- localised
- generalised
- environmental
- hereditary
How might localised hard tissue defects form in enamel?
- trauma
- damage to primary tooth
- causes damage to permanent tooth
- infection
- caries then abscess in primary tooth
- defect apparent in permanent tooth
Provide examples of generalised environmental hard tissue defects in enamel
- fluorosis
- hypoplasia associated with childhood illness
What is fluorosis and how does it present?
- increased fluoride content in enamel
- uptake during enamel development
- mild
- diffuse white flecks across teeth
- generally good appearance
- patients may not like discrepancy
- more severe
- diffuse brown patches
How can fluorosis be managed and what warning must be given to patients?
- can successfully remove marks
- only surface layer of enamel affected
- micro abrasion therapy
- advise that teeth will be normal enamel
- colour will be darker
- veneers
- usually composite
- patient can chose shade
- vital bleaching
- disguises whiter areas
What is enamel hypoplasia associated with childhood illness?
- inadequate enamel formation in association with a childhood illness
- areas of missing enamel
- chronological pattern
- can see areas on different teeth
- correspond to time of illness
- once better, enamel forms normally
How can enamel hypoplasia associated with childhood illness be managed?
- composite veneers
When investigating a enamel hypoplasia associated with childhood illness what 3 time periods must be investigated?
- prenatal
- neonatal
- postnatal
What does investigation of the prenatal period in relation to generalised enamel hypoplasia involve?
- any issues with the mother
- rubella
- congenital syphilis
- cardiac issues
- kidney disease
- drug history
- thalidomide
- deficiencies
- fluoride
- vitamins A & D
What does investigation of the neonatal period in relation to generalised enamel hypoplasia involve?
- prematurity
- hypoplasia/hypomineralisation common
- meningitis
What does investigation of the postnatal period in relation to generalised enamel hypoplasia involve?
- otitis media
- measles
- chickenpox
- TB
- pneumonia
- diptheria
- vitamin deficiencies (A, C and D)
- heart disease
- long term health problems (e.g. organ failure)
- cardiac conditions have a strong link to enamel defects
Provide an example of a generalised hereditary enamel defect
amelogenesis imperfecta
What is the prevalence of amelogenesis imperfecta and what are the genetic links?
- 1:14,000
- familial inheritance
- autosomal dominant
- most common in Europe and USA
- recessive
- most common in Middle East
- x-linked
- autosomal dominant
- check for associated systematic disorder
- family history
- can be a new mutation
- mild form in relatives
- never diagnosed
How can amelogenesis imperfecta be diagnosed?
- family history
- positive affirmation not required
- generally affects both dentitions
- worse in permanent
- often no diagnosis in primary
- affects all teeth
- tooth size, structure and colour
- radiographs
- no change in radiolucency between enamel and dentine
What gene mutations have been found in amelogenesis imperfecta and what kind of molecules are they?
- extracellular matrix molecules
- amelogenin
- enamellin
- kallikrein 4
How does the hypoplastic type of amelogenesis imperfecta form?
the enamel crystals do not grow to the correct length
How does the hypomineralised type of amelogenesis imperfecta form?
the crystallites fail to grown in thickness and width
How does the hypo maturational type of amelogenesis imperfecta form?
enamel crystals grow incompletely in thickness or width but to normal length with incomplete mineralisation
What problems are associated with amelogenesis imperfecta?
- sensitivity
- less enamel protecting dentine and pulp
- caries/acid susceptibility
- carious lesions form
- even with reasonable diet/OH
- erosion
- dentine quickly uncovered
- carious lesions form
- aesthetics
- brown colour
- honeycomb like appearance
- white colour with flecks
- can be poor or good
- mild appears similar to fluorosis
- brown colour
- delayed eruption
- anterior open bite
What solutions are available for amelogenesis imperfecta?
- preventive therapy
- enhanced prevention route
- composite veneers/composite wash
- improves aesthetics
- reduces sensitivity
- fissure sealants
- if molars not too badly affected
- metal/ceramic onlays
- can be challenging
- bonding system less effective
- can be challenging
- stainless steel crowns
- when 6s have just erupted
- replaced with more aesthetic option
- when older
- when 6s have just erupted
- orthodontics
- for anterior open bite
- not just aesthetic
- can be very challenging
- debonding very common
- bonding systems do not work as well
- may have to put metal bands around all teeth
- for anterior open bite
What systemic disorders may be associated with enamel defects (not amelogenesis imperfecta)?
- epidermolysis bulls
- incontinenta pigmenti
- Down syndrome
- Prader-Willi
- porphyria
- tuberous sclerosis
- pseudohypoparathyroidism
- Hurler’s
Provide examples of structural anomalies affecting dentine
- dentinogenesis imperfecta
- dentine dysplasia
- odontodyspluasia
- systemic disturbance
What is dentine dysplasia?
- normal crown morphology
- amber radiolucency
- pulpal obliteration
- short constricted roots
What is odontodysplasia?
- localised arrest in tooth development
- thin layers of enamel and dentine
- large pulp chambers
- ‘ghost teeth’ appearance radiographically
What kind of systemic disturbances can cause anomalies in dentine?
- nutritional
- metabolic
- drugs
How many types of dentinogenesis imperfecta are there and what are they called?
- 3 types
- Type II
- associated with bone conditions
- osteogenesis imperfecta
- associated with bone conditions
- Type II
- autosomal dominant
- not associated with other conditions
- Brandywine
- Type II
How is dentinogenesis imperfecta diagnosed?
- appearance
- amber/translucent/grey colour
- family history
- associated osteogenesis imperfecta
- patient in wheelchair
- multiple bone fractures
- blue sclera of eye
- both dentitions affected
- radiographically
- bulbous crowns
- look similar to primary teeth
- must look at root morphology
- obliterated pulp
- pulp large when first erupted
- very quickly obliterated
- very challenging for endodontics
- occult abscesses
- no demonstrative disease on crown
- bulbous crowns
- enamel loss
- enamel formed normally
- lost very quickly as not attached at ADJ
What is Brandywine dentinogenesis imperfecta?
- localised ot Brandywine, Maryland, USA
- tri-racial mix
- native american
- irish
- afra-american
- not many new genes being introduced
What problems are associated with dentinogenesis imperfecta?
- aesthetics
- caries/acid susceptibility
- spontaneous abscess
- very difficult to treat
- poor prognosis
What possible solutions exist for dentinogenesis imperfecta?
- prevention
- enhanced prevention route
- composite veneers
- difficult to bond
- over dentures
- attempt to protect teeth
- removable prosthesis
- stainless steel crowns
- as many teeth as possible
Which hereditary dentine defects are limited to dentine only?
- dentinogenesis imperfecta type II
- dentine dysplasia types I and II
- fibrous dysplasia of dentine
What general disorders may be associated with hereditary dentine defects?
- osteogenesis imperfect
- Ehlers-Dablos syndrome
- brachio-skeletal genital syndrome
- rickets
- hypophosphatasia
What 3 parts of treatment must be considered for tooth structure defects?
- prevention and pain control
- restoration of lost tissue
- harness growth
What are the 5 components of dental management of tooth structure defects?
- continuous dental care
- management of growth and development
- removable prosthesis
- crowns
- interceptive orthodontics
What structure anomalies can exist affecting cementum?
- cleidocranial dysplasia
- hypoplasia of cellular component
- hypophosphatasia
- hypoplasia or aplasia of cementum
- early loss of primary teeth
- nothing holding teeth into bone
What anomalies of eruption exist?
- premature exfoliation
- delayed exfoliation
What can cause premature eruption?
- high birth weight
- precocious puberty
- natal/neonatal teeth
- 1:2000/3000 births
What can cause delayed eruption?
- pre-term and low birth weight
- malnutrition
- associated general conditions
- Down syndrome
- hypothyroidism
- hypopituitarism
- cleidocranial dysplasia
- gingival hyperplasia/overgrowth
- pseudo delayed eruption
- teeth have erupted but not visible
- pseudo delayed eruption
Why might natal teeth be extracted and what impact does this have?
- inhalation risk
- teeth are part of the normal eruption series
- just erupted extremely early
- must warn that there will be a gap left
What are the possible causes of premature exfoliation?
- trauma
- following pulpotomy
- reason not known
- hypophosphatasia
- immunological deficiency
- cyclic neutropenia
- Chediak-Higashi syndrome
- Histiocytosis X
What are the possible causes of delayed exfoliation?
- infra-occlusion
- appearance of tooth sinking into gum
- 1-9%, more common in males
- first primary molar most common
- congenital absence of premolar
- usually exfoliate by 11-12 years
- must remove if ankylosed
- double primary teeth
- can last longer in the mouth
- hypodontia
- no permanent successor to replace
- ectopic permanent successor
- permanent not pushing primary out
- trauma
- tooth may be ankylosed
