Dental Anomalies Flashcards
What can dental anomalies be categorized into
number
size/shape
structure
eruption & exfoliation
What are the dental anomalies affecting number
hypodontia
hyperdontia
hypodontia
What is the most common tooth to be missing
mandibular premolar
maxillary lateral incisor
hypodontia
What is the least common tooth to be missing
first permanent molar
upper central incisors
What is the prevalence of hypodontia
3.5-6.5%
What are the conditions associated with hypodontia
- Ectodermal dysplasia
- Down syndrome
- Cleft palate
- Hurler’s syndrome
- Incontinentia pigmentii
What are the aims of treamtent for hypodontia
prevention
restore function and aesthetics
What are the problems experienced by those who have hypodontia
- Abnormal shape/form of present teeth (cone shaped/straight sided small teeth)
- Spacing
- Submergence/infraocclusion of primary teeth
- Deep overbite
- Reduced lower face height
What are solutions for the problems experienced by those who have hypodontia
- Overdenture
- Partial denture
- Composite
- Porcelain veneers
- Fixed prosthesis
- implants
What is the chronology of dental management for hypodontia
- Diagnosis
- Removable prosthesis (while awaiting definitive tx)
- Orthodontics (to make restorative treatment easier)
- Composite buildups to improve shape and size of present teeth
- Porcelain veneers
- Crowns/bridges
- Preventative treatment (all the way through as we cannot afford to lose more teeth)
hypodontia
Why do we wait until a patient is in their 20s for veneers
prior to this, gingival margin moves position
What is hyperdontia aka
supernumerary
What is the prevelance of supernumerary teeth
1.5-3.5%
What jaw is hyperdontia more common in
maxilla
What condition is there higher frequency of hyperdontia
cleidocranial dysplasia
What are the 4 types of supernumerary
- conical
- tuberculate
- supplemental
- odontome
Describe a conical supernumerary
cone shaped
Describe a tuberculate supernumerary
barrel shaped
has tubercles
Describe a supplemental supernumerary
looks like a tooth of a normal series
lateral incisor most common
remove the lateral incisor which is hardest to position correctly
Describe odontome supernumerary
irregular mass of dental hard tissue
can be compound or complex
What is complex odontome
o Complex is when the calcified dental tissues are simply arranged in an irregular mass bearing no morphologic similarity to rudimentary teeth
What is compound odontome
o Compound is when the dental tissues are arranged in a more oderly pattern than complex
What is the most common cause of delayed eruption of the permanent incisor teeth
supernumerary
What are dental anomalies affecting size/shape
- microdontia
- macrodontia
- double teeth
- odontomes
- taurodontism
- dilaceration
- accessory cusps
- dens in dente
What is the incidence of microdontia
2.5%
more common in females
What is the prevalence of macrodontia
<1%
What are the 2 types of double teeth
gemination
fusion
What is gemination
double teeth
one tooth splits into 2
What is fusion
double teeth
2 teeth form to make 1
What is taurodontism
Flame shaped pulp
Tooth otherwise looks normal
Real risk is pulp exposure during restorative work
What is an example of an accessory cusp
talon cusp which is an extra cusp on an anterior tooth which arises as a result of evagination on the surface of a crown before calcification
What is dens in dente
tooth within a tooth
Invagination of the enamel organ into the dental papillae that begins at the crown and often extends to the root even before calcification of the dental tissues
Invaginations can have their own pulp system
What should be done asap for dens in dente teeth
seal them
prevent bacterial ingress as root canal treatment is near impossible for these teeth
What are dental anomalies which effects the roots
short root anomaly
What can be the cause of short roots
o Radiotherapy
o Dentine dysplasias
o Accessory roots
o Orthodontic tx
What teeth are short roots most common in
permanent maxillary incisors
How can the aetioloy of enamel deefects be split up
localised vs general
If the enamel defect is localised, what is it likely to be and what are the probable causes
- localised enamel hypoplasia
- due to trauma / infection (abscess) of primary tooth
If the enamel defect is generalised, what can this further be classified into
environmental vs hereditary
What is the most common cause for environmental enamel hypoplasia
fluorisis
How does fluorosis present in its milder form
symmetrical white marks
treated with microabrasion/veneers/vital bleaching
What is another cause of environmental enamel hypoplasia
- MIH associated with childhood illness
- chronolgoical hypomineralisation
What is chronolgoical hypomineralisation
generalised form of hypoplasia with a characteristic presentation of symmetrical defects with a chronological pattern, with only parts of the teeth developing (enamel secretion) at the time of the insult affected)
What are prenatal conditions that can result in enamel defects
o Rubella
o Congenital syphilis
o Thalidomide
o Fluoride
o Maternal A&D deficiency
o Cardiac/kidney disease
What are neonatal conditions that can result in enamel defects
o Prematurity
o Meningitis
What are post natal conditions that can result in enamel defects
o Otitis media
o Measles
o Chickenpox
o TB
o Pneumonia
o Diphtheria
o Deficiency of vitamin A, C, D
o Heart disease
o Long term health problem
What are hereditary causes of enamel defects
amelogenesis imperfecta
What is the prevelance of AI
1:14000 prevalence
How can enamel defects be hereditary
- Enamel formation needs multiple genes to transcribe the process of crystal growth and mineralisation
These genes can become mutated - Gene mutations found so far involve enamel extracellular matrix molecules amelogenin and enamelin and kallikrein 4
What are the 4 types of amelogensis imperfecta
- hypoplastitc
- hypomineralised
- hypomaturational
- mixed with taurodontism
Describe hypoplastic AI
Enamel crystals do not grow to correct length
Normal minerall content but chunks of enamel missing, different shape
Due to error in secretory phase when the template is laid down, however mineralisation stage is as normal
Describe hypomineralised AI
Crystallites fail to grow in thickness and width
Describe hypomineralised AI
Crystallites fail to grow in thickness and width
Normal shape but not correct mineral content
Results in marks
Abnormal mineralisation stage
Describe hypomaturational AI
Enamel crystals grow incompletely in thickness or width but to normal length with incomplete
What is the most common type of trait that results in AI
- Autosomal dominant trait is most common in USA/Europe
Is there systemic disease associated with AI
Not usually
What do we look at to diagnose AI
o Family history prevalence
o Generally, effects both dentitions but usually worse in permanent
o Can affect tooth size/structure/colour
o Radiographs will show similar radiolucency between enamel and dentine
o Affects all teeth
What are problems caused by AI
o Sensitivity (less enamel covering dentine/pulp)
o Caries/acid susceptibility
o Poor aesthetics (brown honey-comb like lesions)
o Poor OH (pain on brushing)
o Delayed eruption
o Anterior open bite
What are solutions for problems caused by AI
o Enhanced prevention
o Composite veneers/composite wash
o Fissure sealants
o Metal onlays
o Stainless steel crowns
o Orthodontics
Why do we do composite veneers for AI patients and what problems do we face
Improve appearance and sensitivity
Composite veneers can be difficult as the differing enamel structure can impact bond strength
When do we do fissure sealants for AI patients
if molars not significantly effected
When do we do metal onlays for AI patients
if molars significantly effected
Why do AI patients need orthodontics and what problems may be faced
Often required due to AOB
However brackets more likely to debond due to differing enamel structure impacting bond strength
What systemic disorders are associated with enamael defects (not AI)
o Epidermolysis bullosa
o Incontinenta pigmenti
o Down’s
o Prader-willi
o Porphyria
o Tuberous sclerosis
o Pseudohypoparathyroidism
o Hurler’s
What are anomalies effecting dentine
dentinogenesis imperfecta
dentine dysplasia
odontodysplasia
What are the 3 types of dentinogenesis imperfecta
type 1
type 2
brandywine
What is type 1 DI
osteogenesis imperfecta
What is type 2 DI
autosomal dominant (no other underlying medical conditions)
What do we look at to diagnose DI
o Appearance
o Family history
o Associated osteogenesis imperfecta
o Both dentitions affected
o Radiography shows
o Enamel loss
What will we see on the radiograph if a patient has DI
Bulbous crowns
Obliterated pulps (seen in type 1 & 2)
Why is enamel lost more quickly in dentinogenesis imperfecta
due to lack of connection at ADJ
What are problems caused by DI
o Aesthetics
o Caries/acid susceptibility
o Spontaneous abscess
o Poor prognosis
What are solutions to problems caused by DI
o Prevention
o Composite veneers
o Overdentures
o Removable prosthesis
o Stainless steel crowns
What is dentine dysplasia clinical/radiographic appearance
- Normal crown morphology
- Amber look
- Pulpal obliteration
- Short constricted roots
What is odontodysplasia
- Localised arrest in tooth development
- Thin layers of enamel and dentine
- Large pulp chambers
- Results in ‘ghost teeth in x-ray
What is systemic disturbances that can result in dentine defects
- Nutritional
- Metabolic
- Drugs
What general disorders are associated with dentine defects
- Osteogenesis imperfecta
- Ehlers danlos syndrome
- Brachioskeleatl genital syndrome
- Rickets
- Hypophosphatasia
What dentine defects are limited to dentine only
- Dentinogenesis imperfecta type 2
- Dentine dysplasia type1 & 2
- Fibrous dysplasia of dentine
What are anomalies in eruption/exfoliation
premature
delayed
What is premature eruption associated with
Associated with high birth weight
Precocious puberty, when a child’s body begins changing into that of an adult too soon (before 8 for girls and 9 for boys)
Natal/neonatal teeth
What is delayed eruption associated with
Associated with pre-term & low birth weight children
Malnutrition
Associated general conditions
Gingival hyperplasia/overgrowth
What are the assocaited general conditions linked to delayed eruption
- Downs
- Hypothyroidism
- Hypopituitarism
- Cleidocranial dysplasia
How is gingival hyperplasia linked to delayed eruption
- Pseudodelayed
- Gingiva covering the teeth
What is the aetiology of premature exfoliation
Trauma
Following pulpotomy (unsure of how it happens)
Hypophosphatasia
Immunological deficiency
Chediak-higashi syndrome
Histiocytosis X
What is the aetiology for delayed exfoliation
infraoccluded
double primary teeth
hypodontia
ectopic permanent successors
following trauma
What is meant by infraoccluded
- Tooth appears as if sinking
- 1-9% permanence
- More common when there is congenital absence, especially for premolars
- Majority exfoliate normally by age 11-12 years old
What is meant by double primary teeth
- Adult and baby teeth present simultaneously
What conditions result in anomalies of cementum
cleidocranial dysplasia
hypophosphatasia
