Dental Anomalies Flashcards
What is Anodontia?
congenital absence of all teeth
What is Oligodontia?
congenital absence of 6 or more teeth
What is Hypodontia?
less than 6 missing teeth as a result of failure of teeth to develop
What is the term used to define failure of teeth that do not develop?
tooth agenesis
What teeth is hypodontia commonly seen in?
laterals, premolars and wisdom teeth
What 2 syndromes can anodontia, oligodontia and hypodontia be associated with?
- down’s syndrome
- crouzon syndrome
What is Hyperdontia?
extra tooth/teeth that may be known as supernumerary or supplemental
What are the 2 types of Hyperdontia?
- supernumerary
- supplemental
What type of Hyperdontia is being described?
- additional tooth that is additional to the normal series (morphology does not resemble a normal tooth) and can be found in almost any region of the dental arch
supernumerary
What type of Hyperdontia is being described?
- an additional tooth that looks identical to its surrounding teeth
supplemental
Where are supernumerary teeth most common?
mesiodens in the maxillary midline
What syndrome is Hyperdontia associated with?
crouzon syndrome
What type of abnormalities are the following?
- amelogenesis imperfecta
- dentinogenesis imperfecta
- shell teeth
- regional odontoplasia (ghost teeth)
- dentinal dysplasia
genetic
What type of abnormalities are the following?
- turner teeth
- congenital syphilis
- severe childhood fever - linear enamel defects
- discolouration eg. tetracycline staining
acquired
What type of abnormality is being described?
- one of the most important causes of malformed permanent teeth
- it is a group of genetic conditions with inherited defects in the encoding of enamel matrix proteins
- characterised by enamel hypoplasia, hypomineralisation, or hypomaturation, with smooth, rough or pitted appearance
- at least 16 different forms
amelogenesis imperfecta
Mutations in what genes can result in amelogeneis imperfecta?
AMELX and ENAM
Mutations in what gene cause X-linked amelogenesis imperfecta?
AMELX
Mutations in what gene cause autosomal inherited forms of amelogenesis imperfecta?
ENAM
What gene located on X-chromosome has a major role in enamel formation?
AMELX
What condition is shown on the image?
hypoplastic amelogenesis imperfecta
What condition is being described?
- defect found in enamel matrix
- pitted enamel, grooved or just very thin, although remains hard and translucent
- easily stained but not particularly susceptible to caries
- males very little enamel, females have ridges
hypoplastic amelogenesis imperfecta
What are the 3 types of amelogenesis imperfecta?
- hypoplastic
- hypomaturation
- hypocalcified
What condition is shown on the image?
hypomaturation amelogenesis imperfecta
What condition is being described?
- normal enamel on eruption but opaque with yellowish colour similar to fluorosis
- soft and easily worn down
- more yellow due to dentine being darker than enamel
hypomaturation amelogenesis imperfecta
What condition is shown on the image?
hypocalcified amelogenesis imperfecta
What condition is being described?
- normal enamel matrix but abnormal calcification
- normal on birth but very chalky and easily broken off
- stains easy and quickly worn away
- incisors show a shouldered form
- dominant and recessive inheritance
hypocalcified amelogenesis imperfecta
What condition does this radiographic description best fit?
- square crown, thin opaque enamel, low or absent cusps, normal enamel density
hypoplastic amelogenesis imperfecta
What condition does this radiographic description best fit?
- normal enamel thickness but density same as dentine
hypomaturation amelogenesis imperfecta
What condition does this radiographic description best fit?
- normal enamel thickness but less dense than dentine
hypocalcified amelogeneis imperfecta
What condition is being described?
- defect in collagen formation
- autosomal dominant - inherited condition affecting both primary and secondary dentitions (primary more severely than secondary)
- gene closely related to osteogenesis imperfecta
- defects found in COL1A1 and COL1A2 genes responsible for making type 1 collagen
- defects in the pro-collagen alpha helix which prevents polymerisation into type 1 collagen
dentinogenesis imperfecta
What are the 2 types of dentinogenesis imperfecta?
- type 1: osteogenesis with opalescent teeth (25% of cases of osteogenesis imperfecta)
- type 2: isolated - no other inherited disorder - opalescent teeth
What type of dentinogenesis imperfecta is shown on the image?
type 2
What type of dentinogenesis imperfecta is shown on the image?
type 1
What condition do the following describe?
- normal looking enamel, brownish, purplish, translucent
- normal form, but bulbous crowns and shortened roots
- enamel is easily lost as chips away, due to poor attachment to dentine
- teeth may wear down to gingiva
- earliest enamel at the EDJ is normal
- deeper however, have fewer tubules, incomplete calcification, abnormal matrix
- pulp chamber lost, odontoblasts degenerate
- loss of EDJ scalloping
dentinogenesis imperfecta
What is the percentage ratio of inorganic and organic components of dentine?
65% inorganic
35% organic
Defects in what 3 genes contribute in dentinogenesis imperfecta?
COL1A1
COL1A2
DSPP
The main organic substance in dentine is type 1 collagen, product of what genes?
COL1A1 and COL1A2
The formation of what condition is being described?
- non-collagenous proteins present in dentine, some interact with collagen to initiate and/or regulate mineralization. The most abundant is DSPP
- mutations in either COL (1A1 or 1A2) or DSPP genes can alter this interaction resulting in abnormal mineralization.
dentinogenesis imperfecta
What are the 2 types of dentinal dysplasia?
type 1 - radicular dentinal dysplasia
type 2 - coronal dentinal dysplasia
Is dentinal dysplasia genetic or acquired?
genetic
What type of dentinal dysplasia is being described?
- more frequent of the two types
- roots very short and conical/blunted - increased mobility
- pulp obliterated before eruption
- periodical radiolucencies
type 1 - radicular dentinal dysplasia
What type of dentinal dysplasia is being described?
- roots normal
- pulp obliterated after eruption and is flame shaped
- deciduous teeth resemble dentinogenesis imperfecta
- permanent teeth have large pulps with apical extensions and pulp stones
type 2 - coronal dentinal dysplasia
What condition is being described?
- often called type 3 dentinogenesis imperfecta
- normal chambers but very little dentine and very large pulp chambers
shell teeth
What condition is being described?
- localised disorder of development
- abnormalities of enamel, dentine and pulp
- hypoplastic and hypomineralised enamel and dentine
- non hereditary and unknown aetiology
- seen at eruption of deciduous teeth or permanent teeth, may affect one or both dentitions, one or may be two quadrants
- affects maxillary teeth more than mandibular teeth
- failure to erupt or erupted yellow malformed crowns, with rough features
- teeth appear ‘ghost like’ with reduced radiopacity - difficult to differentiate enamel and dentine
regional odontodysplasia - ghost teeth
These characteristics are of what condition?
- thin enamel and dentine
- enlarged pulp
- hazy appearance on X-ray
- enamel lacks prisms (rod structure)
- dentine has clefts and globular appearance
- follicle tissue may have calcifications
- caries susceptible, fracture easily
- should allow to erupt before final decision on future
ghost teeth
What condition is being described?
- typically only affects one tooth in the mouth
- it is commonly associated with trauma in the anterior teeth or infection of the deciduous tooth
- the treatment depends on the severity, the goal is to cover or replace the missing and/or damaged outer layer of enamel and cover all the dentine
turners hypoplasia
What condition is being described?
- caused by the bacteria Treponema Pallidum, which is passed from mother to child during foetal development or at birth
- nearly half of all children infected with syphilis while they are in the womb die shortly or after birth
- Hutchinson’s teeth, also known as Hutchinson’s incisor, Hutchinson’s sign or hutchinson-boeck teeth are a sign of this condition
- babies with this have teeth that are smaller and more widely spaced than normal and which have notches on their biting surfaces
congenital syphillis
What condition is shown?
congenital syphillis
What condition is shown?
turners hypoplasia
What condition is being described?
- development disturbance of the enamel resulting in clinically visible horizontal defects in enamel that are present on eruption of the tooth
- it is accepted that the condition is related to periodic physiological disruptions to enamel matrix secretion during times when the teeth are developing
- commonly reported in association with disease of childhood such as measles
- disturbances occurring in utero or soon after birth may affect permanent incisors and occlusal surfaces of first permanent molars in addition to deciduous formation
- affects part of the tooth that is developing whilst the patient has the illness
linear enamel hypoplasia
What condition is shown?
linear enamel hypoplasia
What condition is being described?
- one of the most common defects of teeth
- caused by the overconsumption of fluoride when teeth are developing whether they be deciduous or permanent
- in the UK, it is estimated that 40% of the population have enamel defects and half of these are likely due to fluoride
fluorosis
What condition is shown?
fluorosis
How many ppm in the water supply does fluorosis occur?
2ppm or more
What are the following characteristics of which condition?
- mottled enamel is the most frequently seen effect, not so common in UK
- only affects teeth in development so not a problem when individuals enter area with all teeth erupted
- mottling of deciduous teeth is however rare
- caries rate is however very low in mottled teeth
- paper-white enamel opacities are commonest presentation which may become stained after eruption
fluorosis