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
What is the pathology for fluorosis?
- fluoride combines with calcium fluorapatite
- replaces the hydroxide in the apatite lattice
What is the following describing the pathology for what condition?
- fluoride combines with calcium fluorapatite
- replaces the hydroxide in the apatite lattice, mostly enamel surface, resulting in lower energy for the crystal, increased stability and thus resistant to acid dissolution
- in addition, there is damage to ameloblasts resulting in defective and reduced matrix, when levels are very high, not at intermediate levels (2-6 ppm)
fluorosis
How many ppm does the following occur for fluorosis?
- enamel is pitted, brittle and brown
above 6ppm
How many ppm does the following occur for fluorosis?
- severe mottling due to excessive intake
above 8ppm
What are the 3 main studies into fluorosis?
Holloway study
Cochrane review
Uni of York
What percentage does fluoridated water reduce caries by?
40%
What percentage is the prevalence of tetracycline staining?
3-6%
What condition is being described?
- introduced in 1948 as broad-spectrum antibiotics that may be used in the treatment of many common infections in children and adults
- one of the side effects is incorporation into tissues that are calcifying at the time of their administration
- they have the ability to chelate calcium ions to be incorporated into teeth, cartilage and bone, resulting in discolouration of both the primary and permanent dentitions
- this permanent discolouration varies from yellow to grey to brown depending on the dose or the type of drug received in relation to body weight.
- side effect on the oral cavity is the singular occurrence of ‘black bones’, ‘black or green roots’ and blue-grey to grey-blue darkening of the crowns of permanent teeth
tetracycline staining
What condition is shown?
tetracycline staining
What are the 3 types of macrodontia?
- true relative macrodontia
- generalised relative macrodontia
- single tooth macrodontia
What percentage of the population is affected by macrodontia?
1%
What type of macrodontia is being described?
- rare condition caused by pituitary gigantism, all teeth larger than normal
true relative macrodontia
What type of macrodontia is being described?
- teeth appear slightly larger than normal, often exacerbated by jaw size
generalised relative macrodontia
What are the 3 types of microdontia?
- true relative microdontia
- generalised relative microdontia
- single tooth microdontia
What is the most common type of macrodontia?
single tooth macrodontia
What type of microdontia is being described?
- all the teeth are smaller than the normal size. Very rare and occurs in pituitary dwarfism due to decreased levels of growth hormone the teeth fail to develop to a normal size
true relative microdontia
What type of microdontia is being described?
- teeth appear slightly smaller than normal, often exacerbated by large jaw size
generalised relative microdontinia
What type of microdontia is being described?
- often associated with hypodontia, upper laterals most commonly affected
single tooth microdontia
What condition is being described?
- 2 teeth joined from the fusion of 2 tooth germs (mainly affects deciduous teeth)
fusion
What condition is being described?
- 2 teeth joined together arising from a single tooth germ
gemination
What condition is being described?
- 2 teeth joined together by cementum
concrescence
What condition is being described?
- infolding of the outer surface of a tooth into the interior, common in upper laterals, often symmetrical. Appears as a linear radiopacity at levels of cingulum. The soft tissue within the invagination dies on eruption
dens in dente
What condition is being described?
- occurs in the central groove or lingual ridge of buccal cusp of premolar or molar
dens invaginatus
What condition is this?
moon/mulberry molars
What are the following? - additional roots - root morphology: bifid roots curved roots dilaceration - root grows to one side taurodontism - occurs through disruption in late invagination Hertwigs root sheath pulp stones
anomalies affecting roots and/or pulp
What syndrome are pulp stones associated with?
Ehlers danlos
What are the 2 main types of odontomes?
compound and complex
What condition is being described?
- seem to result from budding of extra-odontogenic epithelial cells from the dental lamina
- these odontogenic entities are clusters of cells that form a large mass of tissues that may be deposited in an abnormal arrangement, but consists of normal enamel, dentine, cementum and pulp
- form when dentition is developing, mainly in second decade of life
odontomes
What type of odontomes is being described?
- still has the 3 separate dental tissues (enamel, dentine and cementum), but may present a lobulated appearance where there is no definitive demarcation of separate tissues between the individual denticles. Usually appears in the anterior maxilla
- twice as common as complex odontomes
compound odontoma
What type of odontome is being described?
- unrecognisable as dental tissues, usually presenting as a radiopaque area with varying densities. It usually appears in the posterior maxilla or in the mandible
- 60% occur in women
complex odontoma
What condition is being described?
- small globules of enamel 1-3mm found on roots of molars
- affects approx. 3% of population
- may have a dentine core and pulp horn
- form below the crest of the gingiva at the trifurcation/bifurcation of mandibular molars
- may predispose to perio pocket formation
enamel pearls
What craniofacial condition is being described?
- premature fusion of the intramembranous bones
- 1:1000-2000 births
- syndromic (15%) or non-syndromic (85%)
- increased intracranial pressure
- deformity due to compensatory growth
- visual and hearing deficits/abnormalities
craniosynostosis
What percentage of craniosynostosis is seen from premature closure of the sagittal suture?
40-58%
What percentage of craniosynostosis is seen from premature closure of the coronal suture?
20-29%
What percentage of craniosynostosis is seen from premature closure of the metopic suture?
4-10%
What percentage of craniosynostosis is seen from premature closure of the lambdoidal suture?
2-4%
What is a visual feature of craniosynostosis?
hypertelorism of the orbits - seem further apart and tall deep forehead
What is the term used for unilateral fusion of the coronal suture?
anterior plagiocephaly
What is the term used for unilateral fusion of the lambdoidal suture?
posterior plagiocephaly
What is meant by the term Doliocephaly?
- relates to the skull being longer due to compensatory growth of the skull in response to increasing brain size
What is meant by the term Brachiocephaly?
- relates to the skull being shorter due to compensatory growth of the skull in response to increasing brain size
What is being described?
- occurs when the sagittal suture fuses prematurely
- most common type of non-syndromic craniosynostosis
- characterised by:
bifrontal bossing
biparietal narrowing
occipital cupping
scaphocephaly/sagittal synostosis
What is the term used for the following?
- coronal synostosis (premature closure of the coronal suture)
- can be bilateral or unilateral
- bilateral tends to be more syndromic and associated with learning difficulties
acrobrachycephaly
What is the term used for the following?
- premature closure of the metopic suture
- limits growth in anterior part of the cranium causing bossing posteriorly
- triangular shaped head
- affects 1:15,000 births
- metopic suture normally closes 2 years but early closure from 3-9 months
trigonocephaly
What is the main gene mutation responsible for the development of certain syndromes linked to craniofacial anomalies?
FGFR
What are the following features of?
- cranial synostosis: affects head shape and size
- skull: sutural bulging
- eyes: ocular proptosis (bulging eyes), shallow orbits, subluxation of the eyeball, widely spaced eyes
- jaws: hypoplastic maxilla (small-poorly developed), mandible prognathism (small jaw)
- small mouth
- nose: wide beak appearance/flattened
- ears: hearing loss, low position
- brain: normal function or decreased 10%
- cleft palate: respiratory problems can relate to open cleft palate
craniofacial syndromes
What does FGFR stand for?
fibroblast growth factor receptor
Crouzon syndrome is linked to a mutation of what gene?
chromosome 10 of the FGFR2 gene
What condition is being described?
- craniostenosis
- autosomal dominant mutation on chromosome 10, FGFR2 gene
- 50:50 new mutations:inherited defect
- premature closing of the orbit and maxillary sutures results in high wide skull with beak nose and protrusion of the eyeball
- early closure of the cranial base - low ears
- sagittal, coronal and lambdoidal sutures can be affected
- the early fusion leads to distortion of bone growth
- when all sutures are affected the skull appears ‘clover leafed’
crouzon syndrome
What condition is being described?
- clover leaf skull appearance, this condition is similar to Crouzon syndrome but also affects hands and feet (syndactyly)
- 1:160,000 births
- autosomal dominant FGFR gene defect
- broad thumbs, great toe
- nasopharyngeal problems, crowding
- high narrow cleft palate
- dental crowding
- bifid uvula
- small maxilla
Apert syndrome
Apert syndrome is linked to a mutation of what gene?
FGFR gene
Pfeiffer syndrome is linked to a mutation of what gene?
chromosome 8 of FGFR1 gene
What condition is being described?
- 1:70,000 births
- chromosome 8, FGFR1 gene
- steep wide bulging skull with full forehead and flat occipital region
- orbits are shallow with small nose
- trapezoid shaped mouth
- mandibular prognathism (small jaw), high arch, cleft palate, nasal obstruction, crowded teeth
- facial asymmetry, pointed and short
Pfeiffer syndrome
What week of foetal development is vital for proper facial development?
5th week
What condition is being described?
- 1:50,000 (1:10,000 caucasian)
- defect of the first pharyngeal arch development
- chromosome 5, TCOF1 gene leads to autosomal dominant condition
- treacle protein (regulates amount of neural crest cells), TCOF1 (treacle ribosome biogenesis factor 1) gene haploinsufficiency
- neural crest cells form but undergo early death (apoptosis) meaning there is a lack of cells to form the structures associated with the first pharyngeal arch
treacher-collins syndrome
Treacher-collins is linked to a mutation of what gene?
chromosome 5, TCOF1 gene
What does TCOF stand for?
treacle ribosome biogenesis factor 1
Treacher-collins syndrome is linked to a defect of what pharyngeal arch?
first
What are the following features, features of what condition?
- hypoplastic mandible, receding chin
- absent zygomatic bone
- cleft palate
- TMJ dysfunction
- absent or small ears, malformation of the ossicles and ear canal
- hypoplastic orbits - shallow and bulged
treacher-collins syndrome
Pierre-robin syndrome is a defect of what pharyngeal arch?
first
What condition is being described?
- first pharyngeal arch syndrome
- downward displacement of the tongue
- small maxilla
- cleft palate
- 1,850-20,000 births
- blindness, deafness, brain or eye damage
Pierre-robin syndrome
What is the term used for ‘posterior displacement of the tongue into the pharynx’ ?
glossoptosis
What is the term used for ‘smaller than normal lower jaw’ ?
micrognathia
What are the 3 treatment considerations for Pierre-robin syndrome?
- cranial helmet for craniosynostosis
- physiotherapy
- surgery
What condition is being described?
- genetic disorder caused by the presence of all, or part of a third copy of chromosome 21 (trisomy 21)
- 1:1000 births
- flat facial profile, upslanting palpebral fissures
- hypodontia
- small nose and ears
- enlarged tongue
- cardiovascular problems
downs syndrome
Downs syndrome is caused by a third copy of what chromosome?
chromosome 21
What is being described?
- an opening in the palate due to a failure of the palatal shelves to come fully together from either side of the mouth and fuse
cleft palate
What condition is being described?
- the presence of one or two vertical clefts in the upper lip, can be unilateral (one side) or bilateral (both sides), resulting from failure of the normal process of fusion of the lip to come to completion during embryonic life
cleft lip
What are 3 environmental factors contributing to the formation of cleft lip/palate?
- maternal epilepsy
- drugs - steroids, diazepam, phenytoin
- folic acid deficiency?
What are 3 syndromes linked to the contribution of the formation of cleft lip/palate?
- pierre-robin syndrome
- downs syndrome
- treacher collins syndrome
A cleft may be picked up by high resolution ultrasound at how many weeks gestation?
20 weeks
How many weeks gestation is the lip usually formed?
5-6 weeks
How many weeks gestation is the palate usually formed?
10 weeks
What type of cleft lip is being described?
- extending through the length of the lip to the nose
complete
What type of cleft lip is being described?
- the split runs from the edge of the philtrum to the margin of the nostril
incomplete
What condition is being described?
- commonest congenital abnormalities of the orofacial structure
- 1:750 live births
- often occur as isolated deformities
- males - family history in 40%
- females - family history in 20%
cleft lip/palate
What is being described?
- divides nasal and oral region
- during early infancy the division enables suckling and breathing
- needed for speech
- develops from 3 parts, frontonasal process which forms anterior part of the palate and 2 lateral maxillary palatal shelves (at the centre point where all 3 join we find the incisive papilla)
- results from failure to meet in the midline
palate
The first surgery to repair a cleft palate usually occurs at what age?
between 9-18 months
Surgery to repair a cleft lip occurs at what age?
10 to 12 weeks
What condition are the following characteristics of?
- tooth development disturbances
- malocclusion - therefore plaque accumulation
- open palate
- lack of muscle control of the lips, tongue, cheeks
- speech issues
- infections
- facial deformities
- hearing loss
cleft lip/palate
What is the term used for when a condition is inherited from only one parent?
autosomal dominant
What is the term used for when a condition is inherited from both parents?
recessive
What is the term used for when a condition is inherited from the X chromosome from both parents?
X-linked recessive trait