PAEDS - dental anomalies Flashcards
when do teeth begin to develop?
6 weeks IUL
what are the stages of tooth development?
initiation - dental lamina
morphogenesis - bud and cap stage
cell differentiation - bell stage
matrix secretion - eruption
what is formed at cap stage?
enamel knot
what is amelogenesis regulated by? and what are the 3 phases?
ameloblasts
- secretory phase
- calcification phase
- maturation phase
what regulates dentinogenesis?
odontoblasts
what is the term used to describe an anomaly of tooth number in which there is developmental absence of primary or permanent teeth?
hypodontia
what is another name for severe hypodontia?
oligodontia - more than 6 teeth absence (excluding third molars)
what stage of development is interrupted to result in hypodontia?
initiation stage
what is the genetic aetiology of hypodontia?
single gene defect - MSX1
what syndromes may have hypodontia as a feature?
ectodermal dysplasias
trisomy 21
cleft lip and palate
solitary median maxillary central incisor syndrome
what environmental factors may cause hypodontia?
sequela of severe disease and cancer tx early on in childhood
list the order of most commonly teeth affected by hypodontia?
lower 5
upper 2
upper 5
lower 1
list clinical features of hypodontia?
failure of primary tooth to exfoliate at expected time
permanent tooth hasnt erupted several months after primary exfoliates
teeth erupt out of sequence
contralateral tooth has been erupted for more than 6 months
teeth appear unusually spaced
primary teeth become infraoccluded
high association with microdontia
association with ectopic teeth
no tooth palpable in the buccal or lingual/palatal sulcus
how is a hypodontia diagnosis confirmed?
radiograph (PA first)
DPT if PA doesnt show enough
what is the multidisciplinary approach for managing hypodontia?
diagnosed by GPD
referred to paeds or ortho depending on age and stage of development
seen in secondary care by paeds, ortho, and restorative
why is OHI paramount for patients with hypodontia?
fewer teeth so ones that remain must be caries free as the patient is likely to undergo ortho and may require a prosthesis
what does treatment for hypodontia involve?
space redistribution, tooth modification and prosthetic replacement
what is cleidocranial dysplasia?
autosomal dominant disorder
- clavicles dont form
- primary teeth dont exfoliate on time
- permanent teeth delayed eruption
- loads of supernumeraries
what is ectodermal dysplasia?
a group of diseases affecting the structures arising from the ectoderm:
- teeth
- hair
- nails
- sweat glands
- salivary glands
what is the most common type of ED?
x-linked hypohydrotic ectodermal dysplasia
what are characteristics of ED?
sparse hair
dry skin
inability to sweat
may also suffer from xerostomia, dry eyes and nasal congestion
what do the teeth of patients with ED present as?
conical appearance
microdontia and hypodontia of multiple teeth
what is the dental anomaly in which there is addition of a tooth/teeth to the normal sequence?
supernumerary teeth
what stage of development do supernumerary teeth form at?
initiation stage
what is the aetiology of supernumerary teeth?
genetic, often runs in families
what syndromes do supernumerary teeth tend to present in?
cleidocranial dysplasia
cleft lip and palate
gardner syndrome
what is the prevalence of supernumerary teeth?
<1% primary dentition
35-50% permanent dentition
M>F
how can supernumeraries be defined?
position; mesiodens, paramolar
shape; conical, tuberculate, supplemental, odontome
what are the most common shapes of supernumerary teeth?
conical
what types of supernumerary teeth are likely to erupt ?
likely to erupt:
conical (if not inverted)
supplemental (particularly incisors)
not likely to erupt:
tuberculate
odontomes
where do you commonly find conical supernumerary teeth?
midline maxilla
often in pairs
often inverted
what teeth are usually supplemental?
lateral incisors
3rd premolars
4th molarsw
what is an odontome?
collection of tooth tissue
compound: denticles
complex: disorganised collection of tooth tissue
likely to impede eruption of nearby teeth
what is the first sign of a supernumerary?
eruption of the supernumerary
delayed eruption of the normal sequence
what are the effects of supernumerary teeth?
crowding +/rotation, malposition, ectopic position of surrounding teeth
common cause for delayed eruption of central incisors
what is the clinical examination for supernumerary teeth?
palpate for the presence and position of unerupted teeth
what is management for supernumeraries?
monitor
simple xla
surgical xla
teeth which have been impeded may need to be surgically exposed +/- ortho repositioned
what is the name for the dental anomaly in which teeth present smaller than the average tooth?
microdontia
what stage of development does microdontia occur at?
morphogenesis
what is the aetiology of microdontia?
genetic component
environmental - childhood illness, cancer treatment
associated with hypodontia
what syddromes are associated with microdontia?
ectodermal dysplasia
cleft lip and palate
what is the prevalence of microdontia?
slightly higher in permanent
F>M
what tooth is most commonly affected by microdontia?
maxillary lateral incisor (peg lateral)
what are clinical features of microdontia?
generalised microdontia presents with spacing
localised microdontia - lateral incisor is small, narrow, and conical or ‘peg shaped’
what are microdont laterals associated with?
palatally ectopic canines
what are radiographic features of microdonts?
lack of resorption of root
presence of wear
poor enamel quality
root may be short and narrow
what is the management of microdonts?
accept
ortho space redistribution
composite build up
extract
what is the name of the dental anomaly in which teeth are larger than average tooth/ teeth?
macrodontia
what is the aetiology of macrodontia?
usually tooth is large because it is a double tooth or has another defect such as a talon cusp
what are the types of double teeth?
fusion: 2 tooth germs joined together, may be associated hypodontia
gemination: one tooth germ divided
what is the prevalence of macrodontia?
true macrodontia is very rare
M>F
associated with supernumeraries
what are clinical features of macrodonts?
large crown
extra cusps or grooves
crowding
what are radiographic features of macrodonts?
root form and root canal anatomy varies
double teeth very from:
2 separate roots
butterfly-shaped with 2 canals or 1 canal to a single large root
what is management of macrodontia?
accept
reshape
extract
what is the definition of dens invaginatus?
(dens in dente) “tooth within a tooth”
enamel is folded in on itself creating an enamel lined cavity within the tooth
what is the Oehlers classification for dens invaginatus?
type I - invagination limited to crown up to ACJ
type II - invagination extends to root beyond the CEJ with no communication to pulp
type III A - invagination extends in to root and communicated laterally with PDL with no pulpal communication
type III B - invagination extends in to root and communicates apically with PDL, with no pulpal communication
what is the aetiology of dens invaginatus?
possible genetic
at what stage of development does dens invaginatus occur?
morphogenesis
what is the prevalence of dens invaginatus?
10%
what teeth does dens invaginatus affect?
upper 2s and 1s
often bilateral
what are clinical features of dens invaginatus?
often subtle
pronounced cingulum pit
first indication may be unexplained loss of vitality in the absence of trauma or caries
what are radiographic features of dens invaginatus?
infold of enamel
additional root canals
root expansion
apical radiolucency due to loss of vitality
what is management of dens invaginatus?
fissure seal deep cingulum pits
RCT for loss of vitality but very complex
xla is root morphology is too complex
what is the name of the disorder of tooth form in which there is an additional cusp or tuberculate AKA talon cusp?
dens evaginatus
what is the aetiology of dens evaginatus?
genetic - different in different populations
at what stage of tooth development does dens evaginatus occur?
morphogenesis
what is the prevalence of dens evaginatus?
asian populations (affects lower 5s)
what teeth commonly have talon cusps?
maxillary incisors
what are clinical features of dens evaginatus?
clinically obvious
cusps can wear down due to attrition
premolars:
central cusp but if worn down then exposure of dentine
may lose vitality without any reason
incisors:
talon cusp palatally - may interfere with occlusion, displacement, prevent ortho
some cusps look like extra teeth
what are radiographic features of dens evaginatus?
pulp extension into extra cusp
what is management for dens evaginatus?
accept and prevent: OHI and fissure seal
additional cusp will contain pulp horn
gradual reduction to encourage reactionary dentine
removal of cusp and pulp capping/ pulpotomy/ RCT
what is the name of the anomaly of tooth form in which there is a bend in the root or crown of the tooth?
dilaceration
what is the aetiology of dilaceration?
acquired defect in permanent tooth, resulting from trauma to the primary tooth
high risk injuries: avulsion or intrusion
position of dilaceration along the long axis of tooth depends on stage of development at time of insult
what is the prevalence of dilaceration?
uncommon complication of trauma in the primary dentition
what teeth does dilaceration most commonly affect?
maxillary centrals
what are clinical features of dilaceration?
failure of eruption
altered path of eruption
ectopic position
dilaceration in crown visible in erupted tooth
what are radiographic features of dilacerated teeth?
difficult to access on plain films
lat ceph will show a dilacerated incisor
CBCT to properly assess morphology
what is management of dilacerated teeth?
mild - ortho aligned
unerupted - surgical exposure and bonding or SR
mild dilacerations of the crown - composite/ shaping
what is the name of the tooth form anomaly in which the pulp chamber is elongated with a low bifurcation?
taurodontism
how can taurodontism be classified?
hypotaurodont
mesotaurodont
hypertaurodont
what is the aetiology of taurodontism?
associated with some types of AI and can present in syndromes such as Trisomy 21 and Klinefelter
at what stage of tooth development does taurodontism occur?
morphogenesis
what is the prevalence of taurodontism?
12%
what are the clinical features of taurodontism?
visible crown appears normal
what are the radiographic features of taurodontism?
long pulp chamber with short root canals
what is the management of taurodontism?
no management unless the tooth requires tx for another reason
may be more difficult to perform RCT
xla more challenging
are short roots a disorder?
yes, disorder of tooth form
what is the genetic aetiology of short roots?
genetic - dentine dyplasia
short root anomoly
what is the environmental aetiology of short roots?
arrested root development due to loss of vitality prior to apexogenesis
arrested root development due to illness or tx e.g., childhood cancer during root formation
root resorption caused by trauma or ortho, ectopic teeth, pathology
what is the prevalence of short roots?
depends on cause
genetically, very rare
environementally, common
what are clinical features of short roots?
may be mobility
pain or sinus if loss of vitality
other associated anomalies like microdontia and enamel defects (if caused by childhood illness)
what are radiographic features of short roots?
dentine walls thin and wide root canals (where there is arrested development due to loss of vitality)
roots may be tapered (where there is arrested development without loss of vitality)
dentine walls thin and root canal normal width with blunted apex and irregularity in outline of root (where there has been resorption of previous fully formed teeth)
what is management of short roots?
non-vital teeth need RCT with apexification
vital teeth must be taken care with ortho and perio must be well maintained
where roots are very short plans must be made for their eventual loss
