Theme 4 Dental anomalies Flashcards
3 causes of impacted teeth
- lack of space
- pathology - cysts, odontomes, tumours
- syndromes
2 syndromes casing supernumerary teeth
cleidocranial dysostosis + gardeners syndrome
most popular impacted teeth?
8 > upper 3 > upper 1 > lower 4 > lower 5 > supernumerary
8 > 3> lower 4/5 > 1
when can you extract a 3rd molar
- must have pathology
- tumour resection
- prior to orthographic surgery
signs and symptoms of impacted teeth
retention of primary teeth tooth missing swelling mobility, tilting, loss of vitality of adjacent tooth periocoronitis
radiographic signs that IAN is close to tooth?
darkening of root
diversion/narrowing of canal
interruption of cortical outline
diversion/narrowing of root
what imaging is used to further assess lower 3rd molar extractions?
CBCT
6 treatment options for impacted teeth
- leave
- remove
- expose
- transplant
- coronectomy
- interceptive ortho
3 functions of elevators
- dilate socket
- move tooth along natural path of withdrawal
- remove bone
purpose of bone removal in MOS
reveal tooth
create point of application
access the furcation
relieve + impaction
common sequelae to transplanting a tooth
resorption - leading to early RCT
what treatment may be indicated in very high risk impacted 3rd molars
coronectomy
hard tissue complications to extraction
teeth - damage adjacent, retained roots, displace teeth/roots, OAC
bone - fracture tuberosity, fracture mandible, sequestrum
soft tissue complications of MOS
mechanical burns
crushing flap
poor flap design
neurovascular damage
most common missing teeth
8 > upper 2s > lower 5s
permanent > primary
F >M
genes related to number of teeth
homeobox, MSX1, PAX9
3 types of supernumerary teeth
mesiodens
paramolar
distomolar
most common supernumerary teeth
upper 2s > lower 5s > uppers 5s
what is hypohidrotic ectodermal dysplasia?
hypodontia/anodontia associated with lack of hair, sweating + saddle nose
what are cleft lip/palate, downs, croutons, ellis van creveld + oral facial digital all associated with?
hypodontia
3 syndromes associated with micro/macro dontia?
Ehlers danlos
downs
congenital heart disease
2 causes of double teeth
fusion or germination
what is concrescence?
roots of two or more teeth are united by cementum alone after formation of the crowns
what is taurodontism?
pulp chamber has a greater pico-occlusal height
dental manifestations of Ehlers danlos
microdontia, short roots, pulp stones, fragile mucosa, juvenile periodontitis
(increased bleeding)
oral manifestations of congenital syphilis
infection of tooth germ by treponema palladium
Hutchinson’s incisors - screw driver shaped with notch
mulberry molars - nodular cusps
moon molars - dome shaped crowns
what does xs fluoride cause
fluorosis - hypoplastic/hypomineralised enamel
2 main groups of amelogensis imperfects?
- hypoplastic
2. hypomineralised
how to tell difference between fluorosis + AMELX
AMELX involves all teeth
what bone disease is dentinogensis type I associated with
osteogenesis imperfecta
4 causes of abnormalities of dentine
- local cause - infection, trauma
- dentingenesis imperfecta
- dentinal dysplasia
- environment - rickets, hypophosphatasia, juvenile hypoparathyroidism
in which type of collagen is there a defect in osteogenesis imperfecta
type I
what is type II dentinogenesis imperfecta?
hypo mineralised dentine - teeth only
clinical features of dentinogensis imperfecta
discoloured teeth - grey/brown tint
bulbous crowns
rapid attrition
pulp chamber larger
radiological - thin short blunt roots, pulp chamber becomes obliterated
2 types of dentinal dysplasia
type I = radicular
type II = coronal
what anticonvulsant drug can cause rickets
phenytoin
oral manifestations of rickets
enamel hypoplasia
dentine abnormalities
what is regional odontodysplasia
rare idiopathic condition
localised hypoplastc, abnormal form, delayed eruption
what is hypercementosis?
ankylosis
causes of hypercementosis/ankylosis
- idiopathic
- infection
- overloaded teeth
- functionless/unerupted
- pagets disease
2 causes of hypocementosis
cleidocranial dysplasia
hypophosphatasia
causes of localised delayed eruption
retention of primary hypodontia abnormal crypt position reduced space dangerous/eruption cyst
4 causes of generalised delayed eruption
- hypothyroidism - cretinism
- rickets
- cleidocranial dysplasia
- downs syndrome
what is a dentigerous cyst
follicular cover of unerupted tooth can become cyst
- can turn into keratocysts
- can appear radiographically the same as ameloblastoma
complications of impacted teeth
- gap may close before eruption
- internal resorption if doesn’t erupt
- resorption of adjacent root/impacted roots
- dentigerous cysts
- infection - hard to clean
2 options for parallax
- 2 PAs
2. occlusal + DPT
rule for parallax
Same way
Lingual
Opposite way
Buccal
how do palatally displaced teeth appear on radiograph
magnified
what is an odontome
amorphous collection of tooth tissue - should be removed
compound or complex
what is an open exposure?
apically repositioned flap
hole maintained by retainer/cover plate + Coe-pak (ZnOE) dressing
what is a closed exposure
mucoperiosteal flap raised
gold chains, brackets, magnets use
which 4 impacted teeth are indicated for removal
- palatal canines with shortened TP, open/close canine space, risk to adjacent tooth
- buccally excluded canines
- mandibular mental canines
- palatal premolars
