paeds 2nd year Flashcards
early problems
gingival cysts
congenital epulis
natal tooth
eruption cysts
when would you extract a natal tooth?
- if mobile - inhalation risk
- feeding problem
- trauma (ulcer)
when would you treat a congenital epulis?
- causing feeding problems
- respiratory problem
what happens to a congenital epulis as you age?
shrinks
what should be done for gingival and eruption cysts?
keep eye
when do teeth start to form?
week 5 IUL
when does hard tissue formation start?
week 13 IUL
what do systemic disturbances during calcification cause?
defects in Enamel which was forming
- birth - 2nd molars
approximate calcification of crowns at birth
1/2 central incisors 1/3 lateral incisors tip of canines 1/2 1st molars 1/3 2nd molars tip of cusps of FPM
multifactorial theories of eruption process
cellular proliferation at apex
localised change in bp/hydrostatic pressure
metabolic activity within PDL
resorption of overlying hard tissue
resorption of overlying hard tissue
due to enzymes in dental follicle - dark halo on radiograph
need remodelling of bone/ primary tooth tissue for eruption
BUT not necessary for tooth to erupt to cause resorption of bone
what happens when the dental follicle is activatedin eruption?
initiate OC activity in alveolar bone ahead of tooth
once crestal bone breached - follicle likely to play lesser role
- into supra-alveolar phase
theories about tooth pushing into mouth that have been discounted as major factors?
root elongation
PDL
local changes in vascular pressure
bone growth at where is essential for eruption?
at base of crypt (socket)
- but could be reactive to tooth movement
when does eruption stop?
when tooth contacts something - usually opposing arch
throughout life - compensate for vertical growth of jaws and tooth wear
primary dentition - lower/upper eruption
generally lowers before uppers except lateral incisors
what may variation in primary dentition eruption be due to?
genetic?
when do contralateral teeth usually erupt in primary dentition?
within 3m of each other
at what age is the primary dentition usually complete?
2.5-3years
very variable - some normal children have no teeth at 1
primary dentition - lower a
6m
primary dentition - lower b
12m
primary dentition - lower c
16m
primary dentition - lower d
13m
primary dentition - lower e
24m
primary dentition - upper a
8m
primary dentition - upper b
9m
primary dentition - upper c
17m
primary dentition - upper d
14m
primary dentition - upper e
25m
order of eruption primary dentition
A B D C E
primary dentition - how is permanent teeth fitting into the arch?
anterior spacing so no crowding in permanent
anthropoid/primate spacing
leeway space
facial growth
proclined path of eruption of permanent incisors - increases AP arch length so more space
primate/anthropoid spacing
- mesial to U 3
- distal to L 3
leeway space
extra MD space occupied by the primary molars and canine which are wider than the premolars and canine which will replace them
leeway space U arch
1.5mm per side
leeway space L arch
2.5mm per side
how does the facial skeleton grow?
downwards and forward
when does the mixed dentition stage begin and end?
when 1st permanent tooth erupts until exfoliation of last primary tooth
usually 6-11/12/13 years
FPM - exfoliation of U3
permanent dentition - order of eruption U arch
1st molars then front to back except canines
6 1 2 4 5 3 7 8
permanent dentition - order of eruption L arch
1st molars then front to back
6 1 2 3 4 5 7 8
permanent dentition - L/U eruption
generally L before U except 2nd premolars
where do permanent incisors develop?
palatal to primary
permanent dentition - L1
6yrs
permanent dentition - L2
7yrs
permanent dentition - L3
9yrs
permanent dentition - L4
10yrs
permanent dentition - L5
11yrs
permanent dentition - L6
6yrs
permanent dentition - L7
12yrs
permanent dentition - U1
7yrs
permanent dentition - U2
8yrs
permanent dentition - U3
11yrs
permanent dentition - U4
10yrs
permanent dentition - U5
11yrs
permanent dentition - U6
6yrs
permanent dentition - U7
12yrs
ugly duckling phase
transient spacing U1s due to
- close proximity of roots to erutping 2s, 3s
- self correct when canine erupts
primary incisor root
may bend towards distal
what do primary incisor edges often show?
considerable wear
primary canines morphology
proportionately larger m-d - bulbous
mesial edge straighter
primary U first molar
irregularly quadrilateral narrower lingually than buccally MD groove 3 roots MB tubercle
primary U second molar morphology
transverse ridge - MP to DB 3 roots 2 distinct fissures - mesial c, distal straight largest cusp usually MB similar to U FPM
primary lower 1st molar
rectangular, broad m-d MB tubercle 4 cusps 2 roots buccal steeply lingually inclined
primary lower 2nd molar
similar to L FPM
3 buccal cusps - largest usually mesial
2 roots
primary incisor crowns
smaller and plumper
E in cervical region bulbous
distal edge of crown flares a bit more
Ls smaller
MIH definition
hypo mineralisation of systemic origin of 1-4 permanent molars, frequently associated with affected incisors
if on other teeth not MIH
MIH appearance
'cheesy molars' patches/whole tooth incisors v well demarcated - white/yellow/brown - not symmetrical
MIH prevalence
10-20%
MIH most commonly affected teeth
4 molars
MIH tx need
10x more tx
fear and anxiety more common
behavioural management problems more common
hypomineralisation
Qualitatative enamel defect.
Reduced mineral content
- problem with amelogenesis
- secretory phase fine, maturation phase problem
bonding to hypo mineralised teeth
may be harder to bond to
hypoplasia
Quantitative defect : reduced bulk/thickness of E
amorphous
- secretory phase of amelogenesis affected
true hypoplasia
E never formed
acquired hypoplasia
post-eruptive loss of E bulk
bonding to hypoplastic teeth
should bond properly
why is it hard to determine the aetiology of MIH?
unclear diagnostic criteria
most parents can’t remember details from 8-10years before
variations in quality and completeness of case records
study pops small
critical period for MIH formation
generally agreed 1st year of life - developmental condition not hereditary
E matrix of crown of FPMs is complete by one
is MIH hereditary or developmental?
developmental
MIH 3 clinical periods of enquiry
pre-natal
perinatal
post-natal
MIH prenatal enquiry
health in 3rd trimester
MIH perinatal enquiry
birth trauma/anoxia
hypocalcaemia
pre-term birth (higher prevalence)
MIH post-natal enquiry
prolonged breastfeeding (past 6m) dioxins in breast milk fever and meds (infections - measles, rubella, chicken pox) SE status rural v urban
yellow brown MIH teeth histology
more porous - whole enamel layer
white/cream MIH teeth histology
inner parts of E affected
how does MIH histology explain why sensitivity/difficult to anaesthetise?
increase in neural density in pulp horn and subodontoblastic region
lots more innervation
MIH histology and immune cells
increase in immune cells, esp with post-eruptive E loss
MIH histology vascularity
increase in vascularity in sensitive MIH samples
MIH 3 pain mechanism theories
dentine hypersensitivity
peripheral sensitisation
central sensitisation
MIH pain mechanisms - dentine hypersensitivity
porous E/exposed D facilitates fluid flow within dentinal tubules to activate A delta nerve fibres (hydrodynamic theory)
MIH pain mechanisms - peripheral sensitisation
underlying pulpal inflammation leads to sensitisation of C fibres
MIH pain mechanisms - central sensitisation
from continued nociceptive input?
MIH clinical problems
loss of tooth substance - breakdown of E - toothwear faster - secondary caries (poor resistance) sensitivity - not all - some - can cause OH problem as may be too painful to brush appearance
MIH tx options for FPMs
composite/GIC Rx
SSCs - much harder on FPM
adhesively retained copings - gold best
extraction around 8.5-9.5yrs
MIH tx of affected incisors
acid pumice microabrasion - removes yellow/brown marks external bleaching - makes rest of tooth whiter so less of a contrast localised composite placement - camouflage full composite veneers full porcelain veneers >20yrs
considerations for extracting HFPMs
dental age - radiograph
skeletal pattern
future ortho needs
quality of teeth e.g. caries
what is ideal to see when timing ext of HFPMs?
calcification of bifurcation of L7s
before L7 erupts starts to drift forwards
like to see developing 8s - not always possible