Local Causes of Malocclusion Flashcards
what is a local cause of malocclusion
a localised problem or abnormality within either arch, usually confined to one, two or several teeth producing a malocclusion
what are the local causes of malocclusion
variation in tooth number
variation in tooth size or form
abnormalities of tooth position
local abnormalities of soft tissues
local pathology
what are the issues we have with variation in tooth number
supernumerary
hypodontia
retained primaries
early loss of primaries
unscheduled loss of permanents
with is a supernumerary tooth
a tooth or tooth like entity which is additional to normal series
where do supernumeraries usually occur
anterior maxilla
what are the four types of supernumeraries
conical
tuberculate
supplemental
odontome
what is a conical supernumerary
small peg shaped tooth close to midline
what can conical supernumeraries do to eruption pattern
not prevent eruption but displace adjacent teeth
what is a tuberculate supernumerary
barrel shaped paired tooth which does not erupt
what do tuberculate supernumeraries do to eruption pattern
prevent eruption of permanent upper incisors
what are supplemental supernumeraries
extra teeth of normal morphology
what can an odontome either be
compound = discreet denticles
complex = disorganised mass of dentine, pulp and enamel
what is hypodontia
developmental absence of one or more teeth
what teeth are commonly affected with hypodontia
upper laterals
second premolars
when should you have alarm bells of retained primaries
when there is a difference of more than 6 months between shedding of contra lateral teeth
why are primary teeth sometimes retained
absent successor
ectopic successor or dilacerated
infra-occluded (ankylosed) primary molars
dentally delayed development
pathology/supernumerary
what do you do if there is an absent successor in retained primary teeth
maintain primary tooth for as long as possible or extract tooth early to encourage space closure
refer to ortho
what is an infra occluded primary molar
tooth fails to achieve or maintain the occlusal relationship with adjacent teeth
why does early loss of primaries occur
trauma
periapical pathology
caries
resorption by successor
what does localisation of crowding depend on
which tooth extracted
when tooth extracted
patients inherent crowding
what is balancing extraction
extraction of tooth from opposite side of same arch
what is balancing extraction for
minimise midline shift
what is compensating extraction
extraction of tooth from the opposing arch of same side
what is compensating extraction for
maintain occlusal relationship
what do you do when early loss of incisors
no compensating or balancing
what do you do when early loss of canines
consider balancing extraction
what factors influence the impact of loss of permanent 6s
age at loss
crowding
malocclusion
what happens to lower arch when 6s are lost
if 7s erupted then poor space closure
if lost early then distal drift of 5s
what will unplanned loss of central incisor result in
drift of adjacent teeth if lost early
long term space if lost late
what do you when central incisor is lost
maintain space by reimplanting or denture
what problems come with macrodontia
crowding
asymmetry
aesthetics
what problems come with microdontia
spacing
what are the different types of abnormal form that a tooth can have
peg shaped laterals
dens in dente
geminated/fused
talon cusps
dilaceration
accessory cusps
what teeth are most commonly ectopic
third molars
upper canines
first permanent molars
upper centrals
what do you check for with ectopic maxillary canines
palpable buccal canine bulge from 9 years onwards
what is the clinical assessment for ectopic canines
visualisation/palpation of bumps of 3
inclination of 2
mobility of c or 2
colour of c or 2
what radiographs are needed to localise ectopic 3
OPT and upper anterior oblique occlusal
how do you manage an ectopic canine
prevent
extract c to encourage position of 3
retain 3 and observe
surgical exposure and ortho alignment
extraction of 3
autotransplantation
how do you manage ectopic first molars
separator
attempt distalise of 6
extract e
what are transpositions
interchange in position of two teeth
what teeth most commonly swap places
upper canines and first premolar
lower canines and incisors
how do you treat transpositions
accept
extract
correct
what are the local abnormalities of soft tissues caused by
digit sucking
fraenum
tongue thrust
what happens due to digit sucking
proclined upper incisor
retroclined lower incisor
anterior open bite
unilateral posterior crossbite
what can a labial fraenum cause
median diastema
