Local Causes of Malocclusion

Question 1

what is a local cause of malocclusion

Answer 1

a localised problem or abnormality within either arch, usually confined to one, two or several teeth producing a malocclusion

Question 2

what are the local causes of malocclusion

Answer 2

variation in tooth number
variation in tooth size or form
abnormalities of tooth position
local abnormalities of soft tissues
local pathology

Question 3

what are the issues we have with variation in tooth number

Answer 3

supernumerary
hypodontia
retained primaries
early loss of primaries
unscheduled loss of permanents

Question 4

with is a supernumerary tooth

Answer 4

a tooth or tooth like entity which is additional to normal series

Question 5

where do supernumeraries usually occur

Answer 5

anterior maxilla

Question 6

what are the four types of supernumeraries

Answer 6

conical
tuberculate
supplemental
odontome

Question 7

what is a conical supernumerary

Answer 7

small peg shaped tooth close to midline

Question 8

what can conical supernumeraries do to eruption pattern

Answer 8

not prevent eruption but displace adjacent teeth

Question 9

what is a tuberculate supernumerary

Answer 9

barrel shaped paired tooth which does not erupt

Question 10

what do tuberculate supernumeraries do to eruption pattern

Answer 10

prevent eruption of permanent upper incisors

Question 11

what are supplemental supernumeraries

Answer 11

extra teeth of normal morphology

Question 12

what can an odontome either be

Answer 12

compound = discreet denticles
complex = disorganised mass of dentine, pulp and enamel

Question 13

what is hypodontia

Answer 13

developmental absence of one or more teeth

Question 14

what teeth are commonly affected with hypodontia

Answer 14

upper laterals
second premolars

Question 15

when should you have alarm bells of retained primaries

Answer 15

when there is a difference of more than 6 months between shedding of contra lateral teeth

Question 16

why are primary teeth sometimes retained

Answer 16

absent successor
ectopic successor or dilacerated
infra-occluded (ankylosed) primary molars
dentally delayed development
pathology/supernumerary

Question 17

what do you do if there is an absent successor in retained primary teeth

Answer 17

maintain primary tooth for as long as possible or extract tooth early to encourage space closure
refer to ortho

Question 18

what is an infra occluded primary molar

Answer 18

tooth fails to achieve or maintain the occlusal relationship with adjacent teeth

Question 19

why does early loss of primaries occur

Answer 19

trauma
periapical pathology
caries
resorption by successor

Question 20

what does localisation of crowding depend on

Answer 20

which tooth extracted
when tooth extracted
patients inherent crowding

Question 21

what is balancing extraction

Answer 21

extraction of tooth from opposite side of same arch

Question 22

what is balancing extraction for

Answer 22

minimise midline shift

Question 23

what is compensating extraction

Answer 23

extraction of tooth from the opposing arch of same side

Question 24

what is compensating extraction for

Answer 24

maintain occlusal relationship

Question 25

what do you do when early loss of incisors

Answer 25

no compensating or balancing

Question 26

what do you do when early loss of canines

Answer 26

consider balancing extraction

Question 27

what factors influence the impact of loss of permanent 6s

Answer 27

age at loss
crowding
malocclusion

Question 28

what happens to lower arch when 6s are lost

Answer 28

if 7s erupted then poor space closure
if lost early then distal drift of 5s

Question 29

what will unplanned loss of central incisor result in

Answer 29

drift of adjacent teeth if lost early
long term space if lost late

Question 30

what do you when central incisor is lost

Answer 30

maintain space by reimplanting or denture

Question 31

what problems come with macrodontia

Answer 31

crowding
asymmetry
aesthetics

Question 32

what problems come with microdontia

Answer 32

spacing

Question 33

what are the different types of abnormal form that a tooth can have

Answer 33

peg shaped laterals
dens in dente
geminated/fused
talon cusps
dilaceration
accessory cusps

Question 34

what teeth are most commonly ectopic

Answer 34

third molars
upper canines
first permanent molars
upper centrals

Question 35

what do you check for with ectopic maxillary canines

Answer 35

palpable buccal canine bulge from 9 years onwards

Question 36

what is the clinical assessment for ectopic canines

Answer 36

visualisation/palpation of bumps of 3
inclination of 2
mobility of c or 2
colour of c or 2

Question 37

what radiographs are needed to localise ectopic 3

Answer 37

OPT and upper anterior oblique occlusal

Question 38

how do you manage an ectopic canine

Answer 38

prevent
extract c to encourage position of 3
retain 3 and observe
surgical exposure and ortho alignment
extraction of 3
autotransplantation

Question 39

how do you manage ectopic first molars

Answer 39

separator
attempt distalise of 6
extract e

Question 40

what are transpositions

Answer 40

interchange in position of two teeth

Question 41

what teeth most commonly swap places

Answer 41

upper canines and first premolar
lower canines and incisors

Question 42

how do you treat transpositions

Answer 42

accept
extract
correct

Question 43

what are the local abnormalities of soft tissues caused by

Answer 43

digit sucking
fraenum
tongue thrust

Question 44

what happens due to digit sucking

Answer 44

proclined upper incisor
retroclined lower incisor
anterior open bite
unilateral posterior crossbite

Question 45

what can a labial fraenum cause

Answer 45

median diastema