Orthodontic Assessment Flashcards
Why do we do an orthodontic assessment?
to determine if any malocclusions are present
identify any underlying causes
decide if treatment is indicated (either refer or devise treatment plan)
What age do we do a brief ortho exam
9 years old
What age do we do a comprehensive examination
when the premolars/canines erupt so 11/12 years
When do we do an ortho examination
when older patients first present
if a malocclusion develops later in life
What is the ideal occlusion
hypothetical
rarely found in nature
What are Andrews 6 keys for ideal occlusion
Molar relationship crown angulation (mesio-distal top) crown inclination no rotations no spaces flat occlusal planes
Describe the molar relationship seen in Andrews 6 keys
the distal surface of the disto-buccal cusp of the upper first permanent molar occludes with the mesial surface of the mesio-buccal cusp of the lower second permanent molar
What is a normal occlusion
more commonly observed than ideal occlusion
What is a minor deviation occlusion
do not constitute an aesthetic or functional problem
What is a malocclusion
more significant deviations from the ideal that may be considered unsatisfactory (aesthetically or functionally)
What are significant factors in the past medical history
allergy (Ni or Latex)
epilepsy/drugs
drugs
imaging
What are significant factors in the past dental history
frequency of attendance
nature of previous treatment
co-operation with previous treatment
trauma to permanent dentition
What are habits that are relevant to ortho
thumb sucking
lower lip sucking
tongue thrust
chewing finger nails
When doing an extra oral exam what do we look at
skeletal bases
soft tissues
TMJ
What do we compare the patient to parent for
malocclusion - especially class III growth potential
What do the teeth sit on
individual skeletal bases which are connected to the skull bases
What happens if you have an increased cranial base angle
then the posterior and anterior cranial bases are at a higher angle and there is a tendency for a large overjet as the mandible is further back
What planes is a facial skeletal pattern considered in (looking at the skeletal bases)
antero-posterior
vertical
transverse
How is the skeletal assessment done in the anteroposterior plane
via visual assessment
palpate the skeletal bases
How should the head be positioned for an extra oral examination
Frankfurt plane horizontal to the floor
What is a class I (AP skeletal assessment)
maxilla 2-3mm in front of mandible
What is a class II (AP skeletal assessment)
maxilla more than 3mm in front
What is a class III (AP skeletal assessment)
mandible in front of the maxilla
What is the function of direct palpation of the skeletal bases
can see how bases relate to one another
How is the vertical skeletal assessment done
by look at the angle between the frankfort plane and the mandibular plane angle
want to see where these two lines meet - should meet at the back of the head
What is the mandibular plane angle
it is the lower border of the mandible
What should be expected if the FMPA meets before the back of the head
will be expecting minimal overbite or an anterior open bite inside the mouth
would expect no contact with the front teeth as the back teeth meet first
If there’s a reduced FMPA angle what is expected
the two lines don’t meet at the back fo the head
expect them to have a deep bite, the jaws are too close together
How is the skeletal assessment done laterally
look at the mid saggital reference line
can pick up mandibular asymmetry
What should we look at when looking at the lips in the EO exam
competent/incompetent
lower lip level
lower lip active
What should we look at when examining the tongue in the EO exam
position, habitual and swallowing
What should we look at with speech
lisping
What are competent lips
meet at rest
relaxed mentalis muscle
What are incompetent lips
do not meet at rest
relaxed mentalis muscle
What is a tooth trap
upper teeth rest on lower lip so are proclined forward slightly
What is the effect of a hyper active lower lip
may retrocline lower incisiors
indicates likely stability at the end of tx
What is a tongue thrust associated with
tongue thrust on swallow is associated with anterior open bite
can be endogenous or adaptive tongue thrust
What is the issue sometimes with treating AOB from tongue thrust
may cause relapse of the AOB at the end of the treatment if its endogenous
What are the two main ways of sucking digits
if its a thumb it causes asymmetrical problem
if two digits causes symmetrical problem
What is the occlusal effect of sucking a thumb
proclamation of upper anteriors
retroclincation of lower anteriors
localized AOB or incomplete OB
narrow upper arch with or without a unilateral posterior cross bite
these effects will be superimposed by the existing skeletal pattern and incisors relationship which can make the issue worse
When examining the TMJ what should we examine
path of closure range of movement pain, click from joint deviation on opening muscle tenderness
What should we look out for when examining the TMJ
mandibular displacement
discrepancy in RCP and ICp
What should we check for the intra oral examination
OH and periodontal health count teeth teeth of poor prognosis assess crowding/spacing/rotations inclination/angulation palpate for canines if not erupted note teeth fo abnormal shape or size
What should we look at in the IO exam for the lower arch
degree of crowding
presence of rotations
inclination of canines
angulation of incisors to mandibular plane
What should we look at in the IO exam for the upper arch
degree of crowding
presence of rotations
inclination of canines
angulation of incisors to frankfort plane
What kind of angle do we want for the angulation of incisors to the frankfurt plane
110 degrees
What do we look at when the teeth are in occlusion when the teeth are in maximum interdigitation or Rcp
incisor relationship over bite/open bite molar relationship (angle's classification) canine relationship cross bites centre lines
What are the different incisor relationships
Class I
Class II - div 1 and div 2
Class III
overjet, overbite, centrelines
What is a class I incisor relationship
the lower incisor edges occlude with or lie immediately below the cingulum plate of the upper central incisors
What is a class I incisor relationship
the lower incisor edges lie posterior to the cingulum plateau of the upper incisors
What is a class II incisor relationship
the lower incisor edges lie posterior to the cingulum plateau of the upper incisors
What is a class II div 1 incisor relationship
the upper incisors are proclined or of average inclination and there is an increase in overjet
What is a class II div 2 incisor relationship
the upper central incisors are retroclined
the overjet is usually minimal or may be increased
What is a class III incisor relationship
the lower incisor edges lie anterior to the cingulum plateau of the upper incisors
overjet is reduced or reversed
What is an overbite
overlap of the teeth
What is an average overbite
upper incisors cover 1/3 to 1/2 of lower incisor crowns
What are the diff types of overbites
average reduced AOB increased and complete contacts tooth increased and complete contacts palate increased but incomplete
What is Angles classification
buccal segment
class I class II class III
crossbones
What are the different canine relationships
class II class II class III
won’t get good ortho results if canine relationship is not class I
What are special investigations that can be done prior to ortho
OPT maxillary anterior occlusal lateral ceph vitality tests study models photographs
What do we do from the info we got in the assessment
summarise important points
assess treatment needs
devise treatment aims if appropriate
plan treatment
Describe an ortho summary
name, age, sex
HPC, RMH, RDH
incisor relationship, skeletal base, ST
teeth present/absent, OH, poor prognosis
lower arch, incisor inclination, crowding
upper arch, incisor inclination, crowding
OJ, OB, centrelines, molar relationship, crossbones, miscellaneous
IOTN score
