Orthodontic Diagnosis Flashcards
what is the GDC definition of Orthodontics
development, prevention and correction of irregularities of the teeth, bite and jaws
what are the aims of orthodontics
improve performance of the dentition
aim to provide long lasting adult dentition
list 4 reasons why orthodontics is carried out
dental health
aesthetics
psychological well being
specific issues i.e not aligned, supernumerary etc
define hypodontia
missing teeth
define supernumerary teeth
extra teeth
define overjet
horizontal distance between incisal edges of upper and lower incisors
AKA protrusion
increased in Class II div I
define reverse overjet
class III lower teeth further forward
define overbite
vertical overlap of upper anterior teeth over lower anterior teeth
define anterior open bite
anterior teeth don’t meet in occlusion
no overlap between upper and lower anterior
define submerged teeth
deciduous
depressed below the occlusal plane
ankylosed to bone
mainly primary molars
define crossbite
tooth is more buccal/lingual in comparison to other teeth in the arch
define posterior cross bite
top posterior teeth bite down inside the lower posterior teeth rather than maxilla
due to narrow maxilla and upper dental arch
define anterior crossbite
upper teeth sitting behind lower teeth
aka underbite or reverse overjet
When does the mandible start to develop?
6th week inter-uterine life
where are the maxilla and mandible derived from?
1st pharyngeal arch
what is one of the earliest bones to develop in the head?
mandible- 6th week iu
how is maxilla formed
intramemembranous ossification - 6th week iu
define intramembranous ossification
direct laying down of bone into the connective tissue (mesenchyme)
dirrect differentiation of mesenchymal cells to osteoblasts
no cartilage is involved
how does the maxilla grow
downs and forwards due to extensive remodeling and bony deposition at sutures within the naso-maxillary complex
define displacement
growth which causes the mass of a bone to be moved in relation to other bones
define drift
change in position of a bony stricture to to remodeling of that stricture
how is the mandible formed
intramembranous ossification- 6th week iu
at what age do teeth start to erupt
6 months
when is primary dentition complete
3 years
when does the permanent dentition start to form
6 years - 6s
who can be given antibiotic prophylaxis for infective endocarditits
those consider in a special consideration group- SDCEP so need non-routine management
what is phenytoin and what can it cause
anti-epileptic
gingival overgrowth/hyperplasia
what is rheumatic fever and how is it linked to dentistry
an inflammatory disease which affects heart, joints, skin etc
tends to occur after Group A streptococcal infection (strep throat or scarlet fever)
what are side effects of bisphosphonates
delayed tooth eruption
impaired bone healing
osteoradionecrosis of the jaw
what to do if someone has a severe bleeding disorder
avoid extractions if possible
why should a diabetic patient have good OH
as risk of periodontal breakdown
what advice should be given to a patient that uses an inhaler
rinse mouth and appliance after using inhaler
what is recurrent apthous ulcerations
painful ulcers in oral mucosa
can be exacerbated by trauma from appliances
give examples of habits that can cause problems
thumb sucking
nail biting
pen chewing
musical instruments
how should the patient be positioned when measuring the skeletal pattern
natural head position
teeth in maximum interdigitation
in which 3 planes is a skeletal pattern assessed
anteroposterior- view from side
vertical- viwe from side
transverse- view from front and above
what are the classifications of a skeletal pattern
Class I- mandible 2-3 mm posterior to maxilla
Class II - mandible retruded relative to maxilla
Class III- mandible protruded relative to maxilla
what type of radiograph can be taken when assessing anteroposterior skeletal pattern
lateral cephalogram
in which 2 ways can the vertical skeletal pattern be masuered
Lower facial height
FMPA- Frankfort mandibular plane angle
Describe lower facial height
the distance from the eyebrow to the base of the nose should equal the distance from the base of the nose to the lowest point of the chin
if the nose-chin distance is greater then the lower facial height is increased and if less than the eyebrow-nose then the lower facial height reduced
describe FMPA
Frankfort Mandibular Plane Angle
if the two meet at the back of the head, angle is normal
if they meet beyond the back of the head, the angle will be reduced
if they meet before the back of the head, angle is increased
what can be measured to test the transverse skeletal pattern
occlusal plane symmetry- pt bites on to tongue spatula
what can a tongue thrust cause
anterior open bite
what are problems thumb sucking can cause
increased overjet
open bite
posterior crossbite
narrow upper arch
What should be observed with the labial segment
aligned, crowding, spaced
if any rotations or displacements
how is crowding measured
mild- 4mm or less
moderate- 5-8mm
severe- >9mm
what can be measured within the labial segment
overjet
overbite
centrelines
anterior cross bite
what should be observed within the buccal segment
crowding, rotations, displaced teeth
crossbites- unilateral/bilateral
which radiograph would you take to observe overall dental assessment
DPT
which radiograph would you take to check for skeletal discrepancies
lateral cephalogram
which radiograph would you take to check for root resorption or check position on unerupted canine
upper anterior occlusal
which radiograph would you take for assessment ofimpacted teeth or bone assessment of cleft lip and palate
CBCT
what is IOTN and what are the 2 elements
index of orthodontic treatment need
dental health component
aesthetics component
what is the dental health component
single worst feature is noted and categorised in one of the 5 grades
what is ‘mocdo’
to identify single worst feature for dental health component missing overjet crossbites displacement of contact points overbite
what are the grades for the dental health component for IOTN
1- no treatment
5- severe treatment need
how is the aesthetics component measured
10 standard photographs
1- most aesthetically pleasing
what is the problem with the aesthetics component
can be subjective class III or anterior openbites not included in photos
what equipment can be used to measure IOTN
IOTN ruler
why are retention appliances important?
to prevent relapse
