orthodontics need to know Flashcards
give occlusal presentations of a digit sucking habit
proclined upper incisors
retroclined lower incisors
anterior open bite/incomplete open bite
posterior crossbite
narrower upper arch
how is the posterior dentition affected by a digit sucking habit?
narrow arch created by masster muscle constantly pushing upper posterior teeth palatally
posterior crossbite can then be observed when narrowed upper arch meets lower arch
what are common causes of an unerupted central incisor?
- congential absence
- unerupted supernumerary preventing eruption
- pathology
list steps to help with diagnosis of unerupted central incisor
take detailed histroy- check for environmental/hereditary factors and history of trauma
intraoral exam- sequence of eruption, presence of contralateral tooth, rotation/displacement of other teeth in region
check for presence of labial/palatal swellings which may indicate presence of the tooth
take a radiograph
what are the 4 principles for an unerputed central incisor?
remove supernumerary/deciduous if present
create space for the tooth
monitor for at least 18 months
expose the incisor if it doesnt erupt on its own and place a gold chain- orthodontic traction
what is the treatment of an unerupted central incisor?
removal of any obstruction with creation of space
removal of obstruction only
surgical intervention- incision
orthodontic traction
define local malocclusion
localised problem with either arch (1/2/3 teeth)
can be due number, size/form, position, soft tissue or a pathology
ectopic, impacted, missing, trauma, habits, supernumeracy
what are the types of supernumerary teeth?
conical
tuberculate
supplemental
odontome
what are examples of variation in tooth number
supernumary teeth
hypodontia
Retained primary teeth
early loss of primary teeth
unschedules loss of permanent teeth
what are the types of supernumary teeth
conical
tuberculate
supernumary
odontome
what are 2 ways to assess AP skeletal pattern
direct Palpation of skeletal bases
visual assessment of the relationship between soft tissue A and soft tissue B
what are possible non-skeletal factors that can because class 2 div 2 occlusion
lip trap
digit sucking
crowding
what appliance can be used to correct class II div 2 malocclusion
functional appliance - twin block
how does mandibular growth occur
growth occurs at condylar cartilage
growth occurs by surface remodelling ( resorption and deposition of bone)
results in increase in height of the ramus and increase in the length of the dental arch to accomodate teeth
growth is downwards and forwards
pt w history of trauma presents unhappy with appearance of front tooth. what part of the physical exam is important?
palpation of the labial sulcus
what radiographs are used for an 8 year old boy with previous trauma to central incisor?
periapical
anterior occlusal **of maxilla **
how can you assess vertical skeletal relationship?
- assess relationship of frankfort and mandibular plane angles
- lower anterior face hieght compared to total anterior face height
how should the patients head be positioned during clincical assessment?
frankfort plane parallel to floor to avoid error in assessment
define class III incisor malocclusion
lower incisors occlude/would occlude anterior to cingulum of upper incisors
define class I incisor relationship
the lower incisor edges occlude with or lie immediately below the cingulum plateau of the upper central incisors
define class II incisor relationship
the lower incisor edges lie posterior to the cingulum plateau of the upper incisors
define class II division 1 incisor relationship
the upper incisors are proclined or of average inclination and there is an increase in overjet
define class II division 2 relationship
the upper central incisors are retroclined. The overjet is usually minimal or may be increased
how would you describe a patient with class III occlusions skeletal relationship in terms of growth and development
maxillary hypoplasia
mandibular prognathism
mahow would you describe a patient with class II occlusions skeletal relationship in terms of growth and development
maxillary prognathism
mandibular hypoplasia
define incompetent lips
lips dont meet at rest when the mentalis muscle is relaxed
define competent lips
when lips meet at rest when the mentalis muscle is relaxed
what is a lip trap?
when the lower lip is trapped behind the central incisors
can result in proclined central incisors
how can class II div 1 affect the lips?
can make lips incompetnet
correcting the relationship would give competent lips
explain a hyperactive lower lip
causes retroclined lower incisors
what are local causes of malocclusion?
- variation of tooth number
- variation in tooth sizer of form
- abnormalities of tooth position
- local abnormalities of soft tissue
- local pathology
what are examples of variation in tooth number?
- supernumary teeth
- retained primary teeth
- hypodontia
- early losee of primary teeth
- unschelduled loss of permanent teeth
what teeth are most affected by hypodontia?
upper lateral incisors
lower premolars
what are the reasons for retained primary teeth?
- absent successors
- ectopic successors
- dilaceration
- infraoccluded primary molars
- pathology
- supernumeray teeth
define balancing extraction
extracting the same tooth from the oppostire side of the same arch
prevent midline shift
define compensating extraction
removal of same tooth from opposing arch in order to maintain occlusal relationship
what treatment is required if the upper 6s are lost early?
no treatment
what treatment is required if lower 6s ar lost early?
compensating extraction of upper 6s
what occurs if the lower 6 is lost too early?
distal drift of 5
what treatment is required for unscheduled loss of central incisor?
maintain space for a simple denture or implant
whateffect does tongue thrust have on the occlusion
Causes anteriro open bite
What criteria is checked on intra oral examination for hard tissues
degree of crowding and rotations
Inclination of canines
angulations of insisors to appropraite plane
(lowers - mandibular plane)
(uppers - frankfort plane)
how do you help a child stop a digit sucking habit?
positive reinforcment
bitter tasting nail polish
plasters covering nails
fixed appliance- tongue rake
removable apliance
when would an anterior open bite resolve by itself?
if you intercept within 3 years of eruption
child needs to be <10 years
what does ARAB stand for?
- active component- The components that will be moving the teeth with the application of force
- retention-the resistance to displacement forces
- anchorage- resistance to unwated tooth movement
- baseplate-connects all the components together as a unit, provides anchorage and assists with retention
how do you expand the upper arch?
AC- midline palatal screw
R- 12, 26, 14, 24- adams clasps
B- posterior bite plane in self cure PMMA
what would you use to reduce overjet and overbite?
roberts retractor 0.5 HSSW
0.5mm ID tubing
flat anterior bite plane
what can be used to retract buccally placed canines?
buccal canine retractor 0.5mm HSSW, 0.5mm ID tubing
what can be used to retract a canine?
palatal finger spring and guard 0.5mm HSSW
what are z-springs used to correct?
anterior crossbite
what is the function of a z-spring?
to move palatally placed teeth in a buccal direction
what are the stages of fitting a URA?
- Ensure the patients details match the details supplied for the appliance
- Check the appliance matched the design specifications
- Inspect the appliance and run your finger over all surfaces looking for sharp or potentially traumatic areas
- Check the integrity of the wirework
- Insert the appliance into the patient’s mouth, immediately looking for areas of blanching or soft tissue trauma
- Check the posterior retention (Adam’s clasp). Firstly the flyovers, then the arrowheads are correctly engaging the appropriate undercuts.
- Apply the same principle to the anterior retention
- Activate the appliance (1mm movement approximately per month)
- Demonstrate to the patient the correct procedure for insertion and removal of the appliance (ensure that the patient demonstrates this correctly)
Book a review appointment 4-6 weeks later
what information should you give to a patient receiving a URA?
- The appliance will feel big and bulky- this is normal and they will get used to it
- It may cause initial excessive salivation- will pass within 24 hours
- May impinge speech for a short period of time- practise reading a book aloud at home and this will subside
- May cause initial discomfort or ache-this is normal and means the appliance is working
- To be worn 24/7 including meal times and sleep
- Remove after every meal and clean with a soft brush
- Remove and store in a protective container when participating in contact or active sports
- Avoid hard or sticky foods that may damage the appliance and be cautious with hot food or drinks
- Missing appointments and non-compliance will significantly lengthen the treatment time
Provide emergency contact details in case any problems arise
what is the aim of the IOTN?
index of orthodontic treatment need
Attempts to rank malocclusion in terms of the significance of various occlusal traits for an individual’s health and perceived aesthetic impairment
identifies individuals who would most benefit from orthodontic treatment
what are the 2 components of the IOTN?
aesthetic component
dental health component
what are the grades for the dental health component of IOTN?
1- none
2- little
3- borderline need
4- needs treatment
5- need treatment
prescription for anterior crossbite
prescription for posteiror crossbite
name components that can be used for retention
- adams clasp
- southend clasp
- labial bow
- c-clasp
what is the border position?
the retruded axis
describe RCP on posselts envelope
retruded contact position
what is a border movement?
movement determined by anatomy of the TMJ and associated musculature
why is the retruded axis important?
it is a reproducible jaw position
what is ICP on posselts envelope?
intercuspal position
what is Pr
maximum protrusion
what is T on posselts envelope
maximal mandibular opening with full anterior-inferior translation of condylar heads
