orthodontic assessment Flashcards
what needs to be gathered during history taking process
- patients complaint
- medical history
- dental history
- habit
- physical growth status
- patients motivation
- socio-behavioural factors
what are the two types fo problems
- pathological = relating to disease
- developmental = related to malocclusion
what medical conditions can affect ortho
- epilepsy
- latex allergy
- nickel allergy
- diabetes
- heart defects with a risk of IE
- bleeding disorder
- asthma
- learning difficulties
how can epilepsy affect ortho
- needs to be under control before starting treatment
- extra-oral headgear may present an unacceptably high risk
- stress may induce seizure
- antiseptic phenytoin may cause gingival hyperplasia
how can latex allergy affect rotho
- need to use alternative products and gloves
how can nickel allergy affect ortho
- intra-oral reactions are very rare
- use plastic coated headgear to avoid contact with skin
- if intra-oral allergy is confirmed, then use nickel free products
how can diabetes affect ortho
- patient may be more prone to intra-oral infections and periodontal problems
- be aware of risk of hypoglycaemia
- treatment should be avoided if poorly controlled diabetes
how can heart defects affect ortho
- AB cover used to be prescribed routinely but not anymore
- clinician should refer to patients doctor and cardiologist
how does bleeding disorders affect ortho
- precautions should be taken
- generally doesnt affect orhto
- avoiding trauma to soft tissues is important
how does asthma affect ortho
- steroidal inhalers mey predispose to candida infections so need to have excellent OH
how does Bisphosphonates affect ortho
- predispose to osteonecrosis and affect bone turnover
- patients physician should be contacted
what does dental history tell us
- previous dental experiences
- gives an idea of their attitudes/compliance
- need to know nay on-going dental problems
- also need to know history of problems
what do we need to know about habits
- patient should be asked about digit sucking
- need to know duration of habits
- nail biting can also predispose to an increased root resorption
what 3 dimensions must you clinically examine the face
- anteroposteriorly (AP)
- vertically
- transversely
what do you examine in AP
- extra oral = maxilla to mandible - Class I, II or III
- intra-oral = incisor classification, overjet, canine relationship, molar relationship, anterior cross bite
what do you examine in vertical
- extra oral = facial thirds, angle of lower border of mandible to maxilla
- intra oral = overbite, anterior open bite, or lateral open bite
what do you examine in transverse
- extra oral = facial asymmetry
- intra oral = centre lines, posterior cross bite
what views does patient need to be examined in
- frontal view = to assess vertical and transverse planes
- profile view = to assess vertical and AP planes
how is the AP assessment done
- assess relationship between maxilla and mandible to each other and cranial base
- assess relationship of lips to vertical line known as zero mediation
- palpate intra-oral anterior portion of maxilla and mandible
- assess convexity of the face by determining the angle between the middle and lower thirds of the face in profile
how is the vertical assessment done
- in 2 ways = measuring angle of lower border of mandible to maxilla OR using rule of thirds
- thirds = face split into thirds and any discrepancy in the thirds can suggest a facial disharmony
- angle = place a finger on lower border of mandible to give an idea of the angle
how is the transverse assessment done
- examined from frontal view but also looking down on face
- any significant asymmetry should be noted
- the soft tissue nasion, middle part of upper lip at vermilion border, and the chin should all be aligned
what would a normal smile look like
- whole height of upper incisors should be visible with only interproximal gingiva shown
- smile line 1-2mm higher in females
- upper incisors edges parallel to lower lip
- margins of central incisors and canines should be level
- width of smile should be such that buccal corridors are seen
- symmetrical dental arrangement
- upper dental midline should coincide with midline of face
what do you need to assess about lips
- are they competent, potentially competent, or incompetent
- nasolabial angle
what is competent, potentially competent and incompetent lips
- competent = meet together at rest
- potentially competent = position of incisors prevents comfortable lip seal to be obtained at rest, but patients can hold lips together if need be
- incompetent = require considerably muscular activity to obtain lip seal
what should the nasolabial angle be
- between 90-110 degrees
what needs to be assessed of the tongue
- determine how patients create an anterior seal during swallowing and tongue at rest
- in patients with incompetent lips, tongue can thrust forward to create an anterior seal = can be fixed by treatment, unless endogenous
what does the intra-oral assessment allow assessment of
- stage of dental development
- soft tissues and periodontist for pathology
- oral hygiene
- overall dental health, including identifying any caries and restorations
- tooth position within each arch and between arches
what do we need to detect when assessing oral heath
- caries, hypomineralisation, non-vital teeth, tooth wear, teeth of abnormal shape or size, existing restorations which may change the way we can bond to teeth
- pathology needs to be treated and stabilised before we can start ortho
what is assessed in each dental arch
- crowding
- alignment of teeth = displacement and rotation
- inclination of labial segment
- angulation of canines
- arch shape and symmetry
- depth of curve of Spee
what is assessed when arches are in occlusion
- incisor relationship and buccal relationship
- incisor classification
- overjet
- overbite
- centrelines
- canine relationship
- molar relationship
- cross bite
how is the overjet measured
- measured from labial surface of most prominent incisors to labial surface of mandibular incisor
- normally is 2-4mm
what are the different levels of crowding
- 0-4mm = mild
- 4-8mm = moderate
- > 8mm = severe
how is the overbite measured
- measures how much the maxillary incisors overlap the mandibular incisors
- 3 features to note = amount of overlap, whether the lower teeth are in contact with the opposing teeth or soft tissues (complete) or if they are not touching anything (incomplete)
- normal = 1/3 coverage of crown of lower incisor
what is it called if there is no overlap at all between upper incisor and lower
- anterior open bite
what is a crossbite
- discrepancy in the buccolingual relationship of the upper and lower teeth
- can be anterior or posterior
what is a buccal crossbite
- buccal cusps of the lower teeth occlude buccal to the buccal cusps of the upper teeth
what is a lingual crossbite (scissor bite)
- the buccal cusps of the lower teeth occlude lingual to the lingual cusps of the upper teeth
what happens if there is a displacement of the mandible on closure of the mouth
- caused be premature contact
- cause mandible to be positioned further anteriorly, or to the left or right to get intercuspation
- as a result of this there will eb a difference between RCP and ICP
- in this case, ortho treatment should be based on RCP as this is the position the jaw will return to
what are the extra-oral photograph views taken
- full facial frontal at rest
- full facial frontal smiling
- facial 3/4 view
- facial profile
what are the intra-oral photographs views taken
- frontal occlusion
- buccal occlusion = left and right
- occlusal views of upper and lower arch
what radiographs are taken
- DPt
- cephalometric
- upper standard occlusal radiograph
- periapical
- bitewing
what can radiographs provide information on
- presence or absence of teeth
- stage of development of permanent dentition
- root morphology of teeth
- presence of ectopic or supernumerary teeth
- presence of disease
- relationship of the teeth to skeletal dental bases and cranial base
why do we take DPT
- good for presence, position and morphology of unerupted teeth
why do we take upper occlusal radiographs
- view of maxillary incisor region
- assess root form of incisors, detect presence of supernumerary teeth, and located ectopic canine teeth
why do we take periapical radiographs
- assess root form and local pathology
why do we take biting radiographs
- assess caries and condition of restorations
what is a CBCT used
- accurate location of impacted teeth and more accurate assessment of any pathology
- assess alveolar bone coverage
- cleft palate
- assess alveolar bone height and volume
- TMJ or airway analysis
- planning of some complex combined ortho and orthognathic surgery cases
- only use when conventional radiography has failed
why do we take an orthodontic assessment
- to determine if there are any malocclusions present
- identify any underlying causes
- decide if treatment is indicated
when do we carry out an orthodontic assessment
- brief examination often at age 9 = mixed dentition
- comprehensive examination when premolars and canines erupt = age 11-12 but can vary a lot
- interoceptive orthodontics
- when older patients first present
- if a malocclusion develops later in life = periodontal disease can affect malocclusion
what is the ideal occlusion defined by
- gold standard by which occlusal irregularities may be judged off
- based on Andrews 6 keys
what are Andrews 6 keys
- 1 = molar relationship (distal surface of the disto-buccal cusp of the upper 1st permanent molar occludes with the mesial surface of mesio-buccal cusp of lower 2nd permanent molar
- 2= crown angulation = mesio-distal tip
- 3 = crown inclination = tip of teeth
- 4= no rotations
- 5 = no spaces
- 6= flat occlusal plane (no curve of Spee
what is not part of Andrew’s keys but is still important
- if patient has a small lateral incisor, then all teeth have to be that little bit further forward
what are minor deviations to normal occlusion
- things that do not constitue an aesthetic or functional problem
what are malocclusion
- more significant deviations from the ideal that may be considered unsatisfactory
- can be aesthetically or functionally
- may require treatment
- whole spectrum
what in history of presenting complaint could indicate pathology
- if something has changed rapidly
what conditions are a contraindication to ortho
- allergy to nickel or latex
- epilepsy/drugs = if poorly controlled then don’t want to give patient removable appliance
- drugs
- imaging = delay treatment until these are completed
why does the patient need to be comfortable coming to the dentist
- lots of appointments
- long process
how can previous treatment influence ortho
- if patient has a heavily restored dentition, then this could indicate that they are not a good candidate for ortho
what needs to be considered within social history
- travelling distance/time
- car owner/public transport
- parents work
- school exams = try work around these are ortho can be uncomfortable
what habits can affect tooth position and how
- thumb sucking = procline upper teeth
- lower lip sucking = procline upper teeth
- tongue thrust = afffect tooth position
- chewing fingernails = can cause root resorption
why must you carefully consider ortho for patients with small roots
- it can lead to further resorption
what must you compare the patient to the parent for
- malocclusion
- growth potential = especially in class III malocclusions
why must you consider the dente-skeletal relationships
- teeth are on individual skeletal bases
- mandible is on posterior cranial base
- if the mandible is further back, then it increases the tendency for an overjet
what position does the patients head need to be for an AP assessment
- Frankfurt plane need to be horizontal parallel to the floor
- top of the ear to the base of the orbit needs to be parallel to the floor
how do we assess the AP relationship
- visual assessment = test anterior innermost curvature of the upper lip to give maxillary position, against the innermost curvature of the lower lip for mandibular position
- palpate skeletal bases
what is class I AP relationship
- maxilla is 2-3mm in front of mandible
- this is normal
what is class II AP relationship
- maxilla more than 3mm in front of mandible
- mandible is positioned further back in the skull
- retrognathic
- need to bring mandible forwards
what is class III AP relationship
- mandible in front of maxilla
- can have a reverse overjet
what do we look at in the vertical assessment
- Frankfort Mandibular Plane Angles (FMPA)
- top of ear to point at the base of the orbit compared with eh mandibular place
what is the normal FMPA
- lines meet at the back of the head
what is an increased FMPA
- lines meet well before the back of the head
- high angle
- expect minimal overbite or anterior open bite with no contact at the front teeth as posterior are meeting first
what is a reduced FMPA
- lines don’t meet at the back of the he’d
- expect them to have a deep bite
how is the lateral assessment done
- mid-sagittal reference line
- everyone is slightly asymmetrical
- normall cupids bow is in th midline
- tip of the nose should be ignored
- compare where chin point is to that line
- if you think there is asymmetry look down on patient from above as well
- good for determining mandibular asymmetry but not maxillary
what are competent lips
- lips that meet at rest when there is a relaxed mentalis muscle
what are incompetent lips
- lips that do not meet at rest when there is a relaxed mentalis muscle
- can influence tooth position
- can get a lip trap
what is a lip trap
- may procline upper incisors
- may lead to relapse of an overjet if persists at the end of treatment
- has a significant effect on upper teeth
- when a patient swallow, can still see the upper teeth as the lower lips are behind
- important to get competent lips at the end of treatment
what can lower lip activity cause
- hyperactive lower lip may retrocline lower incisors
- indicates likely instability at the end of treatment
- quite rare
- any attempt to push lower incisors forward will relapse again
what can tongue thrust on swallowing be associated with
- anterior open bite
what is the normal mechanisms for swallowing
- tongue goes up and back and pushes the bolus to the back of the mouth, then the pharyngeal muscles take over automatically
why are we born with an anterior swallow
- because we have no teeth
- but once we have teeth 99.5% of people adapt to push tongue back instead of forward
what is the difference between an endogenous and an adaptive tongue thrust
- adaptive = possible to close AOB with treatment and tongue will go back to how it should be
- endogenous = it will relapse again
- some people say a lisp is a sign of an endogenous tongue thrust
what are the two ways of digit sucking
- thumb sucking = cause asymmetrical problems depending on which side
- two fingers = cause symmetrical problems
what are the occlusal features of a sucking habit
- proclination of upper anteriors
- retroclination of lower anteriors
- localised AOB or incomplete OB
- narrow upper arch +/- unilateral posterior crossbite
how does thumb sucking cause narrow upper arch
- because thumb is there, their tongue is much lower and the cheeks are being pushed inwards which pushes molar teeth in
- upper teeth become narrower
- patient bites togethers and teeth contact cusp to cusp
- but then the teeth will move to get intercuspation
- and this results in a unilateral posterior cross bite
can ortho help speech
- no
- need to tell patient this from the start
can ortho cause or treat TMJ problems
- no
what is mandibular displacement
- when patent comes together in RCP there is movement either left or right or forward to get teeth in ICP
- 1mm or so is not a problem
- 2-4mm is ok
- > 4mm is a problem
- the more displacement there is in a crossbite, the more urgency there is to treat it to prevent TMJ problems
- RCP≠ICP
what do we need to look at intra-orally in our assessment
- oral hygiene and periodontal health
- count the teeth - from the back
- teeth or poor prognosis
- assess crowding/spacing/rotations
- inclination/ angulation
- palpate for canines if not erupted and patient is 10
- note teeth of abnormal shape/size
what is the instance of hypodontia
- 3-4%
what is the instance of supernumerary teeth
1-2%
what is the instance of ecoptic canines
1-2%
what is the instance of impacted first permanent molars
- 3.5-6.5%
why do patients need food OH for ortho
- can get a lot of decalcification around the brackets
- a lot of patients will not get ortho if the risks outweigh the benefits
what can the degree of crowding b
- uncrowded, mild, moderate or severe
- if severe, then think about extractions
why might you want to extract rotated teeth
- because once you remove the appliance, they will just rotate again
how can canines be inclined
- mesial, upright or distal
- if canines are tipped forward it is easy to tip back, but if they are tipped back it is difficult to tip forward
how can incisors be angled to the mandibular plane
- upright, proclined, retroclined
- assess angle alone
- looking for 90 degrees
in the upper arch, how do we assess angulation of incisors
- assess them in relation to the Frankfort plane
- ideally about 110 degrees
what is class I incisor relationship
- normal overjet, normal overbite
- lower incisor edges occlude with or lie immediately below the cingulum plateau of the upper central incisors
how many division of class II incisors relationship are there
- 2
what is class II division 1 incisor relationship
- the lower incisor edges lie posterior to the cingulum plateau of the upper incisors
- dominant features is an increased overjet, front teeth beyond lower
- upper incisors are proclaimed or of average inclination and there is an increase in overjet
what is class II division 2 incisors relationship
- the lower incisor edges lie posterior to the cingulum plateau of the upper incisors
- central incisors are retroclined
- overjet is usually minimal of may be increased
what is class III incisor relationship
- usually, lower teeth occlude anterior to upper teeth, but can get class 3 just on the edge
- the lower incisors edges lie anterior to the cingulum plateau of the upper incisors, over is reduced or reversed
what is overjet
- the distance between the upper and lower incisors
- measure the biggest
how is an overbite measured
- to do with the overlap of the teeth
- average or normal = upper overlap half to 1/3 of crown of lower incisors
- if less = reduced
- if no overlap = anterior open bite
- if increased = can be contacting tooth or palate, can be complete or incomplete
what is another name for the molar relationship classification
- Angle’s classification
- buccal segment relationship
what is class I molar relationship
- mesiobuccal cusp of upper 6 occludes with buccal groove of lower 6
- normal
what is class II molar relationship
- mesiobuccal cusp of the upper 6 occludes in front of the buccal groove of lower 6
- occludes between lower 5 and 6
what is class III molar relationship
- mesiobuccal cusp of the upper 6 occludes behind the buccal groove of the lower 6
- between 6 and 7
what is class I canine relationship
- upper canine distal to lower
what is class II canine relationship
- anterior to lower canine
what is class III canine relationship
- behind lower canine
what is the key thing to look for when looking for crossbite
- displacement
how are centra lines assessed
- midline of the face
- looking at how you would rated the upper centre line to lower and both to the facial midline
what is good about OPT radiographs
- used a lot
- good view of the dentition
- used to look for unerupted teeth, stage of development, any pathology and length of roots
what is not good about OPT
- not clear in the midline so need another radiograph to get that information
what radiograph is often taken along with an OPT
- maxillary anterior occlusal
when ar lateral cephalograms used
- more specialised
- used to perform measurements on angles between points on the skull
- get more information to allow us to plane treatment by relating skeletal bases to each other and the cranial base
- gives us more info about teeth angulation from the maxilla and mandible
why are study models used
- for monitoring changes in treatment and monitoring development of dentition
- good if patients got partially erupted tooth and want to see how things change over time
why are photographs used
- to monitor changes
what do we need to do with the information gathered in our assessment
- summarise the important points
- assess treatment need = IOTN
- devise a treatment aim
- plan treatment
what does IOTN stand for
- index of orthodontic treatment need
- helps decide whether we need to treat patient or not
- gives an indication of benefit of dental health to treatment and psychosocial benefit
what does all this information gathered make up
- the basis of your referral letter
what does the AP assessment assess
- mandible to maxilla position
what does the vertical assessment assess
- assess Frankfort plane and mandibular plane and see where the lines of each intersect
- looking at length of face
what does the transverse assessment assess
- asymmetries
difference between the incisors relationships
- lower incisors edge in relations to the cingulum plateau of upper incisors = difference between class I, II or III
- incisors angulation = difference between Class II div 1, and class II div 2
- overjet = difference between class II and class III
