Orthodontic Assessment Flashcards
why complete an orthodontic assessment
- Determine if any malocclusions are present
- Identify any underlying causes
- Decide if treatment is indicated (either refer or devise treatment plan)
when to complete an orthodontic assessment
- Brief examination often at aged 9 years
- Comprehensive examination when premolars and canines erupt (11-12 years)
- When older patients first present. If a malocclusion develops later in life
- It is never too late to have orthodontic treatment
ideal occlusion
- Ideal occlusion
- Hypothetical, rarely found in nature
- Gold standard by which occlusal irregularities and treatment may be judged
Andrew’s 6 keys (1972)
Andrew’s 6 keys
- Molar relationship – 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 (Class I)
- Crown angulation (mesio-dtal tip)
- Crown inclination
- No rotations
- No spaces
- Flat occlusal planes (no curve of spee)
Teeth in right size proportionally
normal occlusion
more commonly observed than ideal occlusion
- Minor deviations
- Do not constitute an aesthetic or functional problem
malocclusion
- Are more significant deviations from the ideal that may be considered unsatisfactory (aesthetically or functionally)
- may require treatment, but pt factors may influence decision
orthodontic assessment is undertaken in
history and examination
history for orthodontic assessment
same as every other dental and medical history
- presenting complaint (P/C)
- prioritise them in pt view if multiple
- how much does it bother patient?
- Need to be compliant and willing for treatment
- History of P/C
- Past medical history
- Few conditions now are a contra-indication for orthodontics
- Allergy (Ni or Latex)
- Epilepsy/drugs (needs to be controlled for removable)
- Drugs
- Imaging
- Few conditions now are a contra-indication for orthodontics
- Past dental history
- Frequency of attendances (got to be comfortable coming)
- Nature of previous treatment (high caries rate?)
- Co-operation with previous treatment
- Trauma to permanent dentition
- E.g. of permanent incisors
- Can cause ortho issues
- Compared to l incisor lost clear lamina dura
- E.g. of permanent incisors
- Social/family history
- Travelling distance/time
- Car owner/public transport
- Parents work?
- School exams?
habits that can affect occlusion
- Thumb sucking
- Lower lip sucking
- Tongue thrust
- Chewing finger nails
examination components for orthodontic assessment
Extra-oral
- Skeletal base
- Soft tissue
- TMJ
Intra-oral
Compare patient to parent for
- Malocclusion
- Especially class III malocclusions
- Growth potential
Dentoskeletal relationships (teeth on bases attached to skeletal skull)
facial skeletal pattern - components for consideration
3 planes
- antero-posterior
- vertical
- transverse
how to do anterior-posterior skeletal assessment
- visual assessment
- palpate skeletal bases
anterior posterior skeletal assessment
classes
- Class I – maxilla 2-3mm in front of mandible
- Class II – maxilla more than 3mm in front of mandible
- Class III – mandible in front of maxilla
vertical skeletal assessment involves
frankfort-mandibular plane angle (FMPA)
can be
- average (meet at occiput)
- reduced (meet after occiput)
- increased (meet before occiput)
frankfort mandibular plane angle
frankfort horizontal plane parallel to the ground
lower border of mandible
should meet at occiput
lateral skeletal assessment
mid-sagittal reference line
extra-oral examination for ortho assessment
looks at soft tissues - can influence tooth position
- Lips
- Competent/incompetent
- Lower lip level
- Lower lip activity
- Tongue
- Position
- Habitual and swallowing
- Habits
- Thumb/digit sucking
- Speech
- Lisping
competent lips
meet at rest with relaxed mentalis muscle
incompetent lips
do not meet at rest when relaxed mentalis muscle
lip trap
- may procline upper incisors;
- may lead to relapse of overjet if persists at the end of Tx
lower lip activity
- hyperactive lower lip may retro cline lower incisors
- indicates likely instability at end of tx
tongue position and swallowing pattern
- tongue thrust on swallowing can be associated with an anterior open bite (AOB)
- can be either endogenous or adaptive tongue thrust (cause or effect?)
- may cause relapse of AOB at end of treatment if endogenous
- lisp can be a sign
- may cause relapse of AOB at end of treatment if endogenous
occlusal effects of thumb and digit sucking
- proclination of upper anteriors
- retroclination of lower anteriors
- localised AOB or incomplete OB (partially covered)
- narrow upper arch +/- unilateral posterior crossbite (upper posterior teeth get narrowers)
remember that effects will be superimposed on existing skeletal pattern and incisor relationship
aymmetric or symmetric
TMJ in orthodontic assessment
- path of closure
- range of movement
- pain/click from joint
- deviation on opening
- muscle tenderness
mandiular displacement is
Discrepancy in retruded contact position and inter-cuspal position
RCP does not = ICP
e. g.Displacement of mandible up and to the right from RCP to ICP
* note centre line positions
how to ensure to get thorough orthodontic assessment
- always look for (and expect) the unexpected
- almost ignore/put to one side the obvious, to ensure to check full state
what to check on intra oral examination
- oral hygiene and periodontal health
- count the teeth (from the back)
- teeth of poor prognosis
- assess crowding/spacing/rotations
- inclination/angulation
- palpate for canines if not erupted
- note teeth of abnormal shape/size e.g. peg laterals
teeth present here
Upper lateral missing 22,
teeth present here
supernumerary lower lateral (lower L)
why is it imp to consider oral hygiene in orthodontic assessment
mindful that orthodontics can go wrong and thus have a knock on negative effect on oral health
4 aspects of orthodontic assessment for lower arch
- Degree of crowding
- Uncrowded
- Mild
- Moderate
- Severe
- Presence of rotation
- Inclination of canines
- Mesial
- Upright
- Distal
- Angulation of incisors to mandibular plane
- Upright
- Proclined
- Retroclined
4 aspects of orthodontic assessmet for upper arch
- Degree of crowding
- Uncrowded
- Mild
- Moderate
- Severe
- Presence of rotations
- Inclination of canines
- Mesial
- Upright
- Distal
- Angulation of incisors to Frankfort plane
- Upright
- Proclined
- Retroclined
orthodontic assessment when teeth in occlusion
- Maximum interdigitation or RCP
- Incisor relationship (BSI definitions)
- Overjet
- Overbite/open bite
- Molar relationship (Angle’s classification)
- Canine relationship
- Cross bites
- Centre lines
british standards institute of incisor classification (BSI)
- Class I
- Class II
- Division 1
- Division 2
- Class III
Overjet, overbite, centrelines
BSI incisor class I
The lower incisor edges occlude with or lie immediately below the cingulum plateau of the upper central incisors.
BSI incisor class II
The lower incisor edges lie posterior to the cingulum plateau of the upper incisors.
- Division I - The upper incisors are proclined or of average inclination and there is an increase in overjet.
- Division 2 - The upper central incisors are retroclined. The overjet is usually minimal or may be increased.
BSI incisior class II div 1
The lower incisor edges lie posterior to the cingulum plateau of the upper incisors.
Division I - The upper incisors are proclined or of average inclination and there is an increase in overjet.
BSI incisor class II div 2
The lower incisor edges lie posterior to the cingulum plateau of the upper incisors.
- Division 2 - The upper central incisors are retroclined. The overjet is usually minimal or may be increased.
BSI incisor class III
The lower incisor edges lie anterior to the cingulum plateau of the upper incisors. The overjet is reduced or reversed.
overjet
upper teeth protrude outward and sit over the bottom teeth.
Having an overjet doesn’t only affect your appearance.
You can have also difficulty chewing, drinking, and biting.
HORIZONTAL
overbite
- Average
- Reduced
- AOB
- Increased
- Incomplete?
- Complete?
- Tooth or palate?
VERTICAL
classification for buccal segment relationship (canine)
Angle Classification
I, II, III
MB upper FPM occlude MB groove lower FPM
- Anterior – class II
- Posterior – class III
Angle Classification class I
- (upper canine behind lower canine – need for good ortho Tx)
MB upper FPM occlude MB groove lower FPM
Angle Classification
Class II
(upper canine anterior to lower canine (can get half))
MB upper FPM occlude MB groove lower FPM
Anterior – class II
Angle Classification
Class III
- (upper canine is well behind lower canine (between 4 and 5 rather than 3 and 4))
MB upper FPM occlude MB groove lower FPM
Posterior – class III
crossbite
form of malocclusion where a tooth (or teeth) has a more buccal or lingual position (that is, the tooth is either closer to the cheek or to the tongue) than its corresponding antagonist tooth in the upper or lower dental arch. In other words, crossbite is a lateral misalignment of the dental arches.
centrelines in orthodontic assessment
- Looking at how would relate the upper to lower centrelines and the two centrelines to the facial midline
4 special investigations that can be used in orthodontic assessment
- radiographs
- vitality tests
- study models
- photographs
radiographs used in orthodontic assessment
usually good to have 2 views to localise position of unerupted teeth, length and position of roots
- OPT
- Any pathology/unerupted teeth/length roots
- Not overly clear in midline due to spine superimposition
- Maxillary anterior occlusal
- Lateral cephalogram
- See pt in profile view
- Measurements – angles, distances – between points on skull
- Help plan Tx – skeletal bases, cranial bases relationship
- Monitor changes in pt
why are vitality tests used in orthodontic assessment
Trauma
- e.g. Chip and discolouration – vitality test prior to ortho Tx
study models use specific to orthodontic assessment
- Monitoring changes in Tx
- Monitoring development of dentition
whats in the orthdontic summary
- HPC, RMH, RDH, RSH (R = relevant)Name, age, sex of patient
- Incisor relationship, Sk base (AP, V, T), ST
- Teeth present/absent, OH, poor prognosis
- Lower arch, incisor inclination, crowding
- Upper arch, incisor inclination, crowding
- OJ, OB, centrelines, molar relationship, crossbites, and miscellaneous
- IOTN score
Basis of referral letter
purpose of incisior relationship
to class malocclusion
what to do with the information gathered in orthodontic assessment
- Summarise the important points
- Assess treatment need (IOTN)
- Benefits to dental health
- Benefits to social wellbeing
- Help decide extent of treatment needed
- Devise treatment aims if appropriate
- Plant treatment
how to get frankfort plan parallel to the floor
eye contact with themselves in mirror
how and points to chek when assessing transverse midline skeletal relationship
Hold mirror handle over glabella and see if points align
- Chin
- Lip fulcrum
- Nasal septum
when trying to remember what to consider in deciding malocclusion
think of (3)
- How does the lower incisor edge relate to the cingulum plateau of the upper incisor? (class I/II/III)
- What is the incisor angulation? (class II/1 or class II/2)
- Describe the overjet (class II/ class III)
