Orthodontics Flashcards
How can digit sucking be prevented?
Behaviour management therapy
Plasters, gloves, bitter flavoured agents
URA with rake
Habit reversal
What are four examples of conditions of tooth movement?
Hypodontia
Supernumerary
Early loss of permanent teeth
Late loss of primary teeth
What are the four types of supernumerary teeth?
Conical
Tuberculate
Odontome
Supplemental
What are the anatomical features that influence tooth mobility?
Width of pdl
Height of pdl
Inflammation
Number, shape, length of roots
What are pathological causes of tooth mobility?
Periodontal disease
Periapical abscess
Trauma
External inflammatory resorption
When should we intervene in tooth mobility?
Progressively increasing
Symptomatic
Creates difficulty with restorative treatment
What are the treatment options for an impacted 6?
Distal disking of the e
Orthodontic separation
Distalise the 6
Extract e
If under 7, wait 6 months
What are the treatment options for an unerupted central incisor?
Remove predecessor
If under 9- wait 12 months
If over 9- surgical exposure and orthodontic movement with gold chain
What is a balancing extraction?
Removal of tooth from opposite side of the same arch to maintain the position of the centreline
What is a compensating extraction?
Removal of a tooth from the opposing quadrant to maintain buccal occlusion
What should you do following Xla of a’s and b’s
Do nothing
What should you do following Xla of c’s
Balance
What should you do following Xla of d’s
Small shift: balance
What should you do following Xla of e’s
Space maintainer
What is an example of a removable space maintainer?
URA (passive)
What is an example of a fixed space maintainer?
Band and loop
Palatal/lingual arches
What factors should be considered for Xla of 6’s
Bifurcation of 7’s
8’s present
Class 1 occlusion
Mesial angulation of lower 6
Moderate lower crowding
Mild/moderate upper crowding
What is mild crowding measured as?
0-4mm
What are the treatment options for mild crowding?
No Xla
Xla 5
What is moderate crowding measured as?
5-8mm
What is the treatment for moderate crowding?
Xla 5s or 4s
What is the measurement for severe crowding?
> 8mm
What is the treatment option for severe crowding?
Xla 4s
What are the aims of ortho treatment?
Stable
Aesthetic
Functional
What are the indications for ortho treatment?
Malocclusion
Risk of trauma/disease
Impaired oral function
Unaesthetic
What are the contraindications to ortho treatment?
Uncontrolled epilepsy
Poor attendance
Poor OH
What are the benefits of ortho treatment?
Increased confidence
Increase dental health
Decrease trauma
What are the risks of ortho treatment?
Relapse
Root resorption
Decalcification
What are the limitations of ortho treatment?
Teeth only stable in the neutral zone
No effect on skeletal patterns
Movement limited by size and shape of alveolar process
What does ARAB stand for?
Active Component
Retention
Anchorage
Baseplate
What does Active Component mean?
Induces a displacement force
What does Anchorage mean?
Resistance to unwanted tooth movement
What does Retention mean?
Resistance to displacement forces
What does a Baseplate provide?
Anchorage
Connection
Cohesion
Adhesion
Stability
What is Newton’s 3rd Law?
For every action, there is an equal and opposite reaction
What should be on the lab card for treatment of an anterior cross bite on 12 ?
Aim: Please construct a URA to correct and anterior crossbite on 12
A: z-spring 0.5mm HSSW on 12
R: Adams clasp 0.7mm HSSW on 16, 26, 14, 24
A: yes (moving 1 tooth)
B: self cure PMMA + posterior bite plane
What should be on the lab card for treatment of a posterior crossbite?
Aim: Please construct a URA to expand the upper arch
A: Midline palatal screw
R: Adams clasp 0.7mm HSSW on 16, 26, 14, 24
A: Reciprocal anchorage
B: Self cure PMMA + posterior bite plane
How often should the active component be activated if in the anterior region?
Once a month
How often should the active component be activated if in the posterior region?
Once a week
What is the rule for tooth movement in association with bone remodelling?
Only 1-2 teeth should be moving 1mm per month
What are the options for retentive components?
Adams clasp 0.7mm (0.6mm in deciduous)
Southend clasp 0.7mm
Labial bow 0.7mm
C-clasp 0.7mm
What is the effect of thumb sucking on the skeletal pattern?
Proclamation of upper anteriors
Retroclination of lower anteriors
Localised anterior open bite
Incomplete open bite
Narrow upper arch with unilateral posterior cross bite
What is a class I incisor relationship?
The lower incisors occlude with or lie immediately below the cingulum plateau of the upper incisors
What is a class I incisor relationship?
The lower incisors occlude with or lie immediately below the cingulum plateau of the upper incisors
What is a class II div I incisor relationship?
The upper incisors are proclined (increased overjet).
The lower incisors occlude posterior to the upper incisors
What is a class II div II incisor relationship?
The upper incisors are retro lines (decreased overjet).
The lower incisors occlude posterior to the upper incisors
What is a class III incisor relationship?
The lower incisal edge occludes anterior to the cingulum plateau of the upper incisors
What is a class I molar relationship?
The mesiobuccal cusp of the upper first permanent molar occludes with the mesiobuccal groove of the lower first permanent molar
What is a class II molar relationship?
The mesiobuccal cusp of the upper first permanent molar occludes anterior to the mesiobuccal groove of the lower first permanent molar
What is a class III molar relationship?
The mesiobuccal cusp of the upper first permanent molar occludes posterior to the mesiobuccal groove of the lower first permanent molar
What is a class I canine relationship?
The mesial slope of the upper canine lies within the canine-first premolar embrasure
What is a class II canine relationship?
The mesial slope of the upper canine lies in front of the distal slope of the lower canine
What is a class III canine relationship?
The mesial slope of the upper canine lies behind the distal slope of the lower canine
What is local malocclusion?
Where the occlusion of 1-3 teeth on either arch prevents the teeth from exhibiting ideal occlusion
What are reasons for abnormalities in tooth number?
Early exfoliation
Unplanned loss of permanent teeth
Hypodontia
Loss of permanent teeth
How can we measure anterio-posterio skeletal relationship?
Measuring the ANB angle in a cephalogram
Measuring clinically using two fingers to establish the relationship between the maxilla and mandible
How can we measure the vertical skeletal relationship?
FAMP
LAFH:FAFH
How should the head be positioned for a cephalogram?
Frankfort plane
What factors promote osteoclastic bone resorption?
Interleukin-1
Prostaglandin E2
RANKL
Colony Stimulating Factor
What is the force applied for tooth movement?
10-20g
What are the factors affecting the rate of tooth movement?
Magnitude of force
Age of patient
Duration of force
Anatomy of bone
Why is an orthodontic assessment carried out?
Determine the nature of any malocclusion present
Identify underlying causes
Decide if treatment is indicated and either refer or devise a treatment plan
When is an orthodontic assessment carried out?
Brief examination aged 9 years
Comprehensive examination when premolars and canines erupt (11-12 years)
When older patients first present
If malocclusion develops later in life
What are the features of an ideal occlusion in regard to molar relationship?
The distal surface of the disco-buccal cusp of the upper first permanent molar occludes with the mesial surface of the mesial buccal cusp of the lower second permanent molar
What are the features of an ideal occlusion? (Andrews 6 keys)
Molar relationship
Crown angulation
Crown inclination
No rotations
No spaces
Flat occlusal planes
What is normal occlusion?
More commonly observed than ideal occlusion
Minor deviations that do not constitute an aesthetic or functional problem
Malocclusions are more significant deviations from the ideal that may be considered unsatisfactory
May require treatment, but patient factors may influence decision
What are the features of a history for an orthodontic patient at assessment?
Presenting complaint
How much does it bother the patient
History of presenting complaint
Past medical history
Past dental history
Social/family history
What medical conditions are a contra-indication to orthodontic treatment?
Allergy to Ni or Latex
Epilepsy/drugs
Drugs
Imaging
What are the features of past dental history for an orthodontic patient at assessment?
Frequency of attendance
Nature of previous treatment
Co-operation with previous treatment
Trauma to permanent dentition
What are the features of social/family history for an orthodontic patient at assessment?
Travelling distance/time
Car owner/public transport
Parents work
School exams
What are the features of a habit history for an orthodontic patient at assessment?
Thumb sucking
Lower lip sucking
Tongue thrust
Chewing finger nails
What are the features of an extra-oral exam for an orthodontic patient at assessment?
Palpate skeletal bases
Soft tissue
TMJ
What should you compare an orthodontic patient to their parent for?
Malocclusion
Growth potential
What planes is the facial skeletal pattern considered in?
Antero-posterior
Vertical
Transverse
How can a skeletal assessment be carried out?
Visual assessment
Palpate skeletal bases
What are the options for AP skeletal relationship?
Class I
Class II
Class III
What is a Class I skeletal relationship?
Maxilla 2-3mm in front of mandible
What is a Class II skeletal relationship?
Maxilla more than 3mm in front of mandible
What is a Class III skeletal relationship?
Mandible in front of maxilla
What are the vertical measurements for a skeletal assessment?
Frankfort-Mandibular Plane Angle (FMPA)
What are the lateral measurements for a skeletal assessment?
Mid saggital reference line
What are the soft tissue features of an intra-oral exam for an orthodontic patient?
Lip: competence, lower lip level, lower lip activity
Tongue: position, habitual and swallowing
Habits: tongue, digit sucking
Speech: lisping
What does lip incompetence indicate?
End of treatment instability
What does a hyperactive lower lip indicate?
End of treatment instability
What can a hyperactive lower lip result in?
Retroclined lower molars
What is tongue thrust associated with?
Anterior open bite
What are the occlusal features of a digit sucking habit?
Proclination of upper anteriors
Retroclination of lower anteriors
Localised AOB or incomplete OB
Narrow upper arch +/- unilateral posterior crossbite
What should be focused on when carrying out an extra oral exam on the TMJ?
Path of closure
Range of movement
Pain, click from joint
Deviation on opening
Muscle tenderness
Mandubular displacement
What should be focused on when carrying out an intra-oral exam on an orthodontic patient?
Oral hygiene and periodontal health
Teeth present
Teeth of poor prognosis
Assess crowding/spacing/rotations
Inclination/angulation
Palpate for canines if not erupted
Note abnormal teeth
What should be looked at when carrying out out an intra-oral exam for an orthodontic patients lower arch?
Degree of crowding: uncrowded, mild, moderate, severe
Presence of rotations
Inclination of canines- mesial, upright, distal
Angulation of incisors to mandibular plane: upright, proclaimed, retroclined
What should be looked at when carrying out out an intra-oral exam for an orthodontic patients upper arch?
Degree of crowding: mild. moderate, severe
Presence of rotations
Inclination of canines- mesial, upright, distal
Angulation of incisors to Frankfort plane- upright, proclaimed, retroclined
What is the approximate angle of the upper incisors to Frankfort plane?
110 degrees
What should be focused on when assessing teeth in occlusion for orthodontic patients?
Incisor relationship
Overjet
Overbite/open bite
Molar relationship
Canine relationship
Cross bites
Centre lines
What is a class I incisor relationship?
The mandibular incisor edges lie or are below the cingulum plateau of the maxillary incisors
What is a class II div 1 incisor relationship?
Mandibular incisor edges lie posterior to the cingulum plateau of the maxillary incisors
Maxillary incisors proclined
What is a class II div 2 incisor relationship?
Mandibular incisor edges lie posterior to the cingulum plateau of the maxillary incisors
Maxillary incisors retroclined
What is a class III incisor relationship?
Mandibular incisors edges lie anterior to the cingulum plateau of the maxillary central incisors
What is a class I molar relationship?
The MB cusp of the maxillary first permanent molar occludes with the MB groove of the mandibular first permanent molar
What is a class I canine relationship?
The mesial incline of the maxillary canine occludes with the distal incline of the mandibular canine
The distal incline of the maxillary canine occludes with the mesial incline of the mandibular first premolar
What is a class II molar relationship?
MB groove of mandibular first molar is distal to the MB cusp of the maxillary first molar
What is a class III canine relationship?
The mesial incline of the maxillary canine occludes anteriorly with the distal incline of the mandibular canine
The distal surface of the mandibular canine is posterior to the mesial surface of the maxillary canine by at least the width of the premolar
What is a class III molar relationship?
MB cusp of the maxillary first premolar occludes distally to the MB groove of the mandibular first molar
What is a class III canine relationship?
Distal surface of the mandibular canines are mesial to the mesial surface of the maxillary canines by at least the width of a premolar
Mandibular incisors are in complete crossbite
What special investigations can be carried out for patients at the orthodontic assessment?
Radiogrpahic: OPT, maxillary anterior occlusal, lat ceph
Vitality tests
Study models
Photographs
What do you do with the information gathered from an orthodontic assessment?
Summarise the important points
Assess treatment need (IOTN)
Devise treatment aims if appropriate
Plan treatment
What are the risks with orthodontic treatment?
Decalcification
Relapse
Root resorption
What is the IOTN?
Index of Orthodontic Treatment Need
A rating system that was developed to assist in determining the potential impact of malocclusion on an individual’s dental health and psychosocial well-being
What is the aesthetic component of the IOTN?
10 colour photographs showing different levels of dental attractiveness
Orthodontist must match the patients to these photographs
What is the dental component of the IOTN?
Records the various occlusal traits of a malocclusion that would increase the morbidity of the dentition and surrounding structure
Measured in 5 grades
What would grade 1-4 aesthetic component of the IOTN indicate?
No or minor requirement for treatment
What would grade 5-7 aesthetic component of the IOTN indicate?
Moderate/borderline need for treatment
What would grade 9-10 aesthetic component of the IOTN indicate?
Requires orthodontic treatment
When are coloured vs black and white photographs used for the IOTN?
Coloured photographs used with patients displaying range of dental attractiveness
Monochrome photographs used for the assessment on dental casts
What is the advantage of monochrome photographs in the aesthetic component of the IOTN?
Advantage that whoever is rating will not be influenced by a patient’s oral hygiene, gingival conditions or poor colour matches in restorations
What does MOCDO stand for?
Missing Teeth
Overjets
Crossbones
Displacement of contact points
Overbites
What is 5i on the IOTN?
Impacted teeth (except 8s) due to crowding, displacement, the presence of supernumerary teeth, retained deciduous teeth and any other pathological cause
What is 5h on the IOTN?
Extensive hypodontia with restorative implications (more than 1 tooth missing in any quadrant) requiring pre-restorative orthodontics
What is 5a on the IOTN?
Increased overset greater than 9mm
What is 5m on the IOTN?
Reverse overject greater than 3.5mm with reported masticatory and speech difficulties
What is 5p on the IOTN?
Defects of cleft lip and palate and other craniofacial anomalies
What is 5s on the IOTN?
Submerged deciduous teeth
What does grade 5 on IOTN indicate?
Severe dental health problems requiring treatment
What is grade 4 on IOTN indicate?
Dental health problems requiring treatment
What is grade 4h on IOTN?
Less extensive hypodontia requiring pre-restorative orthodontics or orthodontics to obviate the need for a prosthesis
What is grade 4a on IOTN?
Increased overjet greater than 6mm but less than or equal to 9mm
What is grade 4b on IOTN?
Reverse overset greater than 3.5mm with no recorded masticatory or speech difficulties
What is grade 4m on IOTN?
Reverse overjet greater than 1mm but less than 3.5mm with recorded masticatory and speech difficulties
What is grade 4c on IOTN?
Anterior or posterior crossbites with greater than 2mm discrepancy between retruded contact position (RCP) and intercuspal position (ICP)
What is grade 4l on IOTN?
Posterior lingual crossbite with no functional occlusal contact in one buccal segment
What is grade 4d on IOTN?
Severe contact displacements greater than 4mm
What is grade 4e on IOTN?
Extreme lateral or anterior open bites greater than 4mm
What is grade 4f on IOTN?
Increased and complete overbite with gingival or palatal trauma
What is grade 4t on IOTN?
Partially erupted teeth, tipped and impacted against adjacent teeth
What is grade 4x on IOTN?
Presence of supernumerary teeth
What is grade 3 on IOTN?
Borderline treatment need
What is grade 3a on IOTN?
Increased overjet greater than 3.5mm but less than or equal to 6mm with incompetent lips
What is grade 3b on IOTN?
Reverse overset greater than 1mm but less than or equal to 3.5mm
What is grade 3c on IOTN?
Anterior or posterior crossbites with greater than 1mm but less than or equal to 2mm discrepancy between RCP and ICP
What is grade 3d on IOTN?
Contact displacements greater than or equal to 4mm
What is grade 3e on IOTN?
Lateral or anterior open-bite greater than 2mm but less than or equal to 4mm
What is grade 3f on IOTN?
Deep overbite complete on gingival or palatal tissues, but no trauma
What is grade 2 on IOTN?
Negligible treatment need
What is grade 2a on IOTN?
Increased overjet greater than 3.5mm but less than or equal to 6mm with competent lips
What is grade 2b on IOTN?
Reverse overset greater than 0mm but less than or equal to 1mm
What is grade 2c on IOTN?
Anterior or posterior crossbite with less than or equal to 1mm discrepancy between RCP and ICP
What is grade 2d on IOTN?
Contact point displacements greater than 1mm but less than or equal to 2mm
What is grade 2e on IOTN?
Anterior or posterior open bite greater than 1mm but less than or equal to 2mm
What is grade 2f on IOTN?
Increased overbite greater than or equal to 3.5mm without gingival contact
What is grade 2g on IOTN?
Pre-normal or post-normal occlusions with no other anomalies (inc up to half a unit discrepancy)
What is a unit in orthodontics?
Length of a premolar
What is grade 1 IOTN?
No treatment need
Extremely minor malocclusions including contact displacements less than 1mm
What rules apply when using the dental health component of the IOTN on study casts?
Overjets 3-5-6mm: assume incompetent lips and award grade 3a
Crossbites: assume a discrepancy between RCP and ICP of 3mm and award grade 4c
Reverse overjets: assume masticatory or speech problems are present
What does the top left of the IOTN ruler measure?
Overjet
What does the bottom left of the IOTN ruler measure?
Reverse overjet
What does the right of the IOTN ruler measure?
Contact point displacement and open bite
When can a tooth be regarded as impacted?
If the space between the two teeth next to it is less than or equal to 4mm
When is there considered to be an anterior crossbite?
1 to 3 incisors are in lingual occlusion
When is there considered to be a posterior crossbite?
Cusp to cusp or in full crossbite
When are submerged deciduous teeth considered in IOTN?
If only 2 cusps are visible and/or the adjacent teeth are severely tipped towards each other and closely approximated
What IOTN is necessary for NHS treatment?
DHC- >4 (borderline 3)
Aesthetic component- >6
What are the indications for orthodontic referral during the deciduous dentition?
Severe skeletal discrepancies
Severely delayed dental development
Missing/supplemental teeth
History of head and neck radiotherapy with/without chemotherapy
Advice for balancing/compensating extractions
What are the indications for orthodontic referral during the mixed dentition?
Severe skeletal patterns where early treatment may be appropriate e.g. developing class II/III
Dental anomalies e.g. double teeth, dens in dente, talon cusps
Developmentally missing permanent teeth
Supernumerary teeth
Teeth in unfavourable positions e.g. canines
Impacted first permanent molars
Infraoccluded teeth
Crossbites
Extraction advice where severe crowding evident or first molars have poor prognosis
Advice following trauma to permanent teeth
What are the indications for orthodontic referral during the permanent dentition?
Based on IOTN
When is an orthodontic assessment carried out?
Brief examination at 9 years old
Comprehensive examination when premolars and canines erupt (11-12 years)
When older patients first present
If malocclusion develops later in life
What are the Andrew’s 6 keys?
Molar relationship
Crown angulation (mesio-distal tip)
Crown inclination
No rotations
No spaces
Flat occlusal plane
What is normal occlusion?
Minor deviations that do not constitute an aesthetic or functional problem
What are malocclusions?
More significant deviations from the ideal that may be considered unsatisfactory (aethetically or functionally)
What should be included in an orthodontic diagnosis?
Description of the malocclusion
Determine the cause of the malocclusion
Are the causes dentoalveolar or skeletal
What are examples of causes of malocclusion?
Small teeth - spacing
Early loss of deciduous teeth - crowding
Digit sucking - proclination and increased OJ