Comprehensive orthodontic treatment Flashcards
What is the goal of orthodontic treatment?
To produce the best combination of occlusion, dental and facial aesthetics and stability of outcome
What does the usual orthodontic treatment consists of?
- Fixed orthodontic appliances or aligners on all teeth
- possible extractions with/without growth modifications and orthognathic surgery
- Multidisciplinary coordination for complex cases
How long is Phase I treatment
Usually 1 year followed by retention
When is Phase II treatment commenced?
After eruption or nearing eruption of 7-7s
When is orthognathic surgery performed?
After growth cessation
Except:
- Progressive deformity from growth restriction eg. TMJ ankylosis after trauma/infection
- Severe psychosocial issues
Types of brackets?
Conventional edgewise metal brackets
Self-ligating brackets (metal or ceramic) - without band
Ceramic brackets (not done on lowers as they are harder and will wear down teeth + wire can still be seen
Lingual appliances
How are brackets bonded to the tooth
With CR adhesives
What are the differences in archwires
Material
Size
Arch form
What are the two types of bands
Elastomeric modules
Wire ligatures
What is the ultimate aesthetic option?
Clear aligner trays with composite attachment for more complex cases to attach to aligners
What are the advantages of clear aligners?
- Aesthetics
- Comfort
- Ease of oral hygiene
- Minimal dietary restrictions (eg worry abt brackets coming off)
- Longer appointment intervals
- Control of tooth movement rate
- Certain mechanical advantages
What are the disadvantages of clear aligners
- Compliance dependent
- Several tooth movements can be challenging
- Lab-based fabrication of aligners
(Duration, cost, less flexibility)
What should be done before orthodontic treatment is begun?
- Develop multidisciplinary treatment plan and sequence
- Disease control - caries, active perio, endo lesions
(gingival grafts prophylactically, provisionalisation)
What should be done after orthodontic treatment?
- Good OH control, regular dental checkups and prophylaxis
- Debond after confirmation from other providers
- Immediate retention
What are the three stages for conventional fixed appliances?
- Alignment and levelling
- Space closure and AP/vertical/transverse correction (KIV elastics)
- Finishing (Interdigitation and rotation)
What are the possible orthognathic surgery cases approaches
- Surgery first
- Surgery early
- Conventional three stage method
What are the indications for surgery first approach?
Minimum crowding, bite stable in Class I
Patients do not want transitional stage in conventional method
What are the three stages in the conventional three stage method?
- Pre-surgical orthodontics (Remove DAC) - worsens aesthetics
- Orthognathic surgery
- Post surgical orthodontics
What are the indications for a conventional three stage method?
Significant crowding
Problems in all 3 planes
No stable bite
Severe skeletal discrepancy
Requiring exos
More predictable
What are the main treatment considerations prior to growth modification?
Compliance
OH
Growth status
What are the treatment considerations?
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- C/O
- Compliance + OH
- Med Hx/Medications
- Growth Status
- Facial balance
- Skeletal discrepancies: severity + which planes
- Effects of treatment in one plane on another plane
- Orthodontic camouflage vs orthognathic surgery
- Limits of dentition (recession, instability)
- Crowding + Incisor inclination (exo)
- Missing permanent teeth (Space opening/closing; ability of canine masking (shape, size, gingival margin; Bolton’s discrepancy –> poor interdigitation –> need for disking)
- Long term prognosis of teeth (multidisciplinary)
- Anchorage and periodontal support (esp of anchor)
- Stability (final outcome)
When is chin prominence good
When masking Class II patients
What is the most important for skeletal discrepancies
Normal vertical dimension of lower face
Growth modification is most useful and least useful for which planes?
Most: AP
Lease: Transverse
What are temporary anchorage devices (TADs) used for
Mini screws used to expand treatment possibilities for camouflage
What is orthodontic camouflage
Moving teeth into correct dental relationships but accepting SK discrepancies
What are limits of dentition?
Anterior limits: Proclination
Posterior limits: accommodating teeth by distalisation/extraction of 2nd and 3rd molars
Lateral limits: ant border of ramus
How can space be created?
- Expansion
- Inter-proximal stripping (0.25 per tooth, 0.5 per ant) - for up to 5mm of crowding
- Extractions
Whats the average max and man leeway space
Max: 1.5mm per quad
Man 1.7-2.5mm per quad
What is the drawback of a lower lingual holding arch
cannot mesialise L6 into Class I
Considerations for extractions of teeth
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- Med Hx
- SK discrepancies + growth
- Severity of space deficiency
- Incisor inclination
- Skeletal or dental open bite
- Facial profile
- Molar and canine relationships
- Position of teeth - exo of tilted/displaced tooth; exo 4/5 depending on which is closer to crowding
- Long term prognosis of teeth
- External root resorption or thin/tapered roots
- Status of periodontium (perio compromised –> exo)
- Thickness of alveolar bone
- OJ, OB
- Midline deviations
Surgical cases of Class II usually involves
Man adv: 66%
Mx impaction: 15%
Both: 20%
Surgical cases of Class II usually involves
Man setback
Mx advancement (Lefort I osteotomy)
Both
