Orthodontics Flashcards
IOTN and ectopic canine with cast and radiographs
- Aetiology
~ crowding
~ traums
~ angulation (long path of eruption)
~ genetic ( associated with peg or missing lateral incisor + Class 2 , more in F , 1-2% of population) - Investigations
~ Palpate when 9-10 YO bucally and palatally
~ Check visially for any bulge
~ Check mobility + color of cs and 2’s
~ Check inclincation (distally) of 2s
~ Parallax technique
~ CBCT - Comment on X-ray
~ angulation of 3s
~ signs of resorption
~ Signs of cysts
~ Ankylosis
~ Buccal or Palatal position - Would you refer? Yes as IOTN is 5i meaning high treatment need
- Risks?
~ Ankylosis
~ Root Resorption
~ Cyst formation - Tx options
1. Leave and monitor for a year until Cs Exfoliate ; 3s might erupt spontaneously
- in pts older than 12 , XLA cs and maintain space for 3s to erupt (iseally between age 10-13)
- XLA Cs and surgical XLA of 3s and replace space ( do not do this if pt does not want ortho, tooth ankylosed , not align-able of there are signs of resorption)
- Surgical exposure of 3s with gold chain and orthodontic traction
- Autotransplantation - if there are no signs of ankylosis and pt looks for quicker option
- Risks of doing nothing?
~ Root resorption
~ ankylosis
~ Aesthetics
~ Cyst formation
~ Resorption of crown of 3 or root of 2
What is the difference between closed and open exposure?
- Closed exposure
~ Raising a flap and bonding a gold chain on the tooth , then closing the flap and allow the chain to come dangle through the attached mucosa - tooth will erupt in the attached mucosa which will have goof gingival margin
^ Done if tooth is very high up in the palate and deep - Open exposure
~ Raising a flap and bone and ortho bracket to push the tooth without closing the flap
^ Done when tooth is close to the gingivae
Class 3 malocclusion treatment options for a 20 YO
Normal OJ 2-4mm
- Explain diagnosis of class 3 malocclusion
” your bite is what we would describe as class 3 malocclusion ( we have 3 classes) which means that your bottom front teeth are biting infront of your upper front teeth - affects 3-8% of the population”
Causes
~ Small top jaw
~ reverse overjet
~ proclined lower or retroclined upper
~ High activity of upper lip
- Why treat?
~ aesthetics
~ Dental health ; attrition, gingival recession, mandibular displacement
~ Function; speech and mastication - Treatment options
- Accept and monitor
~ Mild
~ development not yet finished (not in this case)
~ No concerns
~ No dental health indications
^ Risks of doing nothing
~ Anterior crossbite would not self correct and would get worse
~ risk of TMJ due to mandibular displacement
~ risk of toothwear and gingival recession due to crossbite
- URA to correct anterior crossbite with Z-spring (not advisable if upper already proclined or pt is an adult)
~ early correction of incisor relationship - Growth modification to encourage maxillary growth and restric mandibular
~ in growing patient
~ using functional appliances (reverse twin block, Frankel III , chin up) or RME and protraction headgear (works best for younger age) or TADs - Camouflage with fixed appliances
~ accept skeletal classification and correct with fixed ortho of incisor classification
~ Risks include decalcification, root resorption, gingival recession , relapse
~ Benefits include aligning teeth resulting in better function and aesthetics + less toothwear
~ Most likely to XLA of U5s and lower 4s
~ Favourable features ; growth stopped, mild to mod class III , average or increased OB , able to reach edge to edge incisors , little to no dentoalveolar compensation - Orthognathic surgery with combined orthodontics
~ surgical manipulation of maxilla ± mandible to produce favourable results
~ Growth is complete and pt have functional or aesthetic concerns
~ done by an MDT - carfully planned
~ will need pre-surgical orthodontics for 12-18 months - to align arches and undo any dentoalveolar compensation
~ Then sugery to reposition jaws followed by 6 months of fixed orthodntics = 36 months in total
Risks include
~ damage to nerve complications
~ infection
~ bleeding
- Ask about any qs and pt decision then refer to ortho for fixed appliances
( look at notes for example of the interaction)
Ortho Discussion - Class II div 1
Class II div 1 with severe OJ
What is the IOTN
aesthetic component
age of child
what normally to expect at this age
how to manage
would you refer and what level of urgency ?
what is the risk of no treatment?
Study models and photos provided
- Explain Class II div 1 to pt
~ maxilla more than 2-3mm infront of mandible (skeletal)
~ lower incisors edge lie posterior to the cingulum of the upper centrals , upper centrals are proclined or of average with increased OJ
~ Causes
^ Skeletal ; retrognathic mandible
^ Dental ; proclined upper incisors and increased OJ
^ ST ; lip trap , tongue thrust or parafunctional habits (digit habit)
~ Dental factors
^ increased OJ
^ variable OB
^ may have good alignment
^ Parted lips resulting in dry gingivae increasing the risk of gingivitis
~ Reasons for treatment
^ Aesthetics
^ dental health
^ Risk of trauma from proclined incisors
^ OJ more than 9mm leading to twice the risk for trauma
- Management options
1. Accept
^ Pt not concerned with mild OJ increase
^ Give advice and use of mouthguard for trauma
- Attempt growth modification
^ restrict growth of maxilla and encourage growth of mandible + retrocline upper incisors
^ Pt still growing
^ Use headgear to restrain growth of maxilla
^ Functional appliances ( twin block) ; utilise , eliminate or guide the forces of muscle function, tooth eruption and growth to crrect the malocclusion
^ Used during pubertal growth spurt - URA
^ limited role unless there is very mild class II
^ when OJ is due to incisor inclination
^ needs favourable OB - Orthognathic surgey
^ when growth is complete
^ severe skeletal descripency
^ Fixed appliances required before during and after surgery
- Refer as 5A high treatment need
Retained ULA and Unerupted UL1
Photos of discoloured 61
PA of dilacerated floating 21
8 year old pt
Please identify the problem present for this patient and discuss its further investigation and management with your examiner
IOTN 5i
- Causes of retained 61 and unerupted 21
~ Trauma to A causing damage to 1 which may lead to several complications;
^ ankylosis
^ arrested tooth formation
^ Dilaceration
^ Displacement
^ Odontome
^ Ectopic position
~ Lack of permanent successor - hypodontia
~ Ectopic tooth germ
~ Crowding
~ Supernumerary - tuberculate most common
~ Cysts
~ infraoccluded retained primary
- Signs
~ Discolouratoin of A
~ Retained A
~ Lateral erupted before central ; lateral displacement or mobility
~ more than 6 months after eruption of contralateral tooth - Investigations
~ Radiographs for parallax ;
PA + Ant occlusal
OPT + Occlusal
~ CBCT for 3D view
~ palpate
~ assess deciduous tooth (mobility and colour) - Management
- Leave and monitor
^ possile cyst/ resorption/ ankylosis , unlikely to erupt as dilacerated - XLA of A and maintain space for spontaneous eruption of 1
^ cyst formation risk
^ might not erupt as dilacerated - Surgical removal of both teeth and space maintenance + plan to replace
- Surgical exposure with fixed applianced and ortho alignement
^ Make space by ortho
^ surgicallly expose 1 after XLA of A (open of close) - Autotransplantation if
^ tooth not alignable
^ no evidence of ankylosis
^ pt looking for quicker optoin
^ permanent tooth growth is 2/3 to 3/4 of root length
What are the risks associated with autotransplantation?
- Needs RCT when transplanted
- Will become ankylosed
- External root resorption might occur
When to surgically remove ectopic canines and centrals?
- If not deemed alignable (too high - above apical third of incidor root or if too close to midline)
- no significant risk of damaging adj teeth
- Pt happy with appearance and long term prognosis of retained primary
- Radiographic signs of root resorption
- Pt does not want ortho appliances
Ectopic canine with peg laterals in class 2 skeletal and class 2 div2 incisor relationships (6 mins)
1- Skeletal: AP: class 2
Vertical: FMPA, slighlty reduced Transverse symmetrical
2- Soft tissues:
Lip: competent, no lip trap Nasolabial angle: high (obtuse) Smile line: normal
IO:
OH: good
Tooth erupted, quality, poor prognosis, tooth wear
Incisal relationship: class 2 div 2
Lower arch: alinged, retroclined LI
Upper arch: mildly spaced, midline
diastema, retroclined UI OB: increased, complete 70%
OJ: mildly increased- 3mm
R Molar class 2 L molar class2 half unit
Centreline : coincident U and L, coincient to midline
- Identify problems
1. increased OJ
2. increased OB
3. Peg laterals
4. Ectopic canines - Dental health implications
1. Risk of trauma from OJ + speech , confidence, mastication
2. Risk of trauma from OB ( palatal ulcers , gingival recession in lower anteriors)
3. Canine ; risk of resorption+ ankylosis and failure to move canine with traction + potential need for complex restorative treatment
4. Risk of cyst formation - Position determination from radiographs provided (canines)
^ Use parallax technique
^ 2 PAs for horizontal
^ vertical - SLOB
^ Explanation
“ the tube head shifted up from OPT to oblique occlusal, the canine moved together with the tube-head compared to the incisor. according to SLOB rule , the canine is palatal to the incisor )
Decalcification (6mins)
Patient wants you back over some advice to avoid decalcification , diet advice , and toothbrushing instructions
- Decalcification is the formation nof early caries, clinically this appears as white spot lesions , this is a reversible stage of caries formation
^ bacteria within the plaque biofilm produce acids which cause the breakdown of enamel
^ Happens when plaque accumulates and is not removed
^ Can progress to deeper caries if ledt untreated
^ they usually form around brackets and bands near the gingival margins - Risk factors for decalcification
~ Poor OH
~ Poor plaque control
~ Poor diet
~ History of recent caries - Prevented by
Good patient selection
^ Good motivation
^ Good OH
^ Low caries risk
^ no toothwear
- OH advice
^ TB and single tufter TB for brackets
^ Use of floss and ID brushes
^ Brush twice daily using methodical approach
^ Use F toothpaste
^ brush after meals as brackets trap food
^ Use disclosing tablets to identify missed areas - Diet advice
^ Limit sugars amount and frequency (limit to mealtimes and limit to less than 3 times daily)
^ Avoid hard or sticky foods , sport drinks m fizzy drinks
^ Ideally drink only water and milk
^ Snack on healthier snacks
^ Be careful of hidden sugars
^ Rinse mouth after eating - Fluoride
^ High F toothpaste ; 2800 ppm pr 5000 ppm
^ Warn regarding overdose and children
^ MW - 225ppm , use between meals
^ FV using profluoride as duraphet could stain , every 4 months - Prescriptions
^ Sodium F toothpaste 0.619% / 1.1%
^ Send 75ml / 51g
^ Brush teeth after meals using 1 cm before spitting out twice daily
URA (6 mins)
Faults/activation/delivery checks and care instructions
Required to fit upper removable appliance to a 9 year old child
Examine the prescription and appliance
look for defects and answer the examiners question
Show how to make adjustments to adam’s clasp and active component (palatal finger spring) , and what is a FABP used for
- FABP used to correct or reduce overbite by having a block of acrylic anteriorly taking teeth out of occlusion and allowing them to overerupt and correct OB
- Components Faults
^ Z-spring encased in acrylic
^ UR6 adams clasp arrowhead fault
^ UL6 adam’s clasp flyover fault - Prescription faults
^ Southend clasp included meaning appliance will not work
^ Adam’s clasp on ULC not D
^ FABP instead of FPBP - How you would rectify these errors? remake appliance by taking new impressions
- Activating palatal finger spring
^ 1-1.5mm activation using 65 pliers
^ Come in perpendicular to appliance , put conical part in coil and uncoil
What are the checks when fitting an upper URA?
- Check for correct patient
- Check it matched the prescription
- Check wirework integrity - ensure not sharp edges or wires protruding
- Try in appliance
- Check for any blanching or trauma
- Check posterior retention - flyover , then arrowheads
- Check anterior retention
- Activate to produce 1mm of movement per month
- Demonstrate insertin and removal
- Review every 4-6 weeks
What instruction would you give a pt after delivery of URA
- Will feel big and bulky but will get used to it
- Likely to impinge on speech so practice reading out loud
- Mild discomfort but it means that it is working
- Initial increase in saliva ; will get better in 24-48 hours
- Wear 24/7 including meal times
- Remove and clean with a soft brush after every meal
- Store in a safe container when taking part in contact sports
- Avoid hard and sticky foods
- Be cautious with hot food and drinks as base of plate acts as an insulator
- non compliance will lengthen the treatment
- Contact if there is a problem (give emergency contacts)
Describe the ARAB for designing URA?
A - active component - move the teeth with force - 0.5mm
R - retentive component - resistance to displacement forces ; 0.7mm in permanent and 0.6mm in decidious
A - anchorage - resistance to unwanted tooth movement
B - baseplate - provides Anchorage , holds components together ; helps with retention ( adhesion and cohesion)
^ Self cure PMMA
^ knife edge acrylic helps stops the tongue from playing with URA
Design a URA for an overbite reduction
A -
R - 16,26 adam’s clasps 0.7mm HSSW
A - v
B - Self cure PMMA / FABP OJ + 3mm
Design a URA to reduce overjet and continue to reduce overbite
A - 22-12 Robert’s retractor 0.5mm HSSW + 0.5mm ID tubing
R - 16,26 adam’s clasps 0.7mm HSSW + 13/23 mesial stops 0.6mm HSSW
A - not ideal
B - Self cure PMMA / FABP OJ + 3mm
Design a URA to retract canines palatally placed
A - 13/23 palatal finger spring and gaurd 0.5mm HSSW
R - 16/26 adams clasp and 11/21 Southend clasp 0.7mm
A - only moving 2 teeth
B - Self cure PMMA
Design a URA to retract bucally placed canines and reduce OB
A - 13/23 buccal canine retractor 0.5mm + 0.5mm ID tubing
R - 16/26 Adam’s clasps 0.7mm + 11/21 Southend clasp 0.7mm
A - only moving two teeth
B - Self cure PMMA / FABP + 3mm
Design a URA to correct anterior crossbite
A - Z spring 0.5mm
R - 16/26 Adam’s clasp + 14/24 Adam’s clasp 0.7mm
A
B - Self cure PMMA + Posterior bite plane
Design a URA to correct posterior crossbite
A - midline palatal screw
R -16/26 Adam’s clasp + 14/24 Adam’s clasp 0.7mm
A - reciprocal anchorage
B - Self cure PMMA + posterior biteplane
