Orthodontics Flashcards
(19 cards)
On examination, the patient had Class II div 1 incisors with a 9mm overjet and a deep bite. There is total 4mm interdental spacing in the maxillary anterior sextant. Class II molars are present bilaterally, and buccal crossbite of the left premolars. A midline shift of 1mm of the lower dentition to the right can be noted. There is a retained tooth 53, and 13 is not palpable in the buccal sulcus.
Below are the study models and an OPT of the same patient.
Given the above information, discuss the following with the examiner:
a) What is the IOTN for this patient?
b) Considering their age, explain the orthodontic management options for this patient?
c) What are the risks to the patient if they are not treated?
d) Why is this patient more susceptible to dental trauma?
IOTN and ectopic canine with cast and radiographs
IOTN - 5i due to impacted canines
Management options :-
- Identify the need for specialist orthodontic management with repositioning of ectopic canines
- Do nothing and monitor
not recommended as risks associated with increased overjet and ectopic canines - Camouflage
extraction of upper premolar with orthodontics to move incisors to class I to improve soft tissue profile , unlikely in this case due to ectopic canine - Orthodontics with surgical exposure
XLA retained primary and expose permanent canine, attached with a gold chain for orthodontic traction to realign canine into position (best option) - Orthodontics with orthognathic surgery
~ What are the risks to the patient if they are not treated? (permanent canine)
* increased risk of trauma
* PC becomes more ectopic
* PC never erupts
* Root resorption in adjacent teeth
* Resorption of PC crown
* Cyst formation around PC
* Ankylosis of PC
~ Why is the patient more susceptible to dental trauma?
Overjet is over 9mm which is twice as likely to suffer trauma, especially if incompetent lips
~ PArallax
Palatal through vertical shift
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
Attending your clinic is a 20-year old complaining of chewing difficulty and expresses a strong desire to improve his aesthetic appearance. [6]
Below are clinical photographs taken at the initial appointment. They have a class III incisal and skeletal relationship with marked mandibular prognathism.
Explain to the patient the benefits of treating his malocclusion and the different options that are available to him.
~ introduction
~ benefits of treating malocclusion
* improved facial and dental aesthetics
* improved dental health
1. toothwear due to current relationship of teeth (attrition)
2. Recession and trauma to gingivae
3. shifting of lower jaw contribute to chronic jaw problems (TMD)
4. Better cleansability with treatment as less crowding
” due to the complexity of your case, you will benefit most from being managed by a dentist who is very experienced in orthodontics. They will provide you with the best treatment options specific to your case, Today I can provide you with the waays they may manage this. “
~ Management options
1. Accept and monitor ; not ideal as does not solve any issues
2. Fixed appliances ; some teeth may be taken out to create space for repositioning the arch and allowing for specific tooth movements with fixed braces. This will mask the underlying jaw relationship but will not change it. This will take around 12-24 months.
3. Orthognathic surgery with fixed orthodontics; this involves using fixed braces to reposition teeth into ideal position for about 12-18 months , then orthognathic surgery is carried out to reposition your jaw to desired relationship, This will fix both aesthetic and eating issues. howerever there are several risks with this (procedure/GA)
~ Orthodontic treatment risks
* increased decay risk around brackets
* shortening of roots
* damage to gums/cheek if appliance break
* return of teeth to original place (need retainer life long)
* Recession of gum line
You are provided with a set of casts from a 13-year old patient. [12]
On examination, the patient had Class II div 1 incisors with a 9mm overjet and a deep bite. There is total 4mm interdental spacing in the maxillary anterior sextant. Class II molars are present bilaterally, and buccal crossbite of the left premolars. A midline shift of 1mm of the lower dentition to the right can be noted. There is a retained tooth 53, and 13 is not palpable in the buccal sulcus.
Below are the study models and an OPT of the same patient.
Given the above information, discuss the following with the examiner:
a) What is the IOTN for this patient?
b) Considering their age, explain the orthodontic management options for this patient?
c) What are the risks to the patient if they are not treated?
d) Why is this patient more susceptible to dental trauma?
When finished with this, the examiner will provide you with further instructions.
IOTN = 5i due to ectopic canine
- identify the need for referral to orthodontist as high treatment need
~ management options
1. Accept and monitor
- Risk of trauma due to increased overjet
- Risk of cyst formation / root//crown resorption due to ectopic canines
- Camouflage , XLA of upper pre-molar then fixed ortho to convert to class I incisal relationship
- Orthodontics with surgical exposure
- XLA retained primary teeth
- expose canines and attach to orthodontic traction using gold chain to realign into position for Class 1 incisal relationship - Orthodontics with orthognathic surgery ; when growth has stopped
~Risks if not treated
- trauma to incisors
- canine becomes more ectopic
- canine never erupts
- root resorption of adjacent teeth
- cyst formation around PC
- resorption of PC crown
- Ankylosis of PC
~ why patient more susceptible to dental trauma?
overjet more than 9mm twice as likley to suffer trauma especially if incompetent lips
~ Parallax (vertical shift)
Crown tip moves up with x-ray tube as becomes closer to apical third of lateral incisor roots = palatally placed
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 of 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
