Orthodontics COPY Flashcards
Patients undergoing orthodontic
treatment may commonly experience discomfort for a few days after the appliance is fitted or adjusted.
why
This is a result of the physiological changes occurring within the periodontal ligament (PDL). As forces are applied to the teeth during orthodontic treatment, the PDL is compressed and stretched. These changes cause the cells within the PDL to release chemical messengers that initiate an inflammatory cascade to cause the pattern of bone resorption and deposition required for tooth
Unfortunately, these chemical
messengers, coupled with the reduced blood flow due to compression of the PDL, stimulates pain.
Anti-inflammatory analgesics,
such as Ibuprofen, have been proven to be effective at reducing pain. 4,5 However, as many of these medications work by inhibiting chemical messengers involved in the inflammatory response that causes pain,
why might this be a problem during orthodontic treatment
they have the potential to affect the inflammatory process required for tooth movement.
Fortunately, this is not seen when such analgesics are used in low doses and for short durations, as is usually the case when managing orthodontic related pain. 3 Therefore anti-inflammatories, such as Ibuprofen
400 mg taken three time daily, are still the most commonly used and recommended method of orthodontic-related pain relie
The use of orthodontic appliances
is associated with oral lesions, such as erosions and ulcers. The irritation from the appliance can either precipitate or exacerbate such
relief is achievable with the use of
relief is achievable with the use of topical anaesthetic directly applied to the site with a microbrush. The patient can then be advised to re-apply topical anaesthetic to the lesion as required
Antiseptic mouthwashes, such
as chlorhexidine, may be a useful aid in managing ulcerations
what is this and why is it used
orthodontic wax
pliable material that can be used to cover prominent components of the orthodontic appliance to prevent it from irritating the soft tissue
how do you manage trapped food in orthodontic appliance
This is easily treated using dental floss or an interdental brush to gently remove the food from between the tooth and the appliance.
Patients may report that their
braces are irritating the lips/cheeks; this often occurs soon after the appliance is initially fitted and is usually more pronounced when the patient is eating. Treatment involves placing
placing non-medicated relief wax over the area causing irritation
Ligatures are the small wires
or elastic bands that hold the archwire to the bracket. When an elastic ligature becomes loose it can be repositioned using tweezers. If a wire ligature becomes loose, do not attempt to
do not attempt to replace it.
If a ligature is lost then the
archwire is not secured within the bracket and may result in a reduction in the effectiveness of the appliance on the tooth. Therefore, the orthodontist should be
notified so that he/she can advise when the patient should arrange for it to be replaced
Sometimes the end of the
archwire protruding distal to the last bracket/ band can start to irritate the patient’s mouth. The wire should be
The wire should be bent so that it is flat against the tooth and not protruding into the soft tissues. This can be done with wire benders or a flat plastic. If this is not possible, then the end of the wire can be covered in relief wax and the orthodontist should be informed
. In situations where the protruding wire is causing significant discomfort and the patient will not be able to see his/her orthodontist urgently, then the wire can be clipped using sharp wire cutters or distal-end cutters. Alternatively, the whole wire can be removed by first removing the ligatures then removing the wire, however, this should be a very last resort. It is important to avoid inhalation or ingestion of the small piece of wire after it has been cut. This can be achieved by using gauze around the area and/or distal end-cutters which grip the snipped piece of wire after it has been cut
Occasionally, removable
appliances break. If this happens, the orthodontist should be informed as soon as possible and will then take the appropriate
action. The patient should be advised to stop using the appliance if the damage renders the appliance a potential
airway risk or will cause marked trauma.
Components, such as a
palatal/lingual arch or a molar band, can fracture or become loose causing irritation or trauma to the patient. If the component is not mobile, it should be covered with
orthodontic relief wax and a review appointment arranged with the orthodontist. However, if the component is very mobile or loose, it can carefully be removed with tweezers whilst protecting the airway to prevent inhalation
Orthodontic retainers are either
fixed or removable and their purpose is to hold the teeth in their new position after
active treatment is complete. It is now widely accepted that patients should wear their retainers long term to prevent relapse, which can be for many decades. However, patients are usually discharged from their orthodontist 12 months after the active treatment has been completed. Therefore, patients may present to their GDP if they have lost or broken their retainer.
Removable retainers can easily be repaired if the damage is minor. An accurate impression of the arch should be taken and sent to the laboratory with the broken appliance. However, if the damage is more extensive, or the appliance is lost, a new retainer will need to be made. To do this, an accurate impression of the arch is required and the type and design of the retainer should be clearly stated on the laboratory ticket
Fixed retainers are bonded to
the palatal/lingual surface of teeth and are used where even minimal amounts of tooth movement are deemed unacceptable by the patient
If a fixed retainer de-bonds from a tooth but is securely attached to adjacent teeth and lies passively on the tooth in question, it can be re-bonded. This is done by carefully removing any residual composite, preparing the tooth surface with acid etch and bond and replacing the composite to secure the wire without distorting it.
The most common allergy in orthodontics is to
Nickel
Owing to the popularity of nickel-containing jewellery and body piercings, many patients have been exposed to nickel before undergoing orthodontic treatment and may be sensitized to the metal. This can precipitate a Type IV delayed hypersensitivity immune response when they are re-exposed to nickel in orthodontic appliances.
s not usually immediate but develops after a few days or weeks so that patients may present to a GDP first. The intra-oral clinical signs and symptoms can be quite varied but may include
include gingivitis not caused by plaque, gingival hyperplasia, labial desquamation, burning sensation, metallic taste, angular cheilitis, numbness/altered sensation, labial swelling or soreness of the tongue
Fortunately, the majority of
patients who are sensitized to nickel can still wear nickel-containing orthodontic appliances without eliciting a response, as it is thought that a much
higher concentration of nickel is needed to produce a response in the oral mucosa than is required on the skin.
Airway obstruction
A true emergency arises when
a loose component or small removable appliance obstructs the airway. If the object is still visible in the mouth, attempts should be made to remove it with the patient reclined, otherwise the patient should be encouraged to cough the object out. If this is not successful immediately, call for help and call an ambulance
Ingestion of an orthodontic
component or appliance is not uncommon, and is usually asymptomatic and causes no injury to the patient, therefore requiring no treatment besides monitoring the stool to check that the component has passed naturally. However, if the component becomes lodged in the oesophagus or oropharynx, the patient may experience pain or vomiting. In such situations, the patient should immediately
be sent to hospital for advice and management, ideally with an example of the component that has been ingested. If the component has not yet reached the stomach it can be removed via fibre-optic endoscopy.
Regardless of the symptoms,
a patient should always be referred to the Accident and Emergency (A+E) department at a local hospital when the ingested component is more than how many cm long
component is more than 5 cm long as there is a higher risk of obstruction and perforation of the gastrointestinal tract, so removal may be advised instead of allowing the component to pass naturally. It is important when a patient is sent to the hospital that the referral letter includes information about the component, such as its size, shape, flexibility and radio-opacity, as well as information about the incident, such as when the object was swallowed. This will help in locating the component and predicting the outcome.
removable appliance fabricated mainly in
acrylic and wire
- Removable appliances are not
permanently attached to
teeth
what are the active components for removable appliances
Active components: springs,
biteplanes,
screws, and bows.
what is this types of removable appliance
- space maintainer
what is this type of removable appliance
presurgical infant orthopedics for cleft lip and palate
what is this type of removable appliance
active plates
what is this type of removable appliance
retainer
what is this type of removable appliance
functional appliance
what are the advantages of removeable appliances
- Can be removed for OH and sports
* Increased anchorage
* Easy to adjust
* Less iatrogenic damage
* Baseplate can be modified
* Good at moving blocks of teeth
* Can be passive
* Lower cost
what are the disadvantages of removeable appliances
- Need good patient compliance
* Limited movements- tipping
* Affects speech
* Technician required
* Lower appliances difficult to
tolerate
* Inefficient at multiple tooth
movements
what are the components of a removeable appliance
. Active components
* Retentive components
* Anchorage
* Baseplate
what is the function of springs as an active component
to move a single tooth or groups of teeth
springs are constructed using stainless steel wire, what thickness is it cut at?
0.5mm
0.7mm
force and deflection of stainless steel spring is calculated using this formula
F = d.r4/l3
what does the RDI stand for
R = radius of the wire
D = deflection of the wire
I = Length of the wire
increasing the radius of the wire by 2 will result in the force applied increasing by 16
to achieve single tooth movement no more than how much gram can be applied to the tooth
25-40 grams
how do reduce the tipping tendency to a minimum with springs
apply force close to the gingival margin of the tooth
what is the function of a Z-spring
It is used to push one anterior tooth from the lingual (palatal) side in a labial direction
what is the function of a T spring
T Spring is used for the buccal movement of a single premolar or molar tooth. Good retention is required to resist the displacing effect of the spring. Activation is by pulling the spring away from the acrylic at an angle of 45°
what is function of palatal finger springs
Palatal finger springs are often used in removable orthodontic appliances to tip teeth in a mesiodistal direction. There is general consensus that a force of 30-50 g is required to tip a single-rooted tooth, with an activation of about 3 mm for a spring with a load/deflection rate (LDR) of 15 g/mm.
what is the function of buccal canine retractors
Buccal Canine Retractor: The buccal canine retractor is used when the tooth must be moved palatally and distally. It is made of 0.7mm stainless steel wire to provide sufficient strength
screws can be embedded into the baseplate.
this can be activated by the patient turning a key, causing expansion or distalisation (gain space by moving posterior teeth distally)
how many ways can an active screw expand?
and for each quarter turn on the screw how much does it separate?
an active screw can expand x2 or x3 ways
each quarter turn increases the separation by 0.25mm
what is an adams clasp
An Adams clasp is a component used to retain a custom-made medical device in the mouth. The clasp functions by engaging the mesiobuccal and distobuccal undercuts of a tooth, typically the maxillary first molar
- Adams’ or Delta cribs – mainly used on
n molars and premolars
but can be incisors and canines. Cribs are less effective on
primary teeth- less undercut.
what type of hook is this
ball hook
adams clasp/crib engages undercuts at the mesial and distal corners of the edges, it should engage in how much of the undercut
1mm
what is newtons third law
for every action there is an equal and opposite reaction
what is anchorage
Anchorage in orthodontics is defined as a way of resisting movement of a tooth or number of teeth by using different techniques.
what is a URA
upper removeable appliance
what is a base plate
Acrylic base plate. The material most often used for base plate is cold cure or heat cure acrylic. It forms a major part of the removable appliance. Base plate acts as a support for pressure sources and distributes the reaction of these forces to the anchorage areas.
how does a base plate support anchorage
through palatal coverage
what must you do when fitting in a removeable appliance
- Check that the appliance is the correct one for the patient!
- Check acrylic for sharp edges (esp. in palatal rugae area)
- Fit appliance in patients mouth. Note any rocking, or areas that do not fit and
adjust if necessary - Tighten clasps and check retention
- Activate springs and check that teeth are free to move (trim acrylic if necessary)
what are aligners
Clear, removable plastic appliances which can produce small
tooth movements.
Treatment involves a series of aligners
who can provide aligners as treatment
Specialists and dentists who have sought appropriate training
and are competent to provide the treatment to a satisfactory
standard.
what is buccal capping
Buccal capping is prescribed when occlusal interferences need to be eliminated to allow tooth movement to be accomplished. Buccal capping is produced by carrying the acrylic over the occlusal surface of the buccal segment teeth and has the effect of propping the incisors apart.
WHY IS IT NECESSARY TO REDUCE THE OVERBITE
BEFORE REDUCING THE OVERJET?
As incisors tip, the lower incisors prevent further
overjet reduction due to increasing overbite
By incorporating an anterior bite plane, the overjet
can be successfully reduced without increasing the
overbite as the incisors tip palatally
what do bite opening allow for posterior teeth to do
posterior teeth erupt in space
what is the purpose of bite opening appliances
bite opening appliances allow for posterior occlusion to not take place, which in hand allows eruption
What type of movement does a removable appliance bring about?
tilting of teeth
What are the components of a removable appliance?
active component
retentive component
anchoring component
baseplate
Identify the instruments
adams pliers
Identify the instrument
spring forming pliers
name this clasp
southend clasp
what is the function of the southend clasp
It provides retention in the anterior region. The wire is adapted along the cervical margin of both the central incisors. The distal end of the wire crosses over the occlusal embrasures and end as retentive arms on the palatal side
name this clasp
plint clasp
These clasps are designed to engage the undercut interproximally. This design affords minimal retention and can have the effect of prising the teeth apart.
name the clasp and its function
ball-ended clasp
Ball clasps are typically used as auxiliary retention in conjunction with other clasps. They are usually placed tightly into the interproximal embrasure between two posterior teeth
what are the arrows pointing to on this adams clasp
bridge and arrowhead
what is the name of the part on a adams crib that is attached to the acrylic
fly-over
bending near the arrowhead does what?
moves arrowhead towards tooth
engages more retention
bending in the middle of the flyover does what
moves arrowhead down and towards tooth
what is the function of labial bow?
anterior retention
what is the function of an active labial bow
An active labial bow produces both horizontal and vertical force vectors resulting in palatal/lingual tooth movement and extrusion of tooth. It is used for retraction of proclined incisors. Since the labial bow causes tipping of the crown, simultaneous labial root tipping occurs.
what type of labial bow is this and what is its indication
short labial bow
contacts the most prominent labial surfaces of the anterior teeth and ends in two U-shaped loops that extend as retentive arm between the canine and premolars
indication:
closure of space mesial to canines
minor overjet reduction
retention
what type of labial bow is this and what is its indication?
long labial bow
modification to short labial bow
two U shaped loops extends between two premolars
indication:
minor overjet reduction
small amount of anterior space closure
closure of space distal to canine
guide of canine during canine retraction
what type of labial bow is this and what is its indication?
roberts retractor
indication:
patients having severe anterior proclination with overjet over 4mm
what is the function of this bite plane
lower incisors occlude on it - dicluding posterior teeth
useful when wanting to reduce overbite, as it causes eruption of molars
how can we resolve a overbite
place a biteblock on a removeable appliance, this will diclude the anteriors and posterior teeth, allowing for posteriors to erupt
what is buccal capping
buccal capping covers molars with PMMA from baseplate
-used when occlusal interferences would prevent desired tooth movement
-used when overbite reduction undesirable
how would you activate a Z spring
adjust from palatal spring first
then adjust labial spring
how much movement with a quarter turn on a screw
0.25 mm
how often would a patient turn on the screw of their removeable appliance
appliance is intended to move bucally
rapid expansion
turn screw 1/4 turn twice a weak
what are fixed appliances
brackets/bonds attached to the teeth
- Mainly used in permanent dentition but can be used in
interceptive treatment in the mixed dentition (sectional
appliances).
Control of the teeth in 3 planes of space.
fixed appliances controls tooth movement in three dimensions what are they
tipping
bodily movement
torque
what are the indications for fixed appliances?
Multiple tooth movements needed
* Rotations
*Bodily movement
*Space closure ( extractions or hypodontia)
* Lower arch treatment
what are the contraindications for fixed appliances
*Poor oral hygiene
*Active caries
*Poor motivation
*Good dietary control- avoid hard/sticky foods,
restrict sugars and acids
what are the risks of fixed appliance on teeth
decalcification
root resorption
loss of periodontal support
tmj dysfunction
failed treatment and relapse
reversible risks - pain, ulceration
what are molar band tube
Orthodontic tubes are also called molar tubes that are fitted around the back of your teeth when constructing a set of braces. It provides a solid anchor to the archwire used in orthodontics. Everyone did not need molar tubes, but those who need should take care to maintain their integrit
if there is no space for a molar band tube what can be used to create space?
seperators - the ones used in paeds for hall crown
Gold Chain, Eyelets and Buttons
why are they used
they have many functions.
primarilly to allign teeth
what are self ligatating braces
Self-ligating braces use a built-in mechanism in the bracket to hold the archwire in place. This is in contrast to traditional braces, which use elastic ties or metal wires to secure the archwire. People with self-ligating braces may have shorter orthodontist appointments, easier cleaning, and less discomfort
why would someone opt for ceramic braces than the traditional one
discretion
Ceramic braces, also known as clear braces, are orthodontic tools used to straighten teeth and fix bite problems. They consist of clear or tooth-colored ceramic brackets attached to the surface of your teeth with similarly colored wires and rubber bands, which provide more discretion.
Mesenchymal cells differentiate to
Osteoblasts
calcification
= BONE
Cartilage cells - undergo
Calcified matrix
Osteogenic invasion
= BONE
Area of condensation above ventral
part of developing mandible
Develops in cone shaped cartilage
Migrates inferior & fuses with
mandibular ramus
cone shaped cartilage replaced by
bone but upper end persists acting
as growth cartilage
development of maxilla involves remodeling - what is it
A process involving deposition and resorption occurring on
opposite ends
what are functional appliances
Functional appliances are removable braces that work on the upper and lower teeth at the same time. For example, with an appliance known as a Twin Block, when you bite together the blocks on the braces fit together in a certain way that encourages your jaws to grow or move into the correct biting position.
twin blocks are placed to fix which type of bite
class 2
would you perform orthognathic surgery on someone still going through the growth phase
no
what is the growth phase age for girls
8-13
what is the growth phase age for boys
10-15
a headgear restrains what type of growth
restrains maxillary growth
functional appliance stimulates what growth
mandibular growth
the use of a headgear/functional appliance is used on patients who have what type of class
class 2
what does a reverse headgear do?
stimulates maxillary growth
what does a chin cup do
restrain mandibular growth
what does a chin cup do
restrain mandibular growth
the use of reverse headgear and chin cup are targeted for the treatment of which malocclusion
class 3
headgears are best worn during which stage of development
pre-pubertal
headgear should be work preferentially how long
12-14 hours a day
compliance is important
the plastic blocks on the upper and lower portions can be used to control eruption of the teeth, but they also work as part of the functional appliance because they have these?
inclines
these inclines on the upper and lower block force the patient to advance the mandible
what is the definition for functional appliance
An appliance that utilises or redirects the
forces of the masticatory and / or the
circum-oral muscles to produce or permit
tooth movement and may modify facial
growth
how does the herbst functional appliance work
piston and tube device passively pushes mandible forward as patient bites
what is the second step in orthodontic treatment
Treatment planning is the second step in the
treatment of any patient; the first step being diagnosis
of the problem.
It involves planning space requirements, choice of
appliance and the retention regimen.
what is needed in the full diagnostic records
history and examination
study models
photographs
radiographs
what can you refer to when deciding if the patient needs treatment
clinical judgement
IOTN
what must the patient show if he wants treatment
motivation and cooperation
what can help you determine if this is the right time to begin orthodontic treatment
dental stage
growth
motivation
what can help you determine if this is the right time to begin orthodontic treatment
dental stage
growth
motivation
alternative source of space can be created through extractions, what non-extraction methods can be used
increased arch length
- distal movement posterior teeth
- anterior movement of incisors
increased arch width
interproximal reduction
how much space is required to indicate extractions?
0-4 mm space required = no extraction
4-8 mm space required = borderline
8+ mm space required = extractions
angle vs tweed
extraction vs non extraction
which tooth is the favourite choice of extractions and why
premolars
no aesthetic impact on smile
space near crowding
straightforwad extraction
molars provide good anchorage for appliances
what are the indications for extraction of the first premolars
when most space is required
When canines crowded
what are the indications for extraction of the 2nd premolars
- When less anterior crowding
– Allows molar to move forwards
what would be the indications for the extraction of first permanent molars
long treatment
when of poor quality - caries or large restorations
what are the indications to extract the lateral incisors regarding the upper canine
useful when canine is ectopic
paltallay or bucally
upper 4 in good position
no evidence that removal of third molars prevents
lower incisor crowding
definition of mixed dentition
Period from eruption of the first permanent molar until the shedding of the last deciduous tooth.
eruption of the first permanent tooth is at
6 years old.
what is the sequence of eruption of adult teeth in the mandibular arch
1st permanent molars & then front to back. i.e. 6, 1,2, 3, 4, 5, 7, 8.
what is the sequence of eruption of adult teeth in the maxillary arch
1st permanent molars & then front to back EXCEPT3’s. i.e. 6, 1, 2, 4, 5, 3, 7, 8
which arch erupts first
Lower teeth erupt BEFORE upper teeth EXCEPT 5’s
abnormalities in tooth formation regarding orthodontics include?
crown root dilaceration
supernumeraries
peg shaped incisors
hypodontia
what is crown root dilaceration
Trauma causes displacement of unerupted permanent crown and root formation continues in different direction
Can occur at any part of root
Usually, trauma in deciduous dentition
supernumary teeth can present as
exact copies of adjacent teeth - supplemental teeth
or
contain tooth material but dont look like teeth - conical or tuberculate supernumaries
supernumeray can occur anywhere most common in the
premaxilla
if suppernumary occur in maxillary midline they are called
mesiodens
peg shaped incisors
unkown aetiology
commonly affects lateral incisors
cause spacing and problems with aesthetics
increased risk of ectopic canines
what is hypodontia
congenital absence of one or more teeth
can be hereditary
most commonly affects upper 2’s and lower 5’s
spacing and aesthetics biggest problems
hypodontia
more common in the permanent dentition
presents with
delayed exfoliation of deciduous teeth
or
delayed eruption of permanent teeth
radiographs confirm diagnosis
Eruption cyst
Impactedteeth (deciduous and permanent)
Infra-occluded deciduous teeth
Retained deciduous teeth
Cross bites in the mixed dentition
these are examples of
abnormalities in eruption and exfoliation
what is this
Appear as blue mucosa overlying an unerupted tooth
Most common over E’s and 6’s
Asymptomatic
Resolve as tooth erupts
what is an impacted teeth
Deciduous or permanent teeth that fail to erupt fully
Can be partly erupted
impacted teeth are usually as a result of
an obstruction ( supernumerary)
Primary failure of eruption
Insufficient space
Ectopic teeth ( erupting/forming in wrong position)
Infra occluded and retained deciduous teeth
Infraoccluded deciduous teeth-
- Often incorrectly called submerging
- Usually due to ankylosis-adjacent teeth erupt and ankylosed teeth remain unchanged vertically- gives appearance of submerging
- Due to no permanent successor
- Idiopathic
when would you leave a infra occluded and retained decidious teeth
leave insitu if missing permanent successor
Avulsion of deciduous incisors can result in
a centre line shift in incisors
what can a fibrous mucosa do reference to eruption
a fibrous mucosa is allot more harder which can result in delayed eruption
intrusion of decidious incisors can cause deflection of permanent successor through?
crown root dilaceration
what is balancing extractions
if you take a tooth out on one side of arch may consider extracting the contra lateral tooth
c’s and d’s most likely to have an effect on a centre line shift
what is compensating extractions
If extract in one arch consider extracting the same tooth in the opposing arch
If extract a lower 6 can get over eruption of the upper 6 which can cause occlusal interference
what can cross bites cause
displacement-tooth and jaw
tooth wear
crossbites can be fixed with which URA
screw URA
at what age should the 1st permanent molars be extracted (caries/poor prognosis/MIH)
if you want 7’s to erupt well
optimum age 9-10
what are the complications of digit sucking
- Prolcined upper anteriors
- Retroclined lower incisors
- Buccal segment crossbites
- Reduced overbite or anterior open bite
WHAT CAN BE USED FOR THE MANAGEMENT digit sucking
Deterrent devices/habit breakers
* Elastoplast on finger
* Encouragement
* Nail varnish
what is the reason for the cause of this diastema
missing upper laterals
what is the reasons for the cause of this diastema
supernumaries - mesiodems
what is the management of median diastema
- radiograph to exclude pathology
- try and eliminate cause if possible
- likely to reduce as permanent teeth erupt
- less than 3mm rarely require Rx
- large diastema
- fixed appliances
- permanent retention
- fixed appliances
