Lecture 8 Flashcards
___ is credited as the first person to use an appliance to straighten teeth. what year was this?
pierre fauchard in 1728
what was the design of the appliance that fauchard first used to straighten teeth? what type of movement did it produce?
- it was an arch shaped metal band with holes drilled in preselected sites, with strings to pull the teeth into alignment
- like a hawley retainer, this device only created tipping movements of teeth
who is edward angle?
- he became the first acknowledged exclusive specialist in orthodontics in the world in 1892
- he developed angles classification of occlusion
- he developed the angle school of orthodontics and formally established orthodontics as the first specialty in dentistry
angle coined the term ___ to refer to abnormalities of tooth position, and classified various abnormalities of the teeth and jaws
malocclusion
what was angles first book?
treatment of malocclusion of the teeth and fractures of the maxillae: angle’s system
what is the angles classification that is still used today?
- angle class I
- angle class II
- angle class III
in 1910, angle developed the ___ and ___ appliance. what was it?
- pin and tube appliance
- it had gold and platinum bands and attachments for most of the teeth
was angle’s pin and tube appliance easy to use? why or why not?
- it was very difficult to use and had many disadvantages
- the appliance required adjustments every few days to position the pins during treatment
- the appliance also wasn’t capable of controlling tooth rotations
the ___ bracket developed slowly, and angle went through many different types of bracket designs from 1915-1932 until he finally developed the ___ bracket
- edgwise
- twin
what was the edgewise appliance?
- all modern orthodontics are based on this appliance
- it had identical brackets for all the teeth and tooth movements were accomplished by placing necessary bends in rectangular archwires to position all the teeth
what are some of the different types of edgewise brackets to choose from?
- self-ligating
- ceramic
- plastic
- metal
- single wing
- twin
what are the two different slot size dimensions to choose from for edgewise brackets?
- 0.22 inch (0.55mm)
- 0.018 inch (0.45mm)
the ___ is the most common and widely used system today and incorporates a rectangular arch wire, which fits into a rectangular slot in the bracket
edgewise appliance system
what are the different prescriptions that each edgewise orthodontic bracket comes with?
torque, angulation, and offset
what is the theory behind the edgewise straight wire system?
through a prescription in the orthodontic bracket, you can place a straight rectangular wire in the brace, which then will place all the proper tips, torques, in and outs, and angulations on all the teeth
T or F:
the buccal surfaces of the maxillary incisors are aligned, and the lingual surfaces of the mandibular incisors are aligned
- false
- you want to align the surfaces of the teeth that will be occluding
- so the lingual of the maxillary incisors and canines should be aligned, and the buccal of the mandibular incisors and canines should be aligned
in practice, the edgewise straight wire system does a good job of doing what?
getting the teeth in the “ball park”
using the edgewise straight wire system, due to individual variation in teeth, ___ typically need to be placed in the archwires to finish orthodontic cases
positioning bends
the most popular self-ligating bracket is the ___ bracket
damon
what are some of the claims made about damon brackets?
- shorter treatment times (6 months shorter treatment time because patients don’t have to have as many orthodontic visits)
- less painful treatment (greater comfort throughout treatment, lighter forces to move teeth)
- won’t have to extract teeth (damon brackets produce a broader, natural smile and a nicer profile)
- eliminates the need for rapid palatal expansion and head gear
adherence to the tenets of evidence-based orthodontic practice requires that, for any orthodontic intervention applied to a patient, what 3 factors must be integrated?
- the relevant scientific evidence
- the clinician’s expertise
- the patient’s needs and preferences
___ are types of literature reviews that collect and critically analyze multiple research studies or papers
systematic reviews
___ are studies in which people are allocated at random to receive one of several clinical interventions
randomized controlled trials
___ studies typically observe large groups of individuals, recording their exposure to certain risk factors to find clues as to the possible causes of disease
cohort studies
___ are studies that compare patients who have a disease or outcome of interest with patients who do not have the disease or outcome
case-control studies
___ and ___ are detailed reports of symptoms, signs, diagnoses, treatment, and follow-up of an individual patient
case series and case reports
___ and ___ are beliefs or judgements about something given by an expert on the subject
editorials and expert opinions
what is the hierarchy of scientific evidence, from the top of the pyramid to the bottom, and which areas include most of dental research?
- systematic reviews
- randomized controlled trials
- cohort studies
- case-control studies (used in dental research)
- case series, case reports (used in dental research)
- editorials, expert opinions (used in dental research)
regarding maxillary expansion, does lateral expansion of the dental arch by self-ligating brackets “grow” buccal alveolar bone?
- this claim is weakly supported by low-level evidence that has not been independently confirmed
- currently, no peer-reviewed scientific evidence supports this claim
regarding maxillary expansion, is lateral expansion of the dental arch by self-ligating bracket systems comparable with lateral expansion gained by rapid maxillary expansion followed by conventional edgewise treatment?
- this claim is weakly supported by low-level evidence that has not been independently confirmed
- currently, no peer-reviewed scientific evidence supports this claim
regarding maxillary expansion, is lateral expansion of the dental arch gained by self-ligating bracket systems stable in the long term?
- this claim is weakly supported by low-level evidence that has not been independently confirmed
- currently, no peer-reviewed scientific evidence that lateral expansion of the dental arch with a self-ligating bracket system has long-term stability
are self-ligating bracket systems more efficient and more effective than conventional edgewise brackets systems in treating malocclusions?
- current evidence does not support the assertion that self-ligating bracket systems are more efficient or more effective in treating malocclusions
- current evidence does not indicate differences between self-ligating systems and conventional systems for treatment time, rate of alignment, rate of space closure, final arch dimensions, or occlusal outcomes.
- data from a few studies do indicate that chair time is, on average, 20 seconds less per arch, and final mandibular incisor inclination is, on average, 1.5° less for self-ligating bracket systems
do self-ligating bracket systems provide less friction between archwire and bracket?
- the evidence for less friction between archwire and self-ligating brackets presently comes from results found under specific laboratory conditions, which do not fully emulate a clinical setting
- in-depth understanding of friction between bracket and archwire in vivo, and its relationship to tooth movement, remains uncertain
- the difference between static friction and sliding friction needs to be considered in studies
do self-ligating bracket systems provide lower clinical forces compared with conventional brackets?
- at present, no studies have measured the forces in vivo to answer this question
- two in-vitro studies suggest that initial forces on buccally or lingually displaced teeth might be greater in self-ligating systems compared with conventional brackets
do patients treated with self-ligating bracket systems experience less pain during treatment?
-at this time, there is insufficient data that compare self-ligating bracket systems and conventional bracket systems with regard to the pain experienced by patients during orthodontic treatment
are conventional edgewise brackets less hygienic than self-ligating brackets?
-evidence does not support the claim that conventional edgewise brackets are less hygienic than self-ligating brackets
T or F:
sliding friction is higher than static friction
- false
- static friction is higher than sliding friction
the ___ bracket system has a narrow slot where an archwire is loosely fitted and held in place with a locking pin and only round wires are used
begg bracket system
___ orthodontic treatment is an alternative for patients who don’t want to show their braces in their mouth
lingual ortho treatment
what are the advantages of lingual braces?
improved esthetics is the only advantage
what are the disadvantages of lingual braces?
- increased cost
- difficult to work with
- all wires must be bent around the different sizes of the teeth to position them
- do not have direct vision of the braces when doing adjustments
- very technique sensitive
- patients could experience tongue discomfort and speech difficulties
- occlusal interferences
what are the steps to bonding brackets?
- prophy the tooth surface
- etch the surface using 37% phosphoric acid for 30 seconds then rinse with water
- seal/prime tooth surface
- spatula bonding cement into the wire mesh on the base of the bracket
- place the bracket on the tooth and light cure for 20-30 seconds
how are bands placed?
- prophy tooth surface
- apply glass ionomer cement to the interior of the bands
- cement in place
what are the indication for using bands instead of bonded brackets?
- to provide better anchorage
- for teeth that will need both lingual and labial attachments
- teeth with short clinical crowns
- tooth surfaces that are incompatible with successful bonding
what are the two types of orthodontic bands?
- plain (no bracket)
- with bracket
___ bonding is the placement of brackets directly on the patients teeth, and ___ bonding is the fabrication of a splint on a model which contains the brackets
- direct
- indirect
what are the advantages of direct bonding?
- don’t have to fabricate a bonding splint
- don’t have errors in splint placement
- can directly clean off excess adhesive before cure
what are the disadvantages of direct bonding?
- longer chair time/doctor time
- can be difficult to place some brackets
what are the advantages of indirect bonding?
- placement of all the brackets all at once
- reduced chair time
- more precise location of brackets, especially lingual appliances
- can control thickness of resin between the tooth and the bracket interface
- can be delegated to staff
what are the disadvantages of indirect bonding?
- very technique sensitive
- clean up of excessive adhesive can be difficult
what is invisalign?
- created as an alternative to braces
- uses a series of clear aligners that patients swap out every two weeks to align their teeth
how does invisalign work?
- PVS impression, treatment plan, patient pictures and x-rays are submitted to invisalign
- patient’s treatment is finalized using Align software
- receive trays from invisalign
- bond attachments
- interproximal stripping
- begin treatment
- patient’s swap out new trays every 2-3 weeks until treatment is complete
what are the pros of invisalign?
- patient doesn’t have to wear braces
- improved esthetics
what are the cons of invisalign?
- patient compliance is critical
- trays have a difficult time “grabbing” the teeth even with the attachments, causing errors in the final result
- patient must occlude on the invisalign trays throughout treatment, and posterior open bites are often seen
- poor modalities to place inter-arch forces on the teeth
- patients often require limited orthodontic treatment at their completion of invisalign to correct mistakes
in a study conducted on the efficacy of tooth movement using invisalign, the mean accuracy of tooth movement was ___%. the most accurate movement was ___. the least accurate movement was ___, specifically ___.
- 41%
- lingual constriction (47.1%)
- extrusion (29.6%)
- mesiodistal tipping of the mandibular canines (26.9%)
according to a study comparing invisalign with traditional orthodontic brackets, which group finished treatment sooner?
- on average, invisalign patients finished 4 months sooner than those with fixed appliances
- however, invisalign did not treat malocclusions as well as braces
what cases are best treated with invisalign?
- a very compliant patient
- adults (not teenagers) with a class I molar and canine relationship
- 2-4mm of crowding or 2-4mm of spacing
- patients without rotations
- patients where intrusive and extrisive movements are minimal
what is six month smiles?
- “braces in a box” kit provided to general dentists with all of the parts included
- dentist pays a fee and attends a 2-day seminar to become a provider
- at the “braces on” appointment, the brackets are placed using mouthpieces provided by the company and the wires are installed
how does the cost of six month smiles compare to traditional braces?
it is generally less expensive but cost varies depending on specific treatment goals and location
what is the smile care club?
- uses dental professionals to oversee a patients treatment
- patient takes pictures of their teeth and impressions of themselves, and the smile care club, with the input of the overseeing doctor, provide a treatment plan for the patient without ever seeing the patient
- a series of aligners are made and sent to the patient who switches them out, much like invisalign, until they have a “perfectly straight smile”
what are “do it yourself” braces aimed towards?
- the market of budget-conscious individuals who have always wanted the benefits of orthodontic treatment but for some reason never received treatment
- also overseas, braces are looked at as a status symbol, and many youth will place the braces themselves to impress others
what can happen if people try to use elastics and tied floss to close spaces between teeth?
- the elastics used to close the space slide down the lateral aspects of the teeth to the cervical margin
- a patient that wear the elastic overnight can wake up and no longer see the elastic because it has become submerged below the gingival margin
- if the elastic is not removed, it will continue to move apically, destroying the gingival attachment and bone, causing the teeth to fall out
