Lecture 16 Flashcards
adult orthodontic treatment falls into what two groups?
- younger adults from 20-30 who desired but did not receive comprehensive orthodontic treatment as youths
- older individuals who have other dental problems and need orthodontics as part of a larger treatment plan
T or F:
treatment for older adults has been the fastest growting area in orthodontics during the last decade
true
why is adult orthodontic treatment more difficult than on children?
due to the absence of growth, which means that growth modification to treat jaw discrepencies is not possible, which leaves only camouflage or surgical options
adult orthodontic treatment is often carried out to facilitate other dental procedures, which are necessary for what 3 things?
- control disease
- restore function
- and/or enhance appearance
sometimes adult orthodontics will only involve part of the dentition, with the primary goal of making it easier or more effective to ___
replace missing or damaged teeth
limited adult orthodontic treatment can involve what 3 procedures?
- repositioning teeth that have drifted after extractions or bone loss
- alignemtn of anterior teeth to allow more esthetic restorations
- forced eruption of badly broken down teeth to expose sound root structure
what should the 3 main goals of limited adult orthodontic treatment be?
- improve periodontal health
- establish favorable crown-root ratios and position the teeth so that occlusal forces are transmitted along the long axes of the teeth
- facilitate restorative treatment (implants, optimal esthetics, etc.)
planning limited adult treatment requires what two steps?
- collecting an adequate diagnostic database
- developing a comprehensive but clearly stated list of the patients problems
planning limited adult treatment cannot be overemphasized since the solution to the patients specific problems involve the synthesis of ___
many branches of dentistry
along with the standard orthodontic records, an adults orthodontic records should also include ___, which typically are not included in younger healthier patients, and are important to identify ___ and ___
- a full set of full mouth xrays
- bone height and periodontal health
in addition to full mouth xrays, an adults orthodontic records should include ___ because they facilitate planning of associated restorative procedures
articulator-mounted casts
can we move teeth that have had endodontic treatment?
since the response of the PDL (not the pulp) is the key element in tooth movement, movement of endodontically treated teeth is possible
would you expect damage to the root apex when moving endodontically treated teeth because these teeth are no longer vital?
severe root resorption is not typically seen and should not be expected as a consequence of moving non-vital teeth
T or F:
moving teeth that have received RCT or previous trauma is not a concern, as orthodontics typically does not aggravate pre-existing conditions
false
pre-existing conditions can flare up during orthodontic treatment, so patients should always be informed that teeth with pulpal problems may develop further problems in the affected teeth
what are the guidelines for orthodontically moving a traumatically intruded tooth?
if a tooth has been non-vitalized by intrusive trauma and required pulp therapy, and if the tooth is to be orthodntically extruded, then root resorption is less likely if a calcium hydroxide fill is maintained until the tooth movement is complete and then the root canal filling is placed
treatment time is dependant on what two things?
the severity of the problem and the amount of tooth movement desired
once all of the problems have been identified and categorized, the key treatment planning question is ___
- will orthodontic treatment be necessary
- it is also important to consider the difference between realistic and idealistic treatment planning
when a first permanent molar is lost and is not replaced, the second molar typically drifts mesially and the premolars often tip distally and rotate into the space between them. what issue can this cause?
- as the teeth move, the adjacent gingival tisue becomes folded and distorted, forming a plaque-harboring pseudopocket that may be virtually impossible for the patient to clean
- repositioning the teeth eliminates this potentially pathologic condition and has the added advantage of simplifying the ultimate restorative procedures
it is important to note that uprighting a tipped molar increases ___, while it reduces ___
- crown height
- the depth of the mesial pocket
what is one of the most significant complications of molar uprighting and why?
- a patient developing a high mandibular plane angle
- it can lead to an increased open bite and loss of anterior guidance
after molar uprighting, subsequent ___ decreases occlusal interference and also improves the crown to root ratio of the molar
crown reduction
how long does a molar need to be orthodontically held in place before restorative procedures can be performed?
- an uprighted molar should be held in the correct position to allow the lamina dura and PDL to reorganize for 2 months for simple uprighting
- an uprighting molar should be held in the correct position for 6 months if uprighting plus osseous surgery, grafts have been performed
what are the two different ways to upright a molar, and what are the advantages of each?
- uprighting by distal crown movement leads to increased space for a bridge pontic or implant
- uprighting by mesial root movement reduces space and might eliminate the need for a prosthesis
which is the more difficult way to upright a molar (distal crown movement vs mesial root movement)?
- mesial root movement
- it can be very time consuming to accomplish, especially if the alveolar bone has resorbed in the area where the first molar was extracted and cortical bone has filled into the extraction site
if a third molar is present, should both the second and third molars be uprighted?
- for many patients, distal positioning of the third molar would move it into a position in which good hygiene could not be maintained or it would not be in functional occlusion
- in these circumstances, it is more appropriate to extract the third molar and simply upright the remaining second molar
if there is slow progress of the movement during molar uprighting, it is most likely due to a ___ that is disrupting the molars movement
occlusal interference
if both second and third molars are to be uprighted, a significant change in ___ is required and treatment time will also increase
technique
T or F:
normal angulation of a molar improves the direction and distribution of occlusal forces
true
T or F:
normal angulation of a molar increases the amount of tooth reduction required for parallelism of the abutments for a bridge
false
it decreases the amount
T or F:
normal angulation of a molar decreases the possibility of endodontic, periodontic, or more complex prosthodontic procedures
true
T or F:
normal angulation of a molar compromises the durability of restorations, due to inadequate force distribution
false
it increases the durability of the restorations, due to better force distribution
normal angulation of a molar improves the periodontal environment by eliminating ___
plaque-retentive areas
normal angulation of a molar improves ___ contour and ___ ratio
alveolar bone contour and crown to root ratio
there has been a heightened trend towards ___ in the general public, which has challenged dentistry to look at ___ in a more organized and systematic manner
- esthetics
- dental esthetics
patient treatment is superior when ___ work together to achieve a common goal and to begin with the end in mind
all the different fields of dentistry
interdisciplinary dental treatment requires good communication, and questions my be andswered and agreed upon to obtain optimum ___ and ___ for the patient
dental health and esthetics
what are the 8 guidelines that the dental team should follow when planning interdisciplinary treatment?
- realistic objectives
- create a diagnostic setup
- determine the sequence of treatment
- stabilize/correct any active disease
- position teeth to facilitate restorative treatment
- evaluate gingival esthetics
- take progress radiographs
- all members interact during finishing
two wall periodontal defects are best treated with periodontal surgery with or without adjunctive orthodontics. what case requires orthodontics?
- when two walls are remaining in an interproximal region and the patient cannot maintain the area, it is difficult for a periodontist to completely resolve the defect with resective or regenerative treatment
- these defects often require orthodontic eruption of the affected tooth, followed by crown lengthening to improve the restorability of the tooth
T or F:
one, two, and three wall defects are resolvable with orthodontics
false
three wall defects are not resolvable with orthodontics, and are instead generally treated with regenerative therapy using either autogenous or alloplastic bone grafts in the affected area
orthodontic treatment can begin how long after 3-wall defects have been treated with regenerative therapy?
6 months after placement of the bone graft and the area has been shown to be stable
___-wall defects are the type which are treated most efficiently with orthodontics
one
why are one-wall defects difficult for periodontists to manage? what can eliminate these defects?
- resective surgery could be too destructive, and regenerative therapy is inappropriate
- orthodontic eruption of the tooth can eliminate these defects
when orthodontic brackets are placed on an adult patient, the decision as to where to place these brackets or bands is not determined by the anatomy of the tooth, but rather by the ___
interproximal bone level
if the bone level is flat between adjacent teeth and the marginal ridges are at significantly different levels, correction of the marginal ridge discrepancy orthodontically produces a ___ defect in the bone, which could cause ___
- hemiseptal
- this could cause a periodontal pocket between the two teeth
what method produces the best occlusal results and improves periodontal health in patients with inadequate interproximal bone levels?
- the bone should be leveled orthodontically and any remaining discrepancies between the marginal ridges should be equilibrated
- patients should be seen every 2-3 months by their dentist or periodontist during the leveling process to control inflammation in the interproximal region
in a patient with advanced horizontal bone loss, the bone level may have receded several millimeters from the CEJ. as this occurs, the ___ becomes less favorable
- crown to root ratio
- by aligning the crowns of the teeth, the clinician may perpetuate tooth mobility by maintaining an unfavorable crown to root ratio
what problems can occur when aligning the crowns of teeth, disregarding the bone level? how can these problems be corrected?
- significant bone discrepancies occur between healthy and periodontally diseased roots, which could require periodontal surgery
- many of these problems can be corrected by using the bone level as a guide to position the brackets on the teeth
- in these situations, the crowns of the teeth may require considerable equilibration, but bone health, periodontal health, and crown to root ratios will all be improved and the patient may not require periodontal surgery
___ lesions require special consideration because they are the most difficult lesions to maintain and can worsen during orthodontic therapy
furcation
all patients with furcation lesions are to be maintained on a ___ month periodontal recall schedule and monitored very closely
2-3 month
furcation defects are typically divided into what 3 classifications?
- class I - very shallow and do not enter the furcation deeply; these are typically just observed and monitored during orthodontic treatment
- class II - extend into the furcation but does not completely go through
- class III - lesion goes completely through the furcation
a patient with a class III furaction can be treated by eliminating the furaction by doing what?
- hemisecting the crown and roots of the tooth (works well for mandibular molars) but this procedure reqruies endodontic, periodontial, and restorative procedures
- if a patient is to be undergoing orthodontic treatment, the tooth is moved first and then the tooth is hemisected after treatment is complete
- this treatment is an option that should be considered in special circumstances, but implants may be a better alternative to hemisecting treatment
long term incisal wear with subsequent overeruption results in ___ and ___
short clinical crowns and disproportionate marginal gingiva
assuming that the bony attachment follows the tooth during the eruptive process, there are two ways for clinicians to address the esthetic concerns associated with long term incisal wear with subsequent overeruption. what are they?
- crown lengthening
- orthodontic intrusion
___ exposes cementum and subsequently requires a more invasive, full coverage restoration
crown lengthening
___ provides the potential benefit of limiting the restored area to enamel and often results in a more conservative bonded veneer restoration
orthodontic intrusion
orthodontic intrusion is beneficial restoratively only if ___, which is what happens in the absence of disease
if the bone level and gingival margin follows the tooth as it moves apically
often when a patient with overerupted, worn down teeth is referred to the orthodontist, the restorative dentist requests that the orthodontist does what?
opens the patients vertical dimension
T or F:
although some clinicians believe that patients with anterior tooth wear are “overclosed” and need to have their vertical dimensions increased, this diagnosis and the resulting treatment plan are usually inappropriate
true
in patients with overerupted, worn down teeth, the problem is typically ___ secondary to ___
compensatory eruption of the anterior teeth secondary to incisal wear
in patients with overerupted, worn down teeth, the problem for restorative dentists is that there is insufficient space to restore these teeth without further ___, ___, and/or ___
- tooth reduction
- crown lengthening
- root canal treatment
in addition to restorative dentistry to correct overerupted, worn down teeth, an orthodontist can do what? what does this allow?
- intrude the maxillary and/or mandibular incisors
- this creates restorative space, moves the gingival margins apically, and eliminates the need for further tooth reduction
in patients with severe attrition of the mandibular anterior teeth, there may be insufficient crown length either to ___ or to ___
place an orthodontic bracket or to permit adequate ferrule for tooth preparation
in severe attrition cases, ___ and ___ prior to orthodontic intrusion may be appropriate
- periodontal surgery and crown lengthening
- if there is not 1.5mm of ferrule, then crown lengthening surgery should be performed first to establish adequate ferrule, then the teeth should be intruded orthodontically to create the correct vertical position prior to restoration
- this will provide access to bond orthodontic brackets to intrude the teeth
when determining how to provide restorative space in the patient with a deep anterior overbite, the first step is to determine the patients ___
correct occlusal plane
how do you establish the patients correct occlusal plane?
identify the occlusal contact point between the maxillary and mandibular second moalrs posteriorly and the level of the patients upper lip at rest anteriorly; these reference points are points that cannot be changed but that are important to stability and esthetics
T or F:
opening the vertical dimension by extruding maxillary and/or mandibular molars is stable in adults
false
they are not stable in adults since adults are not growing
although opening an adults vertical dimension is not an ideal form of treatment, sometimes it is appropriate to do so. special care must be taken so that when the patients vertical dimension is opened, there is not an impingement on the patients ___, which is typically ___mm
freeway space, which is typically 2-4mm
if the treatment plan involves opening the patients vertical dimension, every tooth will need to be crowned/restored, so ___ should be evaluated
- crown to root ratios
- these patients are best treated by a prosthodontist and these cases should be referred out
what is an appropriate esthetic treatment option for a patient with triangular shaped central incisors that produce and open gingival embrasure after orthodontic treatment (assuming the roots of the central incisors are parallel to each other)?
- recontour the mesial surfaces of the central incisors though interproximal stripping
- this creates a diastema
- as the diastema is closed, the tooth contact moves gingivally and the papilla move incisally, elimating the diastema
if a patient severely fractures the crown of their tooth, the general practitioner must evaluate if the toth can be restored or if the tooth must be extracted. ___ should always be considered in these situations as possible treatment, to aid in the restoration of these teeth.
orthodontic forced eruption
without orthodontic forced eruption, what might happen to a tooth with a severely fractured crown?
- extraction
- periodontal crown lengthening, which often results in long unaesthetic teeth with visible restorative margins
if a patient accidentally injures their anterior teeth, and if the damage is minor with small fractures of the enamel, these can be restored with ___ or ___
light cured composite or veneers
what are the consequences if a patient accidentally injures their anterior teeth and the fractures extends beneath the level of the gingival margin and terminate at the level of the alveolar ridge?
- restoration of the fractured crown is impossible because the tooth preparation would extend to the level of the bone
- this overextension of the crown margin could result in an invasion of the biologic width of the tooth and cause persistent inflammation of the marginal gingiva
what treatment should be done if a patient accidentally injures their anterior teeth and the fractures extends beneath the level of the gingival margin and terminate at the level of the alveolar ridge
- erupt the fractured root out of the bone and move the fracture margin coronally so that it can be properly restored
- if the fracture extends too far apically, it may be better to extract the tooth
during slow extrusion, in the normal cours of tooth movement, bone and gingival tissues follow the eruption of the tooth under ___ forces
low-intensity extrusive forces
in rapid extrusion, when stronger traction forces are exerted, coronal migration of the tissues supporting the tooth is less pronounced because ___
the rapid movement exceeds their capacity for physiologic adaptation (like controlled extraction of the tooth)
rapid extrusion is associated with what risk?
- the periodontal ligament will be torn and tooth ankylosis may occur
- rapid extrusion can also place high intrusive forces on the adjacent teeth which could result in root resorption
what is the disadvantage of slow eruption?
it may require a periodontal crown lengthening procedure to recontour the gingiva and bone once the orthodontic eruption is complete
what are the 6 criteria for determining whether a tooth should be forcibly erupted or extracted?
- root length
- root form
- level of fracture
- relative importance of the tooth
- esthetics
- endo/perio prognosis
in determining whether a tooth should be forcibly erupted or extracted, what are the root length considerations?
- the root should be long enough so that a 1:1 crown to root ratio will be preserved after eruption
- if the fracture extends to the level of the bone, the tooth must be erupted 4mm
if a fracture extends to the level of the bone, the tooth must be erupted 4mm. what is accounted for in this 4mm?
the first 2.5mm moves the fracture margin far enough away from the bone for biologic width, and the other 1.5mm allows for the proper amount of tooth to accommodate the ferrule rule
___ is the height between the deepest point of the gingival sulcus and the alveolar bone crest, typically ___mm
- biologic width
- 2.5mm
invasion of the biologic width for additional restorative retention will cause ___ with a premature loss of the restoration
iatrogenic periodontal disease
when a restoration margin is placed too far below the gingival tissue crest, it will impinge on the gingival attachment apparatus and a ___ is created and made worse by the patients inability to clean this area
contstant inflammation
T or F:
when determining if forced eruption is a viable treatment option, the root form should be narrow and tapered
false
- the root should be broad and non tapering
- a root with signficant taper could compromise esthetics
when determining if forced eruption is a viable treatment option, what are the internal root form considerations?
- the root canal should not be more than 1/3 the overall width of the root
- if the root canal is wide, the distance between the external root surface and the root canal filling will be narrow, which may cause the walls of the crown preparation to be too thin
when determining if forced eruption is a viable treatment option, with respect to level of fracture, if the entire crown is fractured ___mm apical to the level of the alveolar bone, it is difficult, if not impossible to attach to the root to erupt it
2-3mm
when determining if forced eruption is a viable treatment option, with respect to esthetics, if the patient has a ___, then any type of restoration in this area will be more obvious
- a high lip line and displays 2-3mm of gingiva when smiling
- in this situation, keeping the patients own tooth would be much more esthetic than any type of implant or prosthetic replacement
when determining if forced eruption is a viable treatment option, if the tooth has a significant periodontal defect, or cannot be treated endodontically, it may not be possible to ___
retain the tooth
one of the most important factors in the successful placement of endosseous implants is the presence of ___
adequate alveolar bone at the recipient site
___ associated with destructive periodontal disease frequently results in osseous defects that may complicate subsequent implant placement
alveolar bone loss
typically, osseous defects resulting from peridontal disease are treated prior to, or at the time of, implant surgery using the principles of ___
- guided bone regeneration
- under certain circumstances, such defects may be managed nonsurgically by orthodontic extrusion
how can orthodontic extrusion be used to manage osseous defects?
it can be used to increase the vertical bone height and volume prior to implant placement and may also assist in the preservation of the interdental papillae and can further enhance gingival esthetics
what are the disadvantages of forced orthodontic eruption?
- wearing an orthodontic device amy cause esthetic problems and may adversely affect oral hygiene
- duration of treatment
- conservative periodontal surgery may be necessary at the end of the procedure
