Lecture 13 Flashcards
what the the 2 main causes of relapse after ortho treatment?
1-continued growth
2-tissue rebound
patients who have continued growth into malocclusion after completion of ortho tx need active retention in 1 of what 2 forms?
1-extraoral forces with retainers (headgear)
2-functional appliance
what fibers extend inter-proximally over the alveolar bone and are embedded in the cementum of adjacent teeth?
transeptal fibers
- form interdental ligament
- keep teeth in contact
what are the two ways to deal with rebound after ortho tx?
1-overtreatment
2-adjunctive perio surgery
how many mm of over treatment should be done for class II or III, and crossbite correction?
1-2 mm
*hold rotated teeth slightly over corrected for a few months
what are the 3 types of retainers given to patients after ortho?
1-hawley retainers
2-essix
3-bonded perm. retainers
what kind of bone is present when moving a tooth?
transitional
when moving a tooth, how long does it take for woven bone to mature to lamellar bone?
12 weeks
*3 month window where you MUST wear retainer full time
the rational for retainers is to allow time for PDL. How long does that take?
3-4 month
- wear your retainer 24/7
- part time for up to a year
In circumferential supracrestal fibrotomy you cut into the gingival sulcus down to the ____ of the _____
crest, alveolar bone
*interproximally labially and lingually (unless margins are thin)
Alternatively to CSF you can make and incision _____mm below hight of bone ______ and ______
1-2 mm, labially and lingually
*less chance of recession
T/F CSF or the papilla-dividing procedure should be done prior to ortho tx
FASLE. done after they have been aligned for several months
CSF is ineffective in what 3 circumstances?
1-irregular growth
2-disruption of envelope of stability
3-parafunctional habits
what is the primary indication for CSF?
severely rotated teeth
*most common on lateral incisors
what demographic is the fastest growing area in ortho?
older adults
adult tx is more difficult because there is no growth so treating jaw discrepancies must be done by what 2 things?
1-camouflage
2-sugery`
6 benefits for adult ortho
1-better access to clean 2-improve certain osseous defects 3-forced eruption to restore fracture 4-correct gingival embrasures 5-improve gingival margin esthetics 6-improve adjacent teeth for implants
3 goals of LIMITED adult ortho
1-improve perio health
2-establish favorable crown to root ratios
3-facilitate repositioning for things like implants
what are the 2 required steps for treatment planning limited adult ortho
1-diagnostic data
2-list of patient problems
*mounted casts, FMX
once all problems have been IDed what is the key treatment planning question for adult ortho?
is it necessary
when a perm. molar is lost and not replaced the 2nd molar drifts _____ and the premolars drift _______ and rotated into that space forming a ______
- mesially
- distally
- pseuopocket
T/F uprighting a tipped molar by distal crown movement leads to decreased space for pontic?
FALSE, increases space
uprighting the molar by mesial root movement does what to space needed for a prosthesis?
reduces it
- might eliminate the need for a prosthetic
- time consuming
if both 2nd and 3rd molar are tipped, should they both be uprighted?
probably not, moves 3rd into hard position to clean. extract
uprighting a tipped molar ________ the crown height while ______ depth of mesial pocket
increases, reduces
*crown reduction often necessary to improve crown to root ratio
how long should an uprighted molar be held in position?
2 months (simple) 6 months if grafts or osseous surgery occurred
7 benefits of uprighting a molar
1-improves distribution of occlusal forces
2-decreases reshaping needed if an implant is placed adjacently
3-decreases potential for endo, pros, or perio
4-longer durability of restoration
5-improves perio environment (no psudopocket)
6-improves alveolar bone contour
7-better crown to root ratio
what are the 8 guidelines in interdisciplinary treatment?
1-realistic objectives 2- diagnostic set up 3-treatment sequence 4-stabilize/correct active disease 5-position teeth to facilitate restorative tx 6-evaluate gingival esthetics 7-radiographs 8-all members interact when finishing
what # of wall defects are best treated with perio surgery, w/ or w/o braces?
2 wall perio defect
T/F three wall defects are not resolvable with ortho
TRUE
- best fixed with bone grafts
- ortho can be done 6months later if desired
what # of wall defects are best treated with ortho?
1 wall defects
when placing an ortho bracket on an adult it is NOT determined by the _______ of the tooth, but by the interproximal ____________
anatomy, bone level
- bone should be leveled by ortho
- perio recall 2-3 months during tx
T/F aligning teeth by the crowns my perpetuate tooth mobility if the teeth have an unfavorable crown to root ratio due to recession
true
*place brackets using bone level
what are the most difficult lesions to maintain during ortho?
furcations
*2-3 mo recall
when trying to move a tooth with a class 3 furcation via ortho, what can you do to the tooth?
hemi-section the crown
- requires endo, perio, and restorative procedures
- move 1st, hemisect 2nd
long term incisal wear with subsequent over eruption results in what 2 things?
1-short clinical crowns
2- disproportionate marginal gingiva
what 2 things can be done to correct long term incisal wear?
1-crown lengthening
2- ortho intrusion
T/F ortho intrusion is more conservative than crown lengthening for patients with long term incisal wear?
true!
*limits restored area to enamel only (veneer)
T/F it is appropriate for a dentist to request the ortho increase the pts vertical when there are worn down teeth
FALSE
*teeth usually undergo compensatory eruption keeping vertical the same
what 3 things can ortho do for worn down teeth?
1-create restorative space
2-move gingival margins apically
3- eliminate the need for further tooth reduction
T/F patients with severe attrition of mandibular anteriors may have insufficient crown length to place bracket or ferrule for crown
true
- need 1.5mm ferrule
- perio crown lengthening is useful here
what is the first step to provide restorative space in the pt with deep overbite?
correct occlusal plane
how do you identify the correct vertical plane?
contact between 2nd mand and max molar and level of upper lip anteriorly
what are some of the downsides of using crowns rather than ortho to straighten teeth?
esthetics, gingival height, bone height, perio pockets, possible RCT, plaque traps, buccal lingual width, occlusal force direction
sometimes black triangles appear after ortho if teeth are themselves triangularly shaped. What can you do?
recontour the teeth mesial/distally
T/F ortho forced eruption can be used when a tooth fracture extends below gingival margin and terminates at alveolar ridge
true
*without forced eruption restoration may violate biological width
during slow extrusion what 2 things normally follow the tooth?
bone and gingival tissues
what is a disadvantage of slow eruption?
crown lengthening may be necessary to recontour the gingiva and bone
what are the 6 criteria to determine if extraction or forced eruption is called for?
1-crown to root ratio 2-root form 3-level of fracture 4-relative importance of the tooth 5-esthetics 6-endo/perio prognosis
If a fracture extends to the level of the bone, how many mm must the tooth be forcibly extruded?
4mm
- 2.5 to clean biologic width
- 1.5 for crown ferrule
considering root form for forced eruption what should the root and canal shape be?
root: broad and not tapered
canal: not more than 1/3 of overall width
T/F if a tooth if fractured 2-3mm apical to alveolar bone it is nearly impossible to attach the root to erupt it
true
T/F ortho extrusion can be used to increase vertical bone height and volume prior to implant placement PLUS assist in preservation of the interdental papilla
true
what are the three disadvantages of forced ortho eruption?
1-wearing ortho
2-duration of tx
3-possible need for perio surgery
