Biomechanics, Techniques and Appliances 25% 16Q Flashcards by Beatriz Tejera

How many grams of force do you need to intrude a maxillary central?

25g

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How many grams of force do you need to intrude a maxillary central + lateral?

50g

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How many grams of force do you need to intrude a maxillary central + lateral + canine?

100g

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How many grams of force do you need to intrude a maxillary canine?

50g

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How many grams of force do you need to intrude a mandibular central + lateral?

40g

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How many grams of force do you need to intrude a maxillary central?

20g

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How many grams of force do you need to intrude a maxillary central + lateral + canine?

80g

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How many grams of force do you need to intrude a maxillary canine?

40g

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Moment = ________ x _________

moment = foce x distance

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tendency for force to produce rotation

moment

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what is created when a line of force does not go through the of resistance?

a moment

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A higher moment to force ratio produces more ( crown / root ) movement than ( crown / root ) movement

`root

crown

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What are placed in areas of largest bending movement so it can create the most gentle force

helices

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parallel forces in opposite direction

couple

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___________ movements require a force and a moment

bodily

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what movement is created when M_c/M_F = 0

Pure tipping or uncontrolled tipping

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what movement is created when 0 < M_c/M_F < 1 ?

Controlled tipping

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what movement is created when M_c/M_F = 1 ?

bodily movement

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what movement is created when M_c/M_F > 1 ?

torque

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the center of rotation of a tooth is approximately

⅓ down the root in bone

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the center of resistance of a tooth is approximately

the midpoint of the root

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which appliance can create controlled incisor tipping with CR at the apex

lip bumper

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force requirement (in g) for intrusion

15-25g

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force requirement (in g) for tipping, rotation and extrusion?

50-75k

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force requirement (in g) for translation?

100-125g

force requirement (in g) for canine retraction?

100-150g

a 0:1 - 5:1 moment to force ratio will produce which type of tooth movement?

uncontrolled tipping

a 7:1 moment to force ratio will produce which type of tooth movement?

controlled tipping

a 10:1 moment to force ratio will produce which type of tooth movement?

translaiton

a 12:1 moment to force ratio will produce which type of tooth movement?

tooth movement

Force = (1/Distance)² This means that if the distance decreases by ½, force increases by \_\_\_x

Force = (1/Distance)² This means that if the distance increases by ½, force decreases by \_\_\_%

44%

the duration threshold for light force to produce movements is ___ - ___ hours

4 - 6hrs

In a physiologic response to sustained pressure, movement begins after ___ hours

48hrs

on average, RPE treatment will move the A point 2.5mm ____________ and 3.5mm \_\_\_\_\_\_\_\_\_\_\_

2. 5mm downward 3. 5mm forward

to determine that a crossbite is skeletal, you will see dental compensations. upper molars will have ______ crown torque and lower molars will have _________ crown torque

buccal lingual

the limit

the limit to expansion is the

zygomatic arch or pterygoid plates

the mandibular limit to expansion is the

coronoid process of the mandible

After RPE, stabilization is needed for ___ - ___ months to re-establish the suture

4 - 6months

the maxillary mid-palatal suture is _________ tissue that is mainly __________ with osteogenic surfaces on each side.

fibrous collagen

can RPE reduce nocturnal enuresis (involuntary urination)?

yes

in RPE, the dental:skeletal effects of expansion are ___ : \_\_\_

1 : 1

During bonding we use \_\_\_% ________________ acid as etch. This removes ___ - ___ microns of enamel.

37% phosphoric acid 3-10 microns

Omission of air-dispersion step ( increases / decreases ) shear bond strength in self-etching primer system

decreases

Porcelain etch for bonding is made of \_\_\_% \_\_\_\_\_\_\_\_\_

10% HCl

Bracket adhesive with Fl- releasing etching gel has significantly ( higher / lower) bond strength

higher

Fl- applied to teeth before bonding ( increases / decreases ) bond strength

decreases

Fl^-prevents dental caries by decreasing enamel \_\_\_\_\_\_\_\_\_\_\_\_\_

solubility

1st order wire bends are

in / out rotation and BL thickness

2nd order wire bends are:

up / down – align marginal ridges

3rd order wire bend are:

torque

When pt has steep premolar cusps: finish with ( increased / decreased ) OB

increased

reorganization of the PDL occurs in ___ - ___ months

3 - 4 months

the class II div 2 characteristic that is most prone to relapse is:

deep bite

*Case: rotated incisors, deep bite, large overjet. Most likely to relapse?*

*Rotation*

which periodontal fibers most important in stability / relapse?

supracrestal fibers

After orthodontic treatment, these things can happen: 1. Reduction in root \_\_\_\_\_\_\_ 2. Reduced _______ support 3. Crowding 4. Rotation

1. length 2. alveolar bone

In Little's post-tx relapse study he found that \_\_\_/\_\_\_ of mandibular incisors relapse

⅔

Burstone stated that the upper occlusal plane should be relatively ______ and not allow more than \_\_\_mm of incisal show at rest

flat 3mm

Soft tissue thicknesses increase more in ( females / males )

females

The incidence of canine impactions is ___ - \_\_\_%

1 - 2%

With canine impaction cases, the incidence of the impaction being bilateral is \_\_\_%

The 3 options for labially positioned impactions are:

closed eruption, apically positioned flap, excisional

For labially positioned impacted canines, choose (closed eruption / apically positioned flap ) for a better esthetic outcome

closed eruption

For labially positioned impacted canines, an apically positioned flap is good when:

when the canine is angles mesiodistally and when there is an inadequate amount of gingiva

For labially positioned impacted canines, excisional technique is good when there is \_\_\_mm or more of attached gingiva and the tooth is below the \_\_\_\_\_\_\_\_\_\_\_\_\_

3mm mucogingival junction

**Palatal** impactions are \_\_\_x more likely than labial impaction

If tip is distal to lateral root, removal of C will resolve \_\_\_% of cases

91%

If tip is past midline of lateral root: removal of C resolves \_\_\_% of cases

64%

When a mesiodens causes the impaction of a central incisor, the _____________ technique should be used to bring it into the arch

closed eruption

T/F: Functional appliances accelerate Mn growth, but treated pts do not have larger mandibles

True

According to Bancceti's articles, with the use of a twin block appliance, overall changes are \_\_\_% dental and \_\_\_% skeletal

45% 55%

with the use of a twin block appliance, which parts of the mandible show and increase in size?

body ramus length

With a twin block appliance, the lower incisors are capped to prevent:

proclination and extrusion

The twin block appliance allows you the ability to increase VDO by:

removing acrylic from lower part of appliance so mandibular teeth will erupt

Biomechanics, Techniques and Appliances 25% 16Q Flashcards

(76 cards)