Orthodontic Assistant Practice Exam

Orthodontics is the dental specialty that deals with

the growth and development of the jaws and face

The condition in which the mandible is located ahead of the maxilla is called

prognathism

The best way to motivate adolescents toward good oral hygiene habits is by

relating to social acceptance and appearance

Removal of bands may be accomplished with

anterior band slitting pliers

A headgear appliance is worn

as the orthodontist prescribes

A positioner is worn

after the removal of fixed appliances

In placing TP springs, an important consideration is

to place them from the lingual surface

The instrument of choice in ligating an archwire is a

ligature-tying pliers

Direct bracket bonding is advantage because the procedure

allows the dentist less clinical chair time

The attachment either welded or soldered to the bands that secure the archwire is the

bracket

Brass separators are removed by

cutting opposite the pigtail with ligature cutters

What instrument is used to place elastic separators?

Elastic separating pliers

The patient should be instructed to clean his or her retainer

after each meal

Cephalometry is

taking measurements of the skull

Cephalometric tracings are made over

extraoral radiographs

The cephalometric headplate taken most often is the

lateral skull headplate

An open bite refers to a condition wherein

the anterior teeth do not contact

Overjet is the

horizontal distance between maxillary and mandibular teeth

A type of measuring device commonly used to take intraoral measurments is a (an)

flexible millimeter ruler

When seating and sizing bands using a band pusher type of instrument, it is necessary to maintain control by

establishing a stable fulcrum before applying pressure

Class III malocclusion is

a protruded position of the mandible in relation to the maxilla

Vertical overbite refers to the

vertical overlap of the incisal edges of maxillary and mandibular anterior teeth

Class II maloclussion is

retruded position of the mandible in relation to the maxilla

The head-stabilizing device used in cephalometrics is called a (an)

cephalostat

During cementation of bands, the cement is placed

on all surfaces within the band

The attachment of anterior plastic brackets directly to teeth can be accomplished by

acid etch bonding

Cervical anchorage (headgear) is an

appliance that exerts distal forces on maxillary teeth

After active orthodontic treatment is finished , what appliance is used to stabilize the teeth?

A retainer

When determining the length of a preformed archwire, you measure the distance from

first molar to first molar

In the removal of an archwire

ligature ties, then the archwire, are removed one side at a time from the buccal tube

The most common type of removable retainer is a

Hawley retainer

What is used to tie the archwire onto orthodontic brackets?

Ligature wire

When removing separators, care must be taken to

avoid injuring the interdental papillae

A useful instrument for removing elastic separators is

a sickle scaler

A TP spring is a type of

Separator

An elastic separator is placed by

stretching and pushing through the contacts

When placing an archwire, one should

insert the wire into one side of the buccal tubes, then guide it into the brackets

The importance of the ligature wire is that it

holds the archwire in place

When ligating with a tie wire, the tie wire should be

bent at a 45-degree angle

Select the instrument used to check for loose bands

Howe pliers

After cutting brass wire separators, the pigtails are cut to

2-3 mm

What instrument is used to cut ligature ties in the removal of an archwire?

Pin and ligature cutters

When placing headgear

insert one side of facebow first, then the other

The type of appliance that has cemented bands and lingual or labial archwires is referred to as

a fixed appliance

If an orthodontic elastic separator has been swallowed or has disappeared, the assistant should

look for the elastic separator in the oral cavity and inform the dentist if it is not located in the oral cavity

To check for loose bands

use the Howe pliers in an occlusal and gingival direction to see if the band moves

Which of the following is (are) used to determine if an alginate impression tray is the correct size for the maxillary arch?

Tray extends to cover the maxillary tuberosity, and tray should fit well up the periphery

When inspecting and evaluating an alginate impression, the assistant must check for which of the following?

Surface detail, proper extension over retromolar area and peripheral roll, and deficiencies in the peripheral impression

The brass separating wire should NOT interfere with

Occlusion, gingival tissue, and chewing

Which of the following is (are) the correct procedure(s) for mixing zinc phosphate cement for band seating?

Spatulate over a large area of slab and use a cool slab

The information needed for the diagnosis and treatment planning of an orthodontic case includes

complete medical history,

radiographs and tracings,

study models,

photographs

An important function of the dental assistant in an orthodontic practice is to

motivate and reinforce oral hygiene home care

A finished Hawley retainer may have

an acrylic palate,

a labial wire,

arrow clasps

Before cementation

brackets are waxed,

bands are arranged in cementation order,

teeth are isolated and dried,

teeth are coronal polished

Orthodontic bands with metallic bracket attachements are designed to be

cemented on teeth as a means of anchoring archwires

In reference to an orthodontic study cast model

trimmed models must be polished and labeled,

a model trimmer is used to establish right angles,

white orthodontic plaster is used,

wax bite is used to occlude models while trimming the heel.

If an archwire does not go in

check for a crushed bracket,

the molar band tube is blocked,

check width and diameter of archwire

In the placement and removal of elastic ligatures, which of the following instruments may be used?

locking hemostat, and scaler

After removal of the orthodontics bands, all excess cement should be removed because

gingival irritation may occur,

teeth will not occlude properly,

teeth may appear discolored,

cement is irritating to the interproximal surfaces of teeth

On which surface(s) is the archwire located?

Labial or lingual surface

One of the most important tasks of the assistant when attempting to support an anxious patient is to be

patient centered

A water irrigator is used

to remove loose food debris

To be of maximum benefit to the teeth, the optimum fluoride concentration is

1 ppm

Which of the following are considered detergent foods?

Apples

Using the heel or toe of the brush is helpful for cleaning which tooth surface?

Lingual surfaces of teeth of anterior teeth

According to the manufacturer, regular preventative maintenance for the model trimmer includes all of the following EXCEPT

replacing rag wheels

Gypsum materials used for orthodontic procedures are best stored in a

air tight dry container

If a wire is used to intrude tooth #8 and the bracket is placed upside down, what effect will this cause on tooth #8?

Intrude

Extrude

Rotate

extrude

If there is a very narrow maxilla, what kind of malocclusion will develop?

Malocclusion II

What kind of attachment is placed when sheath is added to the band?

Lingual arch

When a headgear is placed on the cervical or pull up areas what kind of malocclusion is it correcting?

Malocclusion II

What is the benefit of the etch-primer used on the enamel?

Strongest bond

An OA assistant is placing brackets noticed one of them slides off the position, what should they do?

Ask the orthodontist to reposition it

What kind of wire is stiff enough to re-rotate an anterior tooth?

Braided

What is the most common wire to control torque?

What is a bracket made of?

Stainless Steel

What is the prescription value and differences of the 1st and 2nd bicuspid brackets in the lower portion of the mouth?

The buccal portion of the tooth is different

What is the quality value of a braided wire, and what is the difference to a stainless steel wire?

Stiffer

What is a malocclusion II division I?

When the anterior teeth are protruded

When you place a band on a molar more mesially than distally, how will this molar rotate?

distally

Where do you place a band?

below the height of contour

When you place a bracket on a lateral anterior tooth too mesially, how will this tooth rotate?

ligual?

What kind of tie do you use for elastic when moving teeth intermaxillary?

Kobiachi

What is the movement of torque?

Buccal-lingual

If the groove of a maxillary molar is occluding with the buccal side of the mandibular molar, what kind of bite will you be correcting?

Crossbite

Where do you place the elastic to correct a malocclusion II?

anterior to posterior

When there is mobility on an anterior tooth and loss of gingiva, the reason is:

Traumatic occlusion

Where do you place the headgear wire?

Maxillary tube

In an orthodontic numeric system what number is tooth number 5 and 21?

upper right 4 and lower left 4

In orthodontic numberic system what number tooth is number 1 and 22?

upper right 7 and lower left 3

What instrument do you use when you see cement on a tooth after removing a band?

Ultrasonic

What is the best etching time for an ideal bond?

30 seconds

What is the most common bracket slot size?

18 x 22

What kind of pliers do you use to tie a wire tie?

Matheau

Which archwire is wider?

maxillary

What direction do you point the scaler tip when removing cement?

occlusal

When you sit a band and put pressure, which part are you careful with when placing the metal part of the bite stick?

the occlusal enamel of the tooth

What sets the curing process in a normal environment?

Normal and ultraviolet light