Appliances + Mechanics of Action

Question 1

In class 2 patients with a restrusive mandible, functional appliances posture the mandible _____

Answer 1

Forward

Question 2

In class 3 patients with a protrusive mandible, function appliances _____ the mandible ______ or direct _____ of the teeth

Orthopaedic remodeling may occur in the bone of the _____ or at the ______ (joint)

Answer 2

Rotate the mandible down or direct eruption of the teeth

Mandible or at the condyle (joint)

Question 3

In deep bite patients, function appliances can hold the teeth apart promoting ____ _____ of _____ teeth and this over bite reduction

In open bite patients, guidance of teeth and alveolar bone occurs although functional appliances is not always the appliance of choice for open bite patients

True or False

Answer 3

Supereruption of posterior teeth

True

Question 4

Sequence of events for combined Orthodontics and orthognathic surgery : (7)

1. ______ ______ to align the teeth so they will occlude properly after surgery
2. in the hospital under general anesthetic the oral surgeon ____ and _____ (osteotomy) the maxilla or mandible (or both) then _____ the jaws so the teeth occlude properly
3. after surgery, metallic screws or plates and elastics or wires (fixation) so the teeth with be occluding in surgical splint and bone will heal in the proper position
4. patient with stay in the hospital for several days after surgery
5. at 1 week after patient is seen post op by _____ and ______ to check healing/appliance/jaw position radiographically
6. weeks after the oral surgeon will remove _____ so the patient will resume ______
7. ______ orthodontic Treatment may start as soon as deemed necessary 6-___ weeks (to allow healing) and continues until complete

Answer 4

1. Orthodontic treatment
2. Cuts and repositions (osteotomy) then repositions
3. By oral surgeon and orthodontist
4. Remove jaw fixation wires/elastics and resume function
5. Active 6-8

Question 5

Refers to a component of the fixed or removable appliance worn in the mouth which acts to resist the unwanted effects of the desired force

Answer 5

Intraoral anchorage

Ex:the acrylic plate of a removable appliance- the force of the active element (spring/screw) is greater in its effect against the individual tooth or small area of bone than against the greater tissue surface area (acrylic plate) against which the reciprocal force is exerted
Or groups of adjacent teeth ligated together in a fixed appliance against which force is applied to a smaller group of teeth- the larger unit has greater root surface area than the smaller one and thus is more difficult to move

Question 6

____ refers to a removable or fixed appliance worn partly outside of the mouth, which acts to resist the unwanted effects or the desired force

Answer 6

Extraoral anchorage

Ex:
A) retraction headgear- the anchorage unit is the tissue of the back of the neck (cervical) or the occipital part of the skull
B) protraction headgear- the force against the maxilla is resisted by force against the chin, forehead, or cheekbones
C) fixed-temporal devices; for osteogenesis distraction procedure

Question 7

Hawley appliance function/characteristics

Answer 7

• typically used as a passive retainer for after debanding. Can be used for incisor retraction or modified to serve as a removable crib appliance
• used for either arch, incorporates a labial bow from cuspid to cuspid [canine], plus some design for molar clasp; both for appliance retention

Question 8

Bite plane appliance (similar to maxillary hawley) characteristic/function

Answer 8

Thick acrylic palatial to maxillary anterior teeth, recurved springs may be substituted for Adams clasps if maxillary first molar bands are present

The thick acrylic prevents the posterior teeth from occluding and allows the posterior teeth to erupt.

For treatment of a deep bite in mixed or permanent dentition

Question 9

Active plate functions and characteristics

Answer 9

Actives plates can be designed to:produce palatial expansion, unilateral posterior cross bite correction of a single tooth or groups of teeth, anterior cross bite correction of a single tooth or groups of teeth, space regaining, and canine retraction

Expansion screws are generally adjusted by the patient as per doctor instructions
Springs are adjusted by doctor

Question 10

Removable Functional Appliances

Answer 10

Can be thought as actives plates that fix the maxilla and mandible simultaneously
Intended to correct orthopaedic problems (class 2, class 3, and open bite); can be modified to produce similar movements as active plates
Cause changes in dental eruption patterns=helping to “correct” dental malrelationships
Ex: activator, bionator, Frankel, twin block

Question 11

Construction bite

Answer 11

Thick wax occlusal registration with the jaws positioned closer to an ideal position, than normal for that patient
Allows the appliance to be customized for its particular orthopaedic purpose

Question 12

Clear sequential aligner (Invisalign)

Answer 12

Fabricated from computer generated model 
(PVS or Cerec scans)
This technique is best for class 1 malocclusions with mild to moderate dental problems, crowding, excess space, overjet or overbite reduction

Question 13

Twin block appliance

Answer 13

Maxillary & Mandibular components
The anterior bite registration positions the mandible forward
The maxillary/mandibular portions have specifically designed inclines to help the patient “slide” the mandible forward repeatedly during function
Posterior acrylic is removed to allow for differential tooth eruption
After 8-12 months the appliances are removed and braces are used to complete tooth alignment and detailing

Question 14

Positioner

Answer 14

Is a type of retainer that fits the maxilla and the mandible simultaneously
Consists of a flexible rubber-like material and looks like a mouth guard
Can produce minor tooth movement, a feature that allows debanding prior to absolute finishing of the case
The teeth are reset on the models into an ideal position, the positioner is built around this as-yet-unattained ideal position.
Through appliance wear the teeth are moved into the ideal position, teeth should still have orthodontic mobility, the positioner should not be too uncomfortable
Patient will wear the positioner passively, but also exercises into it

Question 15

Headgear

Answer 15

Combination of fixed molar bands and a removable framework and traction mechanism
Retraction designs are used to restrict maxillary growth, or maintain maxillary molar positions (anchorage device)
Protraction headgear is to “pull forward” the upper teeth, or in some cases the lower teeth

Question 16

Space maintainers

Fabricated of heavy gauge stainless steel wire soldered to the lingual of the first permanent molar bands and are intended to _______ _____ _____ of first molars. Spurs may present _____ ______ or incisors

Answer 16

Prevent medial tip of first permanent molars
Prevent distal tip of incisors
Maxillary space maintainers rest passively on the soft tissue of the anterior part of the palate
Mandibular space maintainers prevent lingual collapse of incisors through solid (but passive) contact with the cingulum of the incisors
Is inserted into lingual sheaths on the molar bands and tied in with steel ligature wire

Question 17

Bonded lingual retainer
Heavy gauge round wire can be bonded from canine-to-canine or premolar-to-premolar in the mandible
Light gauge round wire can be bonded from each mandibular tooth
Light braided wire can be bonded directly to the lingual surface of specific maxillary anterior teeth

Answer 17

The maxillary bonded retainer is used for permanent or semi-permanent retention of a diastema or other specific problem, and may involve some or all 6 anterior teeth
The mandibular bonded retainer is used for varying durations

Question 18

Transpalatal Arch (TPA)
Is a single heavy gauge wire which is inserted into lingual sheaths or soldered the to lingual aspect of the maxillary molar bands, with a variable number and design is intervening loops
Does not contact the palate

Answer 18

TPA’s can be used passively for anchorage or actively to intrude, torque, rotate, expand, construct, or distalize maxillary molars
When used passively, the TPA maybe be soldered to molar bands or tied in with steel ligatures to molar lingual sheaths (not “active”)
When used actively, the TPA is tied in, not soldered (allowed movement)

Question 19

Crib

Answer 19

Passive appliance with a vertical “fence” in the anterior part of the palate
Prevent thumb sucking or excessively forward tongue posture during rest or function
Cribs can be used as a tool in myofunctional therapy to retrain dysfunctional swallowing pattern
1 year wear to ensure habit correction
Can be made to be removable (disadvantage as success depends on patient)

Question 20

Passive appliances checks

Answer 20

Space maintainers and cribs may require periodic recementation
Recementation is often annual to check for caries on the molars
Loose appliance needs to be recemented
Recall every 3-4 months for observation

Question 21

Rapid palatal expansion

Answer 21

Involved heavy force, frequent adjustment, frequent observation, and rapid realization of treatment objective (weeks)

Question 22

Slow palatal expansion

Answer 22

Involves less frequent adjustment and observation, and slower realization of treatment objective (months)

Question 23

Hyrax
Consists of a mid-palatal screw connected via heavy gauge wire to bands on first premolars (or first primary molars) and first molars

Answer 23

Patient adjusts the screw with a “key” in accordance with prescribed schedule
Used for either rapid or slow palatal expansion, good appliance in an adolescent or older patient due to its heavy construction
Adjustment is as per dr instructions/patient need