Treatment Of Class 2 Cases

Question 1

Class 2 division 2 patients typically exhibit an ___ maxilla, a ____ mandible, an ___ growth pattern, ___ maxillary central incisors, and a ____ chin as well as a deep bite.

Answer 1

Orthognathic

Retrognathic and short

Brachyfacial

Retroclined

Relatively prominent

Question 2

Class 2 patients are divided into 6 separate horizontal types and 5 vertical types based on various skeletal and dentalalveolar characteristics. What are the 6 horizontal types?

Answer 2

Type A: maxillary dental protraction

Type B: Maxillary prognathism, dental protraction

Type C: Maxillary retrognathism with flared or upright incisors; mandibular severe retrognathism with flared lower incisors

Type D: Maxillary retrognathism with dental protraction; severe mandibular retrognathism

Type E: Maxillary prognathism and dental protraction + mandibular dental flaring

Type F: Mandibular retrognathism

Question 3

Class 2 patients are divided into 6 separate horizontal types and 5 vertical types based on various skeletal and dentalalveolar characteristics. What are the five vertical class types?

Answer 3

Type 1: mandibular plane steeper than normal, steeper functional occlusal plane, palate tipped somewhat downward, anterior cranial base tipped upward

Type 2: mandibular plane, functional occlusal plane, and palatal plane are all flatter than normal and are nearly parallel

Type 3: Palatal plane tipped upward anteriorly

Type 4: mandibular plane, the functional occlusal plane, and the palatal plane are all tipped markedly downward

Type 5: palatal plane is tipped downward; cranial base tipped downward

Question 4

True or false… in the transverse dimension, buccal segments of class 2 patients often appear normal.

Answer 4

True. However, a 3-4mm transverse discrepancy usually exists at the level of the first molar due to a narrow maxillary arch. This is readily observable if the mandible is moved into the class 1 relationship at the molar.

Question 5

Treatment options for vertical correction in growing class 2 patients could include…

In non-growing patients, surgical correction options such as…

Answer 5

Bite blocks and various types of headgear.

LeFort 1 maxillary impaction and alveolar procedures

Question 6

___% of skeletal class 2 discrepancies are due to ____

Answer 6

75%

Mandibular retrognathia

Question 7

___% of the US population have an overjet of greater than ___mm. ___% have an overjet between __-___mm. And 1/3rd of the population have class 2 occlusal discrepancies

Answer 7

15%

38%

Question 8

What is Type A horizontal class 2 type?

Answer 8

Maxillary dental protraction

Question 9

What is Type B horizontal class 2 type?

Answer 9

Maxillary prognathism

Dental protraction

Question 10

What is Type C horizontal class 2 type?

Answer 10

Maxillary retrognathism with flared or upright incisors

Mandibular severe retrognathism with flared lower incisors

Question 11

What is type D horizontal class 2 type?

Answer 11

Maxillary retrognathism with dental protraction

Severe mandibular retrognathism

Question 12

What is Type E horizontal class 2 type?

Answer 12

Maxillary prognathism and dental protraction + mandibular dental flaring

Question 13

What is type F horizontal Class 2 type?

Answer 13

Mandibular retrognathism

Question 14

What are the 5 treatment options for class 2 malocclusion?

Answer 14

Extra-oral traction

Distalizing appliances

Functional jaw orthopedics (FJO)

Camouflage

Surgery

Question 15

____ can be used when class 2 problems are dentoalveolar in nature. It corrects class 2 problems by moving the ____ distally into a class 1 relationship

Answer 15

Molar distalization

Maxillary first molar

Question 16

Name 5 distalizing appliances that are usually very effective, because they require little, if any, cooperation from the patient

Answer 16

Plates

Pendulum (pendex)

Distal jet

Jones jig

Jasper jumper

Question 17

What is functional jaw orthopedics?

Answer 17

FJO is the utilization of appliances that work by forward positioning of the mandible. This results in altering the activity of postural muscles of the craniofacial complex, causing changes in skeletal and dental relationships.

The goal is to enhance mandibular growth by allowing the full expression of the genetic potential and encouraging remodeling at the glenoid fossa.

Question 18

Why is repeated advancement of FJO appliances required?

Answer 18

The lateral pterygoid activation causes adaptive growth response at the condyle. However, the lateral pterygoid activity decreases after 6-8 weeks.

Question 19

Name 6 typical result s shown from FJO therapy

Answer 19

Condylar growth during treatment: 1-3mm

Fossa displacement, growth, and adaptation 3-5mm with a dominant vertical vector

Most favorable growth direction: 0.5-1.5mm

Withholding of downward and forward maxillary growth: 1-1.5mm

Differential upward and forward eruption of lower buccal segments:1.5-2.5mm

Headgear effect: 0-0.5mm

Question 20

Describe Type 1 vertical class 2

Answer 20

Mandibular plane steeper than normal

Steeper functional occlusal plane

Palate tipped somewhat downward

Anterior cranial base tipped upward

Question 21

Describe Type 2 vertical class 2

Answer 21

Mandibular plane, functional occlusal plane, and palatal plane are all flatter than normal and are nearly parallel

Question 22

Describe type 3 vertical class 2

Answer 22

Palatal plane tipped upward anteriorly

Question 23

Describe type 4 vertical class 2

Answer 23

Mandibular plane, functional occlusal plane, and the palatal plane are all tipped markedly downward

Question 24

Describe type 5 vertical class 2

Answer 24

Palatal plane is tipped downward

Cranial base tipped downward

Question 25

What are three treatment considerations for treatment of Type A horizontal class 2

Answer 25

Extraction of upper bicuspids + orthodontic retraction and uprighting Distalization of upper dentition into class 1 Surgery: anterior maxillary alveolar osteotomy setback and uprighting of upper centrals and lateral after extraction of upper bicuspids and orthodontic retraction of canines

Question 26

What are 2 treatment considerations for Type B horizontal class 2?

Answer 26

Headgear (growing patient) Surgery: maxillary anterior alveolar setback (non-growing patient) with extractions of upper bicuspids

Question 27

What are 3 treatment considerations for Type C horizontal class 2

Answer 27

Complex skeletal and dentoalveolar considerations Extraction of upper and lower bicuspids, orthodontics + functional appliance Extraction of upper 5/lower 4s, orthodontics to close spaces and upright incisors + surgery: maxillary and mandibular differential advancement

Question 28

What are 2 treatment considerations for Type D class 2 horizontal?

Answer 28

Orthodontic + functional appliance (growing patient) Surgery: mandibular advancement (non-growing patient)

Question 29

What are 3 treatment considerations for Type E horizontal class 2?

Answer 29

Headgear Bimaxillary protrusion-extraction of upper and lower bicuspids Extractions + surgery (non-growing patient)

Question 30

What are 2 treatment considerations for Type F horizontal class 2?

Answer 30

Functional appliance (growing patient) Surgery: mandibular advancement (non-growing patient)

Question 31

When is functional appliance therapy indicated?

Answer 31

The primary indication for FJO is mandibular skeletal protrusion Functional appliances remove abnormal and restrictive muscular activity that prevents the normal development of the maxilla and mandible as well as appropriate development of dental arches

Question 32

Greater mandibular length is obtained when functional appliance treatment is performed during...

Answer 32

The circumpubertal growth period Ideally, functional appliance therapy should be started in the late mixed dentition or early permanent dentition followed by Phase 2 therapy to align the permanent dentition. (It may be imitated in early mixed dentition for pts who have severe problems)

Question 33

In the absence of severe dentoskeletal compensations, functional appliance therapy, when should FJO be initiated?

Answer 33

At the beginning of cervical vertebrae maturation stage CS3 to maximize the treatment effects and reduce the need for posttreatment retention

Question 34

What are the two basic types of functional appliances commonly used today?

Answer 34

Tooth born and tissue born The only tissue born is the functional regulator - Frankel 2 All others are tooth born (herbst, twin block, bionator, MARA)

Question 35

What are some of the effects commonly seen with tooth-born functional appliances?

Answer 35

Increase in mandibular length Maxillary molars move distally Mandibular molars move mesially Maxillary incisors tip lingually Mandibular incisors procline

Question 36

Name three examples of removable functional appliances

Answer 36

Activator Bionator Twin block

Question 37

Name two fixed functional appliances

Answer 37

Herbst MARA

Question 38

Name 4 situations that usually require orthodontic treatment prior to FJO

Answer 38

Severe maxillary constriction Deep impinging bite Maxillary incisor retroclination and mandibular incisor proclination and spacing Moderate to severe crowding

Question 39

Why should severe maxillary constriction be treated before FJO? How is this accomplished?

Answer 39

It is often advantageous to expand the maxilla prior to class 2 correction to allow the buccal segments to appropriately interdigitate in the final class 1 position. This can be done with a rapid palatal expander prior to FJO.

Question 40

Why should a deep impinging bite be treated prior to FJO? How is this accomplished?

Answer 40

In order to allow for forward posturing of the mandible, deep impinging bites should be corrected utilizing a utility arch to intrude, tip, or reposition the incisors.

Question 41

Why should maxillary incisor retroclination and mandibular incisor proclination and spacing be treated prior to FJO? How is this accomplished?

Answer 41

Over 30% of class 2 patients present with maxillary incisors in a retroclined position. This inclination problem must be corrected to allow appropriate mandibular advancement. In addition, flaring as well as spacing of the lower incisors must be corrected to allow for maximum mandibular advancement

Question 42

Why should moderate to severe crowding be corrected prior to FJO? How is this accomplished?

Answer 42

Space supervision or serial extraction may be required depending on the severity of the upper and lower dental crowding

Question 43

Bionators are classified in three categories. What are they?

Answer 43

Bionators to open, Maintain Or close the bite

Question 44

True or false... in both types of Herbst appliances, a hyrax-type screw may be included to expand the maxilla as the mandible is positioned forward

Answer 44

True

Question 45

Step-by-step mandibular advancement is achieved with the Herbst appliance by adding ___ to the mandibular part of the bite jumping mechanism

Answer 45

Shims

Question 46

Describe the MARA design

Answer 46

Although modifications can be made to accommodate upper or lowe rexpansion, a trans palatal arch, a lower lingual arch, intrusion mechanics, and asymmetric cases, the basic MARA design is as follows: Four crowns on the first molars Arms soldered to the lower crowns Archwire tube for upper and lower arches soldered to all crowns Upper elbows shimmed to provide the desired advancement Lower lingual arch soldered to crowns Option specs includes occlusal holes to assist with crown removal

Question 47

Typically, a MARA device produces ___% skeletal change and ___% Dental change

Answer 47

47% (mainly increase in mandibular length) 53% (mainly due to distalization of maxillary molars)

Question 48

A Forsus appliance provides a mesial and intrusive force on the ___ arch and a distal and intrusive force on the ___ arch.

Answer 48

Mandibular Maxillary

Question 49

In an untreated class 2 patient, there is about a ___% chance of a favorable change in the class 2 relationship, a ___% chance of no change, and a ___% chance the condition will worsen

Answer 49

30% 50% 15%

Question 50

Functional appliance or headgear treatment has shown a __-__% chance of producing a favorably or highly favorable result and about a __% chance of no change

Answer 50

70-80% 20%

Question 51

What is the best scenario to do class 2 camouflage treatment?

Answer 51

Pt is too old for growth modification Mild-moderate skeletal discrepancy Reasonably good alignment of teeth Good vertical proportions Reasonably good facial esthetics Overjet that results more from maxillary protrusion than mandibular retrusion It is most appropriately used when the patient has a mild class 2 skeletal relation with a class 2 dental malocclusion.

Question 52

What is the typical treatment for class 2 camouflage treatment?

Answer 52

Extraction of upper first bicuspids and lower second bicuspids (or only extraction of upper first bicuspids)

Question 53

Since skeletal class 2 problems are most often due to ___ or ___, surgical treatment usually consists of ___, ____, or ___.

Answer 53

Mandibular deficiencies Clockwise rotation of the mandible due to excessive vertical growth of the maxilla ``` Mandibular advancement (66%) Maxillary impaction (15%) Or combination (20%) ```

Question 54

Larger than __mm of overjet in a non-growing patient usually suggests the need for surgical correction. This is especially tru if the lower incisors are ___ relative to the pogonion, the mandible is ___, or if the anterior face is too ___.

Answer 54

10mm Protrusive Short Long

Question 55

If there is a significant dentofacial deformity, early orthognathic surgery may improve the health of the patient in regard to what things?

Answer 55

Speech Airway Anatomy Occlusion Esthetics TMJ function Masticatory function Psycho-social factors In the absence of a severe deformity, however, surgical mandibular advancement before the growth spurt is questionable. When the mandibular growth rate is normal, mandibular advancement can be stable due to continued normal growth of the mandible in its new position.