Treatment Of Class 2 Cases Flashcards
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.
Orthognathic
Retrognathic and short
Brachyfacial
Retroclined
Relatively prominent
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?
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
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?
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
True or false… in the transverse dimension, buccal segments of class 2 patients often appear normal.
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.
Treatment options for vertical correction in growing class 2 patients could include…
In non-growing patients, surgical correction options such as…
Bite blocks and various types of headgear.
LeFort 1 maxillary impaction and alveolar procedures
___% of skeletal class 2 discrepancies are due to ____
75%
Mandibular retrognathia
___% 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
15%
38%
What is Type A horizontal class 2 type?
Maxillary dental protraction
What is Type B horizontal class 2 type?
Maxillary prognathism
Dental protraction
What is Type C horizontal class 2 type?
Maxillary retrognathism with flared or upright incisors
Mandibular severe retrognathism with flared lower incisors
What is type D horizontal class 2 type?
Maxillary retrognathism with dental protraction
Severe mandibular retrognathism
What is Type E horizontal class 2 type?
Maxillary prognathism and dental protraction + mandibular dental flaring
What is type F horizontal Class 2 type?
Mandibular retrognathism
What are the 5 treatment options for class 2 malocclusion?
Extra-oral traction
Distalizing appliances
Functional jaw orthopedics (FJO)
Camouflage
Surgery
____ 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
Molar distalization
Maxillary first molar
Name 5 distalizing appliances that are usually very effective, because they require little, if any, cooperation from the patient
Plates
Pendulum (pendex)
Distal jet
Jones jig
Jasper jumper
What is functional jaw orthopedics?
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.
Why is repeated advancement of FJO appliances required?
The lateral pterygoid activation causes adaptive growth response at the condyle. However, the lateral pterygoid activity decreases after 6-8 weeks.
Name 6 typical result s shown from FJO therapy
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
Describe Type 1 vertical class 2
Mandibular plane steeper than normal
Steeper functional occlusal plane
Palate tipped somewhat downward
Anterior cranial base tipped upward
Describe Type 2 vertical class 2
Mandibular plane, functional occlusal plane, and palatal plane are all flatter than normal and are nearly parallel
Describe type 3 vertical class 2
Palatal plane tipped upward anteriorly
Describe type 4 vertical class 2
Mandibular plane, functional occlusal plane, and the palatal plane are all tipped markedly downward
Describe type 5 vertical class 2
Palatal plane is tipped downward
Cranial base tipped downward
What are three treatment considerations for treatment of Type A horizontal class 2
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
What are 2 treatment considerations for Type B horizontal class 2?
Headgear (growing patient)
Surgery: maxillary anterior alveolar setback (non-growing patient) with extractions of upper bicuspids
What are 3 treatment considerations for Type C horizontal class 2
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
What are 2 treatment considerations for Type D class 2 horizontal?
Orthodontic + functional appliance (growing patient)
Surgery: mandibular advancement (non-growing patient)
What are 3 treatment considerations for Type E horizontal class 2?
Headgear
Bimaxillary protrusion-extraction of upper and lower bicuspids
Extractions + surgery (non-growing patient)
What are 2 treatment considerations for Type F horizontal class 2?
Functional appliance (growing patient)
Surgery: mandibular advancement (non-growing patient)
When is functional appliance therapy indicated?
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
Greater mandibular length is obtained when functional appliance treatment is performed during…
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)
In the absence of severe dentoskeletal compensations, functional appliance therapy, when should FJO be initiated?
At the beginning of cervical vertebrae maturation stage CS3 to maximize the treatment effects and reduce the need for posttreatment retention
What are the two basic types of functional appliances commonly used today?
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)
What are some of the effects commonly seen with tooth-born functional appliances?
Increase in mandibular length
Maxillary molars move distally
Mandibular molars move mesially
Maxillary incisors tip lingually
Mandibular incisors procline
Name three examples of removable functional appliances
Activator
Bionator
Twin block
Name two fixed functional appliances
Herbst
MARA
Name 4 situations that usually require orthodontic treatment prior to FJO
Severe maxillary constriction
Deep impinging bite
Maxillary incisor retroclination and mandibular incisor proclination and spacing
Moderate to severe crowding
Why should severe maxillary constriction be treated before FJO? How is this accomplished?
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.
Why should a deep impinging bite be treated prior to FJO? How is this accomplished?
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.
Why should maxillary incisor retroclination and mandibular incisor proclination and spacing be treated prior to FJO? How is this accomplished?
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
Why should moderate to severe crowding be corrected prior to FJO? How is this accomplished?
Space supervision or serial extraction may be required depending on the severity of the upper and lower dental crowding
Bionators are classified in three categories. What are they?
Bionators to open,
Maintain
Or close the bite
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
True
Step-by-step mandibular advancement is achieved with the Herbst appliance by adding ___ to the mandibular part of the bite jumping mechanism
Shims
Describe the MARA design
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
Typically, a MARA device produces ___% skeletal change and ___% Dental change
47% (mainly increase in mandibular length)
53% (mainly due to distalization of maxillary molars)
A Forsus appliance provides a mesial and intrusive force on the ___ arch and a distal and intrusive force on the ___ arch.
Mandibular
Maxillary
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
30%
50%
15%
Functional appliance or headgear treatment has shown a __-__% chance of producing a favorably or highly favorable result and about a __% chance of no change
70-80%
20%
What is the best scenario to do class 2 camouflage treatment?
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.
What is the typical treatment for class 2 camouflage treatment?
Extraction of upper first bicuspids and lower second bicuspids (or only extraction of upper first bicuspids)
Since skeletal class 2 problems are most often due to ___ or ___, surgical treatment usually consists of ___, ____, or ___.
Mandibular deficiencies
Clockwise rotation of the mandible due to excessive vertical growth of the maxilla
Mandibular advancement (66%) Maxillary impaction (15%) Or combination (20%)
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 ___.
10mm
Protrusive
Short
Long
If there is a significant dentofacial deformity, early orthognathic surgery may improve the health of the patient in regard to what things?
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.
