Orthodontics

• Introduction to Orthodontics Question and Answers
• Growth and Development : General Principles and Concepts Question and Answers
• Growth and Development of Cranial and Facial Region Question and Answers
• Development of Dentition and Occlusion Question and Answers
• Functional Development Question and Answers
• Occlusion – Basic Concepts Question and Answers
• Classification of Malocclusion Question and Answers
• Etiology of Malocclusion Question and Answers
• Habits Question and Answers
• Orthodontic Diagnosis Question and Answers
• Cephalometrics Question and Answers
• Skeletal Maturity Indicators Question and Answers
• Model Analysis Question and Answers
• Biology of Tooth Movement Question and Answers
• Types of Tooth Movement Question and Answers
• Anchorage Question and Answers
• Preventive Orthodontics Question and Answers
• Interceptive Orthodontics Question and Answers
• Methods of Gaining Space Question and Answers
• Expansion Question and Answers
• Extractions Question and Answers
• Orthodontic Appliances General Concepts Question and Answers
• Removable Appliances Question and Answers
• Fixed Appliances Question and Answers
• Myofunctional Appliances Question and Answers
• Orthodontic Appliances Question and Answers
• Management of Malocclusion Question and Answers
• Cleft Lip and Palate Question and Answers
• Age Factor in Orthodontic Question and Answers
• Surgical Orthodontics Question and Answers
• Retention and Relapse Question and Answers
• Lab Procedures Question and Answers
• Genetics in Orthodontics Question and Answers
• Orthodontics Miscellaneous Question and Answers

Cephalometrics Important Notes

• Landmarks

• Planes

• Angle of convexity

• Angles

• Wit’s analysis
  • It is a measure of the extent to which the maxilla and mandible are related to each other in antero-posterior direction
  • It is used when the ANB angle is not reliable
• Different analysis

• Tweed’s analysis
  • Forms a triangle by use of three planes

Cephalometrics Long Essays

Question 1. What are diagnostic aids? Describe cephalometrics and its uses.
Answer.

Diagnostic Aids

Comprehensive orthodontic diagnosis is established by the use of clinical implements called diagnostic aids

Cephalometrics:

• Introduced by Broadbent in USA and Hofrath in Germany in 1931
• It describes the analysis and measurements made on the cephalometric radiographs

Types Of Cephalometrics:

• Lateral cephalogram: Provides a lateral view of the skull
• Frontal cephalogram: Provides an antero-posterior view of the skull

Technical Aspects:

• Apparatus – X-ray source
  • Cephalostat – two ear rods
  • Orbital pointer
  • Forehead clamp

Landmarks:

• Used for quantitative analysis and measurements

Types Of Landmarks:

• Anatomic landmarks: Represent actual anatomic structures of the skull
• Derived landmarks: Obtained from anatomic structures

Requirements Of Land Marks:

• Easy to view
• Reproducible
• Provide valid measurements

Examples Of Landmarks:

• Nasion
• Orbitale
• Porion
• Sella

Lines And Planes:

• Obtained by connecting two landmarks

Types Of Lines And Planes:

• Horizontal Planes
  • Sella-Nasion Plane: Connecting sella and nasion
  • Frankfort Horizontal Plane: Connecting orbitale and porion
  • Occlusal Plane: Connecting occlusal surfaces of posterior to anteriors
  • Palatal Plane: Connecting ANS and PNS
  • Mandibular Plane:
    • Tangent to lower border of mandible – Tweed
    • The line connecting gonion & gnathion – Steiner
    • The line connecting gonion & mention – Down’s

Read And Learn More: Orthodontics Short And Long Essay Question And Answers

• Basion – Nasion Plane: Connecting Basion and Nasion
• Bolton’s Plane: Connecting Bolton’s Point and Nation

Vertical Plane

• A.Pog line: Point A to Pogonion
• Facial Plane: Nasion to pogonion
• Facial axis: Ptm point to gnathion
• E.Plane: Soft tissue nose to the soft tissue of the chin

Cephalometrics Uses:

• For diagnosis
• Study of dental and soft tissue structures
• Classify skeletal and dental abnormalities
• Assess facial type
• For treatment planning
• For presuming the changes
• For predicting growth-related changes
• For research work

Cephalometrics Short Essays

Question 1. Cephalogram.
Answer.

Cephalogram

• Cephalogram is a cephalometric radiography introduced by Holly Broadbent and Herbert Hofrath in 1931

Types Of Cephalogram:

• Lateral cephalogram
  • This provides a lateral view of the skull
• Frontal cephalogram
  • Provides an antero-posterior view of skull

Cephalogram Uses:

• For diagnosis
• Study of dental and soft tissue structures
• Classify skeletal and dental abnormalities
• Assess facial type
• For treatment planning
• For presuming the changes
• For predicting growth-related changes
• For research work

Cephalogram Limitations:

• Exposure to a patient is harmful
• Provides two three-dimensional views of three-dimensional structures
• Not well standardized
• Absence of anatomic references
• Has limited relevance

Question 2. Uses of Cephalometrics
Answer.

Uses of Cephalometrics

• For diagnosis
• Study of dental and soft tissue structures
• Classify skeletal and dental abnormalities
• Assess facial type
• For treatment planning
• For presuming the changes
• For predicting growth-related changes
• For research work

Question 3. Cephalostat.
Answer.

Cephalostat

• It is head holding device

• Position: The distance between the X-ray source and the mid-sagittal plane of the patient is 5 feet

Uses Of Cephalostat:

• For standardizing radiography
• Comparing serial radiographs

Question 4. Steiner Analysis.
Answer.

Parameter:

Skeletal

• SNA angle:
  • SN plane and line joining nasion and point A – 82°
  • Increased – Class 2; Decreased – Class 3
• SNB angle:
  • Between SN plane and the line joining nasion and point B – 80°
  • Increased – Class 3; Decreased – Class 2
• ANB angle:
  • Between the line joining Maison and point A and Nation and point B – 2°
  • Increased – Skeletal Class 2; Decreased – Skeletal Class 3
• Mandibular Plane angle:
  • Between SN plane and mandibular plane – 32°
  • Low angle – Horizontal grower; High angle – vertical grower
• Occlusal plane angle:
  • Between occlusal plane and SN plane – 14.5°
  • Indicates growth pattern of individual

Dental:

• Upper Incisor to N-A:
  • Between the long axis of the upper incisor and nasion to point A – 22°
  • Increased – proclination of upper incisors
• Upper Incisor to N-A:
  • Linear measurement between labial surface of upper incisor and line joining nasion to point A – 4mm
• Lower Incisor to N-B:
  • Between long axis of lower incisor and nasion to point B – 25°
  • Increased – Proclined lower incisor
• Lower Incisor to N-B:
  • The linear distance between the labial surface of the lower central incisor and the line joining nasion to point B – 4mm
  • 131°
• Inter-incisor angle:
  • Between the long axis of the upper and lower central incisor
  • Increased – Class 2 div 2, Decreased – Class 2 div 1, Class 1

Soft Tissue analysis

According to Steiner the lips in a well-balanced face should touch a line extending from the soft tissue of the chin to the middle of the ‘S’ formed by the lower border of the nose

• Protrusive – Lips beyond this line – Convex profile
• Retrusive – Lips behind this line – Concave profile

Question 5. Down’s Analysis.
Answer.

Down’s Analysis

Dental

Question 6. Visual treatment objective (VTO).
Answer.

Types Of Visual Treatment Objectives

Clinical VTO:

• It is an aid to decide the type of appliance in skeletal class 2 malocclusion
• The procedure consists of asking the patient to bring the mandible to an edge-to-edge bite relation and note the changes in appearance of the patient at two levels
  • Edge-to-edge relation
  • Midway between existing occlusion and edge-to-edge position
• Interpretation:
• If the profile worsens at the edge-to-edge position, the fault lies in the maxilla
• If the profile improves at the edge-to-edge position, the fault lies in the mandible
• If the profile improves at the midway position, there is a fault in both the maxilla and mandible

Cephalometric VTO:

• It is like a visual plan to predict the normal growth of a patient and anticipate the effects of the treatment for an individual patient
• It permits the development of alternative treatment plans and to set goals in advance for the treatment

Question 7. Tweed’s triangle.
Answer.

Tweed’s triangle

Question 8. Cephalometrics uses, advantages, and disadvantages.
Answer.

Uses Of Cephalometrics:

• For diagnosis
• Study of dental and soft tissue structures
• Classify skeletal and dental abnormalities
• Assess facial type
• For treatment planning
• For presuming the changes
• For predicting growth-related changes
• For research work

Advantages Of Cephalometrics:

• Tangible records that are relatively permanent
• Nondestructive and noninvasive
• Easy to store, transport, and reproduce
• Yield accurate information on the spatial relationship between surface and deep structures
• Low physiological cost

Disadvantages Of Cephalometrics:

• It gives a two-dimensional view of a three-dimensional object
• There can be errors while developing which can limit measuring accuracy to 0.5mm
• Needs a special X-ray apparatus with precise calibration
• Needs complex patient positioning arrays to avoid errors

Cephalometrics Short Questions And Answers

Question 1. Frankfort plane.
Answer.

Frankfort plane

Connects lowest point of orbit and superior border of external auditory meatus i.e. orbitale to portion

Significance Of Frankfort plane: Important in Down’s analysis

• Used in both dental and skeletal parameters

Question 2. Cephalostat.
Answer.

Cephalostat

It is head holding device

Position: The distance between the X-ray source the and mid-sagittal plane of the patient is 5 feet

Question 3. SNB angle.
Answer.

SNB angle

Used in Steiner’s Analysis

Angle: Between SN plane and the line joining nasion and point B

Importance: Indicates relative antero-posterior positioning of the mandible about the cranial base

Value: 80°

Changes:

• Increased – Prognathic mandible [Class 3]
• Decreased – Retrognathic mandible [Class 2]

Question 4. Registration Point.
Answer.

Registration Point

• It is derived from landmarks obtained on cephalogram
• It is the midpoint of the perpendicular drawn from the center of Sella Tursica to the Bolton plane

Question 5. Mandibular Plane.
Answer.

Mandibular Plane

Based on different analysis. There are several mandibular planes

Common are:

• Tangent to lower border of mandible – Tweed
• Line connecting gonion and gnathion – Steiner
• The line connecting Gonion and mention – Down’s

Question 6. SNA angle.
Answer.

SNA angle

Used in Steiner’s Analysis

Angle: Between SN plane and the line joining nasion and point A

Importance: Indicates relative antero-posterior positioning of the maxilla about the cranial base

Value: 82°

Changes:

• Increased – Prognathic maxilla [Class 2]
• Decreased – Retrognathic maxilla [Class 3]

Question 7. Occlusal Plane.
Answer.

Occlusal Plane

It is a denture plane

Extend: Occlusion of posterior to interiors

Significance Of Occlusal Plane:

• The angle formed between the occlusal plane and the SN plane is known as the occlusal plane angle
• It indicates the relation of the occlusal plane to the cranium and face
• It has a mean value of 14.5 degrees

Question 8. Cant of Occlusion.
Answer.

Cant of Occlusion

• Used in Down’s analysis
• The angle between the occlusal plane and the FH plane
• Value: 9.3°
• Range: 1.5 – 14°
• It measures the slope of the occlusal plane relative to the FH plane

Question 9. ANB angle.
Answer.

ANB angle

Used in Steiner’s analysis

Angle: Between line joining nasion to point A and nasion to point B

Significance Of ANB angle: Relative position of maxilla to the mandible

Value: 2°

Changes:

• Increase – Skeletal Class 2
• Decrease – Skeletal Class 3

Question 10. Point A.
Answer.

Point A

It is an anatomic landmark of cephalometric

• The deepest point in the midline between the anterior nasal spine and alveolar crest between two central incisors
• Synonym: Subspinale
• Line/Plane derived from it:
  • A.Pog line
  • A.B plane angle – Used in Down’s Analysis
  • The angle of convexity – Used in Down’s Analysis
  • SNA angle – Used in Steiner’s Analysis
  • ANB angle – Used in Steiner’s Analysis

Question 11. Key Ridge.
Answer.

Key Ridge

• It is an anatomic landmark of cephalometric
• It is the lowermost important point on the contour of the anterior wall of the infratemporal fossa
• In edentulous cases, it is useful in determining occlusion

Question 12. Y axis.
Answer.

Y-axis

Used in Down’s analysis

Synonym: Growth axis

Angle – Between sella – gnathion line and FH plane

Value: 59° [53-66°]

Variations Of the Y axis:

• Increased – Class 2
• Decreased – Class 3

Importance Of Y axis:

• Determines growth pattern
• Greater – Vertical growth
• Lesser – Horizontal growth

Question 13. Wit’s Appraisal.
Answer.

Significance Of Wits’s Apprasial: Measures relation of maxilla to mandible

Use: In nonreliable ANB cases

Obtained by:

Variation Of Wit’s Appraisal:

• Males – BO ahead of AO
• Females – BO coincides with AO
• Skeletal Class 2 – BO behind AO
• Skeletal Class 3 – BO ahead of AO

Question 14. FMA.
Answer.

Cephalometric FMA:

• FM – plane – extending from orbitale to prior
• Mandibular plane
• The angle formed between these two
• Value – 25°

Clinical FMA:

• The angle formed between the lower border of the mandate ble and Frankfort horizontal plane
• Normally intersect at the occipital region

Significance Of FMA:

• Indicates growth pattern
• If coincides
  • At occipital – Normal
  • Beyond occipital – Horizontal
  • Anterior to occipital – Vertical

Question 15. Cephalogram
Answer.

Cephalogram

• Cephalogram is a cephalometric radiography introduced by Holly Broadbent and Herbert Hofrath in 1931

Types Of Cephalogram:

• Lateral cephalogram – provides a lateral view of the skull
• Frontal cephalogram – provides an anteroposterior view of the skull

Cephalogram Uses:

For diagnosis:

• Study of dental and soft tissue structures
• Classify skeletal and dental abnormalities
• Assess facial type
• For treatment planning
• For presuming the changes
• For predicting growth-related changes
• For research work

Question 16. Tweed’s triangle.
Answer.

Formed by:

• Frankfort mandibular plane angle [FMPA] – 25°
  • Angle by the intersection of the FH plane and mandibular plane
• Incisor mandibular plane angle [IMPA] – 90°
  • The angle formed by the intersection of the long axis of lower incisor and mandibular plane
• Frankfort mandibular incisor angle [FMIA] – 65°
  • The angle formed by the long axis of lower incisor and FH plane

Cephalometrics Viva Voce

• Y axis indicates the direction of the growth pattern of the mandible
• Richard A. Riedel introduced the ANB angle
• Cephalometric tracing is made on the frosted surface of an acetate tracing sheet
• E plane is also called the aesthetic plane
• Normal facial angle – 82-95°
• The normal value of the Y axis in Down’s analysis – 53-66°
• The normal value of cant of occlusion – 1.5 – 14°
• Normal value of interincisal angle – 130-150°
• The normal mandibular plane angle in Steiner’s analysis is 29°
• Decreased SNB angle indicates mandibular retrognathism
• Decreased ANB angle indicates skeletal Class 3
• The decreased facial angle indicates skeletal class 2
• A decreased angle of convexity indicates the prognathic profile
• Increased AB plane angle indicates class 3
• Increased upper incisor to NA angle indicates proclined upper incisors
• Increased lower incisor to NB angle indicates proclined lower incisors
• The facial angle indicates antero-posterior positioning of the mandible to the upper face
• AB plane angle signifies the maxilla-mandibular relationship to the facial plane’

Orthodontics Lab Procedures Definitions

• Soldering
  • It is a process of joining metals by the use of a filler metal that has a lower fusion temperature than that of the metals being joined.
• Welding
  • Involves the joining of two metals without introducing a third metal.

Orthodontics Lab Procedures Important Notes

• Types of solders
  • Investment soldering
  • Freehand soldering
• Composition of flux
  • Borax glass – 55%
  • Boric acid – 35%
  • Silica – 10%
• Gases used for soldering.
  • Gas air/oxygen torch flame
  • Hydrogen
  • Natural gas
  • Acetylene
  • Propane

Orthodontics Lab Procedures Short Essays

Question 1. Soldering and Welding.
Answer.

Soldering: It is a process of joining metals by the use of a filler metal that has a lower fusion temperature than that of the metals being joined.

Types of soldering:

Investment soldering:

Indication: Presence of large contact area between metals

• In need of precision
  Procedure: By embedding metals in investment

Freehand soldering:

• Indication: Common orthodontic procedures
• Procedures: Soldering by holding metals precisely

Steps of freehand soldering:

• Clean the surfaces
• Assemble the parts
• Select proper solder and flux
• Select proper joint
• Flux application
• Application of solder
• Quenching

Indications of freehand soldering:

• Join parts of appliances
• Fastens attachments to bands

 

Welding: Involves joining of two metals without introducing a third metal

Welding Procedure:

• Selection of electrode
• Placement of metals between 2 electrodes
• Maintain pressure on it
• Switch on electrode
• Keep it for sometime

Indications of welding:

• For banding
• For brackets and molars tubes

Question 2. Shape Memory Alloy – Nickel titanium alloy is a shape memory alloy.
Answer.

Synonym: Nitinol (Nickel Titanium Naval Ordinance Laboratory)

Inventor: William R. Buchler

Introduced by: Andersen in 1971

Properties of shape memory alloy:

• Super elasticity
• Shape memory
• High working range
• Low stiffness

Advantages of shape memory alloy: Procedure low and more constant force on teeth

Disadvantages of shape memory alloy:

• Cannot be bent
• Cannot be soldered/welded

Orthodontics Lab Procedures Short Questions And Answers

Question 1. Solder and Flux.
Answer.

Solder: Alloys used as filler metal between two metals

Properties of solder:

• Resist tarnish and corrosion
• Low fusion temperature
• Free-flowing
• Similar strength as the metals to be joined
• Colour similar to metals to be joined
• Ex – Gold, silver, copper, zinc, tin and nickel

Flux: means flowing

• Important for good solder joint

Uses of flux:

• Removal of oxide coating of solder
• Dissolves impurities

Read And Learn More: Orthodontics Short And Long Essay Question And Answers

• Prevents oxidation
• Reduces melting point

Flux Composition:

• Borax glass – 55%
• Boric acid – 35%
• Silica – 10%

Question 2. Antiflux.
Answer.

Flux:

• Means flowing
• Important for good solder joint

Uses of Flux:

• Removal of oxide coating of solder
• Dissolves impurities
• Prevents oxidation
• Reduces melting point

 Composition of Flux:

• Borax glass – 55%
• Boric acid – 35%
• Silica – 10%

Antiflux:

• Confines flow of molten solder
• Ex. Lead pencil markings
  • Graphite lines
  • Iron rouge

Question 3. Gases used for soldering.
Answer.

• Gas air/oxygen torch flame
• Hydrogen
• Natural gas
• Acetylene
• Propane

Question 4. Sensitization and stabilization of stainless steel.
Answer.

Sensitization: At 400-900 c, stainless steel resists corrosion and tarnish

• At lower temperatures, carbon reacts with the surface granules and forms chromium iron carbide causing tarnish and corrosion
• This can be prevented by decreasing carbon content or by cold working of stainless steel

Stabilization:

• The process to prevent sensitization
• For it, two/more metals are added, for example, titanium, niobium

Question 5. Irreversible Hydrocolloids (Alginate).
Answer.

Advantages of Irreversible Hydrocolloids:

• Easy to manipulate
• Comfortable
• Inexpensive
• Pleasant taste
• Hydrophilic
• Biocompatible

Disadvantages of Irreversible Hydrocolloids:

• Tears easily, and require immediate pouring
• Incompatible with epoxy resin

Composition of Irreversible Hydrocollids:

• Potassium Alginate
• Calcium sulfate dehydrate
• Potassium sulfate
• Diatomaceous earth
• Sodium phosphate
• Glycol
• Pigments
• Sodium silicofluoride

Orthodontics Lab Procedures Viva Voce

• Gold foil filling is the best example of cold welding
• Welding is a process of joining two metals directly under pressure
• The space provided between the metals to be joined is 0.5 mm
• Borax glass is the main component of dental flux
• The oxidized layer in the metallic surfaces to be joined is removed by antireflux
• Nickel in dental solder gives a white color to the solder
• The copper component in solder gives the yellow color
• Fusion temperature exceeding 150 degrees is used for brazing

Surgical Orthodontics Important Notes

• Pericision/circumferential suprarenal fibrotomy
  • Performed in case of rotations
  • In it, gingival fibres are incised to prevent relapse
  • Performed under LA with several 11-knife

Surgical Orthodontics Long Essays

Question 1. Classify surgical orthodontics. Discuss minor surgical orthodontic procedures.
Answer.

Surgical Orthodontic Procedure

Minor Procedure:

• Extractions
  • Therapeutic
  • Serial
  • Carious teeth
  • Malformed teeth
  • Impacted teeth
  • Supernumerary teeth
• Surgical uncovering of teeth
• Frenectomy
• Pericision
• Transplantation of teeth
• Corticotomy

Major procedures:

• Orthodontic surgeries
• Cosmetic surgeries
• Surgical corrections of clefts
• Surgical RME

Minor Surgical Procedures:

Extraction:

• Therapeutic extraction
  • To gain space
  • Should be atraumatic
• Surgical extraction
  • Removal of some deciduous teeth followed by specific permanent
  • Done during mixed dentition period
  • In severe arch-length deficient
• Supernumerary teeth
  • It leads to malocclusion or development of cyst
  • Thus, needs to be extracted

Surgical Uncovering of Impacted Teeth:

• Impacted teeth cause deflection of teeth
• Common – Maxillary permanent canine
  • Cause – Arch length deficiency, Mucosal/bony barriers
  • These barriers are removed to allow the eruption of impacted teeth

Frenectomy:

• Abnormal labial frenum causes mid-line diastema
• Frenum is excised along with attached fibrous tissue
• Undermining of the mucosa of the lip is done

Corticotomy:

Indication of Corticotomy:

• Proclination with spacing

The procedure of Corticotomy:

Precision:

Synonym – Circumferential Supra-crystal Fibrotomy [CSF]

• It is the procedure to counter the relapse tendency of stretched gingival fibres

Cause of Relapse: Failure of adaptation of transeptal and alveolar crystal group of gingival fibres to the new tooth position

The procedure of Relapse:

Surgical Orthodontics Short Essays

Question 1. Genioplasty.
Answer.

• Used as an adjunctive.

Types of Genioplasty:

Augmentation genioplasty:

• Horizontal osteotomy cut given
• Mobilize the segment and fix

Reduction genioplasty:

• Horizontal osteotomy cut given
• Setback fragment and fix it

Straightening genioplasty:

• Horizontal osteotomy cut given
• Shift it laterally and fix it

Lengthening genioplasty:

• Horizontal osteotomy cut given
• Shift fragment inferiorly

Read And Learn More: Orthodontics Short And Long Essay Question And Answers

• Sandwich grafts in between them

Question 2. Orthognathic Surgery in Maxilla.
Answer.

• Carried out along with orthodontic therapy to correct dentofacial deformities
• Involves fracturing of facial skeletal parts and repositioning them as desired

Steps of Orthognathic Surgery:

• Diagnosis
• Pre-surgical orthodontics
• Mock surgery
• Surgery and stabilization
• Post-surgical orthodontics

Surgical Orthodontics Short Questions And Answers

Question 1. Frenectomy.
Answer.

• Abnormal labial frenum causes midline diastema
• Frenum is excised along with attached fibrous tissue
• Undermining of the mucosa of the lip is done

Question 2. Precision.
Answer.

• Synonym – Circumferential Supra-crystal Fibrotomy [CSF]
  • It is the procedure to counter the relapse tendency of stretched gingival fibres
• Cause of Relapse: Failure of adaptation of transeptal and alveolar crystal group of gingival fibres to the new tooth position

Procedure of Pericision:

Surgical Orthodontics Viva Voce

• Precision is done to prevent relapse of rotation of teeth.
• Precision involves surgical lysis of the gingival.

Retention And Relapse Definition

• Retention
  • Maintaining newly moved teeth in position, long enough to aid in stabilizing their correction.
• Relapse
  • It is the loss of any correction achieved by orthodontic treatment.

Retention And Relapse Important Notes

Types of retention:

• Limited retention:
  • Class 1 non-extraction
  • Deep bites
  • Class 1, Class 2 Div. 1 and Div. 2 extraction
• Natural retention:
  • Anterior cross bites
  • Serial extraction
  • Highly placed canines
  • Posterior crossbite
• Permanent retention:
  • Midline diastemas
  • Rotation
  • Class 2 div.2 deep bites
  • Abnormal musculature
  • Cleft palate patients

Types of retainers:

• Removable:
  • Hawely’s appliance
  • Begg retainers
  • Clip on retainers
  • Wrap-around
  • Kesling tooth position
  • Invisible retainers
• Fixed:
  • Fixed appliance
  • Banded canine to canine
  • Bonded lingual
  • Band and spur retainer

Causes of relapse:

• Periodontal ligament traction
• Growth related changes
• Bone adaptation
• Muscular forces
• Failure to eliminate the original cause
• Role of the third molar
• Role of occlusion

Retention And Relapse Long Essays

Question 1. Enumerate theories of retention. Add a note on causes of relapse.
Answer.

Retention

Definition of retention: By Moyers

• Maintaining newly moved teeth in position, long enough to aid in stabilizing their correction.

Theorems: 9 theorems by Riedel and 10th Moyers

• Moved teeth return to their former position
• Elimination of cause prevents relapse
• Malocclusion should be over-corrected
• Proper occlusion should be achieved
• Bone and adjacent tissues should be provided time to readapt around moved teeth
• Lower incisors must be placed upright
• Corrections carried out during growth periods are less likely to relapse
• Farther the teeth have been moved, the lesser the risk of relapse
• Arch form, particularly mandibular, cannot be permanently altered by appliance therapy
• Many treated malocclusions require permanent retaining devices

Types of retention

Limited retention:

• Class 1 non-extraction
• Deep bites
• Class 1, Class 2 Div. 1 and Div. 2 extraction

Natural retention:

• Anterior crossbite
• Serial extraction
• Highly placed canines

Read And Learn More: Orthodontics Short And Long Essay Question And Answers

• Posterior crossbite

Permanent retention:

• Midline diastema
• Rotation
• Class 2 div.2 deep bites
• Abnormal musculature
• Cleft palate patients

Retainers: Passive appliances that help in maintaining and stabilizing the position of teeth long enough to permit readaptation of supporting structures

Types of retainers

• Removable retainers
  • Hawely’s appliance
  • Begg retainer
  • Clip on retainer
  • Wrap-around
  • Kesling tooth position
  • Invisible retainer

• Fixed retainers
  • Fixed appliance
  • Banded canine to canine
  • Bonded lingual
  • Band and spur retainer

Relapse: It is the loss of any correction achieved by orthodontic treatment

Causes of Relapse:

• Periodontal ligament traction:
  • Due to orthodontic tooth movement, PDL and gingival fibres are stretched
  • They readapt to the newly moved teeth
  • Different fibres require different periods for it
  • Principle fibres – 4 weeks
  • Gingival fibres – 40 weeks
  • If not provided sufficient time, leads to relapse
• Growth-related changes:
  • Due to the continuation of abnormal growth pattern
• Bone adaptation:
  • Normal, bony trabeculae are arranged perpendicular to the long axis of teeth
  • During orthodontic treatment, arranged parallel to the long axis of teeth
  • After treatment returns to original position
• Muscular forces:
  • Abnormal muscle balance
• Failure to eliminate the original cause:
  • The cause should be properly diagnosed and a treatment plan must be done accordingly
• Role of the third molar:
  • Eruption time – 18-21 years i.e. usually after completion of orthodontic treatment
  • Produces pressure
  • Results in crowding recurrence
• Role of occlusion:
  • Failure to eliminate habits like bruxism
  • Failure to achieve centric occlusion

Retention And Relapse Short Essays

Question 1. Define retention, and explain schools of retention.
Answer.

Retention: Maintaining newly moved teeth in position long enough to aid in stabilizing their correction – By Moyers

Schools Of Retention:

• Occlusion School – By Kingsley
  • Proper occlusion is important as it safeguards the stability in the new position of patients
• Apical base school:
  • By Alex Lundstorm, Mc.Cauley and Nance
    • By Alex Lundstorm – Suggest apical base as an important factor in the correction of malocclusions
    • Mc. Cauley – Added inter-canine and intermolar width should be maintained
    • Nance – Noted arch length cannot be permanently increased to a major extent.
• Mandibular Incisor School – Grieves and Tweed
  • Stability increases if mandibular incisors are placed upright
• Musculature School – Rojer
  • Functional muscle is necessary for post-treatment stability.

Question 2. Permanent retention.
Answer.

Conditions of Permanent Retention:

• Midline diastema
• Severe rotations
• Generalized spacing
• Patients with abnormal musculature
• Arch expansion
• Cleft palate patients
• Class 2 div.2 deep bite

Appliances Used:

Retainers: Passive appliances that help in maintaining and stabilizing the position of teeth long enough to permit readaptation of supporting structures

Types of Retainers:

Removable Retainers

Removed and reinserted at patient’s will

• Hawely’s Appliance – By Charles Hawley
  • Consists of – short labial bow, Adam’s clasps on molars

        Modifications of Hawely’s appliance:

• • Long labial bow – for space closure distal to the canine
  • Fitted labial bow – Excellent retention
  • Soldered labial bow
  • Anterior bite plane – for deep bite

       Advantages of Hawley’s appliance:

• • Simple and easy to fabricate
  • Comfortable to patient
  • Acceptable

Begg retainer – By P.R. Begg

Consists Of Begg retainer:

• Labial wire till last erupted molar, curves around it
• Spans palate – Acrylic portion

Advantage of Begg retainer: Eliminate risk of spacing between canine and premolar

Clip on retainer:

• Labial wire covering incisors and canine then wrapped around same teeth lingually

Wrap around retainer:

• Wire wrapped around all erupted teeth labially as well as lingually

Keeping tooth position – By H.D. Kesling

• Thermoplastic rubber covering the clinical crown of upper and lower teeth
• This leads to difficulty in speech and TMJ problems

Invisible retainers: Covers clinical crowns and part of the gingiva on a transparent thermoplastic sheet

Fixed retainers

• Fixed appliance itself
• Banded canine-to-canine retainer
  • Thicker wire over lingual surface soldered on canine bands
• Bonded lingual retainers
  • Stainless steel/Etglioy wire is etched and bonded lingually over interiors
• Band and spur
  • For rotation
  • The moved tooth is bands and spur are soldered over it.

Retention And Relapse Short Questions And Answers

Question 1. Define retention.
Answer.

By Moyers

• Maintaining newly moved teeth in position, long enough to aid in stabilizing their correction

Question 2. Define relapse.
Answer.

• It is the loss of any correction achieved by orthodontic treatment

Question 3. Causes of relapse.
Answer.

• Periodontal ligament traction
• Due to orthodontic tooth movement, PDL and gingival fibres are stretched
• They readapt to the newly moved teeth
• Different fibres require different periods for it
• Principle fibres – 4 weeks
• Gingival fibres – 40 weeks
• If not provided sufficient time, leads to relapse

Growth-related changes:

• Due to the continuation of abnormal growth pattern

Bone adaptation:

• Normal, bony trabeculae are arranged perpendicular to the long axis of teeth
• During orthodontic treatment, arranged parallel to the long axis of teeth
• After treatment returns to the original position

Muscular forces:

• Abnormal muscle balance

Failure to eliminate the original cause:

• The cause should be properly diagnosed and a treatment plan must be done accordingly

Role of the third molar:

• Eruption time – 18-21 years i.e. usually after completion of orthodontic treatment
• Procedures pressure
• Results in crowding recurrence

Role of occlusion:

• Failure to eliminate habits like bruxism
• Failure to achieve centric occlusion

Question 4. Conditions where retention is not required/Natural retention.
Answer.

• Anterior crossbite
• Serial extraction
• Highly placed canines
• Posterior crossbite

Question 5. Permanent retention.
Answer.

• Midline diastema
• Rotation
• Class 2 div.2 deep bites
• Abnormal musculature
• Left palate patients

Retention And Relapse Viva Voce

• According to Alex Lundstorm, the apical base is the key to retention
• According to Grieves and Tweed, mandibular incisors are a key factor in retention
• Full-time retention after comprehensive orthodontic therapy is needed for 4-5 months
• Upper anterior crossbite correction with no adequate overbite requires retention of 3-6 months
• Opening of premolar space is a drawback of standard Hawley retainer
• Prevention of wedging effect on extraction site by Hawley retainer can be attempted by long labial bow
• Relapse is the loss of any correction achieved by orthodontic treatment

Miscellaneous Short Essays

Question 1. Mandibular retroguathism.
Answer.

• Refers to more backward placement of jaw.

Features of retrognathism:

• Facial profile – convex
• Facial divergence – Posterior divergent
• Anteroposterior relation – Class 2
• Mento labial sulcus – Deep
• Hyperactive mentalis activity
• Reduced nasolabial angle

Treatment of retrognathism:

• In growing patients – Myofunctional therapy Ex. Activator, FR2
• In non-growing patients
  • Orthodontic camouflage – Extraction of 1st premolars
  • Mandibular advancement

Question 2. Causes of Canine impaction.
Answer.

Question 3. Mechanism of Bone Growth.
Answer.

Bone Deposition and resorption

• Together with bone deposition and resorption is called bone remodeling

Effects of bone deposition and resorption:

• Change in size
• Change in shape
• Change in proportion
• Change in bone relationship with adjacent structures

Cortical Drift

• Movement of bone occurs towards bone deposition called cortical drift
• If bone deposition and resorption are equal
• Thickness of bone remains, constant
• If bone deposition is more than resorption
• The thickness of bone is more toward the deposition

Displacement

• Movement of whole bone as a unit

Primary displacement:

• Displacement of bone as a result of its own growth

Secondary displacement:

• Displacement of bone as a result of growth of adjacent bone

Question 4. Causes of Root resorption.
Answer.

Question 5. Envelope of Discrepancy.
Answer.

• It helps in treatment planning
• The choice of treatment depends on the movement of the teeth required
• By orthodontic (fixed mechanotherapy) the tooth can be moved only at a specific distance

Read And Learn More: Orthodontics Short And Long Essay Question And Answers

• If the movement of teeth beyond this limit is required, orthopedic/functional appliances can be used
• Beyond this limit, the treatment of choice is orthognathic surgery

Question 6. Self-correcting Anomalies/Transient Malocclusions.
Answer.

Miscellaneous Short Questions And Answers

Question 1. Apertognathia.
Answer.

It is a condition in which there is space between upper and lower teeth when some teeth are in contact at one/more points

Question 2. Growth site and Growth center.
Answer.

Growth site:

• These are growth fields that have a special significance in the growth of a particular bone
• Posses intrinsic growing potential
  Example. Condyle, maxillary tuberosity

Growth Centres:

• These are growth sites that control the overall growth of bone
• Have growth potential
  Example. Epiphyseal plates of long bones

Question 3. Cranial Base Flexure.
Answer.

• During the embryonic phase, the cranial base is flexed between the pituitary fossa and sphenoccipital junction
• It is accompanied by developing brain stem

Cranial Base Flexure Results

• Downward placement of foramen magnum
• Aids in increased neurocranial capacity
• Downward displacement of the face
  Age: 10th week of IU life, Angle – 65th

Question 4. Carpal Index.
Answer.

• One of the skeletal maturity indicator
• Used as a part of hand wrist
• Carpals – consist of eight small bones arranged in

Proximal Row

• Scaphoid
• Triquetral
• Lunate
• Pisiform

Distal row

• Trapezium
• Trapezoid
• capitate
• Humate
• These bones show specific patterns of appearance, ossification, and union
• These are compared with standards

Question 5. Torquing Auxillaries.
Answer.

Torquing Auxillarie Springs:

• Made of stainless steel /Ni – titanium
• Force exerted is directly proportional to the diameter and modulus of elasticity of the material of the wire
• Stainless steel exerts greater force

Question 6. Sterilization in Orthodontics.
Answer.

Definition: Defined as the destruction of all life forms

Types of Instruments:

• Critical – Penetrate the mucosa
• Semi-critical – Touches mucosa but does not penetrate
• Least critical – Surfaces touched during treatment

Instruments Requiring Sterilization:

• Mirrors
• Explorers
• Banding and bonding instruments
• Bands
• Pillers
• Ligature directors

Question 7. Growth Trends.
Answer.

By overlapping consequent cephalograms Tweed, designed a pattern of growth called “Growth trends”

Groups

Type A

• Simultaneous growth of maxilla and mandible
• 25% of case
• ANB angle unchanged

Type A subdivision

• Protruding maxilla
• ANB angle increased

Type B

• Increase in maxillary growth

Type B subdivision

• ANB angle large
• Unfavorable

Type C

• Increased growth of the mandible
• Decreased ANB angle

Type C Subdivision

• Mandibular incisors touches lingual surfaces of maxillary incisors

Question 8. Growth Curve.
Answer.

• Indicates the degree of difference between two growing individuals in all four planes including the time factor
• As everyone does not have the same growth pattern, deviation from normal growth pattern cannot be diagnosed
• Thus the growth of such individuals is compared with a standard growth chart

Question 9. Fontanelles.
Answer.

• They bridge the gap between bones that limit them.
• Made up of durameter, primitive periosteum and aponeurosis

Frontanelles Importance:

• Indicates brain development
• A depressed level indicates dehydration
• Increased level indicates increased intracranial pressure

Question 10. Safety valve mechanism.
Answer.

• Increase in inter-canine width is one of the important factor in overcoming incisal liability
• At the age of 12, maxillary anterior prolines such that inter-canine width increase

Significance of safety value mechanism:

• This increase in maxillary inter canine width hinders the forward growth of the mandible
• This increase in width behaves like it holds the forwardly growing mandible

Question 11. Curve of Spee.
Answer.

• It is antero-posterior curve of occlusion
• It begins from the tip of lower canine to the cusp tips of bicuspids and molars upto the condyle

Significance of curve of Spee:

• Normal value – 1.5 – 2mm
• If the curve is extended, it forms a circle of about 4 diameter
• It represent the axial alignment of lower teeth
• It requires a gradual progressive increased mesial tilting of teeth towards the molar

Question 12. Anterior bite plane and its mode of action.
Answer.

Uses of anterior bite plane: For treatment of deep bite

Mode of action:

• Consist of the flat ledge of acrylic behind the upper anterior
• When the patient bites the mandibular incisors contact the bite plane, thus dis occlude the posterior due to which they are free to erupt

Components of anterior bite plane:

• Adam’s clasp on molar – As a retainer
• Labial bow – Counter any forward component of force on upper anterior

Question 13. Orbital law of canine.
Answer.

• It is used in Simon’s classification
• Orbital plane perpendicular to Frankfort horizontal plane is used
• This plane is dropped down from the bony orbital margin directly under the pupil of the eye
• According to Simon, this plane should pass through the distal third of the upper canine
• This is known as “Simon’s law of canine “or” Orbital law of canine”

Orbital law of canine significance:

• It is used to describe malocclusion in a sagittal plane
• When the dental arch is farther from the orbital plane it is called protraction
• When the dental arch is closer then it is called retraction

Myofunctional Appliances Important Notes

• Definition of myofunctional applications
  • Myofunctional appliances are defined as loose fitting or passive appliances which harness natural forces of the oro-facial musculature that are transmitted to the teeth and alveolar bone through the medium of appliance
• Visual treatment objective [VTO]
  • Helps in realizing the therapeutic goals
  • Helps to motivate the patient to cooperate by making the patient realize the esthetic improvement
• Types of bionator
  • Standard appliance
  • Class 3 appliance
  • Open bite appliance
• Classification of myofunctional appliances
  • According to Tom Graber
    • Group A – Teeth supported Ex. Catlan’s appliance
    • Group B – Teeth/tissue supported
      Example. Activation
    • Group C – Vestibular positioned Ex. Lip bumper
  • Removable – Activator
    • Semifixed – Bass appliance
    • Fixed – Herbst
  • Classical – Activator
    • Hybrid – Bass
  • Teeth borne passive – Activator
    • Tooth borne active – Elastic open activator
    • Tissue-borne passive-oral screen
    • Tissue borne active – FR
    • Functional orthopaedic magnetic appliance
• Frankel regulator

Myofunctional Appliances Long Essays

Question 1. Classify myofunctional appliances. Name components of FR – 2 and describe its mode of action.
Answer.

Classification Of Myofunctional Appliances:

• According to Tom Graber
  • Group A – Teeth supported Ex. Catlan’s appliance
  • Group B – Teeth/tissue supported
    Example. Activation
  • Group C – Vestibular positioned Ex. Lip bumper
• Removable – Activator
  • Semifixed – Bass appliance
  • Fixed – Herbst
• Classical – Activator
  • Hybrid – Bass
• Teeth borne passive – Activator
  • Tooth borne active – Elastic open activator
  • Tissue-borne passive-oral screen
  • Tissue borne active – FR
  • Functional orthopaedic magnetic appliance

Frankel Appliance

• It is myofunctional appliance developed by Professor Rolf Frankel of Germany

Components Of Myofunctional Appliances:

Acrylic component:

• Buccal shields
  • Extends deep into the vestibule
  • Helps in unrestricted dentoalveolar development
  • Also causes periosteal bone deposition
• Lips pads
  • Helps in the elimination of abnormal perioral muscle activity
  • Eliminates lower lip trap
  • Causes periosteal pull resulting in bone growth
• Lower lingual pad
  • Stimulates protractor muscles of the mandible by activating proprioceptors

Wire component:

• Labial bow
  • Adapted on labial surfaces of the lower anteriors
• Canine extensions
  • Eliminates restrictive muscle function
  • Helps in transverse development in the canine region
• Palatal bow
  • Prevents supra eruption of first permanent molars

Read And Learn More: Orthodontics Short And Long Essay Question And Answers 

• Upper lingual wire
  • Runs between the upper canines and first deciduous molars
• Lower lingual springs
  • Prevents supra eruption of the lower incisors
  • Screens the tongue pressure from lower incisors
  • For proclaiming the lower incisors actively
  • Causes bite opening by the relative intrusion

Lingual Cross Over Wire:

• Runs between mandibular first and second premolar

Mode Of Action Of Frankel Appliance:

Increase in transverse and Sagittal intra-oral space:

• Buccal shields and lip pads:
  • Eliminates abnormal muscular forces
  • Favours forces from tongue
  • Exerts outward pull on connective tissue and muscles
  • This transmits force on the bone
  • Results in bone formation
  • Leads to lateral movement of dental alveolar region
• Increase in vertical space:
  • Frankel appliance does not contact posterior teeth
  • Thus, they are free to erupt
  • This leads to an increase in vertical intra-oral space
• Mandibular protraction:
  • By lingual pads
  • These apply pressure on the lingual alveolar process
  • Causes activation of protractor muscles
  • Position the mandible mesially
• Muscle function adaptation:
  • Overcomes abnormal muscular forces
  • Rehabilitates muscles
  • Causes muscle pull
  • This leads to bone formation
  • Massages soft tissues
  • Improves blood circulation
  • Improves muscle tone
  • Prevent hyperactivity of mentalis
  • Eliminates lip trap
  • Establishes lip seal

 

Question 2. Define and classify myofunctional appliances. Discuss indications and mode of action of the activator.
Answer.

Definition:

• Myofunctional appliances are defined as loose fitting or passive appliances which harness natural forces of the oro-facial musculature that are transmitted to the teeth and alveolar bone through the medium of appliance

Classification Of Myofunctional Appliances:

• According to Tom Graber
  • Group A – Teeth supported Ex. Catlan’s appliance
  • Group B – Teeth/tissue supported
    Example. Activation
  • Group C – Vestibular positioned Ex. Lip bumper
• Removable – Activator
  • Semifixed – Bass appliance
  • Fixed – Herbst
• Classical – Activator
  • Hybrid – Bass
• Teeth borne passive – Activator
  • Tooth borne active – Elastic open activator
  • Tissue-borne passive-oral screen
  • Tissue borne active – FR
  • Functional orthopaedic magnetic appliance

Activator Of Myofunctional Appliances:

• Activator is myofunctional appliance described by Andresen and Haupl

Indications Of Myofunctional Appliances:

• Class 1 open bite
• Class 1 deep bite
• Class 2 div. 1
• Class 2 DDiv 2
• Class 3
• Preliminary treatment
• Post-treatment retention
• Decreased facial height

Mode of Action Of Myofunctional Appliances:

• Prevents dentoalveolar growth of maxilla
• Moves it distally
• Move mandible forward
• Stretches elevator muscles
• Adaptation of condyle

Question 3. Classify myofunctional appliances. Describe indications, construction and trimming of the activator.
Answer.

Classification Of Myofunctional Appliances:

• According to Tom Graber
  • Group A – Teeth supported Ex. Catlan’s appliance
  • Group B – Teeth/tissue supported
    Example. Activation
  • Group C – Vestibular positioned Ex. Lip bumper
• Removable – Activator
  • Semifixed – Bass appliance
  • Fixed – Herbst
• Classical – Activator
  • Hybrid – Bass
• Teeth borne passive – Activator
  • Tooth borne active – Elastic open activator
  • Tissue-borne passive-oral screen
  • Tissue borne active – FR
  • Functional orthopaedic magnetic appliance

Activator Of Myofunctional Appliances:

• Activator is myofunctional appliance described by Andresen and Haupl

Indications Of Myofunctional Appliances:

• Class 1 open bite
• Class 1 deep bite
• Class 2 div. 1
• Class 2 Div 2
• Class 3
• Preliminary treatment
• Post-treatment retention
• Decreased facial height

Construction Of Myofunctional Appliances:

Trimming:

For Vertical control: 

• Intrusion:
  • Acrylic – Over incisal edge/cusp tips
  • Labial bow – Below the height of the contour initially
• Extrusion:
  • Acrylic – Lingual surface
  • Labial bow – Above the height of contour gingivally
    For Sagittal control:
  • Protrusion
  • Acrylic – lingual surface
  • Labial bow – Passive, away from teeth

Retrusion:

• Acrylic – Away from the lingual surface
• Labial bow – Active

Movement of posterior teeth in the sagittal plane:

• In class 2 – Acrylic over the mesial lingual surface of maxillary molars
• Distolingual surface of mandibular molars

Movement of teeth in the transverse plane:

 

Myofunctional Appliances Short Essays

Question 1. Jasper jumper.
Answer.

Jasper jumper is a flexible, fixed tooth-borne appliance introduced by Jasper in 1980

Jasper jumper Indications:

• Class 2 malocclusion with maxillary excess and mandibular deficiency

Effects Of Jasper jumper

• Skeletal effects:
  • Holds and displaces maxilla distally with a small shift of point A distally
  • Clockwise rotation of the mandible
  • Forwarded movement of condyles
• Dental changes:
  • Posterior tipping and intrusion of upper molars and palatal tipping of maxillary incisors
  • Anterior translation and tipping of mandibular teeth and intrusion of mandibular incisors

Jasper jumper Advantages:

• It produces continuous forces
• Allows a greater degree of mandibular freedom
• It is easier to maintain better oral hygiene

Question 2. Name components of FR2 and describe the uses of buccal shields.
Answer.

Components Of FR2:

Acrylic component:

• Buccal shields
• Lip pads
• Lower lingual pad

Wire component:

• Labial bow
• Canine extensions
• Palatal bow
• Upper lingual wire
• Lower lingual springs
• Lingual cross-over wire
• Support wire for lip pads

Use of Buccal Shields:

• Prevents abnormal muscular forces
• Creates forces on tissue
• This leads to bone formation
• Rehabilitates muscles
• As it stands away from posterior teeth, it allows their eruption

Question 3. Mode of action of functional appliance.
Answer.

Force Application:

Force Elimination by

• Bite planes – Effects:
  • Disocclude the posterior teeth
  • Differential eruption of posteriors
  • Intrusion of incisors
  • Downward and backward mandibular rotation
  • Reduces mandibular prognatism
• Shields/Screens – Effects:
  • Prevents muscular forces on dentoalveolar structures
  • Allows unrestricted growth of the jaw
• Construction bite – Effects:
  • Displaces mandible from its rest position
  • Stretches muscles
  • Displaces mandible in sagittal and transverse plane

Question 4. Case Selection for Functional Appliances.
Answer.

Factors Considered:

Age – Growing patient:

• Between 10 years of age and pubertal growth phase

Social considerations:

• Patients living far from the clinic
• Hostelites

Dental considerations:

• Uncrowded cases
• Local irregularities

Skeletal considerations:

• Moderate to severe skeletal class 2 malocclusions
• Low angle cases
• High-angle cases with deep bites
• Class 2 Division 2
• Mild class 3 malocclusions

Question 5. Oral Screen.
Answer.

Synonym – Vestibular Screen:

• Introduced by Newell in 1912

Principle Of Oral Screen:

• Application of muscular forces to teeth by applying forces of circumoral to teeth
• Elimination of forces to teeth and allow them to move due to forces exerted by the tongue

Oral Screen Indication:

• Interception of habits
• Treatment of mild malocclusions
• For muscular exercises
• Correction of mild anterior proclination

Management Of Oral Screen:

• Frequency of wear – During the night 2-3 hours during day time

Question 6. Frankel 2.
Answer.

Uses of Frankel 2 – For treatment of class 2 division 1 and division 2 malocclusion.

Components Of Frankel 2:

Acrylic:

• Buccal shields
• Lip pads
• Lower lingual pad

Wire:

• Palatal bow
• labial bow
• canine extension
• Upper lingual wire
• Lingual cross-over wire
• Support wire
• Lower lingual spring

Functions Of Frankel 2:

Acrylic components:

• Eliminate the muscle as well as lip function over the dentoalveolar segment

Wire component:

• Palatal bow – Prevent supra eruption of posteriors
• Canine loops – Help in transverse development in the canine region
• Labial bow – Passive
• Lingual stabilizing bow – Prevents lingual tipping of incisors
• Lower lingual springs – Screen tongue pressure
• Procline lower incisors
• Lingual cross-over wire
• Labial support wires – Support lip pads

Question 7. Explain the treatment procedure in a child of 8 years with a deficient maxilla, the appliance used and the mode of action.
Answer.

An 8 years old child is a growing child

• Thus my function appliance can be used to facilitate the change
• Among them, Frankel regulator 3 can be used

 

 

Mode of Action:

• In transverse and sagittal intraoral space
  • By acrylic component
• In vertical space
  • As the appliance is kept free from posterior teeth
• Muscle function adaptation
  • Overcomes abnormal perioral muscle activity

Question 8. Difference between Activator and Frankel Appliance.
Answer.

Question 9. Lip Bumper.
Answer.

Combined removable fixed appliance

Mode of Action:

• Force application/elimination

Uses Of Lip Bumper:

• Interception of lip biting habits
• Increases arch length
• Reduces crowding
• In the case of active mental activity
• For augmentation of anchorage
• For visualization of 1st molar
• Used as space regainer

Designs Of Lip Bumper:

• Stainless steel wire from one molar to the opposite molar passing away from the anterior
• Acrylic portion from canine to canine

Myofunctional Appliances Short Questions And Answers

Question 1. Herbst Appliance.
Answer.

By Emil Herbst in the early 1900’s.

Herbst Appliance Indications:

• Post-adolescent patient – treatment of Class 2
• TMJ disorders
• Interception of mouth breathing habit

Types Of Herbst Appliance:

• Banded Herbst
• Bonded Herbst

Effects Of Herbst Appliance:

• Class 1 molar correction
• Increase in mandibular growth
• Visualization of molar
• Reduction of over-jet
• Increase SNB and decrease SNA

 

 

 

Question 2. Twin Block.
Answer.

Design: Consist of inclined planes with intermaxillary and extraoral traction

Acrylic Components:

• Upper inclined plane – Covering lingual cusps of upper posterior till mesial ridge of upper 2nd PM [Premolar]
• Lower inclined plane – From lower anterior upto distal marginal ridge of 2nd premolar
  • The angle between them – 45

Wire components:

• Modified arrow head clasp – To retain the upper plate
• Molar tube – for attachment of face bow
• Jack screw – for maxillary expansion
• Interdental ball clasp – Retain lower plate

 

Myofuctional Appliances Viva Voce

• Reverse binator is used for Angle’s class 3 malocclusion
• Newell developed an oral screen
• Lip bumper should be worn for 24 hours a day
• Myofunctional appliances harness natural forces from perioral structures
• Oral screening works on both force application and force elimination principle
• Twin block is the most acceptable functional appliance

Cleft Lip And Palate Important Notes

Classification of cleft lip and palate:

• Davis & Ritchie Classification:
  Group 1 – Prealveolar clefts – Involves only lip
  Group 2 – Post alveolar clefts
  Involves palate and alveolar ridge
  Group 3 – Alveolar clefts
  Involves the palate alveolar ridge and lip
• Veau’s Classification [1931]:
  Group 1 – Involves only soft palate
  Group 2 – Involves palate up to incisive foramen
  Group 3 – Involves palate, lip, and alveolar ridge unilaterally
  Group 4 – Involves palate, lip, and alveolar ridge bilaterally
• Carnahan’s Stripped ‘Y’ Classification:

• • Block 1 and 6 – Lip
  • Block 2 and 5 – Alveolus
  • Block 3 and 4 – Hard palate anterior to incisive foramen
  • Block 7 and 8 – Hard palate posterior to the incisive foramen
• Lahshal Classification:
  • L – Lip
  • A – Alveolus
  • H – Hard palate
  • S – Soft palate
  • H – Hard palate
  • L – Lip

Treatment protocol:

• Immediately after birth
  • Pediatric consultation
• First few weeks
  • Hearing testing
• At 10 – 12 weeks
  • Surgical repair of lip
• 3 months after palate repair
  • Speech & language repair

Read And Learn More: Orthodontics Short And Long Essay Question And Answers 

• 3 – 6 years
  • Soft palate lengthening
• 5 – 6 years
  • Pharyngeal surgery
• At 7 years
  • Orthodontic treatment phase 1
• 9 – 11 years
  • Pre-alveolar bone grafting
• 12 years or later
  • Full orthodontic treatment phase 2
• 15 – 18 years
  • Placement of implant
• 18 – 21 years
  • Surgical advancement
• Final nose & lip revision
  • Rhinoplasty

Millard’s rule:

• Timing of cleft lip repair should be when hemoglobin is 10 gm%, age 10 weeks, weight 10 lbs, and total leukocyte count less than 10,000 per mm3

Cleft Lip And Palate Long Essays

Question 1. Write in detail about the development of the maxilla. Elaborate on etiology and treatment of cleft palate.
Answer.

Development Of Maxilla:

According to Moyers, development refers to all the naturally occurring unidirectional changes in the life of an individual from its existence as a single cell to its elaboration as a multi-function unit terminating in death.

Development Of Pre-Natal Maxilla:

• Around the 4th week of IU life, a prominent bulge appears on the ventral aspect of the embryo.
• Below it, there develops a depression called stomodeum, primitive mouth
• Downward projection developing from the mesoderm overlaps the stomodeum called the front-nasal process
• By around 4th week of IU life, the mandibular arch one of the 5 branchial arches develops
• The mandibular arch gives off a bud from its dorsal end called the maxillary process
• Thus, stomodeum is overlapped

Postnatal Growth Of Maxilla:

• Its growth occurs as

Displacement:

• Primary and secondary displacement leads to the growth of maxilla
• Primary displacement is seen in a forward direction due to the growth of its tuberosity in a posterior direction

Growth at sutures – Sutures involved are:

• Fronto – nasal
• Fronto – maxillary
• Zygomatic – temporal
• Zygomatico – maxillary
• Pterygo – palatine

Surface remodeling:

• Remodeling changes

Cleft Palate:

Etiology:

Predisposing Factors:

• Increased maternal age
  • Women who conceive later
• Racial
  • Mongolids are at greatest risk
• Blood supply
  • Reduces blood supply to the nasomaxillary arch

Treatment Of Maxilla:

The cleft palate is treated at different stages

• Birth-Initial assessment
  • Pre-surgical orthopedics
  • It is done by extra-oral strapping across the premaxilla

• 3 month – Primary lip repair
• 9 – 18 – Palate repair
• 2 years – Speech assessment
• 3 – 5 years – Lip revisional surgery
• 8 – 9 years – Initial interventional orthodontics
• 10 years – Alveolar bone grafts
• 12 – 14 years – Definitive orthodontics
• 16 years – Naal revisional surgery
• 17 – 20 years – Orthognathic surgery

Cleft Lip And Palate Short Essays

Question 1. Classify Cleft lip and Palate (1922).
Answer.

• Davis & Ritchie Classification:
  • Group 1 – Prealveolar clefts – Involves only lip
  • Group 2 – Post alveolar clefts
    • Involves palate and alveolar ridge
  • Group 3 – Alveolar clefts
    • Involves the palate alveolar ridge and lip
• Veau’s Classification [1931]:
  • Group 1 – Involves only soft palate
  • Group 2 – Involves palate up to incisive foramen
  • Group 3 – Involves palate, lip, and alveolar ridge unilaterally
  • Group 4 – Involves palate, lip, and alveolar ridge bilaterally
• Carnahan’s Stripped ‘Y’ Classification:

• • Block 1 and 6 – Lip
  • Block 2 and 5 – Alveolus
  • Block 3 and 4 – Hard palate anterior to incisive foramen
  • Block 7 and 8 – Hard palate posterior to the incisive foramen
• Lahshal Classification:
  • L – Lip
  • A – Alveolus
  • H – Hard palate
  • S – Soft palate
  • H – Hard palate
  • L – Lip

Question 2. Role of Dental Surgeon in treating Cleft lip and palate/Surgical closure of Cleft lip.
Answer.

Surgical Goals:

• Symmetric, well-contoured lip
• Preservation of all functional landmarks
• Minimum scar tissue formation

Timing For Repair:

• Millard’s Rule – Child of 10 weeks old, 10 pounds weight and 10 gm Hb – For cleft lip
• Cleft palate – 12-24 months of age

Surgery:

• Cleft lip – by rotational advancement
• Cleft palate – Closure of soft palate followed by hard palate

Dental Care:

• Sound teeth are essential for the development of the alveolar process
• Malocclusion occurs due to the collapse of the maxilla
• Orthodontic treatment is essential
• Expansion of maxillary arch may be done

Orthognathic Surgery:

• For deficient maxilla – maxillary advancement done/Distraction osteogenesis
• The corresponding retrusion of the mandible is done
• The amount of advancement is largely dependent upon the amount of scarring of the lip and palate and on the elasticity of soft tissues.

Cleft Lip And Palate Short Questions And Answers

Question 1. Cleft lip.
Answer.

Cleft lip

A cleft lip involves a breach in the continuity of the lip formed during facial development

Incidence: 1 in 600 – 1000 births

Associated Problems:

• Dental problems
• Esthetic problems
• Psychological problems
• Speech and hearing problems

Question 2. Teratogens.
Answer.

Teratogens

These are certain drugs/agents transmitted from infected mothers to features causing a disturbance in the growth and development of fetus

Examples Of Teratogens:

Infections Of Terotogens:

• Rubella virus
  • Syphilis

Drugs Of Terotogens:

• Cortisone
• Methotrexate
• Dilantin
• Valium
• Mercepto purine

Question 3. Clinical features of cleft lip and palate
Answer.

Clinical features of cleft lip and palate

• Hypoplastic maxilla
• Shallow gingivo labial sulcus
• Nose deformity
• Hypoplastic teeth
• Supernumerary teeth
• Congenitally missing teeth
• Germinated, fused, conical teeth
• Feeding difficulties
• Posterior crossbite

Cleft Lip And Palate Viva Voce

• German measles during 1st trimester of pregnancy can cause cleft lip/palate
• Cleft lip occurs due to disturbances in 6-8 weeks of IU life
• A cleft palate occurs due to disturbances in 8-10 weeks of IU life
• Cleft palate repair should be attempted between 12-24 months of age
• Cleft lip repair is carried out at 3 months of age
• Bifid uvula is the mildest form of cleft palate
• The lower lip is least affected by cleft
• Increased maternal age increases the risk of clefting
• Cleft lip arises from the failure of fusion between the medial nasal process and maxillary process

Age Factor In Orthodontic Short Questions And Answers

Question 1. Age factor in Orthodontics.
Answer.

Age factor in Orthodontics

Important for diagnosis and treatment planning

• Diagnosis: The following are considered
  • Transient malocclusion

Read And Learn More: Orthodontics Short And Long Essay Question And Answers 

• • Chronological age, skeletal age, and Dental age
  • Growth spurts
• Treatment and age:
  • Early treatment
    • Choose of appliances/therapy
    • Growth modifications possible
  • Late treatment – limited due to
    • Cessation of growth
    • Limited choice of therapy
    • Bone density
    • Periodontal diseases.

Management Of Malocclusion Important Notes

• Overbite
  • It is a vertical overlapping of anterior teeth
  • Value – 2-3 mm
  • Normal over-bite percentage – 33.33%

Management Of Malocclusion Long Essays

Question 1. Discuss a treatment plan for Angle’s Class 2 malocclusion.
Answer.

Treatment Objectives:

Class 2 Div. 1:

• Reduction of overjet
• Reduction of over-bite
• Correction of crowding
• Correction of molar relationship
• Correction of posterior cross-bite
• Normalizes muscles

Class 2 Div. 2:

• Correction of incisor relation
• Relief of gingival trauma
• Correction of crowding
• Correction of molar relation

Treatment Plan:

Growing Patient:

• Skeletal Class 2
  • Maxillary Prognathism
    • Headgear
  • Maxillarly Prognathism and Mandibular Retrognathism
    • Headgear & Myofunctional Therapy
  • Mandibular Retrognathism
    • Myofunctional Therapy
• Dental Class 2
  • Orthodontic Treatment

Non-Growing Patient:

• Skeletal class 2
  • Mild to Moderate Class 2
    • Orthodontic Camouflage
  • Severe Class 2
    • Maxillarly Prognathism
      • Surgical Maxillary Setback
    • Mandibular Retrognathism
      • Surgical Mandibular Advancement
    • Dental Class 2
      • Orthodontic Treatment

Treatment Approaches:

Growth modification:

• Reduces the severity of skeletal relationship
• Carried out during mixed dentition period before cessation of growth
• Involves

Correction of mandibular deficiency

• Mixed dentition period – Activator, FR 2
• After growth cessation – Herbst appliance
• Jasper Jumper

Correction of maxillary prognathism

• Face bow with headgear

Camouflage:

• Done by extraction of teeth
• To reduce overjet, overbite, molar relation, crowding, deep bite
• In excellent inter occupation – Extraction of the upper first premolar
• In unstable molar relation – Extraction of all first premolars

Surgical Correction:

• After cessation of growth
• mandibular advancement and maxillary set back is done

Question 2. Define Preventive, Interceptive orthodontics. Enumerate various modes of bilateral posterior cross bite correction and discuss any one.
Answer.

Definitions: Refer to Interceptive Orthodontic topics

Treatment Of Bilateral Posterior Cross Bite:

Crossbite elastics:

• Stretched between palatal surfaces of maxillary molars and buccal surfaces of mandibular molars
• Worn day and night
• Not worn for more than six weeks as it extrudes teeth

Coffin Spring:

Parts:

• Omega-shaped wire – In mid mid-palatal region
• Free ends of wire – Over slopes of the palate

Read And Learn More: Orthodontics Short And Long Essay Question And Answers 

Quad helix:

• Consist of four helices
• 2 anterior helices
• 2 posterior helices
• Connected by anterior bridge and palatal bridge

Rapid maxillary expansion:

Incorporating screws by splitting of mid-palatal suture

Management Of Malocclusion Short Essays

Question 1. Rotations.
Answer.

• They are tooth movements occurring around the long axis

Types Of Rotations:

• Mesiolingual/Disto-buccal rotation
• Disto lingual/Mesio-buccal rotation
  • Rotated interiors occupy less space
  • Rotated posterior occupies more space

Treatment Of Rotations:

• Space Management – For rotated anterior
• Removable appliances – Z spring along with labial bow
• Fixed appliances
  • Rotation wedges
  • Elastic threads engaged in lingual attachments
  • Force couple
• Retention – By circumferential suprarenal fibrotomy/precision

Question 2. Features of openbite.
Answer.

• Skeletal features:
  • Increase in lower anterior facial height
  • Decrease in upper anterior facial height
  • Increase in anterior and decrease in posterior facial height
  • Vertical maxillary increase
  • Long and narrow face
  • Steep anterior cranial base
  • Downward and forward rotation of mandible
  • Steep mandibular angle
  • Upward tipping of maxillary skeletal base
  • Divergent cephalometric planes
• Dental features:
  • Proclination of upper anterior
  • Narrow maxillalry arch
  • Upper and lower anteriors fail to over lap each other resulting in space between incisal edges of maxillary and mandibular anteriors

Question 3. Midline Diastema.
Answer.

Refers to any spacing/gaps existing in the midline of the dental arch

Etiology:

• Abnormal frenal attachment
• Ugly duckling stage
• Mesiodents
• Congenital missing teeth
• Trauma
• Hereditary
• Pressure habits

Diagnosis:

• Blanch test

Management Of Midline Diastema:

Removable appliance:

• Hawley’s appliance along with finger springs
• Split labial bow along with Adam’s clasp

Fixed Appliances:

• M springs
• Elastic threads
• Elastic chains
• Closed coil spring

Question 4. Management of Class 2 Div. 1 Malocclusion.
Answer.

Interception of Habits associated with it:

• By habit breaking appliances

During Mixed Dentition period:

• In maxillary Prognathism – Headgear
• In mandibular deficiency – Activator

Management of Dento alveolar – Class 2:

• Maintenance of premolar – to prevent mesial drifting of molars
• In premature loss of premolars – Space regainers

Management in Adults

• Camouflage
• Orthoguathic surgery
  • Mandibular advancement in mandibular retrognathism
  • Maxillary setback in Maxillary prognathism

Question 5. Treatment of Class 3 malocclusion.
Answer.

In Pre – Adolescent Child:

• Frankel 3
• Chin cup
• Anterior Facemask
• RME with anterior facemask
• 3D – screws

In Adolescent Child:

• Camouflage

Treatment During Adulthood:

• Orthognathic surgery
• Maxillary advancement by Lhefort 1 osteotomy
• Mandibular setback

Question 6. Open Bite.
Answer.

Condition in which there is lack of vertical overlap between maxillary and mandibular teeth.

Classification of Open Bite:

Based on location:

• Anterior open bite
• Posterior open bite

Based on components:

• Skeletal open bite
• Dental open bite

Etiology:

• Habits
• Abnormal tongue size
• Inherited

Abnormal Growth Pattern:

Management of Open Bite:

• Anterior open bite
  • Interception of habits
  • Box elastics
  • Chin cup with vertical pull head cap
  • Skeletal Open bite
  • Lefort I osteotomy
  • Muscle retraining exercises
• Posterior open bite
  • Interception of habits
  • Vertical elastics

Question 7. Anterior Crossbite.
Answer.

Crossbite: Condition where one/more teeth may be malposed abnormally, buccally or lingually, or labially about the opposing tooth/teeth.

Classification:

• Single tooth crossbite
• Segmental crossbite

Treatment of Anterior Crossbite:

• Use of tongue blade
• Catlan’s appliance
• Z spring
• Screw appliances
• Face mask
• Frankel 3
• Chin cup appliances

Question 8. Deepbite.
Answer.

Excessive vertical overlapping of mandibular anterior by maxillary anterior

Classification of Deepbite:

• Skeletal deep bite
• Dental deep bite

Etiology:

• Over eruption of anteriors
• Infra occlusion of molars

Treatment of Deepbite:

Removable appliances:

Anterior bite plane:

Parts: Adam’s clasps on molars

• Labial bow
• Acrylic behind maxillary anteriors

Mode of action:

As the posteriors erupts upto height of bite plane, its height is further increased.

Myofunctional appliances:

• Activator – Trimmed to allow extrusion of teeth
• Bionator.

Fixed Appliance Therapy:

Use of anchorage bends:

• Bends given in arch wire mesial to molar tubes
• Creates intrusive force on incisors

Reverse curve of spee:

• Resilient arch wires curved in a direction opposite to curve of spee

Utility arches:

• Arch wires are bent to by pass buccal teeth and engaging incisors

Question 9. Cross bite.
Answer.

Cross bite: Condition where one/more teeth may be malposed abnormally, buccally or lingually or labially with reference to the opposing tooth/teeth.

Classification of Cross bite

• Based on location
  • Anterior cross bite
    • Single tooth
    • Segmental
  • Posterior cross bite
    • Unilateral
    • Bilateral
• Based on the nature of crossbite
  • Skeletal crossbite
  • Dental crossbite
  • Functional crossbite

Etiology of Cross bite:

• Persistence of a deciduous teeth
• Arch length – tooth material discrepancy
• Presence of habits such as thumb sucking and mouth breathing
• Retarded development of maxillalry
• Narrow upper arch
• Collapse of maxillary arch
• Unilateral hypo or hyperplastic growth of any of the jaws
• Persistence of a deciduous teeth
• Arch length – tooth material discrepancy
• Presence of habits such as thumb sucking and mouth breathing
• Retarded development of maxilla
• Narrow upper arch
• Collapse of maxillary arch
• Unilateral hypo or hyperplastic growth of any of the jaws

Question 10. Anterior cross bite – etiology and management
Answer.

Definition of Anterior cross bite:

• It is defined as malocclusion resulting from lingual position of the maxillary anterior teeth in relationship with the mandibular anterior teeth.

Etiology of Cross bite:

• Persistence of a deciduous teeth
• Arch length – tooth material discrepancy
• Presence of habits such as thumb sucking and mouth breathing
• Retarded development of maxilla
• Narrow upper arch
• Collapse of maxillary arch
• Unilateral hypo or hyperplastic growth of any of the jaws

Management of Anterior Cross bite:

• Use of removable appliances
  • Use of tongue blade
    • It is used to treat single tooth anterior cross bite
    • It resembles ice cream stick
    • It is placed inside the mouth contacting th epalatal aspect of the tooth in crossbite
    • Rest the blade on the mandibular tooth
    • Patient is asked to rotate the oral part of blade upwards and forward
    • Repeat the exercise for 1-2 hours for about 2 weeks
  • Catlan’s appliance
    • It is lower inclinded plane constructed on maxillary arch
    • Have 45 angulation
    • Forces the maxillary teeth to a more labial position
  • Use of Z spring
    • Used to treat anterior cross bites involving one or two maxillary teeth
    • Used when there is adequate space for labialization
• Use of fixed appliances
  • Multilooped archwires or nickel titanium arch-wires are used for corrections
  • Indications
  • Dental anterior crossbites involving one or more teeth
  • Requirement of more tooth movement along with correction of crowding and rotations
  • Patients who exhibit minimal overbite

Management Of Malocclusion Short Questions And Answers

Question 1. Camouflage treatment.
Answer.

• Done by extraction of teeth
• To reduce overjet, overbite, molar relation, crowding, deep bite
• In excellent inter cuspation – Extraction of upper first premolars
• In unstable molar relation – Extraction of all first premolars

Question 2. Treatment of cross bite.
Answer.

Cross bite: Condition where one/more teeth may be malposed abnormally, bucally or lingually or labially with reference to the opposing tooth/teeth.

Classification Of Cross bite:

• Single tooth cross bite
• Segmental cross bite

Treatment Of Cross bite:

• Use of tongue blade
• Catlan’s appliance
• Z spring
• Screw appliances
• Face mask
• Frankel 3
• Chin cup appliances

Question 3. Imbrication.
Answer.

• Imbrication denotes especially lower incisors arranged in an irregular manner within the arch due to lack of space

Etiology of Imbrication:

• Tooth material-arch length deficiency
• Presence of supernumerary teeth
• Discrepancy in individual tooth size and shape
• Abnormal eruption path
• Rotation and transposition of tooth
• Premature loss of deciduous or prolonged retention of primary tooth

Question 4. Spacing.
Answer.

Etiology of Spacing:

• Disproportion between arch length and tooth material
• Alteration in tooth morphology
• Habits
• Macroglossia
• Premature loss of permanent

Treatment of Spacing:

• Interception of habits
• Removable appliances – labial bow
• Fixed appliance – Elastic chains/threads
• Use of crowns and prosthesis

Question 5. Causes of Crowding.
Answer.

• Arch length – tooth material discrepancy
• Supernumerary teeth
• Prolonged retentiono f deciduous
• Abnormal tooth size and shape
• Premature loss of deciduous causing drifting of adjacent
• Late mandibular growth
• Pressure from erupting third molars
• Reduction of inter-canine width

Question 6. Inclined Plane/Catlan’s Appliance.
Answer.

Uses Of Catlan’s Appliance:

• Treatment of anterior cross bite
• Palatally displaced maxillary incisor

Design Of Catlan’s Appliance:

• Acrylic/metal covering the maxillary incisor at 45 angulation

Disadvantages Of Catlan’s Appliance:

• Problem in speech
• Dietary restriction
• Supra eruption of posteriors

Question 7. Midline Diastema.
Answer.

Refers to any spacing/gaps existing in the midline of the dental arch.

Etiology Of Midline Diastema:

• Abnormal frenal attachment
• Ugly duckling stage
• Mesiodens
• Congenital missing teeth
• Trauma
• Hereditary
• Pressure habits

Management Of Malocclusion Viva Voce

• Rotated posterior teeth occupy more space than normal
• Rotated anterior teeth occupy less space than normal
• Brodie syndrome is scissor bite of first premolar of patient with class 2 division 1 malocclusion
• Narrow upper arch is feature of skeletal posterior cross bite
• Cross bite is abnormal occlusion occuring in transverse plane
• Cross elastic is stretched from palatal surface of maxillary posterior teeth to buccal surface of mandibular teeth
• Cross elastic is best to treat single posterior cross bite
• Coffin spring causes slow and bilateral symmetrical expansion
• Tongue blade therapy is used for anterior cross bite correction
• Flat anterior bite plane is used to correct deep bite in angle class 2 division 2 malocclusion
• Skeletal deep bite is seen in skeletal class 2 division 2
• Deep bite is increased overbite
• Skeletal open bite is treated in adults by surgical correction
• Anterior openbite can be treated in mixed dentition by vertical pull head gear with chin cup
• Closure of space in midline is done by composite build up it th espace is upto 0-2 mm
• Abnormal labial frenum is cause of midline diastema
• Class 3 bionator and Frankel appliance type 3 is used for class 3 malocclusion
• Sagittal split osteotomy is used for management of class 3
• Class 3 malocclusion management involves extraction of lower first premolars and second premolars
• Class 3 elastics are placed between upper molar to lower canine
• For management of class 2 requires correction of maxillary retrognathism
• Class 2 malocclusion is most difficult to treat
• Mild rotations can be treated by NiTi arch wires
• Face mask is used for treatment of class 3 malocclusion