Class ii malocclusion

GOOD MORNING

CLASS II MALOCCLUSION

GUIDED BY:DR. SURESH KANGNEDR. ANAND AMBEKARDR. PRAVINKUMAR MARUREDR. YATISHKUMAR JOSHIDR. CHAITANYA KHANAPURE

PRESENTED BY:

ABHIDNYA MADANSURE

CONTENT• Introduction• Classification• Aetiology• Clinical features• Treatment modalities• Conclusion• Reference

INTRODUCTION• E.H. ANGLE, in 1899

described normal occlusion as an

• “Evenly placed row of teeth arranged in a graceful curve with harmony between the upper and lower arches.”

Textbook of orthodontics by Dr. Samir Bishara

• Angle stated the following:

• In normal occlusion, the mesiobuccal cusp of the upper first molar is received in the sulcus between the mesial and distal (middle) buccal cusps of the lower first molar.


• The mesial incline of the upper canine occludes with the distal incline of the lower canine

• The distal incline of the upper canine occludes with the mesial incline of the buccal cusp of the lower first premolar.


CLASS II MALOCCLUSIONS

• "Distal" relationship of mandible to maxilla .

• The mesiobuccal cusp of the maxillary first permanent molar articulates mesial to the buccal groove of the mandibular first permanent.

Handbook of orthodontics by Robert Moyers; 4th edition


DIVISION 1-The maxillary incisors labioversion

DIVISION 2- maxillary central incisors are near normal or slightly in linguoversion

Maxillary lateral incisors have tipped labially.

CLASS II DIV 2 MALOCCLUSION CLASSIFICATION

• Type a• Type b• Type c &• Type d * Given in orthodontic diagnosis by Rakosi, Jonas and Graber

SUBDIVISION-When the distoclusion occurs on one side.

SKELETAL CLASS II MALOCCLUSIONS

• Skeletal discrepancies are often associated with dental Class II malocclusions.

A] Mandibular DeficiencyB] Maxillary Excess



• Because of small size of the ramus and body of the mandible downward and backward rotation of the mandible.

CLASS I

CLASS II

Natural dental compensation:

• Protrusive mandibular incisors.

• Narrow or constricted maxillary arch.

• Mesiolingual rotation of the maxillary first molars.

*Textbook of orthodontics by Dr. Samir Bishara

MOYER’S CLASSIFICATION OF

CLASS II

Vertical Class II

Class II

Horizontal Class II

A B C D E F 1 2 43 5


HORIZONTAL TYPES:TYPE A: (Dental)

• Normal skeletal profile.

• Maxillary dentition is protracted resulting in class2 molar relation.

• Increased over-jet and over-

bite

TYPE B:

• Mid-face prominence

• Normal mandible


TYPE C:• Retrognathic maxilla and

mandible

• Dental protrusion

• Smaller facial dimension

• More in females

TYPE D:

• Maxillary and mandibular retrognatism

• Max dental protrusionHandbook of orthodontics by Robert Moyers; 4th edition

TYPE E:• Maxillary prognathism and

dental protrusion.

• Mandibular dental protrusion

• (Bimaxillary protrusion)

TYPE F

• Borderline b/w class1 and class II

• Mild skeletal class2 tendencies

• It is a milder form of types B,C,D,E.


• LONG FACE

• Mandibular plane, occlusal plane are steeper than normal.

• Palate tipped downwards.

• Antero-facial height is increased.

TYPE-1

VERTICAL TYPES:


TYPE-2

• Square face.

• Mandibular plane, occlusal plane, Palate and Anterior cranial base are more horizontal.


TYPE-3

• Palate tipped up anteriorly.

• Decreased upper anterior facial height

• Open bite


TYPE-4

• Palatal plane, Mandibular Plane, Occlusal Plane all are tipped downwards.


TYPE-5

• PP tipped down anteriorly

• Deep bite


AETIOLOGY1. Heredity

2. Developmental defects

3. Trauma

4. Physical agents


a) Prenatal trauma and birth injuriesb) Postnatal trauma

a) Premature extraction of primary teethb) Nature of food

a) Thumb-suckingb) Tongue-thrustingc) Lip-sucking and lip-bitingd) Nail-biting

a) Systemic diseasesb) Endocrine disordersc) Local diseases

5. Habits

6. Disease

7. Malnutrition


CLINICAL FEATURES OF CLASS II DIV 1

EXTRAORAL FEATURES• Profile : convex

• Deep mento-labial sulcus

• Upper lip short hypotonic

• Lips- incompetent/competent

• Lip trapTextbook of orthodontics by Dr. Samir Bishara

INTRAORAL FEATURES:• Class II molar relation, • Proclined maxillary anteriors, increased overjet

• Flaring and spaced dentition

• V shaped arch and deep palate

• Deep curve of speeTextbook of orthodontics by Dr. Samir Bishara

Abnormal muscle activities

• Abnormal buccinator activity

• Lower positioning of the tongue

• Which predispose to posterior cross bite

• Hyper active mentalis muscle (retrognathic mandible)


CLINICAL FEATURES OF CLASS II DIV2

EXTRAORAL FEATURES

• Profile: straight/convex

• Reduced lower facial height

• Mento labial sulcus : normal/ deep

• Path of closure- backwardTextbook of orthodontics by Dr. Samir Bishara

INTRAORAL FEATURES:• Class 2 molar relationship

• Retroclined upper central proclined maxillary lateral incisors.

• Overjet- decreased, Deep bites

• U shaped/ square arches

• Deep curves of Spee. Textbook of orthodontics by Dr. Samir Bishara

DIAGNOSIS• History.

• Extra & Intraoral examination.

• Study models.

• Orthodontic photographs.

• Cephalometrics.

STUDY MODELS • To asses the angles classification of molars,

canines, • To determine amount of crowding or spacing

and• presence of other anomalies

PHOTOGRAPHS

• Extraoral and intraoral.

• Extraoral_- used to asses patient’s profile facial asymmetry and smile lines.

• Intraoral photographs are taken to maintain a visual record of all findings.

PANTOMOGRAPH (OPG)• To assess the stage of dental

eruption, missing, supernumerary or impacted teeth, ectopically erupting teeth, and pathologic condition

LATERAL CEPHALOMETRIC RADIOGRAPH

is used to evaluate the relationship of the jaws and teeth

CEPHALOMETRICS

• Steep mandibular plane angle

• Increased or normal SNA angle

• Decreased SNB angle

• Increased ANB angle

• Normal position of pt A but a posterior position of pt B


TREATMENT MODALITIES

Class II malocclusion

Growing Patient Nongrowing patient

Skeletal DentalDental Skeletal

FIXED ORTHODONTIC

TREATMENTSURGICAL

TREATMENTORTHOPAEDIC/ FUCTIONAL APPLIANCES

HEADGEAR• Used in cases of maxillary excess.

• Designed to deliver adequate extraoral orthopaedic force to compress the maxillary sutures.

TYPES OF HEADGEARa) Facebow b) J-hook headgear

ORTHOPAEDIC APPLIANCES


FACEBOW

• Consists of :

outer bow for extraoral attachment

Inner bow for intraoral attachment


J-HOOK HEADGEAR

• 2 separate, curved, large gauge wires with small hooks at the ends.

• More commonly used for retraction of canines or incisors.


• Point of attachment is usually below the occlusal plane- the extraoral force is directed inferiorly and posteriorly.

• Extrude molars.

• Cannot be used in patients with vertical growth pattern.

• Used in cases in which an increase in facial vertical dimension is desired.

Contemporary orthodontics, William Proffit

1. CERVICAL ATTACHMENT OR NECK STRAP

• The point of attachment well above the occlusal plane.

• Extraoral force is directed superiorly and posteriorly.

• Intrude molars & steepen occlusal plane.

• Correction of not only anteroposterior maxillary excess, but also to vertical maxillary excess

Contemporary orthodontics, William Proffit

OCCIPITAL ATTACHMENT OR HEADCAP

Magnitude of force:• Orthopaedic forces to modify bone growth ranges

from 400-600 g.Duration • 12-16 hours per day. Timing of treatment:• Most active period of growth is before eruption of

permanent teeth.• The 2nd active growth phase is ‘adolescence’• Result obtained would be good and relapse chances

are minimal.• Headgear should be worn in the night as active

growth occurs at this time. Textbook of orthodontics by Dr. Samir Bishara

SKELETAL EFFECTS

• Compresses maxillary sutures

• Restricts downward & forward maxillary growth.

• Allows normal mandibular growth.

• Studies have shown- small increase in mandibular growth with headgear.


DENTAL EFFECTS• Prevents downward & forward eruption of maxillary

molar indirectly enhancing mandibular growth.

• High pull headgear -Intrusive effect on molar.

• cervical pull headgear- to extrude molar;

• If continues arch wire from molar to incisors- distal movement of molar can result in lingual movement of maxillary incisors.


REMOVABLE:• Activator• Bionator• Functional

regulator• Twin block

FUNCTIONAL APPLIANCES

FIXED:• Herbst appliance • Jasper jumper• MARA

INDICATIONS OF FUNCTIONAL APPLIANCE

• Active mandibular growth.

• Mandibular deficiency.

• Normal maxillary development.

• Normal or mildly decreased face height.

• Slightly protrusive maxillary incisors and slightly retrusive mandibular incisors.


ACTIVATOR

Developed by Viggo Andresen, Denmark and Karl Haupl Norway. In1908 Introduces new way mandibular closure.• EFFECTS:1)Controls the downward and forward growth of

mandible.2) Prevents forward growth of the maxillary

dentoalveolar process.3) Distal movement of maxillary dentoalveolar

process. *Removable orthodontics, by Graber & Newman

CONSTRUCTION:1)wire component: labial bow 2)Acrylic portion: BITE REGISTRATION:

• Mandibular advancement of 4 to 6 mm

• 5 to 6 mm opening in the molar region.


MODIFICATIONS:

• Modifications by Harvold includs an increased mandibular opening for improved retention and increased soft tissue stretch.

• Posterior facets were replaced with interocclusal acrylic to prevent eruption of the maxillary posterior teeth and to leave space for eruption of the mandibular posterior teeth.


• Acrylic capping over the mandibular incisal edges is done to minimize their protraction.

• The maxillary wire crossing the palate was replaced with palatal acrylic.

• Springs were embedded in the acrylic to displace the appliance forward, forcing the patient to actively "function" to maintain the appliance in place.


BIONATOR

• Developed by Balters in the early 1950’s,

Mode of action• Equilibrium between tongue and the circumoral

muscles is attained.• Establish a normal posture of the tongue• Screen the hyperactive buccinator : passive

expansion.

*Removable orthodontics, by Graber & Newman

• Less bulky compared to Activator• Smaller mandibular lingual flange• A transpalatal wire in place of palatal acrylic• Modified labial bow with buccal extensions that

minimize cheek pressure on the teeth. • The bionator can incorporate either posterior facets

or interocclusal acrylic to prevent or selectively guide eruption.


TWIN BLOCK• The twin block appliance was introduced by a

Scottish orthodontist, William Clark, in 1977.

• More range of mandibular movement.


• Two-piece or split activator using separate maxillary and mandibular appliances.

• Occlusal acrylic portions serve as inclined guide planes and bite blocks.


FUNCTIONAL REGULATOR

• Rolf Frankel

• Also called as Frankel’s appliance

• Recontours the facial soft tissue adjacent to the teeth.


MODE OF ACTION :• Vestibular arena of operation.

• Withholds muscle pressure from the developing jaws and dentoalveolar area.

• Relief of forces from neuromuscular envelope.

• Increase in sagittal and transverse intraoral space.

• Intermittent outward pull creates outward movement of alveolodental structures.


Appliances for class II correction:

FR Ib : Class II Div 1 with deep bite and overjet not exceeding 7 mm.

FR Ic: Class II Div 1 with overjet greater than 7 mmFR II : Class II Div 1 and Div 2

The FR II is the most frequently used appliance.


HERBST APPLIANCE:• In 1905 Emil Herbst introduced a fixed appliance in

Germany

• Consists of a rigid maxillary and mandibular framework.

• The mandible is maintained in a forward position by means of a metal rod and tube telescopic mechanism that is attached from the maxillary first molars to the mandibular first premolars.


JASPER JUMPER

• An American orthodontist, James Jasper, has replaced the rigid telescopic mechanism with a flexible plastic covered open coil spring.

• Attached directly to auxiliary wires with a complete or partial fixed appliance in place.


MARA APPLIANCE

• Mandibular advancing repositioning appliance

• This appliance was introduced by Ralph M Clements and Alex Jacobson.1982

• Composed of a pair of telescopic struts


• Indicated in older adolescents or adults.

• When the skeletal Class II problems are mild to moderate.

FIXED ORTHODONTIC TREATMENT

* Contemporary Orthodontics 4th edition by William Profitt

• In order to create a class I molar relation in class II cases, adequate space should be present in the dental arches.

• This space is absent in many cases.

• Dental camouflage without extraction

• Dental camouflage with extraction


DENTAL CAMOUFLAGE WITHOUT EXTRACTIONS

• Space is required in the maxillary arch - to retract the incisors and eliminate overjet• In the mandibular arch - to protract the

mandibular teeth.

• To gain the space- distalization of maxillary molars.


DISTALIZATION OF MOLAR

• De-rotation of maxillary 1st molar.

• Headgear

• Class II elastics

• Palatal anchorage devices

* Contemporary Orthondontics 4th edition by William Profitt

DE-ROTATION OF MOLARS

• In patients with mild to moderate skeletal Class II malocclusion, the upper molars are likely to be rotated mesially.

• Transpalatal lingual arch or an auxiliary labial arch or the inner bow of a facebow.


• HEADGEAR

• It is now clear that significant distal positioning of the upper molar with headgear occurs primarily in patients who have vertical growth.

• Maximum 2 to 3 mm of distal movement occurs in such cases unless the upper second molars are extracted.


CLASS II ELASTICS • Can be used for distalization, but

there are some problems.

• First, extrusion of lower molars – downward & backward rotation of the mandible.

• Second, -risk of more mesial movement of the lower teeth than distal movement of the upper teeth * Contemporary Orthodontics 4th edition by William

Profitt

PALATAL ANCHORAGE SYSTEMS FOR DISTAL MOVEMENT OF MOLARS

• Mesial movement of teeth is easier than distal movement.

• Successful distal movement of molars, therefore, requires more anchorage than that is supplied by just teeth.

a) NiTi coil springs b)Magnets c)Pendulum appliance * Contemporary Orthodontics 4th edition by William

Profitt

• A-NiTi coil springs compressed against the molars.

• (from an anterior anchorage unit)

• produces a constant force system for the distal movement.



Pendulum appliance• Uses beta-Ti springs that extend from the palatal

acrylic and fit into lingual sheaths on the molar tube.

• It is activated to produce 200 to 250 grams

• Byloff et al found that molar movement of l mm/month.


DENTAL CAMOUFLAGE WITH EXTRACTIONS

• Extraction of1. Maxillary 2nd Molars

2. Maxillary First Premolars Only Or

3. Maxillary And Mandibular First Premolars.


Extraction Of The Upper Second Molars

• Class 1 molar relation is created by distal movement of maxillary 1st molar.

• Distalization of 1st molar is much easier if space is created by extracting the upper second molars.

• Distalization is carried out by using headgear, pendulum appliance as explained previously.


EXTRACTION OF UPPER FIRST PREMOLARS

• With this approach, the objective during orthodontic treatment is to maintain the existing Class II molar relationship &

• Closing the first premolar extraction space entirely by retracting the protruding incisor teeth.

• Anchorage used to prevent mesial migration of molars are:

• Extraoral anchorage

• Transpalatal arch or nance holding arch

• Class II elastics

• Segmental retraction of anteriors.


EXTRACTION OF MAXILLARY AND MANDIBULAR PREMOLARS

• The mandibular posterior segments will be moved anteriorly.

• At the same time, the protruding maxillary anterior teeth will be retracted.

• Class II elastics will be used to close the extraction sites.


When To Schedule Extraction If It Is Indicated?

• If space is required to eliminate crowding or protrusion extractions at the onset of treatment.

• Otherwise, extraction should be done after leveling and alignment.

• Older Extraction - resorbed alveolar bone with constricted facial and lingual cortical plates that inhibit effective space closure.

• New Extraction Sites - precludes this possibility and have highly active osseous turnover, offering an ideal environment for efficient space closure.


• Skeletal Class II problems with little or no remaining growth potential that cannot be treated with orthodontic treatment alone.

• In preparation for orthognathic surgery, it is necessary to remove any dental compensations present and to place the teeth in a favourable position with their supporting bone.

• Maxillary protraction and mandibular retraction.

SURGICAL CORRECTION


MANDIBULAR ADVANCEMENT• Done in mandibular deficiency cases

BILATERAL SAGITTAL SPLIT OSTEOTOMY • Developed by Richard Trauner, and Hugo

Obwegeser.

• Popularly used.

• The mandible can be moved forward or back as desired, and the tooth-bearing segment can be rotated down anteriorly when additional anterior face height is desired Textbook of orthodontics by Dr. Samir Bishara

MANDIBULAR TOTAL SUBAPICAL ADVANCEMENT

• less common

• The goal of this surgery is to advance the entire dentoalveolar segment.

• Eliminates excessive overjet without significantly changing face height or overbite.


MAXILLARY IMPACTION

• Indicated in vertical maxillary excess.

• May include either:• total maxillary osteotomy – maxillary excess in

anterior as well as posterior region .

• bilateral posterior segmental maxillary osteotomies - excess is more in the posterior region.


• Complete levelling of the mandibular arch before surgery.

• Bone is removed at the osteotomy site to permit superior repositioning of the maxilla.

• As the maxilla moves up, the mandible rotates upward and forward around the condylar axis, correcting the anteroposterior occlusal discrepancy.

• Narrow maxilla - the maxillary osteotomy needs to be in 2 or 3 segments to permit expansion of the maxilla.


• Postsurgical orthodontic treatment includes light continuous arch wires and light vertical elastics.

• Placement of a maxillary full-dimension nickel-titanium arch wire is recommended

• Maintains anterior torque while completing root parallelism in the osteotomy sites.


ANTERIOR MAXILLARY SUBAPICAL SETBACK

• In rare situations in which the skeletal Class II malocclusion is caused by a maxillary excess limited to the anteroposterior dimension only.

• Midface protrusion is characteristic of this condition

• The treatment goal is to use the maxillary first premolar space for surgical retraction of the maxillary anterior teeth, maintaining the Class II molar relationship and achieving a Class I canine relationship while reducing overjet.


CONCLUSION• Class II malocclusions are very common malocclusions with

characteristic features.

• Clinical features, x-rays and cephalometrics are useful aids for the diagnosis of such class II malocclusion.

• The treatment of the class II malocclusion depends upon the age of the patient, his/her skeletal discrepancy if any and other dental factors.

• Which should be taken into consideration before starting with the treatment.

REFERENCES

• Textbook of orthodontics by Dr. Samir Bishara

• Orthodontic diagnosis by Rakosi, Jonas and Graber

• Handbook of orthodontics by Robert Moyers; 4th edition

• Removable orthodontics, by Graber & Newman

• Contemporary Orthodontics 4th edition by William Profitt

Date post:	16-Apr-2017
Category:	Health & Medicine
Upload:	abhidnya-madansure
View:	162 times
Download:	13 times

Class ii malocclusion

Health & Medicine